Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/23/14
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:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
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:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
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.
&&
$$
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
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 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
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 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
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
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
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 GOODLAND KS
523 PM MDT SUN JUN 22 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1230 PM MDT SUN JUN 22 2014
THUNDERSTORM ACTIVITY EXPECTED TO RAMP UP QUICKLY AFTER 3 PM MDT
(4 PM CDT) AS A WEATHER DISTURBANCE IGNITES A FEW STORMS IN FAR
EASTERN COLORADO. AS THE DISTURBANCE MOVES EAST A LINE OF STRONG
TO SEVERE THUNDERSTORMS IS EXPECTED PRODUCING LARGE
HAIL...DAMAGING WINDS AND LOCALLY HEAVY RAINFALL. THE HRRR HAS
BEEN SLOWLY INCREASING THE WIND GUST POTENTIAL WITH THE LINE AND
WE COULD EXPERIENCE ANOTHER EPISODE OF 70+ MPH GUSTS. LOWS TONIGHT
IN THE MID 50S WEST...MID 60S EAST.
ON MONDAY MAY SEE SHOWERS AND THUNDERSTORMS IN THE LATE AFTERNOON
HOURS...PRIMARILY ACROSS FAR EASTERN COLORADO. OTHERWISE EXPECT
SOME CLOUDINESS WITH HIGHS IN THE MID 70S TO LOW 80S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 1242 PM MDT SUN JUN 22 2014
A FEW STORMS IN SOUTHEAST COLORADO MONDAY EVENING MAY SNEAK INTO
SOUTHWESTERN PARTS OF THE AREA...BUT BETTER CHANCES WILL BE AFTER
MIDNIGHT AS LLJ STRENGTHENS AND SHORTWAVE TROUGH COMES OUT OF THE
NORTHERN ROCKIES. STORMS MAY BE SLIGHTLY ELEVATED OVERNIGHT...WITH
PARCELS ORIGINATING AROUND 800MB HAVING UP TO 1000 J/KG OF
ELEVATED CAPE AND LITTLE TO NO CIN. LARGE HAIL WILL BE POSSIBLE
OVERNIGHT WITH THESE STORMS. SOME OF THIS ACTIVITY WILL LINGER
INTO TUESDAY MORNING...PARTICULARLY IN SOUTHWEST NEBRASKA...BEFORE
AFTERNOON CONVECTION GETS GOING IN NORTHEAST COLORADO WITH THE
NEXT SHORTWAVE. MODERATE INSTABILITY COMBINED WITH DEEP LAYER
SHEAR OF 30-40KTS SUGGEST ANOTHER ROUND OF SEVERE STORMS AS THEY
SLIDE ACROSS THE AREA TUESDAY EVENING. SOUTHEASTERLY SURFACE WINDS
CONTINUE ON WEDNESDAY WITH A CORRIDOR OF VERY UNSTABLE CONDITIONS
FORECAST BY THE AFTERNOON IN THE WESTERN HALF OF THE FORECAST
AREA. DEEP LAYER SHEAR HOWEVER IS SOMEWHAT WEAKER AT AROUND
30KTS...BUT SHOULD BE ADEQUATE FOR SEVERE STORMS AS NEXT SHORTWAVE
COMES OUT OF NORTHERN COLORADO IN THE AFTERNOON/EVENING.
A SUBTLE PATTERN CHANGE OCCURS IN THE LAST HALF OF THE LONG TERM
PERIOD WITH LONGWAVE TROUGH SETTLING INTO THE NORTHERN ROCKIES.
THE UPPER FLOW OVER THE CENTRAL PLAINS WILL BECOME SOUTHWEST.
SHORTWAVE TROUGHS ROTATING AROUND THE ROCKIES TROUGH OR EVEN THE
RIDGE OVER THE CENTRAL GULF WILL PROVIDE ENOUGH LIFT TO CONTINUE
THE MENTION OF DAILY THUNDERSTORM CHANCES.
TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE
LONG TERM.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 523 PM MDT SUN JUN 22 2014
THUNDERSTORM ACTIVITY ALREADY SPREADING WITHIN THE VICINITY OF
KGLD AND THIS SHOULD OVERSPREAD THE TERMINAL AROUND 00Z. ACTIVITY
MAY NOT REACH KMCK UNTIL AROUND 03Z...SO I DELAYED MENTION FOR
THAT TAF. STRONGER STORMS WILL BE CAPABLE OF PRODUCING BRIEF IFR
VIS AND WINDS IN EXCESS OF 50KT. HAVE KEPT TEMPO 3S-4SM GROUPS
WITH NO MENTION OF HAIL OR WINDS STRONGER THAN 50KT...THOUGH THESE
CONDITIONS CANT BE RULED OUT.
SHORT RANGE GUIDANCE WHICH GENERALLY MATCHES CURRENT RADAR TRENDS
SHOWS THIS ACTIVITY TRANSITIONING EASTWARD BY 06Z..THOUGH IT COULD
LINGER LONGER AT KMCK. ADDITIONAL THUNDERSTORMS WILL POSSIBLE
DEVELOP OVER EASTERN COLORADO MONDAY AFTERNOON...HOWEVER COVERAGE
AT EITHER TERMINAL IS STILL IN QUESTION AS THIS SYSTEM DOES NOT
APPEAR TO BE AS WELL ORGANIZED AS THE CURRENT UPPER LEVEL SYSTEM
WE ARE DEALING WITH.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...99
LONG TERM...024
AVIATION...DR
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 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
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 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...UPDATED
NWS JACKSON MS
901 PM CDT SUN JUN 22 2014
.UPDATE...
00Z UPPER AIR ANALYSIS INDICATES H5 UPPER TROUGH OVER ERN TX AND IS
ALSO EVIDENT IN WATER VAPOR IMAGERY/RUC WIND ANALYSIS. ANOTHER WEAK
S/WV AND FLOW ALOFT IS AIDING IN THE CURRENT SHOWERS/STORMS
DEVELOPING IN THE W/SW AREAS. LEFT SOME POPS IN THE W/SW UNTIL 04Z.
THE DIURNAL ACTIVITY SHOULD WEAKEN AND WE SHOULD BE CLEAR OF
SHOWERS/STORMS FOR A FEW HOURS...WHICH IS INDICATED IN MOST HI-RES
GUIDANCE INCLUDING HRRR/ARW. PUT SOME POPS IN AFTER 09Z IN THE W/SW
AS THE S/WV TO THE W APPROACHES THE AREA AND SOME SHOWERS WILL BE
POSSIBLE IN THESE AREAS. CLOUDS SHOULD THIN SOMEWHAT IN THE E/NE AND
LEAD TO COOLER CONDITIONS IN THE E. WENT SLIGHTLY WARMER THAN MAV IN
THE W DUE TO MID/HIGH CLOUD DEBRIS WHILE DECREASING SLIGHTLY IN THE E
DUE TO LESS CLOUDS. TONIGHT WILL BE SIMILAR THAT SOME PATCHY FOG IS
POSSIBLE BUT MAINLY GROUND FOG IN AREAS THAT RECEIVED RAINFALL.
FORECAST RUC SOUNDINGS AND LOWER PWATS WILL LEAD TO LOWER CHANCES OF
FOG. THUS...NOT GOING TO PUT PATCHY FOG IN THE GRIDS FOR NOW.
OVERALL..ADJUSTED HOURLY TEMPS/DEWPOINTS/SKY COVER/POPS TO CURRENT
TRENDS. REST OF THE FORECAST IS ON TRACK. /DC/
&&
.AVIATION...
SHRA/TSRA ARE CONTINUING TO DIMINISH THIS EVENING. EXPECT PATCHY
AREAS OF MVFR CATEGORY FOG TONIGHT LASTING UNTIL SHORTLY AFTER
DAYBREAK MONDAY. THE LATEST HRRR SUGGESTS LOW STRATUS COULD DEVELOP
IN THE PIB/HBG AREA...BUT EXPECT MID/HIGH LEVEL CLOUDS TO BE MOST
PREVALENT. THE GREATEST REGENERATION OF SHRA/TSRA SHOULD BEGIN LATE
MONDAY MORNING OVER MOST OF THE AREA...PERSISTING INTO EARLY MONDAY
EVENING. /EC/
&&
.PREV DISCUSSION... /ISSUED 238 PM CDT SUN JUN 22 2014/
SHORT TERM...ACTIVE CONVECTIVE AFTERNOON UNDERWAY OVER THE CWA AT
THE MOMENT. THUNDERSTORMS APPEAR TO HAVE DEVELOPED AROUND THE LEADING
PERIPHERY OF 300 MB 35 KNOT JET STREAK...AS ADVERTISED BY THE RAP.
THIS DEVELOPMENT OCCURRING OVER MAINLY EASTERN HALF WHILE THE WESTERN
PORTION APPEARS TO BE BENEFITTING FROM WEAK SHORTWAVE RIDGING.
WHILE THE MAJORITY OF EVENING CONVECTION LOOKS TO OCCUR OVER THE FAR
EAST AND SOUTHEAST...APPROACHING SHORTWAVE OVER EAST TX AND OVERALL
INCREASING TROFFINESS SHOULD ALLOW CONVECTIVE DEVELOPMENT TO RECUR
AFTER MIDNIGHT OVER ALL AREAS AS ADVERTISED BY MODELS.
AS IS THE CASE TODAY...PW VALUES MONDAY NEAR 2 INCHES WILL MAKE
THUNDERSTORMS VERY EFFICIENT RAIN MAKERS AND SLOW MOVEMENT MAY ALLOW
FOR LOCALIZED SHORT TERM PONDING/FLOODING TO OCCUR. NOT GOING TO
RULE OUT A FEW WET MICROBURSTS AS WELL. WHILE VERTICAL TOTALS/LAPSE
RATES ARE NOT AS IMPRESSIVE MONDAY AS TODAY...PRECIP LOADING MAY
STILL BE SUFFICIENT ENOUGH TO DRAG DOWN SOME DECENT WIND SPEEDS. DUE
TO EXPECTED SPARSE OCCURRENCE OF THIS...HOWEVER...WILL LEAVE OUT OF
THE HWO.
SHORTWAVE RIDGING LOOKS TO LIMIT CONVECTIVE POTENTIAL TUESDAY AS PW
VALUES FALL BACK TO AROUND 1.5 INCHES FOR THE AREA. THIS LOOKS TO BE
SHORT-LIVED...HOWEVER...AS A MORE POTENT WAVE MOVING ACROSS THE MID
MS VALLEY TUESDAY AFTERNOON/EVENING WILL DRAG A WEAK COLD FRONT INTO
NORTHERN PORTIONS OF THE AREA AFTER MIDNIGHT TUESDAY NIGHT.
THUS...WILL KEEP SCATTERED POPS RUNNING OVERNIGHT IN THE NORTH.
MOS TEMPS WERE GENERALLY AGREEABLE...HOWEVER...SHAVED HIGHS A COUPLE
DEGREES TUESDAY AS MOS CAME IN A LITTLE WARM IN THE MID 90S. /26/
LONG TERM...WEDNESDAY THROUGH NEXT SUNDAY...DURING THE MIDDLE PORTION
OF THE WEEK...UPPER LEVEL FLOW WILL REMAIN RELATIVELY WEAK AND
PRIMARILY ZONAL. A WEAK SURFACE HIGH WILL REMAIN SITUATED OVER THE
NORTHERN GULF...THOUGH THIS FEATURE IS UNLIKELY TO DO MUCH TO
DISCOURAGE THE SUMMERTIME DIURNAL CONVECTIVE CYCLE WHICH IS FIRMLY
ENTRENCHED ACROSS THE AREA. 00Z GFS/ECMWF RUNS DEPICT A SHORTWAVE
TROUGH MOVING ACROSS THE SOUTHERN PLAINS TOWARD THE MID MS VALLEY WED
INTO THURS...WHICH WOULD LIKELY SERVE TO ENHANCE PRECIP COVERAGE
DURING THAT TIME FRAME. POPS WERE TRENDED TOWARD ECMWF OUTPUT...WHICH
SEEMED TO HAVE A BETTER GRASP OF THESE FEATURES.
FROM THE END OF THE WEEK INTO THE WEEKEND GUIDANCE...ESPECIALLY THE
ECWMF...INDICATES BUILDING MID/UPPER LEVEL RIDGING. THIS WOULD
SUGGEST A DECREASE IN DAILY CONVECTIVE ACTIVITY BACK TO MORE
SEASONABLE LEVELS. ISOLATED PRECIPITATION WOULD STILL BE AROUND...
BUT WITH UPPER FLOW REMAINING WEAK AND MID LEVEL TEMPS WARMING UP
UNDER THE RIDGE...MUCH OF THE CONVECTIVE ACTIVITY WOULD BE
SUPPRESSED. /DL/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 71 89 70 92 / 15 63 21 23
MERIDIAN 69 88 68 91 / 14 74 40 35
VICKSBURG 71 89 69 92 / 18 49 20 19
HATTIESBURG 72 88 71 92 / 16 63 20 29
NATCHEZ 71 87 70 90 / 22 57 19 19
GREENVILLE 73 90 70 91 / 17 52 23 26
GREENWOOD 72 89 70 91 / 14 67 33 26
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DC/EC/26/DL
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
706 PM CDT SUN JUN 22 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 341 PM CDT SUN JUN 22 2014
AT 19Z...WATER VAPOR SHOWED QUASI-ZONAL FLOW ACROSS MUCH OF THE
CONUS WITH AN UPPER LEVEL LOW SPINNING OVER THE CENTRAL
SASKATCHEWAN/MANITOBA BORDER. MULTIPLE WEAK SHORTWAVES COULD BE
PICKED OUT MOVING ACROSS THE ROCKIES...FROM MONTANA DOWN THROUGH NEW
MEXICO. THE STRONGER SHORTWAVE WAS SEEN OVER WESTERN COLORADO AT MID
AFTERNOON WHICH WILL IMPACT THE FORECAST FOR TONIGHT...WITH THE
SECOND MORE DISTINCT SHORTWAVE SEEN OVER EASTERN IDAHO...WHICH WILL
IMPACT THE FORECAST FOR MONDAY. AT THE SURFACE...A COLD FRONT WAS
SITUATED FROM SOUTHWEST KANSAS INTO NORTHWEST MISSOURI. NORTH OF
THIS FRONT COLD AIR HAD ADVECTED INTO NEBRASKA...WITH MID AFTERNOON
TEMPERATURES GENERALLY IN THE 70S AND LOW 80S. DECENT LOW LEVEL
MOISTURE DID REMAIN IN PLACE...AS DEWPOINTS ACROSS THE AREA WERE
STILL IN THE UPPER 50S AND 60S. WITH THE MOISTURE IN PLACE AND STEEP
LOW LEVEL LAPSE RATES...AN EXTENSIVE CUMULUS FIELD HAD DEVELOPED
ACROSS WESTERN NEBRASKA. DESPITE DECENT SB INSTABILITY OF 1500-2500
J/KG WITH NO CAP...ANY SHOWERS AND THUNDERSTORMS HAVE HAD A PROBLEM
MAINTAINING WITH NO ADDITIONAL FORCING IN PLACE.
FOR THIS EVENING AND TONIGHT...ALTHOUGH THE HRRR IS INDICATING
STORMS DEVELOPING OVER SOUTHWEST NEBRASKA AHEAD OF THE MAIN SYSTEM
OVER THE ROCKIES...FEEL THIS ACTIVITY WILL BE WEAK WITH THE LACK OF
FORCING FROM THE SHORTWAVE AND VERY LITTLE IF ANY FORCING COMING
FROM ANY LOW LEVEL MOISTURE TRANSPORT. SO WILL FOCUS ON ACTIVITY
MOVING OUT ONTO THE PLAINS WITH THE MAIN SHORTWAVE. AS THIS SHORTWAVE
OVER WESTERN COLORADO MOVES EAST EXPECT FURTHER DEVELOPMENT OF
CONVECTION ALONG THE FOOTHILLS AND INTO THE HIGH PLAINS. THE
QUESTION WILL BE HOW FAR NORTH THE CONVECTION WILL DEVELOP. THE
LATEST FEW RUNS OF THE HRRR INDICATE ACTIVITY DEVELOPING AS FAR
NORTH AS SCOTTSBLUFF. THESE STORMS WOULD THEN MOVE SOUTHEAST ALONG A
THETA-E GRADIENT. ALTHOUGH THERE IS SUFFICIENT INSTABILITY AND DEEP
LAYER SHEAR WILL BE INCREASING...THE LOCAL AREA WILL BE ON THE
NORTHERN FRINGE OF ANY ACTIVITY AND WITH THE BETTER FORCING OVER
KANSAS EXPECT THE THREAT FOR ANY SEVERE STORMS TO STAY SOUTH OF THE
AREA.
FOR MONDAY THE SHORTWAVE TROUGH NOW OVER EASTERN IDAHO WILL MOVE
ACROSS WYOMING AND THEN ACROSS NEBRASKA FROM NORTHWEST TO SOUTHEAST.
NOT EXTREMELY CONFIDENT ON HOW MUCH COVERAGE OF SHOWERS AND
THUNDERSTORMS THERE WILL BE AS THE AIRMASS WILL BE SLIGHTLY
DRIER...WITH DEWPOINTS MAINLY IN THE 50S AND NO REAL SURGE OF DEEP
MOISTURE ALOFT. AT THE PRESENT TIME THINK ANY CONVECTION WILL BE
MORE ISOLATED TO SCATTERED IN NATURE. THE NEXT QUESTION IS WHERE THE
CONVECTION WILL ACTUALLY BE. THE NAM SHOWS QPF ACROSS MUCH OF THE
FORECAST AREA WHILE THE GFS/ECMWF ARE KEEPING IT MAINLY OVER THE
PANHANDLE AND SOUTHWEST NEBRASKA. HAVE SIDED WITH THE GFS/ECMWF FOR
TODAY AND HAVE LIMITED CHANCES FOR THE WESTERN AREAS. AS FOR HIGHS
ON MONDAY...LOOKING FOR A SLIGHTLY COOLER DAY WITH HIGHS IN THE 70S
AND LOW 80S AS COOLER AIR SLOWLY CONTINUES TO FILTER INTO THE AREA
BEHIND THE UPPER LEVEL SYSTEM OVER SOUTHERN CANADA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 341 PM CDT SUN JUN 22 2014
NORTHWEST FLOW ALOFT WILL PERSIST MONDAY NIGHT THROUGH TUESDAY
NIGHT WITH THE PASSAGE OF TWO DISTINCT DISTURBANCES. MAINTAINED 30
POPS LATE MONDAY NIGHT ACROSS WESTERN ZONES...TO 40 POPS
TUESDAY/TUESDAY NIGHT. PWAT VALUES FROM GFS INDICATE 120 TO NEAR 140
PERCENT OF NORMAL WITH DEEP LAYER SHEAR INCREASING TO 30 TO 40
KTS. THIS SUPPORTIVE OF STRONG THUNDERSTORMS TUESDAY AFTN/EVENING
WITH LOCALLY HEAVY RAINFALL DUE TO SLOW STORM MOTION NEAR 10 KTS.
SECOND DISTURBANCE FORECAST TO LIFT ACROSS LATE TUESDAY NIGHT AND
WEDNESDAY WITH 40 POPS TUESDAY NIGHT...FOLLOWED BY 40 POPS FOR
NCTRL WEDNESDAY.
MAINLY 20 TO 30 POPS THURSDAY THROUGH SATURDAY. DUE TO WEAK RIDGING
OVER THE REGION AND SWRLY FLOW TO OUR WEST WHICH MOVES IN BY
FRIDAY NIGHT...MODEL AGREEMENT IN TIMING AND LOCATION IS RATHER
POOR. TEMPERATURES HOWEVER WILL WARM FROM THE UPPER 70S TO LOWER
80S TUESDAY...MID 80S THURSDAY THROUGH SATURDAY TO AROUND 90 BY
SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 705 PM CDT SUN JUN 22 2014
FOR THE KLBF TERMINAL...THERE IS A THREAT FOR THUNDERSTORMS IN THE
VICINITY OF THE KLBF TERMINAL THIS EVENING. SOME STORMS MAY IMPACT
THE KLBF TERMINAL LATER THIS EVENING AS ACTIVITY MOVES INTO SWRN
NEBRASKA. AT THIS TIME...CONFIDENCE IS LOW. OVERNIGHT INTO MONDAY...EXPECT
MID AND HIGH CLOUDS TO PERSIST ACROSS THE KLBF TERMINAL WITH CIGS
RANGING FROM 5000 TO 10000 FT AGL. FOR THE KVTN TERMINAL...EXPECT
BROKEN MID LEVEL CLOUDINESS OVERNIGHT WITH CIGS AROUND 10000 FT
AGL. CIGS WILL INCREASE TO 20000 FT AGL ON MONDAY. WINDS WILL BE
LIGHT FROM THE NORTH AND NORTHWEST AT AROUND 10 KTS OVER THE NEXT
24 HRS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BROOKS
LONG TERM...ROBERG
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
628 PM CDT SUN JUN 22 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 301 PM CDT SUN JUN 22 2014
THE PRIMARY SHORT TERM FORECAST CONCERN CENTERS AROUND THE CHANCE OF
THUNDERSTORMS THIS AFTERNOON INTO TONIGHT. OVER THE LAST 8 HOURS
HAVE GREATLY REDUCED THUNDERSTORM CHANCES FOR THIS AFTERNOON AND
TONIGHT ACROSS OUR FORECAST AREA. THE GREATEST REDUCTION IN
THUNDERSTORM CHANCES HAS BEEN ACROSS NEBRASKA.
THERE IS MODEST TO EVEN FAIRLY GOOD INSTABILITY ACROSS THE FORECAST
AREA ESPECIALLY ACROSS KANSAS...WITH LITTLE TO NO CIN. WIND SHEAR IS
RATHER WEAK WITH DEEP LAYER 0-6 KM SHEAR OF LESS THAN 30 KTS. THE
BIG ISSUE CENTERS AROUND FORCING OR THE LIFTING MECHANISM FOR
ORGANIZED CONVECTION. FORCING MECHANISMS ACROSS THE REGION INCLUDE
AN UPPER LEVEL SHORT WAVE TROUGH OVER IOWA...A SOUTHWARD SLIPPING
SFC FRONTAL BOUNDARY ACROSS NORTHERN KANSAS...AND A VERY WEAK UPPER
WAVE CENTERED OVER THE BLACK HILLS OF SOUTH DAKOTA EXTENDING INTO
THE NEBRASKA PANHANDLE. THE SFC FRONT IS THE PRIMARY FORCING
MECHANISM CURRENTLY LOCATED OVER OUR FORECAST AREA AND IT IS
GRADUALLY SINKING SOUTH WHERE IT WILL EXIT OUR AREA BY LATER THIS
EVENING. THEREFORE...THUNDERSTORMS SEEM MOST LIKELY LATE THIS
AFTERNOON INTO EARLY THIS EVENING IN CLOSE PROXIMITY TO THE SFC
FRONT OVER NORTHERN KANSAS AND THUS HAVE KEPT POPS AROUND 50/50 IN
THESE SOUTHERN ZONES...WITH THE HIGHER POPS REALLY BEING SOUTH OF
OUR FORECAST AREA TONIGHT. SOME FORECAST MODELS GENERATE CONVECTION
ACROSS THE HIGH PLAINS TONIGHT IN ASSOCIATION WITH THE VERY WEAK
UPPER WAVE...BUT 4 OUT OF 6 MODELS HAVE THIS PRECIPITATION DIEING
OFF BEFORE REALLY REACHING OUR AREA TONIGHT. ONE OUTSIDE WRF RUN AND
THE HRRR DO BRING CONVECTION FROM WESTERN PORTIONS OF NEBRASKA AND
KANSAS INTO OUR FORECAST AREA LATE TONIGHT WHILE MOST MODELS DO NOT.
WILL GO WITH THE MAJORITY GIVEN THERE IS NOT MUCH OF A LOW LEVEL JET
TO HELP SUSTAIN CONVECTION TONIGHT ACROSS OUR FORECAST AREA. ANY
THUNDERSTORMS THAT CAN FORM THIS AFTERNOON OR EVENING ACROSS KANSAS
COULD BECOME SEVERE GIVEN THE HIGHER INSTABILITY ACROSS OUR SOUTHERN
ZONES.
MONDAY...MOST FORECAST MODELS INDICATE THAT WE WILL BE IN BETWEEN
WEAK SHORT WAVE STORM SYSTEMS AND LIKELY DRY. TEMPERATURES WILL BE
MILD WITH A LIGHT NORTHEAST WIND KEEPING THINGS A BIT COOLER THAN
TODAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 301 PM CDT SUN JUN 22 2014
THE WEATHER PATTERN REMAINS UNSETTLED DURING THE EXTENDED PERIODS
WITH INTERMITTENT CHANCES FOR THUNDERSTORMS. AN UPPER LOW PRESSURE
SYSTEM WILL BE TRANSLATING SOUTHEAST FM CANADA TO THE UPPER MIDWEST
REGION AT THE ONSET OF THE EXTENDED WITH THE FLOW ALOFT
TRANSITIONING WEST NORTHWEST FOR A TIME AS ANOTHER TROUGH DIGS INTO
THE PACIFIC NORTHWEST REGION. A SERIES OF WAVES EMBEDDED IN THE
FLOW WILL AID IN TSTM DEVELOPMENT WITH TIMING/PLACEMENT DEPENDENT
UPON WAVE TIMING AND BOUNDARY LOCATIONS AND BOUNDARY LOCATION WILL
BE DEPENDENT UPON HOW CONVECTION UNFOLDS THE PREVIOUS DAY. IT IS
DIFFICULT TO PINPOINT DETAILS ATTM AND WITH THE PROGRESSIVE PATTERN
JUST CANNOT RULE OUT TSTM CHCS NEARLY EVERY DAY. CONVECTION MAY
DEVELOP ALONG THE HIGH PLAINS AND ROLL EASTWARD...OR MAY INITIATE
ALONG A BOUNDARY WITHIN THE AREA.
SREF INSTABILITY PROGS INDICATE THE GREATER INSTABILITY MONDAY NIGHT
WILL RESIDE ALONG THE HIGH PLAINS REGION...WHICH WILL BEGIN TO
SPREAD EASTWARD ON TUESDAY...WITH MUCAPES INCREASING TO NEAR OR JUST
ABOVE 1000 J/KG. WITH THE MORE MARGINAL INSTABILITY ON
TUESDAY...NOT LOOKING FOR MUCH SEVERE WX JUST YET WITH INSTABILITY
FURTHER INCREASING TUESDAY NIGHT INTO MID WEEK WITH RETURN
FLOW...STRENGTHENING NOCTURNAL LLVL JET AND WAA/UPPER RIDGING AHEAD
OF UPPER TROUGH IN THE PACIFIC NW. UPPER RIDGING SETTLES OVERHEAD
FOR THE LATTER PART OF THE WORKWEEK AND MID LEVEL TEMPS INCREASE TO
AROUND 14C SO CAP MAY LIMIT CONVECTION FOR A TIME. MODELS ARE NOT
IN GREAT AGREEMENT ON THE TIMING/PROGRESSION OF THE WESTERN TROUGH
AS IT PUSHES EAST THRU THE MOUNTAINS TOWARDS THE PLAINS AND WILL NEED TO
MONITOR BUT CHCS FOR STORMS INCREASE AGAIN WITH THIS SYSTEM OVER THE
WEEKEND OR EARLY NEXT WEEK. ALL BEING SAID...INTERMITTENT CHANCES
FOR STORMS CONTINUE AND TEMPS LOOK FAIRLY SEASONAL ATTM.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 628 PM CDT SUN JUN 22 2014
VFR CONDITIONS TO CONTINUE THROUGH THE NEXT 24 HOURS.
OCCASIONAL CLOUD COVER WITH A BASE NEAR 3000FT AGL...ALONG WITH
ADDITIONAL CLOUD COVER NEAR 15000FT AGL...CAN BE EXPECTED THROUGH
THE NEXT 24 HOURS. THE SURFACE WIND WILL REMAIN FROM THE NORTH FOR
THE MOST PART DURING THE TAF PERIOD...SUSTAINED AT AROUND 08KTS.
VISIBILITY RESTRICTION IS NOT EXPECTED THROUGH THE NEXT 24 HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...WESELY
LONG TERM...FAY
AVIATION...BRYANT
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...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 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
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
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 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
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 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 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.
&&
$$
UPDATE...CARPENTER
SHORT TERM...15
LONG TERM...MLS
AVIATION...MLS
HYDROLOGY...MLS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
847 AM CDT SAT JUN 21 2014
.MESOSCALE UPDATE...
SURFACE FRONT JUST OUR NORTH WITH SURFACE DEWPOINTS AROUND 70
ACROSS KENTUCKY AND LOWER 70S IN MOST OF MIDDLE TENNESSEE.
CONVECTION CURRENTLY FIRING IN KENTUCKY NEARING LAKE CUMBERLAND
WILL DROP DOWN INTO THE UPPER CUMBERLAND AREA NEXT HOUR OR TWO.
LATEST RUC RUN HAS MUCH DRIER AIR THROUGH THE MID LEVELS WORKING
DOWN ACROSS MOST OF KENTUCKY BY 16Z. THIS DRIER AIR IN THE MID
LEVELS WILL WORK SOUTHWARD AS WE GO THROUGH THE DAY WHILE SURFACE
DEWPOINTS REMAIN AROUND 70. THINK NORTHWEST MIDDLE TENNESSEE WILL
HAVE THE LEAST CHANCE OF GETTING CONVECTION THIS MORNING WITH
CONVECTION CONFINED MAINLY TO THE EASTERN MIDDLE TENNESSEE AND
PLATEAU DURING THE AFTERNOON. TEMPS LOOK ON TRACK.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
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 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 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 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 GREEN BAY WI
1006 PM CDT SUN JUN 22 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
AND NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 954 PM CDT SUN JUN 22 2014
ISOLATED TO SCATTERED SHOWERS CONTINUE OVER CENTRAL AND NORTH
CENTRAL WI AS FIRST OF A FEW SHORT WAVES MOVE THROUGH. GIVEN VERY
LIGHT WINDS ALOFT/SEE 00Z GRB SOUNDING...SHOWER MOVEMENT RATHER SLOW. THUS
LOCALLY HEAVY RAIN POSSIBLE WITH THE SHOWERS AND STORMS. HAVE
FOLLOWED HRRR FOR PCPN COVERAGE THROUGH THE NIGHT INTO MON
MORNING AS SEEMS TO BE CAPTURING CURRENT ACTIVITY BETTER THAN
OTHERS. TREND OF HRRR IS TO INCREASE ACTIVITY AFTER MIDNIGHT OVER
CENTRAL AND NORTHEAST WI. HAVE DECIDED TO GO WITH ISOLD TO
SCATTERED WORDING INTO MON MORNING...AND BACK DOWN TO LIKELY POPS
PER COORDINATION WITH SURROUNDING OFFICES. SPS ISSUED AS EAST
WINDS OFF LAKE MI LEADING TO FOG AT LAKESHORE.
&&
.SYNOPSIS...
ISSUED AT 300 PM CDT SUN JUN 22 2014
COOL WITH ANOTHER WIDESPREAD SOAKING RAIN LATE TONIGHT AND
TOMORROW.
MODEST BAND OF WESTERLIES WL REMAIN OVER THE NRN CONUS DURING THE
PERIOD. THE FLOW ACROSS THE CONUS WL UNDERGO MODEST CHANGES DURING
THE FCST PERIOD...MOST OF WHICH WL BE IN RESPONSE TO DEVELOPMENTS AT
HIGHER LATITUDES. TROFFING DEVELOPING OVER ERN CANADA WL CAUSE
HEIGHTS TO FALL A BIT IN THE ERN CONUS EARLY IN THE WEEK. THAT
SHOULD ALLOW CANADIAN HIGH TO SLIDE SWD...AND PUSH SOME OF THE
MOISTURE OUT OF THE AREA. THEN LATER IN THE PERIOD...STG PAC
JET/UPR TROF DIGGING TOWARD THE PAC NW WL CAUSE RIDGING TO DEVELOP
OVER THE GREAT LAKES RGN.
THIS IS STILL A WET PATTERN...WITH ABV TO MUCH ABV NORMAL PCPN
AMNTS EXPECTED FOR THE PERIOD. BUT ONCE THE ERN CANADA TROF BEGINS
TO DEVELOP...HIGH PRESSURE WL BUILD SWD TOWARD THE RGN. WHILE THE
DRIER AIR WITH THE HIGH MAY NOT BE ABLE TO TOTALLY SHUT DOWN THE
PCPN...PCPN EVENTS DURING THE MIDDLE TO LATTER PART OF THE WK
SHOULD BE MORE IN THE FORM OF SCT SHRA RATHER THAN WIDESPREAD
RAINS. TEMPS WL BE COOL TOMORROW DUE TO PCPN...THEN SHOULD REMAIN
NR OR A LITTLE BLO NORMAL FOR THE WORK WEEK BEFORE WARMING TO ABV
NORMAL LEVELS AS THE UPR RIDGE STARTS TO BUILD OVER THE AREA NEXT
WEEKEND.
&&
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 300 PM CDT SUN JUN 22 2014
MAIN CONCERN IS PCPN POTENTIAL THE NEXT 24 HRS. BAND OF SHRA/TSRA
OVER WRN WI NOW HANDLED POORLY BY THE MODELS. IT SHOULD WEAKEN AS
IT WORKS EWD...BUT NEED TO BRING POPS INTO THE AREA LATE TDA TO
ACCOUNT FOR IT. BY THE TIME IT WEAKENS...SLY FLOW AT 850 MB WL BE
IN PLACE AND MID-LVL SHRTWV WL BE APPROACHING...SO DON/T THINK IT
WL BE WISE TO TRY AND WORK IN A TOTALY DRY PERIOD BEFORE THE MAIN
SYSTEM ARRIVES.
SYSTEM PROGGED TO CROSS THE AREA TOMORROW STILL HAS THE LOOK OF A
HEAVY RAIN PRODUCER. SHRTWV AT 500 MB IS NOT AS DEFINED AS WITH A
CLASSIC SHARS SYSTEM...BUT 700 MB SHRTWV IS PRETTY SHARP AND
ALMOST CLOSED AS IT CROSSES THE AREA. PREFER SLIGHTLY SLOWER MVMT
AS PROGGED BY THE ECMWF. TOOK MON POPS UP TO CATEGORICAL AND KEPT
HVY RAIN ATTRIBUTE IN THE GRIDS. DID TWEAK POPS DOWN ACRS THE FAR W
DURING THE LATE AFTN AS SYSTEM SHOULD BE STARTING TO PULL OUT BY
THEN. BASED ON ECMWF...MOST LIKELY AREA TO GET HEAVY RAINS WOULD
SEEM TO BE C-EC WI. THIS IS THE SAME AREA THAT GOT THE BULK OF THE
RAIN DURING THE PAST WEEK. WILL ISSUE ESF FOR THIS AREA TO RAISE
AWARNESS ANOTHER NOTCH. THIS WL ALLOW SUBSEQUENT SHIFTS TO SEE
WHAT THE CONVECTION NOW HEADING IN FM THE W PRODUCES IN THE WAY OF
RAINFALL BEFORE WE JUMP INTO A WATCH.
WENT WITH BLEND OF GUID FOR TEMPS TNGT...THEN HELD TEMPS DOWN ON
MON DUE TO THE EXPECTED RAINFALL.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 300 PM CDT SUN JUN 22 2014
CONTINUED UNSETTLED WEATHER IS EXPECTED INTO THE WEEKEND. TRIED
TO FIND AN EXTENDED PERIOD OF TIME WHERE THINGS DRIED OUT
EVERYWHERE AND THE WEATHER WAS MORE SUMMER-LIKE...BUT COULDNT
NARROW INTO ANYTHING SPECIFIC. SO CONTINUED CHANCE FOR SHOWERS AND
THUNDERSTORMS FOR THE LONG TERM. WEIGHTED FCST TOWARDS 12Z
GFS/ECMWF AS THEY SEEMED TO BE MOST CONSISTENT FROM RUN TO RUN.
LOW PRESSURE SYSTEM WILL BE EXITING THE AREA MONDAY NIGHT. BEST
CHANCE WILL BE CONFINED TO THE EAST BEFORE MIDNIGHT. WAS TEMPTED
TO REMOVE ALL POPS AFTER MIDNIGHT AS THE SYSTEM FINALLY PULLS
AWAY...HOWEVER WILL STILL HAVE UPPER LEVEL TROUGH AND RRQ OF JET
OVER THE GREAT LAKES REGION. LOWERED POPS AND DRIED OUT CENTRAL
WISCONSIN...BUT DONT FEEL COMFORTABLE REMOVING CHANCES IN NORTH
AND EAST ALL TOGETHER. AREAS OF FOG SHOULD DEVELOP LATE MONDAY
NIGHT AS WELL.
NEXT FEATURE TO FOCUS IS THE FRONT SAGGING SOUTH THROUGH THE CWA
ON TUESDAY. STILL SOME TIMING ISSUES WITH THE FRONTAL PASSAGE.
FAVORED THE GFS ENSEMBLE MEAN...AS IT SEEMED TO BE A GOOD
COMPROMISE BETWEEN THE MODELS. FRONT SHOULD MOVE INTO NORTHERN
WISCONSIN TUESDAY MIDDAY AND THEN MOVE SOUTH THROUGH THE
AFTERNOON...BRINGING WITH IT A CHANCE FOR SHOWERS AND
THUNDERSTORMS. BEST CHANCE FOR PRECIP WILL BE WITH THIS
FRONT...HOWEVER HAD TO BROAD BRUSH THE POPS DUE TO THE NOTED
TIMING DIFFERENCES. MODELS HAVE BEEN TRENDING SLOWER WITH THE
FRONT...SO WAS ABLE TO INCREASE HIGH TEMPS ON TUESDAY. NOT TOO
EXCITED ABOUT ANY STRONG OR SEVERE STORMS...AS INSTABILITY AND
SHEAR WILL BE MARGINAL. STILL WORTH WATCHING HOWEVER...AS
DEWPOINTS AND TEMPS ON TUESDAY KEEP CREEPING UP ON GUIDANCE AND
FRONT WILL BE CROSSING THE AREA.
THE FRONT SHOULD CONTINUE TO SAG SOUTHWARD TUESDAY NIGHT AND
WEDNESDAY AS CANADIAN HIGH PRESSURE BUILDS INTO NORTHEAST
WISCONSIN. LOWERED RAIN CHANCES ACROSS MUCH OF THE AREA WEDNESDAY
AND WEDNESDAY NIGHT SLIGHTLY...HOWEVER WASNT ABLE TO PULL POPS
COMPLETELY AS MODELS STILL HAVE SCATTERED SHOWERS AROUND AS WEAK
IMPULSES MOVE THROUGH THE MEAN ZONAL FLOW. GIVEN THE AMOUNT OF
AVAILABLE MOISTURE...WOULDNT TAKE A LOT TO SQUEEZE OUT SOME RAIN
DROPS. WEDNESDAY AND THURSDAY WILL BE NOTICEABLY COOLER THAN
MONDAY AND TUESDAY AS CANADIAN HIGH PRESSURE DRIFTS ACROSS THE
GREAT LAKES REGION.
MODELS DIVERGE FOR THE END OF THE WEEK WITH LITTLE CHANGES MADE TO
THIS PERIOD. HIGH TEMPERATURES WILL BE DEPENDENT ON THE EXTENT OF
CLOUD COVER AND RAIN COVERAGE. CONTINUED CHANCES FOR SHOWERS AND
THUNDERSTORMS FOR FRIDAY INTO THE WEEKEND.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 954 PM CDT SUN JUN 22 2014
A SERIES OF SHORT WAVES IN EASTERLY FLOW AND SURFACE FRONT/TROF TO
BE FOCUS OF ISOLD TO SCATTERED SHOWERS AND STORMS THIS PERIOD. SOME
MVFR FOG WILL DEVELOP TNGT...BUT AS SHRA ACTIVITY IS EXPECTED TO
LEAD TO MIXING...SO VSBYS NOT EXPECTED TO DROP AS FAR AS THE PAST
FEW NIGHTS EXCEPT NEAR LAKE WHERE FOG OFF LAKE MI WILL AFFECT
COASTAL AREAS. SHOWER ACTIVITY TO SHIFT EAST OUT OF AREA MON
AFTN AS SFC FRONT/TROF PUSHES EAST. &&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........TE
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....SKOWRONSKI
LONG TERM......ALLEN
AVIATION.......TE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
741 PM CDT SUN JUN 22 2014
.UPDATE...
ISSUED AT 740 PM CDT SUN JUN 22 2014
CONCERNING THE FLASH FLOOD WATCH AND HEAVY RAIN POTENTIAL.
TRENDS HAVE REALLY BEEN ON THE DECREASE FOR THE INGREDIENTS NEEDED
FOR FLASH FLOODING TONIGHT. CURRENTLY A WEAKLY CONVERGENT TROUGH
RUNS ABOUT ON I-35 THROUGH IA AND SRN MN THEN ANGLES TO NEAR KAXN
IN MN. FURTHER WEST THE STABILIZING FRONT WAS EXTENDING FROM NW OF
KFSD-KINL AND PROGRESSING SE WITH MID-50S DEWPOINTS /KABR 00Z RAOB
WITH 0.70 INCH PRECIPITABLE WATER/. INDICATIONS ARE FOR A BIT
FASTER COLD FRONTAL PUSH OVERNIGHT INTO THE MORNING HOURS WHICH
MEANS MONDAY WILL NOT HAVE ANY FLASH FLOOD THREAT. PER THE 22.23Z
RAP...THE 925 MB WINDS ARE ALL NW IN THE FORECAST AREA BY 15Z. IN
FACT...MOST WINDS ON AND WEST OF THE MISS RIVER VEER AROUND TO NW
AT 925 MB BY 08Z. THIS PROVIDES A MORE PROGRESSIVE SOLUTION TO ANY
STORM ACTIVITY TONIGHT.
CONCERNING THE STORMS EXPECTED TONIGHT...THE INSTABILITY AFTER
THE AFTERNOON STORMS HAS SEVERELY IMPACTED THE CAPE AVAILABLE FOR
HEAVY RAINFALL TONIGHT. RIGHT NOW THE FORECAST AREA IS IN THE
HUNDREDS OF J/KG OF MUCAPE AND RADAR IS SHOWING LITTLE SIGN OF ANY
ORGANIZED RAIN THREAT. THE COMPLEX NEAR ALBERT LEA MN HAS NOW
DISSIPATED. THERE IS A BIT OF FRONTOGENESIS IN MID LEVELS THAT
TRIES TO PRODUCE SOME LIFT FROM BLACK RIVER FALLS WI INTO NERN IA
OVER NEXT SEVERAL HOURS. BUT WITH LIMITED OR DIMINISHING
CAPES...ANY STORMS THAT FORM WILL STRUGGLE TO PRODUCE HEAVY RAIN.
WITH THAT SAID..THE AIR MASS STILL HAS POTENT MOISTURE /KMPX 00Z
RAOB 1.36 INCH PRECIPITABLE WATER/. IT IS JUST THAT THE
ORGANIZATION AND INSTABILITY ARE NOT THERE FOR HEAVY RAIN. IN
FACT...WILL ALSO ASSESS THE RAIN COVERAGE TONIGHT...IT LOOKS MUCH
TOO HIGH PER LATEST HRRR RUNS AND 22.21Z HOPWRF RUN FROM MPX.
BOTTOM LINE IS WE HAVE STARTED TO MESSAGE A REDUCED FLASH FLOOD
THREAT...AND THE FLASH FLOOD WATCH WILL BE CANCELLED BY 9 PM
UNLESS SOMETHING CHANGES. HAVE ALREADY REMOVED TAYLOR AND CLARK
COUNTIES.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 334 PM CDT SUN JUN 22 2014
THE MAIN FOCUS THROUGH TOMORROW IS ON CONVECTIVE TRENDS AND
WHETHER ANY FLASH FLOODING IS STILL POSSIBLE.
AN MCV FROM OVERNIGHT HAS COME THROUGH MUCH OF THE REGION FROM
LATE THIS MORNING INTO THE EARLY AFTERNOON HOURS AND HAS KICKED UP
A BAND OF CONVECTION/RAIN OUT AHEAD OF IT. MUCH OF THE 22.12Z
GUIDANCE HAS NOT DONE A VERY GOOD JOB OF PICKING UP ON THIS
FEATURE AND STILL WANT TO DEVELOP A WIDE SWATH OF CONVECTION
ACROSS THE REGION THIS EVENING. THE HRRR HAS DONE A DECENT JOB OF
CAPTURING THIS CONVECTION AND CLEARS MOST OF THE REGION FROM THE
WEST EARLY THIS EVENING. THE MOST UNSTABLE AIR MASS APPEARS TO
STAY OUT AHEAD OF THE MCV...SO AM NOT EXPECTING MUCH IN THE WAY OF
SEVERE DEVELOPMENT BEHIND IT. CONFIDENCE IS NOT VERY HIGH WITH HOW
TONIGHT WILL PAN OUT WITH THE MAIN COLD FRONT STILL OFF TO THE
WEST...SO WILL KEEP THE FLASH FLOOD WATCH GOING FOR THE TIME
BEING AND LET THE EVENING PLAY OUT A BIT MORE BEFORE CANNING IT.
THE 22.12Z NAM/GFS/GEM DID TREND FASTER WITH PUSHING THE
PRECIPITATION/MID LEVEL TROUGH/SFC LOW OFF TO THE EAST TOMORROW
MORNING...SO HAVE TRENDED A BIT FASTER WITH ENDING THE RAIN
CHANCES TOMORROW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 334 PM CDT SUN JUN 22 2014
A BRIEF DRY PERIOD IS EXPECTED MONDAY NIGHT INTO TUESDAY MORNING
AS SUBSIDENT AIR COMES IN THE WAKE OF THE TROUGH. ANOTHER COLD
FRONT WILL DROP DOWN FROM CANADA TUESDAY AFTERNOON AND BRING THE
NEXT CHANCE OF RAIN ALONG WITH IT. SKINNY CAPE PROFILE WITH THIS
FEATURE WITH LESS THAN 1000 J/KG OF MLCAPE EXPECTED...SO NOT
THINKING THAT THIS WILL BE A SEVERE WEATHER PRODUCER AT THIS
POINT.
AFTER THAT FRONT DROPS TO THE SOUTH IT APPEARS TO STALL OUT FROM
THE HIGH PLAINS ON DOWN SOUTHEAST THROUGH THE MID MISSISSIPPI
RIVER VALLEY. CONFIDENCE NOT VERY HIGH WITH OUR PRECIPITATION
CHANCES TOWARD THE END OF THE WEEK...BUT ALSO DID NOT HAVE MUCH OF
A CHANCE TO DIG INTO THE DETAILS WITH CONVECTION ON GOING...SO
HAVE GONE WITH THE CONSENSUS OF THE MODEL BLENDS FOR NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 641 PM CDT SUN JUN 22 2014
MESSY AVIATION FORECAST NEXT 6 TO 12 HOURS AS WEAKLY UNSTABLE
AND MOIST AIR MASS REMAINS IN PLACE ACROSS SOUTHEAST MINNESOTA
AND WESTERN WISCONSIN. PULSE...LOOSELY ORGANIZED SHOWERS AND
ISOLATED THUNDERSTORMS HAVE DEVELOPED ALONG I-35 AND NEAR KRST.
UNTIL A COOL FRONT PASSES THROUGH OVERNIGHT...CAN NOT RULE OUT
SHOWERS AND ISOLATED TSTORMS BUT EXPECTING LOW COVERAGE AND
INTENSITY. WOULD THINK SOME OF THE ACTIVITY IS DIURNAL...AND WITH
BEST MOISTURE TRANSPORT MOVING OFF TO THE EAST...THERE SHOULD NOT
BE A HUGE UPTICK IN CONVECTIVE ACTIVITY. THUS...AVIATION IMPACTS
DUE TO STORMS ARE LOW...HOWEVER WILL MAINTAIN A VCSH/VCTS GROUP
THROUGH EARLY OVERNIGHT UNTIL FRONT CLEAR THINGS OUT. PLAN ON VFR
CONDITIONS MONDAY WITH NORTHWEST WINDS USHERING IN A DRIER AIR
MASS...WITH SCATTERED CU DEVELOPING WITH BASES BETWEEN 5 AND 6
KFT.
&&
.HYDROLOGY...
ISSUED AT 334 PM CDT SUN JUN 22 2014
HEAVY RAINFALL FROM LAST WEEK HAS PRIMED THE GROUND FOR ADDITIONAL
FLOODING WITH ANY STORMS THAT MAY MOVE THROUGH. THE STORMS TODAY
HAD SOME BRIEFLY INTENSE RAINFALL RATES AT ABOUT 2 INCHES PER HOUR
THOUGH THEY ONLY LASTED FOR ABOUT A HALF HOUR. MANY AREA RIVERS
ARE STILL ELEVATED FROM THE RECENT RAINFALL AND WILL LIKELY STAY
THAT WAY THROUGH THE WEEK. CONFIDENCE IS NOT VERY HIGH AT THIS
POINT ABOUT WHETHER THE FLASH FLOOD WATCH IS STILL NECESSARY FOR
TONIGHT...BUT WANT TO MAKE SURE THAT CONDITIONS WILL BE OKAY
BEFORE DROPPING IT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR WIZ032>034-041-
042-053>055-061.
MN...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR IAZ008>011-018-
019-029-030.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...ZT
HYDROLOGY...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
641 PM CDT SUN JUN 22 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 334 PM CDT SUN JUN 22 2014
THE MAIN FOCUS THROUGH TOMORROW IS ON CONVECTIVE TRENDS AND
WHETHER ANY FLASH FLOODING IS STILL POSSIBLE.
AN MCV FROM OVERNIGHT HAS COME THROUGH MUCH OF THE REGION FROM
LATE THIS MORNING INTO THE EARLY AFTERNOON HOURS AND HAS KICKED UP
A BAND OF CONVECTION/RAIN OUT AHEAD OF IT. MUCH OF THE 22.12Z
GUIDANCE HAS NOT DONE A VERY GOOD JOB OF PICKING UP ON THIS
FEATURE AND STILL WANT TO DEVELOP A WIDE SWATH OF CONVECTION
ACROSS THE REGION THIS EVENING. THE HRRR HAS DONE A DECENT JOB OF
CAPTURING THIS CONVECTION AND CLEARS MOST OF THE REGION FROM THE
WEST EARLY THIS EVENING. THE MOST UNSTABLE AIR MASS APPEARS TO
STAY OUT AHEAD OF THE MCV...SO AM NOT EXPECTING MUCH IN THE WAY OF
SEVERE DEVELOPMENT BEHIND IT. CONFIDENCE IS NOT VERY HIGH WITH HOW
TONIGHT WILL PAN OUT WITH THE MAIN COLD FRONT STILL OFF TO THE
WEST...SO WILL KEEP THE FLASH FLOOD WATCH GOING FOR THE TIME
BEING AND LET THE EVENING PLAY OUT A BIT MORE BEFORE CANNING IT.
THE 22.12Z NAM/GFS/GEM DID TREND FASTER WITH PUSHING THE
PRECIPITATION/MID LEVEL TROUGH/SFC LOW OFF TO THE EAST TOMORROW
MORNING...SO HAVE TRENDED A BIT FASTER WITH ENDING THE RAIN
CHANCES TOMORROW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 334 PM CDT SUN JUN 22 2014
A BRIEF DRY PERIOD IS EXPECTED MONDAY NIGHT INTO TUESDAY MORNING
AS SUBSIDENT AIR COMES IN THE WAKE OF THE TROUGH. ANOTHER COLD
FRONT WILL DROP DOWN FROM CANADA TUESDAY AFTERNOON AND BRING THE
NEXT CHANCE OF RAIN ALONG WITH IT. SKINNY CAPE PROFILE WITH THIS
FEATURE WITH LESS THAN 1000 J/KG OF MLCAPE EXPECTED...SO NOT
THINKING THAT THIS WILL BE A SEVERE WEATHER PRODUCER AT THIS
POINT.
AFTER THAT FRONT DROPS TO THE SOUTH IT APPEARS TO STALL OUT FROM
THE HIGH PLAINS ON DOWN SOUTHEAST THROUGH THE MID MISSISSIPPI
RIVER VALLEY. CONFIDENCE NOT VERY HIGH WITH OUR PRECIPITATION
CHANCES TOWARD THE END OF THE WEEK...BUT ALSO DID NOT HAVE MUCH OF
A CHANCE TO DIG INTO THE DETAILS WITH CONVECTION ON GOING...SO
HAVE GONE WITH THE CONSENSUS OF THE MODEL BLENDS FOR NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 641 PM CDT SUN JUN 22 2014
MESSY AVIATION FORECAST NEXT 6 TO 12 HOURS AS WEAKLY UNSTABLE
AND MOIST AIR MASS REMAINS IN PLACE ACROSS SOUTHEAST MINNESOTA
AND WESTERN WISCONSIN. PULSE...LOOSELY ORGANIZED SHOWERS AND
ISOLATED THUNDERSTORMS HAVE DEVELOPED ALONG I-35 AND NEAR KRST.
UNTIL A COOL FRONT PASSES THROUGH OVERNIGHT...CAN NOT RULE OUT
SHOWERS AND ISOLATED TSTORMS BUT EXPECTING LOW COVERAGE AND
INTENSITY. WOULD THINK SOME OF THE ACTIVITY IS DIURNAL...AND WITH
BEST MOISTURE TRANSPORT MOVING OFF TO THE EAST...THERE SHOULD NOT
BE A HUGE UPTICK IN CONVECTIVE ACTIVITY. THUS...AVIATION IMPACTS
DUE TO STORMS ARE LOW...HOWEVER WILL MAINTAIN A VCSH/VCTS GROUP
THROUGH EARLY OVERNIGHT UNTIL FRONT CLEAR THINGS OUT. PLAN ON VFR
CONDITIONS MONDAY WITH NORTHWEST WINDS USHERING IN A DRIER AIR
MASS...WITH SCATTERED CU DEVELOPING WITH BASES BETWEEN 5 AND 6
KFT.
&&
.HYDROLOGY...
ISSUED AT 334 PM CDT SUN JUN 22 2014
HEAVY RAINFALL FROM LAST WEEK HAS PRIMED THE GROUND FOR ADDITIONAL
FLOODING WITH ANY STORMS THAT MAY MOVE THROUGH. THE STORMS TODAY
HAD SOME BRIEFLY INTENSE RAINFALL RATES AT ABOUT 2 INCHES PER HOUR
THOUGH THEY ONLY LASTED FOR ABOUT A HALF HOUR. MANY AREA RIVERS
ARE STILL ELEVATED FROM THE RECENT RAINFALL AND WILL LIKELY STAY
THAT WAY THROUGH THE WEEK. CONFIDENCE IS NOT VERY HIGH AT THIS
POINT ABOUT WHETHER THE FLASH FLOOD WATCH IS STILL NECESSARY FOR
TONIGHT...BUT WANT TO MAKE SURE THAT CONDITIONS WILL BE OKAY
BEFORE DROPPING IT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR WIZ017-029-
032>034-041-042-053>055-061.
MN...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...ZT
HYDROLOGY...HALBACH
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 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
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
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 TALLAHASSEE FL
332 AM EDT Mon Jun 23 2014
.Near Term [Through Today]...
A broken line of thunderstorms has gradually shifted southeast
off the Florida Panhandle coast by 06Z. There are some indications
in surface observations that there may be a subtle mesohigh just
offshore, which would create a convergence zone roughly near the
Panhandle coast early this morning. Additionally, MSAS analysis
shows a surface trough extending in a west-east fashion just
inland of the Gulf coast. Convection-allowing models that have
been initialized at 00Z appear to give credence to these features
as a potential convective focus this morning. Nearly all of the
CAMs, regardless of whether or not they are resolving current
offshore convection accurately, show some sort of convective
development in the Florida Panhandle 12-16Z - filling in across
the remainder of our Florida zones in the late morning and early
afternoon. This also happens to coincide with a maximum in PWATs -
as indicated by GOES blended TPW and RAP analysis. We included a
region of 60% PoPs in the Florida Panhandle 12-18Z from
Tallahassee and to the west. For the rest of the day, models
indicate some scattered thunderstorms will remain possible but
very few show more widespread coverage. Therefore, we opted for a
broad 50% PoP in the afternoon hours. Given the possibility for an
early start to convection, highs in the Florida zones may be
closer to 90 degrees, with slightly higher values further inland
in our Alabama and Georgia zones.
.Short Term [Tonight Through Wednesday]...
Ridging remains located off to the east of the region with a
trough moving across the Tennessee River Valley on Tuesday. With
the presence of this trough nearby and still plenty of deep layer
moisture available, expect above normal storm coverage during the
daytime hours. With more storm coverage, expect daytime highs to
generally be in the lower 90s across the area.
By Wednesday, most of the model guidance show deep layer moisture
decreasing which should result in less storm coverage so will show
slightly lower pops than on Tuesday. If some of the guidance is
correct, additional downward adjustments in rain chances may be
necessary. With mid level ridging trying to build back over the
region by Wednesday and less storm coverage expected, temperatures
will be warmer with highs in the mid 90s away from the coast.
.Long Term [Wednesday Night Through Monday]...
Much of the same for the extended range forecast as the local area
will likely remain sandwiched between an upper ridge and upper
trough, with only weak synoptic forcing. Most afternoons will be
dominated by seabreeze convection. Rain chances will remain near
average with high temperatures in the middle to upper 90s.
&&
.Aviation...
[Through 06Z Tuesday]
Through 13Z, some patchy MVFR VIS in light fog will be possible,
but otherwise VFR will prevail with multiple cloud layers. DHN has
had a few instances of IFR/LIFR CIGS in recent hours, but this has
not been sustained for lengthy periods of time. If that becomes
the case, an amendment may become necessary there. Thunderstorm
redevelopment is expected in the Florida Panhandle and Big Bend in
the morning, especially 12-16Z. The most likely impacts from
thunderstorms would be at ECP, TLH, and VLD. Scattered
thunderstorms will be possible in the afternoon. +TSRA could
produce some IFR VIS and brief gusty winds.
&&
.Marine...
A fairly typical summertime pattern will result in light winds and
low seas throughout the next several days.
&&
.Fire Weather...
Red flag conditions are not expected.
&&
.Hydrology...
Rainfall totals for the next 5-7 days will range from 1 to 2 inches
across the area. With all rivers below bank full stage, this
rainfall is not expected to cause significant rises on area rivers.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 90 73 91 72 94 / 60 30 40 20 40
Panama City 87 75 89 76 90 / 60 30 30 20 30
Dothan 91 72 91 72 94 / 50 40 50 30 40
Albany 93 72 91 72 93 / 50 40 60 30 40
Valdosta 92 71 91 71 94 / 50 40 50 30 40
Cross City 90 71 92 71 93 / 50 30 30 20 30
Apalachicola 87 74 89 75 90 / 60 30 30 20 30
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...GODSEY
LONG TERM...HARRIGAN
AVIATION...LAMERS
MARINE...GODSEY
FIRE WEATHER...LAMERS
HYDROLOGY...BOLDEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
348 AM CDT MON JUN 23 2014
.DISCUSSION...
305 AM CDT
A HANDFUL OF FORECAST CHALLENGES THIS FINAL FULL WEEK OF
JUNE...ALTHOUGH IT DOES APPEAR TO BE A MORE QUIET WEEK THAN
LAST...WITH LESS WIDESPREAD STORM/HEAVY RAINFALL CHANCES. ITEMS OF
CONCERN THIS MORNING INCLUDE RAIN AND THUNDER COVERAGE TODAY AS
WELL AS FOG POSSIBILITIES NEAR THE LAKE SHORE.
TODAY AND TONIGHT...
ONCE AGAIN THIS MORNING IT IS A MESSY MID-LEVEL PATTERN WITH
MULTIPLE SMALL SCALE IMPULSES FROM KS TO WI SEEN ON A LONG LOOP OF
SATELLITE WATER VAPOR CHANNEL. OVERALL THOUGH THESE FEATURES COMPOSE
AN UPPER SHORT WAVE TROUGH THAT WILL INCH EASTWARD LIKELY CLEARING
THE AREA BY OR DURING OVERNIGHT. QG FORCING FOR ASCENT IN ADVANCE OF
THIS TROUGH...WITHIN A MOIST AIR MASS OF PRECIPITABLE WATER OBSERVED
OF 1.50-1.75 INCHES...SHOULD SUPPORT MODEST COVERAGE OF SHOWERS
ESPECIALLY THROUGH EARLY AFTERNOON. SCATTERED/EMBEDDED THUNDER
WILL BE MOST PRONOUNCED AHEAD OF ANY OF THE AFOREMENTIONED
IMPULSES...WITH 500-1200 J/KG OF MUCAPE TO WORK WITH THROUGH THE
MORNING PER CURRENT AMDAR DATA AND RAP FORECASTS THROUGH MIDDAY.
DID OUR BEST TO ADD TEMPORAL RESOLUTION IN THE FORECAST OF HIGHER
POPS TODAY...WITH THE GREATER LIKELIHOOD SHIFTING SLOWLY EAST DURING
THE DAY. CONVECTIVE ALLOWING GUIDANCE INDICATES SOME POSSIBLY DEEPER
CONVECTION NEAR MIDDAY/EARLY AFTERNOON ACROSS THE EASTERN FORECAST
AREA...ASSOCIATED WITH INSTABILITY BECOMING MORE ROOTED IN THE
MIXED LAYER GIVEN SURFACE HEATING. WITH WEAK DEEP LAYER SHEAR
/AOB 25 KT/ AND ANY MODEST DCAPE BEING CONDITIONAL ON SOME
SUNSHINE WHICH THERE MAY NOT BE TOO MUCH OF...THINK SEVERE STORM
POTENTIAL IS SMALL AND THAT CHANCE CONFINED TO THE EASTERN
FORECAST AREA.
OBSERVATIONS AND WEBCAMS EARLY THIS MORNING ARE INDICATING THE LEAST
DENSE THE FOG HAS BEEN NEAR THE LAKE SHORE IN SEVERAL MORNINGS.
THUS ITS POSSIBLE THE ADVISORY MAY BE CANCELLED NEAR SUNRISE
DEPENDING ON HOW THINGS LOOK. A LIGHT FLOW PATTERN TODAY MAY FAVOR
A LAKE BREEZE...THOUGH SHOWERS AND POSSIBLE STORMS COULD DISRUPT
THE WIND FIELD AND LAKE FOG. IN ADDITION...LATE DAY VISIBLE
SATELLITE IMAGERY FROM SUNDAY INDICATED THE FOG OVER SOUTHERN LAKE
MI HAD BECOME MORE THIN...SO NOT EXPECTING FOG TO BE A BIG DEAL
MUCH OF TODAY ALONG THE LAKE SHORE. DEPENDING ON EXACT FRONTAL
TIMING...SOME PATCHY FOG MAY SPREAD BRIEFLY INLAND AGAIN THIS
EVENING...AND POSSIBLY INTO NORTHWEST INDIANA OVERNIGHT BEHIND
FROPA WITH THE SYNOPTIC FLOW SHIFTING NORTH-NORTHWEST.
TUESDAY THROUGH THURSDAY...
A LITTLE MORE OF A NORTHWEST PUSH ARRIVES ON TUESDAY AFTERNOON OR
EVENING BEHIND A SECONDARY COOL FRONT. ALONG THIS FEATURE ON TUESDAY
AFTERNOON THERE COULD BE ISOLATED SHOWERS/STORMS AS A JET STREAK
AND ASSOCIATED RIGHT ENTRANCE REGION MOVE OVER THE BOUNDARY DURING
PEAK HEATING. HAVE MAINTAINED THE CHANCES FOR PRECIP ONLY IN THE
NORTHERN FORECAST AREA ON TUESDAY AS THIS FEATURE APPROACHES.
SEMI-ZONAL FLOW IS FORECAST TO PERSIST THROUGH MIDWEEK WITH LITTLE
TO KEY IN ON FOR SHOWER OR STORM CHANCES. WARM AIR ADVECTION AND
POSSIBLY A SHORT WAVE DEPENDING ON WHICH LONG RANGE MODEL ONE
LOOKS AT INDICATE SOME STORM POTENTIAL LATER THURSDAY...BUT
OVERALL NOT TOO EXCITED ABOUT THIS AT THIS POINT. TEMPERATURES
LOOK TO COOL SLIGHTLY WEDNESDAY AND THURSDAY...ALTHOUGH MORE SO
NEAR THE LAKE SHORE. THIS IS ESPECIALLY TRUE ON WEDNESDAY WHICH
LOOKS TO HAVE SHORELINE HIGHS STRUGGLE TO REACH 70.
FRIDAY INTO NEXT WEEKEND...
ENERGY FROM A PERSIST GULF OF ALASKA TROUGH IS EXPECTED TO EVOLVE
INTO THE NORTHWEST U.S. AND WESTERN CANADA DURING THIS PERIOD AND IN
RESPONSE HEIGHTS WILL BUILD ACROSS THE MISSISSIPPI AND OHIO RIVER
VALLEY REGIONS. THE EC HAS TRENDED DOWN FROM THE HEIGHTS AND 850MB
TEMPS IT HAD 24 HOURS AGO...BUT STILL SUPPORTIVE OF AROUND 90
DEGREES FOR WEEKEND HIGHS IF NOT IMPACTED BY ANY CONVECTION...WHICH
THERE LOOKS TO BE AT LEAST SMALL CHANCES FOR AT THIS POINT.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* POTENTIAL FOR IFR/LIFR CIGS AND/OR VSBY IN BR/FG/STRATUS FOR THE
REMAINDER OF THE OVERNIGHT HOURS BECOMING LESS LIKELY AS THE
ENVIRONMENT IS STIRRED UP BY ONGOING SHRA.
* SHRA/TSRA POTENTIAL THIS AFTERNOON AND EVENING.
KREIN
//DISCUSSION...UPDATED 06Z...
MAIN FORECAST CONCERN REMAIN THE POTENTIAL FOR IFR/LIFR
CONDITIONS OVERNIGHT...AND THEN THE TIMING OF TSRA MONDAY
AFTERNOON.
FOR THE REMAINDER OF THE OVERNIGHT HOURS...THE LOWEST CONDITIONS
CONTINUE TO HUG THE COAST VFR CONDITIONS AT THE TERMINAL...OTHER
THAN GYY WHICH IS ONLY AT 3SM BR. THERE IS STILL CONCERN THAT
CONDITIONS WILL DETERIORATE OVERNIGHT...BUT WITH AN AREA OF SHRA
MOVING TOWARD NERN IL THE LOWER LEVELS MAY REMAIN AGITATED ENOUGH
TO MAINTAIN THE VFR CONDITIONS. HOWEVER...WITH LIGHT AND VARIABLE
WINDS AND AMPLE LOW LEVEL MOISTURE...THERE WILL STILL BE
OPPORTUNITY FOR CIGS OR VIS TO DROP RAPIDLY DURG THE PRE-DAWN
HOURS WITH LOW STRATUS AND FOG OOZING INLAND FROM THE LAKEFRONT.
GIVEN THE UNCERTAINTY OF THIS EVEN AT THIS SHORT DURATION...WILL
MAINTAIN THE TEMPO GROUP FOR IFR CONDITIONS BUT DELAY THE POSSIBLE
ONSET.
THE PCPN FORECAST HAS EVEN GREATER UNCERTAINTY. THE ENVIRONMENT
OVER NRN IL/IN REMAINS VERY MOIST AND SHOULD BECOME AT LEAST
WEAKLY UNSTABLE THROUGH THE DAY TOMORROW. A MODERATE SHORTWAVE
ALOFT HAS BEEN CONSISTENTLY FORECAST BY THE MODELS TO CROSS THE
REGION TOMORROW AFTERNOON...AND WILL BE ACCOMPANIED BY A WEAK COLD
FRONT. FRONTAL FORCING WILL BE LOW AS THERE WILL BE ONLY A MINOR
AIRMASS CHANGE WITH THE FRONTAL PASSAGE AND A WINDSHIFT FROM LIGHT
SOUTHERLY WINDS TO LIGHT NWLY WINDS. THERE MAY BE A FEW GUSTS TO
ARND 15KT IN THE WEAK WARM ADVECTION AHEAD OF THE FRONT...BUT
WINDS SHOULD BE LESS THAN 10KT BEHIND THE FRONT. HAVE TRIED TO
NARROW DOWN THE MOST LIKELY PERIOD FOR TSRA TO IMPACT THE
TERMINALS AND ADJUSTED THE PROB30 GROUP TO 19-22Z AT RFD AND
20-23Z AT THE CHICAGO METRO TERMINALS. THIS SHOULD COINCIDE WITH
THE PASSAGE OF THE SHORTWAVE ALOFT AND THE WEAK COLD FRONT AT THE
SURFACE. THE REMAINDER OF THE PERIOD SHOULD THEN BE DRY WITH NWLY
WINDS ARND 10KT AND VFR CIGS/VIS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM IN CIGS/VIS TRENDS FOR THE REST OF THE NIGHT.
* HIGH IN SCT SHRA OVERNIGHT...THOUGH IMPACT WILL BE MINIMAL.
* MEDIUM-HIGH IN WIND TRENDS.
* LOW TO MEDIUM IN TSRA TIMING AND COVERAGE MONDAY AFTERNOON.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...SLIGHT CHANCE FOR TSRA. OTHERWISE VFR.
WEDNESDAY...SLIGHT CHANCE FOR TSRA. OTHERWISE VFR. NORTHEAST
WINDS.
THURSDAY...CHANCE FOR TSRA. OTHERWISE VFR. EASTERLY WINDS.
FRIDAY...CHANCE FOR TSRA. OTHERWISE VFR. SOUTHEAST WINDS POSSIBLY
BECOMING EAST.
SATURDAY...CHANCE TSRA. OTHERWISE VFR.
RC
&&
.MARINE...
315 AM CDT
BROAD HIGH PRESSURE EXTENDS FROM THE GREAT LAKES REGION ACROSS
MUCH OF THE EAST COAST. THE RESULTANT LIGHT AND VARIABLE WINDS
COMBINED WITH RESIDUAL HIGH DEWPOINT AIR OVER THE STILL VERY COLD
LAKE WATERS HAS KEPT DENSE FOG IN PLACE. THE DENSE FOG WILL
CONTINUE WHILE THE HIGH PRESSURE IS SLOWLY ERODED BY A TROUGH OF
WEAK LOW PRESSURE AS IT MOVES ACROSS THE MISSISSIPPI VALLEY
MONDAY MORNING. THE TROUGH AND AN ASSOCIATED WEAK COLD FRONT WILL
MOVE ACROSS THE LAKE LATE MONDAY NIGHT TURNING WINDS FROM LIGHT
AND VARIABLE TO WESTERLY AND NORTHWESTERLY...WHICH WILL BEGIN TO
SCOUR OUT THE FOG FROM THE LAKE. A SECONDARY COLD FRONT WILL DROP
DOWN THE LAKE TUESDAY TURNING WINDS NORTHERLY BRINGING AN END TO
ANY RESIDUAL FOG AS DRIER AIR FILTERS OVER THE LAKE. HIGH PRESSURE
WILL BUILD ACROSS THE UPPER LAKES WEDNESDAY AND THURSDAY KEEPING
CONDITIONS OVER THE LAKE RELATIVELY QUIET...BUT BY THE END OF THE
WEEK...STRENGTHENING SOUTHERLY WINDS OF 15 TO 25 KT WILL DEVELOP
OVER THE LAKE AS THE HIGH MOVES OFF TO THE EAST AND ANOTHER TROUGH
APPROACHES FROM THE WEST.
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM MONDAY.
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 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
323 AM CDT MON JUN 23 2014
.DISCUSSION...
305 AM CDT
A HANDFUL OF FORECAST CHALLENGES THIS FINAL FULL WEEK OF
JUNE...ALTHOUGH IT DOES APPEAR TO BE A MORE QUIET WEEK THAN
LAST...WITH LESS WIDESPREAD STORM/HEAVY RAINFALL CHANCES. ITEMS OF
CONCERN THIS MORNING INCLUDE RAIN AND THUNDER COVERAGE TODAY AS
WELL AS FOG POSSIBILITIES NEAR THE LAKE SHORE.
TODAY AND TONIGHT...
ONCE AGAIN THIS MORNING IT IS A MESSY MID-LEVEL PATTERN WITH
MULTIPLE SMALL SCALE IMPULSES FROM KS TO WI SEEN ON A LONG LOOP OF
SATELLITE WATER VAPOR CHANNEL. OVERALL THOUGH THESE FEATURES COMPOSE
AN UPPER SHORT WAVE TROUGH THAT WILL INCH EASTWARD LIKELY CLEARING
THE AREA BY OR DURING OVERNIGHT. QG FORCING FOR ASCENT IN ADVANCE OF
THIS TROUGH...WITHIN A MOIST AIR MASS OF PRECIPITABLE WATER OBSERVED
OF 1.50-1.75 INCHES...SHOULD SUPPORT MODEST COVERAGE OF SHOWERS
ESPECIALLY THROUGH EARLY AFTERNOON. SCATTERED/EMBEDDED THUNDER
WILL BE MOST PRONOUNCED AHEAD OF ANY OF THE AFOREMENTIONED
IMPULSES...WITH 500-1200 J/KG OF MUCAPE TO WORK WITH THROUGH THE
MORNING PER CURRENT AMDAR DATA AND RAP FORECASTS THROUGH MIDDAY.
DID OUR BEST TO ADD TEMPORAL RESOLUTION IN THE FORECAST OF HIGHER
POPS TODAY...WITH THE GREATER LIKELIHOOD SHIFTING SLOWLY EAST DURING
THE DAY. CONVECTIVE ALLOWING GUIDANCE INDICATES SOME POSSIBLY DEEPER
CONVECTION NEAR MIDDAY/EARLY AFTERNOON ACROSS THE EASTERN FORECAST
AREA...ASSOCIATED WITH INSTABILITY BECOMING MORE ROOTED IN THE
MIXED LAYER GIVEN SURFACE HEATING. WITH WEAK DEEP LAYER SHEAR
/AOB 25 KT/ AND ANY MODEST DCAPE BEING CONDITIONAL ON SOME
SUNSHINE WHICH THERE MAY NOT BE TOO MUCH OF...THINK SEVERE STORM
POTENTIAL IS SMALL AND THAT CHANCE CONFINED TO THE EASTERN
FORECAST AREA.
OBSERVATIONS AND WEBCAMS EARLY THIS MORNING ARE INDICATING THE LEAST
DENSE THE FOG HAS BEEN NEAR THE LAKE SHORE IN SEVERAL MORNINGS.
THUS ITS POSSIBLE THE ADVISORY MAY BE CANCELLED NEAR SUNRISE
DEPENDING ON HOW THINGS LOOK. A LIGHT FLOW PATTERN TODAY MAY FAVOR
A LAKE BREEZE...THOUGH SHOWERS AND POSSIBLE STORMS COULD DISRUPT
THE WIND FIELD AND LAKE FOG. IN ADDITION...LATE DAY VISIBLE
SATELLITE IMAGERY FROM SUNDAY INDICATED THE FOG OVER SOUTHERN LAKE
MI HAD BECOME MORE THIN...SO NOT EXPECTING FOG TO BE A BIG DEAL
MUCH OF TODAY ALONG THE LAKE SHORE. DEPENDING ON EXACT FRONTAL
TIMING...SOME PATCHY FOG MAY SPREAD BRIEFLY INLAND AGAIN THIS
EVENING...AND POSSIBLY INTO NORTHWEST INDIANA OVERNIGHT BEHIND
FROPA WITH THE SYNOPTIC FLOW SHIFTING NORTH-NORTHWEST.
TUESDAY THROUGH THURSDAY...
A LITTLE MORE OF A NORTHWEST PUSH ARRIVES ON TUESDAY AFTERNOON OR
EVENING BEHIND A SECONDARY COOL FRONT. ALONG THIS FEATURE ON TUESDAY
AFTERNOON THERE COULD BE ISOLATED SHOWERS/STORMS AS A JET STREAK
AND ASSOCIATED RIGHT ENTRANCE REGION MOVE OVER THE BOUNDARY DURING
PEAK HEATING. HAVE MAINTAINED THE CHANCES FOR PRECIP ONLY IN THE
NORTHERN FORECAST AREA ON TUESDAY AS THIS FEATURE APPROACHES.
SEMI-ZONAL FLOW IS FORECAST TO PERSIST THROUGH MIDWEEK WITH LITTLE
TO KEY IN ON FOR SHOWER OR STORM CHANCES. WARM AIR ADVECTION AND
POSSIBLY A SHORT WAVE DEPENDING ON WHICH LONG RANGE MODEL ONE
LOOKS AT INDICATE SOME STORM POTENTIAL LATER THURSDAY...BUT
OVERALL NOT TOO EXCITED ABOUT THIS AT THIS POINT. TEMPERATURES
LOOK TO COOL SLIGHTLY WEDNESDAY AND THURSDAY...ALTHOUGH MORE SO
NEAR THE LAKE SHORE. THIS IS ESPECIALLY TRUE ON WEDNESDAY WHICH
LOOKS TO HAVE SHORELINE HIGHS STRUGGLE TO REACH 70.
FRIDAY INTO NEXT WEEKEND...
ENERGY FROM A PERSIST GULF OF ALASKA TROUGH IS EXPECTED TO EVOLVE
INTO THE NORTHWEST U.S. AND WESTERN CANADA DURING THIS PERIOD AND IN
RESPONSE HEIGHTS WILL BUILD ACROSS THE MISSISSIPPI AND OHIO RIVER
VALLEY REGIONS. THE EC HAS TRENDED DOWN FROM THE HEIGHTS AND 850MB
TEMPS IT HAD 24 HOURS AGO...BUT STILL SUPPORTIVE OF AROUND 90
DEGREES FOR WEEKEND HIGHS IF NOT IMPACTED BY ANY CONVECTION...WHICH
THERE LOOKS TO BE AT LEAST SMALL CHANCES FOR AT THIS POINT.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* POTENTIAL FOR IFR/LIFR CIGS AND/OR VSBY IN BR/FG/STRATUS
OVERNIGHT.
* SHRA/TSRA POTENTIAL TONIGHT AND TOMORROW.
KREIN
//DISCUSSION...UPDATED 06Z...
MAIN FORECAST CONCERN REMAIN THE POTENTIAL FOR IFR/LIFR
CONDITIONS OVERNIGHT...AND THEN THE TIMING OF TSRA MONDAY
AFTERNOON.
FOR THE REMAINDER OF THE OVERNIGHT HOURS...THE LOWEST CONDITIONS
CONTINUE TO HUG THE COAST VFR CONDITIONS AT THE TERMINAL...OTHER
THAN GYY WHICH IS ONLY AT 3SM BR. THERE IS STILL CONCERN THAT
CONDITIONS WILL DETERIORATE OVERNIGHT...BUT WITH AN AREA OF SHRA
MOVING TOWARD NERN IL THE LOWER LEVELS MAY REMAIN AGITATED ENOUGH
TO MAINTAIN THE VFR CONDITIONS. HOWEVER...WITH LIGHT AND VARIABLE
WINDS AND AMPLE LOW LEVEL MOISTURE...THERE WILL STILL BE
OPPORTUNITY FOR CIGS OR VIS TO DROP RAPIDLY DURG THE PRE-DAWN
HOURS WITH LOW STRATUS AND FOG OOZING INLAND FROM THE LAKEFRONT.
GIVEN THE UNCERTAINTY OF THIS EVEN AT THIS SHORT DURATION...WILL
MAINTAIN THE TEMPO GROUP FOR IFR CONDITIONS BUT DELAY THE POSSIBLE
ONSET.
THE PCPN FORECAST HAS EVEN GREATER UNCERTAINTY. THE ENVIRONMENT
OVER NRN IL/IN REMAINS VERY MOIST AND SHOULD BECOME AT LEAST
WEAKLY UNSTABLE THROUGH THE DAY TOMORROW. A MODERATE SHORTWAVE
ALOFT HAS BEEN CONSISTENTLY FORECAST BY THE MODELS TO CROSS THE
REGION TOMORROW AFTERNOON...AND WILL BE ACCOMPANIED BY A WEAK COLD
FRONT. FRONTAL FORCING WILL BE LOW AS THERE WILL BE ONLY A MINOR
AIRMASS CHANGE WITH THE FRONTAL PASSAGE AND A WINDSHIFT FROM LIGHT
SOUTHERLY WINDS TO LIGHT NWLY WINDS. THERE MAY BE A FEW GUSTS TO
ARND 15KT IN THE WEAK WARM ADVECTION AHEAD OF THE FRONT...BUT
WINDS SHOULD BE LESS THAN 10KT BEHIND THE FRONT. HAVE TRIED TO
NARROW DOWN THE MOST LIKELY PERIOD FOR TSRA TO IMPACT THE
TERMINALS AND ADJUSTED THE PROB30 GROUP TO 19-22Z AT RFD AND
20-23Z AT THE CHICAGO METRO TERMINALS. THIS SHOULD COINCIDE WITH
THE PASSAGE OF THE SHORTWAVE ALOFT AND THE WEAK COLD FRONT AT THE
SURFACE. THE REMAINDER OF THE PERIOD SHOULD THEN BE DRY WITH NWLY
WINDS ARND 10KT AND VFR CIGS/VIS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW IN IFR/LIFR CIGS AND MVFR/IFR VIS FOR THE REST OF THE NIGHT.
* MEDIUM-HIGH IN SOME SCT OVERNIGHT...THOUGH IMPACT WILL BE
MINIMAL.
* MEDIUM-HIGH IN WIND TRENDS.
* LOW TO MEDIUM IN TSRA TIMING AND COVERAGE MONDAY AFTERNOON.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...SLIGHT CHANCE FOR TSRA. OTHERWISE VFR.
WEDNESDAY...SLIGHT CHANCE FOR TSRA. OTHERWISE VFR. NORTHEAST
WINDS.
THURSDAY...CHANCE FOR TSRA. OTHERWISE VFR. EASTERLY WINDS.
FRIDAY...CHANCE FOR TSRA. OTHERWISE VFR. SOUTHEAST WINDS POSSIBLY
BECOMING EAST.
SATURDAY...CHANCE TSRA. OTHERWISE VFR.
RC
&&
.MARINE...
315 AM CDT
BROAD HIGH PRESSURE EXTENDS FROM THE GREAT LAKES REGION ACROSS
MUCH OF THE EAST COAST. THE RESULTANT LIGHT AND VARIABLE WINDS
COMBINED WITH RESIDUAL HIGH DEWPOINT AIR OVER THE STILL VERY COLD
LAKE WATERS HAS KEPT DENSE FOG IN PLACE. THE DENSE FOG WILL
CONTINUE WHILE THE HIGH PRESSURE IS SLOWLY ERODED BY A TROUGH OF
WEAK LOW PRESSURE AS IT MOVES ACROSS THE MISSISSIPPI VALLEY
MONDAY MORNING. THE TROUGH AND AN ASSOCIATED WEAK COLD FRONT WILL
MOVE ACROSS THE LAKE LATE MONDAY NIGHT TURNING WINDS FROM LIGHT
AND VARIABLE TO WESTERLY AND NORTHWESTERLY...WHICH WILL BEGIN TO
SCOUR OUT THE FOG FROM THE LAKE. A SECONDARY COLD FRONT WILL DROP
DOWN THE LAKE TUESDAY TURNING WINDS NORTHERLY BRINGING AN END TO
ANY RESIDUAL FOG AS DRIER AIR FILTERS OVER THE LAKE. HIGH PRESSURE
WILL BUILD ACROSS THE UPPER LAKES WEDNESDAY AND THURSDAY KEEPING
CONDITIONS OVER THE LAKE RELATIVELY QUIET...BUT BY THE END OF THE
WEEK...STRENGTHENING SOUTHERLY WINDS OF 15 TO 25 KT WILL DEVELOP
OVER THE LAKE AS THE HIGH MOVES OFF TO THE EAST AND ANOTHER TROUGH
APPROACHES FROM THE WEST.
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM MONDAY.
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 PM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
308 AM CDT MON JUN 23 2014
.DISCUSSION...
305 AM CDT
A HANDFUL OF FORECAST CHALLENGES THIS FINAL FULL WEEK OF
JUNE...ALTHOUGH IT DOES APPEAR TO BE A MORE QUIET WEEK THAN
LAST...WITH LESS WIDESPREAD STORM/HEAVY RAINFALL CHANCES. ITEMS OF
CONCERN THIS MORNING INCLUDE RAIN AND THUNDER COVERAGE TODAY AS
WELL AS FOG POSSIBILITIES NEAR THE LAKE SHORE.
TODAY AND TONIGHT...
ONCE AGAIN THIS MORNING IT IS A MESSY MID-LEVEL PATTERN WITH
MULTIPLE SMALL SCALE IMPULSES FROM KS TO WI SEEN ON A LONG LOOP OF
SATELLITE WATER VAPOR CHANNEL. OVERALL THOUGH THESE FEATURES COMPOSE
AN UPPER SHORT WAVE TROUGH THAT WILL INCH EASTWARD LIKELY CLEARING
THE AREA BY OR DURING OVERNIGHT. QG FORCING FOR ASCENT IN ADVANCE OF
THIS TROUGH...WITHIN A MOIST AIR MASS OF PRECIPITABLE WATER OBSERVED
OF 1.50-1.75 INCHES...SHOULD SUPPORT MODEST COVERAGE OF SHOWERS
ESPECIALLY THROUGH EARLY AFTERNOON. SCATTERED/EMBEDDED THUNDER
WILL BE MOST PRONOUNCED AHEAD OF ANY OF THE AFOREMENTIONED
IMPULSES...WITH 500-1200 J/KG OF MUCAPE TO WORK WITH THROUGH THE
MORNING PER CURRENT AMDAR DATA AND RAP FORECASTS THROUGH MIDDAY.
DID OUR BEST TO ADD TEMPORAL RESOLUTION IN THE FORECAST OF HIGHER
POPS TODAY...WITH THE GREATER LIKELIHOOD SHIFTING SLOWLY EAST DURING
THE DAY. CONVECTIVE ALLOWING GUIDANCE INDICATES SOME POSSIBLY DEEPER
CONVECTION NEAR MIDDAY/EARLY AFTERNOON ACROSS THE EASTERN FORECAST
AREA...ASSOCIATED WITH INSTABILITY BECOMING MORE ROOTED IN THE
MIXED LAYER GIVEN SURFACE HEATING. WITH WEAK DEEP LAYER SHEAR
/AOB 25 KT/ AND ANY MODEST DCAPE BEING CONDITIONAL ON SOME
SUNSHINE WHICH THERE MAY NOT BE TOO MUCH OF...THINK SEVERE STORM
POTENTIAL IS SMALL AND THAT CHANCE CONFINED TO THE EASTERN
FORECAST AREA.
OBSERVATIONS AND WEBCAMS EARLY THIS MORNING ARE INDICATING THE LEAST
DENSE THE FOG HAS BEEN NEAR THE LAKE SHORE IN SEVERAL MORNINGS.
THUS ITS POSSIBLE THE ADVISORY MAY BE CANCELLED NEAR SUNRISE
DEPENDING ON HOW THINGS LOOK. A LIGHT FLOW PATTERN TODAY MAY FAVOR
A LAKE BREEZE...THOUGH SHOWERS AND POSSIBLE STORMS COULD DISRUPT
THE WIND FIELD AND LAKE FOG. IN ADDITION...LATE DAY VISIBLE
SATELLITE IMAGERY FROM SUNDAY INDICATED THE FOG OVER SOUTHERN LAKE
MI HAD BECOME MORE THIN...SO NOT EXPECTING FOG TO BE A BIG DEAL
MUCH OF TODAY ALONG THE LAKE SHORE. DEPENDING ON EXACT FRONTAL
TIMING...SOME PATCHY FOG MAY SPREAD BRIEFLY INLAND AGAIN THIS
EVENING...AND POSSIBLY INTO NORTHWEST INDIANA OVERNIGHT BEHIND
FROPA WITH THE SYNOPTIC FLOW SHIFTING NORTH-NORTHWEST.
TUESDAY THROUGH THURSDAY...
A LITTLE MORE OF A NORTHWEST PUSH ARRIVES ON TUESDAY AFTERNOON OR
EVENING BEHIND A SECONDARY COOL FRONT. ALONG THIS FEATURE ON TUESDAY
AFTERNOON THERE COULD BE ISOLATED SHOWERS/STORMS AS A JET STREAK
AND ASSOCIATED RIGHT ENTRANCE REGION MOVE OVER THE BOUNDARY DURING
PEAK HEATING. HAVE MAINTAINED THE CHANCES FOR PRECIP ONLY IN THE
NORTHERN FORECAST AREA ON TUESDAY AS THIS FEATURE APPROACHES.
SEMI-ZONAL FLOW IS FORECAST TO PERSIST THROUGH MIDWEEK WITH LITTLE
TO KEY IN ON FOR SHOWER OR STORM CHANCES. WARM AIR ADVECTION AND
POSSIBLY A SHORT WAVE DEPENDING ON WHICH LONG RANGE MODEL ONE
LOOKS AT INDICATE SOME STORM POTENTIAL LATER THURSDAY...BUT
OVERALL NOT TOO EXCITED ABOUT THIS AT THIS POINT. TEMPERATURES
LOOK TO COOL SLIGHTLY WEDNESDAY AND THURSDAY...ALTHOUGH MORE SO
NEAR THE LAKE SHORE. THIS IS ESPECIALLY TRUE ON WEDNESDAY WHICH
LOOKS TO HAVE SHORELINE HIGHS STRUGGLE TO REACH 70.
FRIDAY INTO NEXT WEEKEND...
ENERGY FROM A PERSIST GULF OF ALASKA TROUGH IS EXPECTED TO EVOLVE
INTO THE NORTHWEST U.S. AND WESTERN CANADA DURING THIS PERIOD AND IN
RESPONSE HEIGHTS WILL BUILD ACROSS THE MISSISSIPPI AND OHIO RIVER
VALLEY REGIONS. THE EC HAS TRENDED DOWN FROM THE HEIGHTS AND 850MB
TEMPS IT HAD 24 HOURS AGO...BUT STILL SUPPORTIVE OF AROUND 90
DEGREES FOR WEEKEND HIGHS IF NOT IMPACTED BY ANY CONVECTION...WHICH
THERE LOOKS TO BE AT LEAST SMALL CHANCES FOR AT THIS POINT.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* POTENTIAL FOR IFR/LIFR CIGS AND/OR VSBY IN BR/FG/STRATUS
OVERNIGHT.
* SHRA/TSRA POTENTIAL TONIGHT AND TOMORROW.
KREIN
//DISCUSSION...UPDATED 06Z...
MAIN FORECAST CONCERN REMAIN THE POTENTIAL FOR IFR/LIFR
CONDITIONS OVERNIGHT...AND THEN THE TIMING OF TSRA MONDAY
AFTERNOON.
FOR THE REMAINDER OF THE OVERNIGHT HOURS...THE LOWEST CONDITIONS
CONTINUE TO HUG THE COAST VFR CONDITIONS AT THE TERMINAL...OTHER
THAN GYY WHICH IS ONLY AT 3SM BR. THERE IS STILL CONCERN THAT
CONDITIONS WILL DETERIORATE OVERNIGHT...BUT WITH AN AREA OF SHRA
MOVING TOWARD NERN IL THE LOWER LEVELS MAY REMAIN AGITATED ENOUGH
TO MAINTAIN THE VFR CONDITIONS. HOWEVER...WITH LIGHT AND VARIABLE
WINDS AND AMPLE LOW LEVEL MOISTURE...THERE WILL STILL BE
OPPORTUNITY FOR CIGS OR VIS TO DROP RAPIDLY DURG THE PRE-DAWN
HOURS WITH LOW STRATUS AND FOG OOZING INLAND FROM THE LAKEFRONT.
GIVEN THE UNCERTAINTY OF THIS EVEN AT THIS SHORT DURATION...WILL
MAINTAIN THE TEMPO GROUP FOR IFR CONDITIONS BUT DELAY THE POSSIBLE
ONSET.
THE PCPN FORECAST HAS EVEN GREATER UNCERTAINTY. THE ENVIRONMENT
OVER NRN IL/IN REMAINS VERY MOIST AND SHOULD BECOME AT LEAST
WEAKLY UNSTABLE THROUGH THE DAY TOMORROW. A MODERATE SHORTWAVE
ALOFT HAS BEEN CONSISTENTLY FORECAST BY THE MODELS TO CROSS THE
REGION TOMORROW AFTERNOON...AND WILL BE ACCOMPANIED BY A WEAK COLD
FRONT. FRONTAL FORCING WILL BE LOW AS THERE WILL BE ONLY A MINOR
AIRMASS CHANGE WITH THE FRONTAL PASSAGE AND A WINDSHIFT FROM LIGHT
SOUTHERLY WINDS TO LIGHT NWLY WINDS. THERE MAY BE A FEW GUSTS TO
ARND 15KT IN THE WEAK WARM ADVECTION AHEAD OF THE FRONT...BUT
WINDS SHOULD BE LESS THAN 10KT BEHIND THE FRONT. HAVE TRIED TO
NARROW DOWN THE MOST LIKELY PERIOD FOR TSRA TO IMPACT THE
TERMINALS AND ADJUSTED THE PROB30 GROUP TO 19-22Z AT RFD AND
20-23Z AT THE CHICAGO METRO TERMINALS. THIS SHOULD COINCIDE WITH
THE PASSAGE OF THE SHORTWAVE ALOFT AND THE WEAK COLD FRONT AT THE
SURFACE. THE REMAINDER OF THE PERIOD SHOULD THEN BE DRY WITH NWLY
WINDS ARND 10KT AND VFR CIGS/VIS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW IN IFR/LIFR CIGS AND MVFR/IFR VIS FOR THE REST OF THE NIGHT.
* MEDIUM-HIGH IN SOME SCT OVERNIGHT...THOUGH IMPACT WILL BE
MINIMAL.
* MEDIUM-HIGH IN WIND TRENDS.
* LOW TO MEDIUM IN TSRA TIMING AND COVERAGE MONDAY AFTERNOON.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...SLIGHT CHANCE FOR TSRA. OTHERWISE VFR.
WEDNESDAY...SLIGHT CHANCE FOR TSRA. OTHERWISE VFR. NORTHEAST
WINDS.
THURSDAY...CHANCE FOR TSRA. OTHERWISE VFR. EASTERLY WINDS.
FRIDAY...CHANCE FOR TSRA. OTHERWISE VFR. SOUTHEAST WINDS POSSIBLY
BECOMING EAST.
SATURDAY...CHANCE TSRA. OTHERWISE VFR.
RC
&&
.MARINE...
303 PM CDT
A MESO HIGH PRESSURE AREA OVER CENTRAL LAKE MICHIGAN INDUCED BY THE
COOL WATERS OF THE LAKE ITSELF WILL REMAIN IN PLACE THIS EVENING
ALONG WITH AN ABUNDANTLY MOIST AIRMASS AND THE ACCOMPANYING AREAS OF
DENSE FOG. THIS FLAT PRESSURE PATTERN WILL GRADUALLY BE REPLACED
WITH INCREASING SOUTHERLY FLOW AS LOW PRESSURE OVER THE CENTRAL
PLAINS MOVES EAST TO TO NORTHEAST IOWA BY DAYBREAK MONDAY. WINDS
WILL TURN MORE EAST ACROSS NORTHERN LAKE MICHIGAN NORTH OF A WARM
FRONT ASSOCIATED WITH THE LOW MOVING SLOWLY NORTH.
THIS LOW WILL THEN MOVE ACROSS WISCONSIN TO THE STRAITS OF MACKINAC
BY DAYBREAK TUESDAY. A COLD FRONT ASSOCIATED WITH THIS LOW
WILL SWEEP EAST ACROSS THE LAKE LATE MONDAY NIGHT... TURNING WINDS
NORTHWEST. THIS WILL FINALLY SWEEP THE DENSE FOG OUT OF THE MARINE
AREA. A SECONDARY COLD FRONT WILL THEN MOVE ACROSS THE LAKE
TUESDAY NIGHT. HIGH PRESSURE WILL BUILD ACROSS THE UPPER GREAT
LAKES WEDNESDAY AND THURSDAY. SOUTH FLOW WILL INCREASE AGAIN
FRIDAY AS THIS HIGH MOVES EAST.
ED F
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM MONDAY.
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 PM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
1136 PM MDT SUN JUN 22 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1230 PM MDT SUN JUN 22 2014
THUNDERSTORM ACTIVITY EXPECTED TO RAMP UP QUICKLY AFTER 3 PM MDT
(4 PM CDT) AS A WEATHER DISTURBANCE IGNITES A FEW STORMS IN FAR
EASTERN COLORADO. AS THE DISTURBANCE MOVES EAST A LINE OF STRONG
TO SEVERE THUNDERSTORMS IS EXPECTED PRODUCING LARGE
HAIL...DAMAGING WINDS AND LOCALLY HEAVY RAINFALL. THE HRRR HAS
BEEN SLOWLY INCREASING THE WIND GUST POTENTIAL WITH THE LINE AND
WE COULD EXPERIENCE ANOTHER EPISODE OF 70+ MPH GUSTS. LOWS TONIGHT
IN THE MID 50S WEST...MID 60S EAST.
ON MONDAY MAY SEE SHOWERS AND THUNDERSTORMS IN THE LATE AFTERNOON
HOURS...PRIMARILY ACROSS FAR EASTERN COLORADO. OTHERWISE EXPECT
SOME CLOUDINESS WITH HIGHS IN THE MID 70S TO LOW 80S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 1242 PM MDT SUN JUN 22 2014
A FEW STORMS IN SOUTHEAST COLORADO MONDAY EVENING MAY SNEAK INTO
SOUTHWESTERN PARTS OF THE AREA...BUT BETTER CHANCES WILL BE AFTER
MIDNIGHT AS LLJ STRENGTHENS AND SHORTWAVE TROUGH COMES OUT OF THE
NORTHERN ROCKIES. STORMS MAY BE SLIGHTLY ELEVATED OVERNIGHT...WITH
PARCELS ORIGINATING AROUND 800MB HAVING UP TO 1000 J/KG OF
ELEVATED CAPE AND LITTLE TO NO CIN. LARGE HAIL WILL BE POSSIBLE
OVERNIGHT WITH THESE STORMS. SOME OF THIS ACTIVITY WILL LINGER
INTO TUESDAY MORNING...PARTICULARLY IN SOUTHWEST NEBRASKA...BEFORE
AFTERNOON CONVECTION GETS GOING IN NORTHEAST COLORADO WITH THE
NEXT SHORTWAVE. MODERATE INSTABILITY COMBINED WITH DEEP LAYER
SHEAR OF 30-40KTS SUGGEST ANOTHER ROUND OF SEVERE STORMS AS THEY
SLIDE ACROSS THE AREA TUESDAY EVENING. SOUTHEASTERLY SURFACE WINDS
CONTINUE ON WEDNESDAY WITH A CORRIDOR OF VERY UNSTABLE CONDITIONS
FORECAST BY THE AFTERNOON IN THE WESTERN HALF OF THE FORECAST
AREA. DEEP LAYER SHEAR HOWEVER IS SOMEWHAT WEAKER AT AROUND
30KTS...BUT SHOULD BE ADEQUATE FOR SEVERE STORMS AS NEXT SHORTWAVE
COMES OUT OF NORTHERN COLORADO IN THE AFTERNOON/EVENING.
A SUBTLE PATTERN CHANGE OCCURS IN THE LAST HALF OF THE LONG TERM
PERIOD WITH LONGWAVE TROUGH SETTLING INTO THE NORTHERN ROCKIES.
THE UPPER FLOW OVER THE CENTRAL PLAINS WILL BECOME SOUTHWEST.
SHORTWAVE TROUGHS ROTATING AROUND THE ROCKIES TROUGH OR EVEN THE
RIDGE OVER THE CENTRAL GULF WILL PROVIDE ENOUGH LIFT TO CONTINUE
THE MENTION OF DAILY THUNDERSTORM CHANCES.
TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE
LONG TERM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1136 PM MDT SUN JUN 22 2014
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK. EARLY IN THE TAF PERIOD SHOWERS WITH EMBEDDED
THUNDERSTORMS WILL CONTINUE TO MOVE EAST ACROSS SW NEBRASKA...WITH
A FEW SHOWERS POSSIBLY MAKING IT AS FAR SOUTH AS KGLD. BY 09Z THIS
ACTIVITY SHOULD BE OUTSIDE THE VICINITY OF BOTH TERMINALS. WINDS
ARE GENERALLY GOING TO BE LESS THAT 12KT THROUGH MOST OF THE TAF
PERIOD...WITH SLIGHTLY STRONGER WINDS IN THE 10-15KT RANGE MONDAY
WHERE THE PRESSURE GRADIENT WILL BE A LITTLE TIGHTER DUE TO
PROXIMITY OF SURFACE TROUGH. ADDITIONAL THUNDERSTORM ACTIVITY IS
EXPECTED MONDAY AND MONDAY NIGHT. THERE IS STILL UNCERTAINTY
REGARDING TIMING AND COVERAGE AT THIS POINT...SO I LEFT MENTION OF
OF THE TAFS DURING THIS UPDATE AFTER THE CURRENT ACTIVITY ENDS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...99
LONG TERM...024
AVIATION...DR
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
422 AM EDT MON JUN 23 2014
.SYNOPSIS...
THE WEATHER WILL BE A LITTLE WARMER AND MORE HUMID TODAY WITH AN
ISOLATED STORM. THE BEST CHANCE FOR WET WEATHER WILL BE TUESDAY INTO
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
DRY WEATHER IS EXPECTED FOR THE START OF THE DAY...ALTHOUGH SOME
HIGH CLOUDS WILL REMAIN OVER EASTERN OHIO. IN ADDITION...MANY
LOCATIONS WILL HAVE SOME FOG. ANY LOCATION COULD SEE AN ISOLATED
THUNDERSTORM TODAY...ALTHOUGH THE FOCUS WILL LIKELY REMAIN OVER THE
LAUREL HIGHLANDS. A FEATURE NOT PREVIOUSLY SHOWN ON MODEL RUNS IS A
SHORTWAVE THAT COULD DEVELOP OVER WESTERN OHIO LATE THIS AFTERNOON
AND TRACK OVER NORTHWESTERN PENNSYLVANIA BY MIDNIGHT. WHILE THE NAM
MOST CLEARLY DEPICTS THIS SHORTWAVE...THE END OF THE RAP MODEL RUN
HINTS AT THIS DEVELOPMENT...AND VARIOUS HIGH RESOLUTION NMM RUNS
ALSO DEVELOP THIS PRECIPITATION DURING THE EVENING HOURS. HAVE
RAISED POPS SLIGHTLY DURING THE EVENING HOURS...DECREASING POPS
AGAIN AFTER MIDNIGHT. WITH UPPER RIDGE BUILDING IN...TEMPS WILL BE
ABOUT FIVE DEGREES WARMER TODAY THAN YESTERDAY.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
UNFORTUNATELY...THE 00Z GFS SUFFERS FROM CONVECTIVE
FEEDBACK...SPINNING UP A SURFACE LOW ALONG THE APPROACHING COLD
FRONT AND SHOWING UNREALISTIC PRECIPITATION AND VORTICITY MAXIMA. AS
A RESULT...THE 00Z GFS WAS NOT USED THROUGH THIS PORTION OF THE
FORECAST.
PRIMARY CHANGE DURING THIS PORTION OF THE FORECAST WAS TO SLOW DOWN
THE TIMING OF THE COLD FRONT. COMPARED TO MODEL RUNS FROM 24 HOURS
AGO...FRONT APPEARS TO BE ABOUT 6 HOURS SLOWER IN ITS ARRIVAL AND
PASSAGE WITH LATEST MODEL RUNS. THIS MEANS MANY LOCATIONS COULD
REMAIN DRY TUESDAY MORNING...ALTHOUGH RAIN IS STILL EXPECTED
EVERYWHERE BY TUESDAY EVENING. STRONG SHEAR VALUES REMAIN CONFINED
TO THE LAKE ERIE SHORELINE...WHICH SHOULD KEEP THE THREAT FOR SEVERE
STORMS FARTHER TO THE NORTH..BUT SOME STRONGER STORMS REMAIN
POSSIBLE WITH MODEST INSTABILITY. BIGGER CONCERN COULD POSSIBLY BE
HEAVY RAINFALL TUESDAY AFTERNOON AND NIGHT WITH PRECIPITABLE WATER
VALUES RANGING FROM 1.5 INCHES ACROSS WV/MD RIDGES TO NEARLY 2
INCHES IN EASTERN OHIO AND NORTHWESTERN PENNSYLVANIA. THESE PWAT
VALUES ARE NEAR THE 99TH PERCENTILE FOR JUNE...AND IF SHOWERS/STORM
TRAIN ALONG THE FRONT...SOME LOCATIONS COULD SEE SEVERAL ROUNDS OF
MODERATE TO HEAVY RAIN. HOWEVER...THE RELATIVELY DRY WEEKEND THAT
JUST OCCURRED SHOULD HELP TO ALLEVIATE CONCERNS.
MOST RAINFALL SHOULD FALL IN ADVANCE OF THE COLD FRONT...WHICH
SHOULD ACTUALLY PASS OVER THE REGION LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING. RAIN SHOULD HANG ON FOR A WHILE INTO WEDNESDAY
AFTERNOON ACROSS THE WV/MD RIDGES...BUT THINK THAT PRECIP CHANCES
WILL DROP QUITE A BIT WEDNESDAY AFTERNOON...WITH NEARLY ALL
LOCATIONS DRY BY WEDNESDAY NIGHT. A COUPLE OF WARM NIGHTS CAN BE
EXPECTED DUE TO THE EXTENSIVE CLOUD COVER. DAYTIME HIGHS WILL BE
SLIGHTLY ABOVE NORMAL TUESDAY AND SLIGHTLY BELOW NORMAL WEDNESDAY
BEHIND THE COLD FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
KEEPING THURSDAY DRY WITH HIGH PRESSURE IN PLACE AND RELATIVELY
LOW MOISTURE. FRONTAL BOUNDARY WILL RETURN NORTHWARD AS A WARM
FRONT THURSDAY NIGHT/FRIDAY...BRINGING HIGHER PRECIPITABLE WATER
VALUES BACK NORTHWARD. FROM HERE ON OUT...EXPECTING A DAILY CHANCE
OF SHOWERS/THUNDERSTORMS AS H500 HEIGHTS SLOWLY RISE AND WE STAY
IN A TYPICALLY WARM AND MOIST SUMMERTIME AIRMASS. DECIDED TO KEY
ON DIURNAL POPS FOR NOW...EVEN THOUGH RIPPLES IN THE WESTERLIES
MAY PROVIDE ENHANCED CHANCES. TEMPERATURES WILL FLOAT TO A BIT
ABOVE SEASONAL LEVELS WITH TIME.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS EARLY TONIGHT FOLLOWED BY MVFR FOG WITH ONLY KMGW
EXPECTED TO REACH IFR. FOG WILL BURN OFF QUICKLY OVER THE COURSE OF
THE MORNING. THE MAJORITY OF THE AFTERNOON WILL BE QUIET...BUT BY
LATE AFTERNOON/ EVENING SHOWERS AND THUNDERSTORMS WILL EXPAND IN
COVERAGE AS THE CAP ALOFT ERODES AND ALLOWS FOR DEEPER CONVECTIVE
DEVELOPMENT.
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
THE BEST CHANCE FOR RESTRICTIONS WILL BE TUESDAY INTO WEDNESDAY
WITH FRONTAL BOUNDARY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
346 AM EDT MON JUN 23 2014
.SYNOPSIS...
THE WEATHER WILL BE A LITTLE WARMER AND MORE HUMID TODAY WITH AN
ISOLATED STORM. THE BEST CHANCE FOR WET WEATHER WILL BE TUESDAY INTO
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
DRY WEATHER IS EXPECTED FOR THE START OF THE DAY...ALTHOUGH SOME
HIGH CLOUDS WILL REMAIN OVER EASTERN OHIO. IN ADDITION...MANY
LOCATIONS WILL HAVE SOME FOG. ANY LOCATION COULD SEE AN ISOLATED
THUNDERSTORM TODAY...ALTHOUGH THE FOCUS WILL LIKELY REMAIN OVER THE
LAUREL HIGHLANDS. A FEATURE NOT PREVIOUSLY SHOWN ON MODEL RUNS IS A
SHORTWAVE THAT COULD DEVELOP OVER WESTERN OHIO LATE THIS AFTERNOON
AND TRACK OVER NORTHWESTERN PENNSYLVANIA BY MIDNIGHT. WHILE THE NAM
MOST CLEARLY DEPICTS THIS SHORTWAVE...THE END OF THE RAP MODEL RUN
HINTS AT THIS DEVELOPMENT...AND VARIOUS HIGH RESOLUTION NMM RUNS
ALSO DEVELOP THIS PRECIPITATION DURING THE EVENING HOURS. HAVE
RAISED POPS SLIGHTLY DURING THE EVENING HOURS...DECREASING POPS
AGAIN AFTER MIDNIGHT. WITH UPPER RIDGE BUILDING IN...TEMPS WILL BE
ABOUT FIVE DEGREES WARMER TODAY THAN YESTERDAY.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
UNFORTUNATELY...THE 00Z GFS SUFFERS FROM CONVECTIVE
FEEDBACK...SPINNING UP A SURFACE LOW ALONG THE APPROACHING COLD
FRONT AND SHOWING UNREALISTIC PRECIPITATION AND VORTICITY MAXIMA. AS
A RESULT...THE 00Z GFS WAS NOT USED THROUGH THIS PORTION OF THE
FORECAST.
PRIMARY CHANGE DURING THIS PORTION OF THE FORECAST WAS TO SLOW DOWN
THE TIMING OF THE COLD FRONT. COMPARED TO MODEL RUNS FROM 24 HOURS
AGO...FRONT APPEARS TO BE ABOUT 6 HOURS SLOWER IN ITS ARRIVAL AND
PASSAGE WITH LATEST MODEL RUNS. THIS MEANS MANY LOCATIONS COULD
REMAIN DRY TUESDAY MORNING...ALTHOUGH RAIN IS STILL EXPECTED
EVERYWHERE BY TUESDAY EVENING. STRONG SHEAR VALUES REMAIN CONFINED
TO THE LAKE ERIE SHORELINE...WHICH SHOULD KEEP THE THREAT FOR SEVERE
STORMS FARTHER TO THE NORTH..BUT SOME STRONGER STORMS REMAIN
POSSIBLE WITH MODEST INSTABILITY. BIGGER CONCERN COULD POSSIBLY BE
HEAVY RAINFALL TUESDAY AFTERNOON AND NIGHT WITH PRECIPITABLE WATER
VALUES RANGING FROM 1.5 INCHES ACROSS WV/MD RIDGES TO NEARLY 2
INCHES IN EASTERN OHIO AND NORTHWESTERN PENNSYLVANIA. THESE PWAT
VALUES ARE NEAR THE 99TH PERCENTILE FOR JUNE...AND IF SHOWERS/STORM
TRAIN ALONG THE FRONT...SOME LOCATIONS COULD SEE SEVERAL ROUNDS OF
MODERATE TO HEAVY RAIN. HOWEVER...THE RELATIVELY DRY WEEKEND THAT
JUST OCCURRED SHOULD HELP TO ALLEVIATE CONCERNS.
MOST RAINFALL SHOULD FALL IN ADVANCE OF THE COLD FRONT...WHICH
SHOULD ACTUALLY PASS OVER THE REGION LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING. RAIN SHOULD HANG ON FOR A WHILE INTO WEDNESDAY
AFTERNOON ACROSS THE WV/MD RIDGES...BUT THINK THAT PRECIP CHANCES
WILL DROP QUITE A BIT WEDNESDAY AFTERNOON...WITH NEARLY ALL
LOCATIONS DRY BY WEDNESDAY NIGHT. A COUPLE OF WARM NIGHTS CAN BE
EXPECTED DUE TO THE EXTENSIVE CLOUD COVER. DAYTIME HIGHS WILL BE
SLIGHTLY ABOVE NORMAL TUESDAY AND SLIGHTLY BELOW NORMAL WEDNESDAY
BEHIND THE COLD FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
DRY CONDITIONS AND SEASONAL TEMPERATURES CAN BE EXPECTED ON
THURSDAY AS HIGH PRESSURE BUILDS IN ACROSS THE FORECAST AREA. ON
FRIDAY FLOW ALOFT WILL BECOME SOUTHWESTERLY...INCREASING THE
CHANCE FOR SHOWERS AND THUNDERSTORMS AS DEWPOINTS CLIMB BACK UP IN
THE THE MID 60S AND AS WARM FRONT LIFTS NORTH ACROSS THE FORECAST
AREA. THIS WILL CARRY INTO SATURDAY AS THE AFOREMENTIONED FRONTAL
BOUNDARY SITS OVER OR JUST NORTH OF THE FORECAST AREA.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS EARLY TONIGHT FOLLOWED BY MVFR FOG WITH ONLY KMGW
EXPECTED TO REACH IFR. FOG WILL BURN OFF QUICKLY OVER THE COURSE OF
THE MORNING. THE MAJORITY OF THE AFTERNOON WILL BE QUIET...BUT BY
LATE AFTERNOON/ EVENING SHOWERS AND THUNDERSTORMS WILL EXPAND IN
COVERAGE AS THE CAP ALOFT ERODES AND ALLOWS FOR DEEPER CONVECTIVE
DEVELOPMENT.
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
THE BEST CHANCE FOR RESTRICTIONS WILL BE TUESDAY INTO WEDNESDAY
WITH FRONTAL BOUNDARY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
523 AM EDT MON JUN 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 522 AM EDT MON JUN 23 2014
WV IMAGERY AND RUC ANALYSIS INDICATED WSW FLOW INTO THE NRN LAKES
BETWEEN A MID/UPPER LEVEL TROUGH FROM MANITOBA INTO THE NRN PLAINS
AND A RIDGE FROM THE OHIO VALLEY INTO QUEBEC. AT THE SFC...A WEAK
TROUGH EXTENDED FROM NE MN INTO WRN WI. A MORE PROMINENT COLD FRONT
STRETCHED FROM JAMES BAY TO NEAR WINNIPEG AHEAD OF HIGH PRESSURE
OVER N CNTRL CANADA. FORCING FROM A WEAK SHRTWV IN NRN WI ALONG WITH
AN AXIS OF HIGHER MOISTURE WITH PWAT VALUES TO 1.4 INCHES...WAS
ENOUGH TO SUPPORT AN AREA OF SHOWERS OVER FROM SW UPPER MI INTO E
CNTRL WI.
TODAY...EXPECT THE SHRTWV AND AREA OF PCPN ONLY SLOWLY MOVE TO THE
EAST THIS MORNING. WITH ONLY WEAK LARGE SCALE FORCING EXPECTED INTO
THE AFTERNOON AND THE POTENTIAL FOR ANOTHER WEAK SHRTWV TO MOVE INTO
THE AREA DURING INCREASED DAYTIME HEATING...THE FCST KEEPS MENTION
OF JUST SCT SHRA WITH THE GREATEST COVERAGE EXPECTED OVER CNTRL
UPPER MI. WITH TEMPS CLIMBING INTO THE MID 70S...THERE MAY BE ENOUGH
INSTABILITY FOR SOME ISOLD/SCT TSRA AS MLCAPE VALUES CLIMB INTO THE
400-800 J/KG RANGE.
TONIGHT...WITH THE LOSS OF DAYTIME HEATING...THE PCPN COVERAGE
SHOULD DIMINISH. HOWEVER...INCREASED QVECTOR CONV AHEAD OF THE MID
LEVEL TROUGH MOVING INTO THE UPPER MS VALLEY WILL SUPPORT CONTINUED
CHANCES FOR SCT SHOWERS AND A FEW TSRA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 421 AM EDT MON JUN 23 2014
ON TUESDAY MORNING...THE MODELS ARE IN GOOD AGREEMENT IN SHOWING THE
COLD FRONT MOVING OVER OR JUST SOUTH OF THE AREA. HOWEVER...THE
850MB TROUGH AXIS HANGS UP OVER LAKE SUPERIOR AS THERE IS LACK OF A
SOUTHWARD PUSH DUE TO THE GENERAL ZONAL FLOW ALOFT. THIS WILL
PROVIDE THE FOCUS FOR PRECIPITATION ON TUESDAY ESPECIALLY SINCE THE
MODELS ARE IN EXCELLENT AGREEMENT IN SHOWING BROAD SYNOPTIC SUPPORT
MOVING THRU AS THE 500MB TROUGH AXIS MOVES THROUGH. AS SUCH...THERE
WILL LIKELY BE SCATTERED SHOWERS ACROSS THE ENTIRE FORECAST AREA
THROUGH THE DAY DESPITE THE SURFACE FRONT BEING SOUTH OF THE REGION.
THE NUMERICAL GUIDANCE ALSO SHOWS MUCAPE VALUES OF 500-1500 J/KG
ACROSS THE REGION DURING THE DAY WITH MID LEVEL LAPSE RATES OF 6+
C/KM...ALLOWING FOR POSSIBLE THUNDERSTORM DEVELOPMENT. BEST CHANCES
FOR THUNDER WOULD BE ACROSS THE SOUTHERN TIER WHERE SFC TEMPS WILL
LIKELY BE IN THE LOWER-MID 70S AND IS WHERE THE BEST INSTABILITY
WILL BE LOCATED. WILL NEED TO KEEP CHANCE POPS ACROSS THE EASTERN
HALF OF THE FORECAST AREA DURING THE TUE EVENING HOURS AS WELL GIVEN
REMAINING MID LEVEL FORCING AND REMAINING DAYTIME INSTABILITY.
AT THIS TIME...WEDNESDAY IS EXPECTED TO REMAIN DRY AND COOL WITH THE
850MB TROUGH AND SFC FRONT REMAINING SOUTH OF THE AREA. STILL SOME
WEAK TROUGHINESS AT 500MB AND AS SUCH WEAK MID LEVEL Q-VECTOR
CONVERGENCE AND MOISTURE PERSISTS ACROSS THE AREA ALL DAY.
HOWEVER...GIVEN LACK OF INSTABILITY AND VERY WEAK MID LEVEL LAPSE
RATES COMBINED WITH ANTICYCLONIC LOW LEVELS WILL KEEP IT DRY FOR
NOW. WOULD NOT BE SHOCKED TO SEE ISOLATED SHOWERS BUT CHANCES ARE
NOT HIGH ENOUGH TO INCLUDE IN THE FORECAST AT TIME TIME.
IN THE EXTENDED...ZONAL FLOW THROUGH THE PERIOD WILL MAKE TIMING OF
PRECIPITATION SOMEWHAT DIFFICULT ESPECIALLY INTO THE WEEKEND.
HOWEVER...THE LONGER RANGE MODELS ARE IN DECENT AGREEMENT ON THE
BROAD SCALE FEATURES WHICH AT LEAST GIVES SOME BASIC CONFIDENCE ON
WHEN THE BETTER CHANCES FOR RAIN WILL BE. ON THURSDAY...THE ECMWF
AND GFS BOTH SHOW A COMPACT VORT MAX MOVING ACROSS THE AREA DURING
THE DAY AS THE 850MB FRONT MOVES BACK NORTH. ALTHOUGH MOISTURE WILL
BE VERY LIMITED...WILL INCLUDE CHANCE POPS FOR THE WESTERN HALF OF
THE FORECAST AREA. BEHIND THIS VORT MAX...UPPER RIDGING BUILDS
ACROSS THE AREA FOR FRIDAY WHICH SHOULD ALLOW FOR TEMPS TO RETURN TO
NORMAL AS WELL AS DRY WEATHER. RETURN FLOW BEGINS IN EARNEST FOR THE
WEEKEND WITH TEMPERATURES LIKELY TO RISE ABOVE NORMAL...AND PERHAPS
A LITTLE MORE HUMIDITY AND SUMMER LIKE WEATHER. THIS WILL ALLOW FOR
CHANCES OF SHOWERS AND STORMS EACH DAY...ALTHOUGH SUNDAY LOOKS LIKE
THE BETTER CHANCE FOR SHOWERS AND STORMS GIVEN LOWERING HEIGHTS
ACROSS THE AREA IN RESPONSE TO THE APPROACHING TROUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 124 AM EDT MON JUN 23 2014
SOME -SHRA MAY IMPACT IWD AND CMX TNGT AS A DISTURBANCE MOVES NEWD
INTO THE UPR GREAT LKS. THESE SITES WL LIKELY SEE DVLPG MVFR
CONDITIONS WITH NOCTURNAL COOLING...ESPECIALLY IF SOME HEAVIER RA
FALLS. NOT OUT OF THE QUESTION THERE COULD BE IFR CONDITIONS
ESPECIALLY AT CMX WHERE MOISTENING OF THE LK COOLED AIRMASS WOULD
RESULT IN FOG/STRATUS...BUT RATHER DRY NATURE OF AIRMASS IN PLACE
NEAR TAF ISSUANCE AND DIMINISHING -SHRA TO THE SW INDICATES THIS CHC
IS NOT THAT HI. AT SAW...LO CLDS NEAR THE LK MI SHORE MAY ARRIVE
LATER TNGT IN LLVL SLY FLOW. AS THE UPR DISTURBANCE EXITS TO THE NE
ON MON AND DAYTIME HEATING TAKE HOLD...ANY FOG/LO CLDS SHOULD DSPT
AND GIVE WAY TO VFR WX. BUT THE LO CLDS COULD BE RESILIENT AT CMX
WITH LK MODIFIED AND PSBLY RA COOLED AIRMASS DOMINATING. MORE
INSTABILITY SHRA AND PERHAPS A TS COULD IMPACT SAW MAINLY IN THE
AFTN AND EARLY EVNG. BEST CHC FOR MORE LO CLDS/FOG TO DVLP WOULD BE
AT CMX...WITH RELATIVELY COOL/MOIST MARINE LYR DOMINATING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 522 AM EDT MON JUN 23 2014
DENSE FOG WILL PERSIST OVER WESTERN LAKE SUPERIOR INTO THIS
AFTERNOON. OTHERWISE...MAINLY LIGHT WINDS WILL PREVAIL INTO TONIGHT.
AS A COLD FRONT MOVES THROUGH THE AREA ON TUESDAY...NORTHEAST WINDS
WILL INCREASE TO 20 KNOTS WITH WAVES BUILDING TO AROUND 4 FEET.
WINDS WILL DIMINISH TUE NIGHT INTO WED AS HIGH PRES BUILDS INTO THE
REGION. MAINLY LIGHT WINDS AT OR BELOW 15 KNOTS ARE THEN EXPECTED
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 2 PM EDT /1 PM CDT/ THIS AFTERNOON FOR
LSZ162-240>248-263>265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
259 AM CDT Mon Jun 23 2014
.SHORT TERM: (Through Wednesday)
Issued at 258 AM CDT Mon Jun 23 2014
A decaying MCV was moving through northeast MO into west central IL
early this morning. A 20-30kt southwesterly LLJ was also interacting
with multiple outflow boundaries across MO/IL at times. These
features should keep isolated to scattered convection percolating
through the early morning hours across parts of the CWA.
DCVA ahead of an approaching mid/upper vort max should provide
sufficient lift within a moist air mass for widespread SHRA/TSRA
today and tonight along a weak cold front with precip lingering into
Tue across the southeastern portion of the CWA. Expect daytime high
temperatures to be a bit cooler today due to widespread cloud cover
and pcpn. Some models depict a surface low developing along the
trailing edge of the surface cold front or effective boundary in OK
which then lifts northeastward through southeastern MO. If this
occurs, then schc-chc PoPs might be too low on Tue night into Wed
across the southeastern CWA.
Kanofsky
.LONG TERM: (Wednesday through Sunday)
Issued at 258 AM CDT Mon Jun 23 2014
The upper air pattern remains nearly quasizonal through the middle
of the week with an occasional synoptic disturbance or remnant MCV
to support SHRA/TSRA through the week. Initially weak upper ridging
over MO/IL on Thu is forecast to amplify by the end of the week in
response to troughing over the West Coast. Expect daytime highs to
warm back into the upper 80s to around 90 degrees by the weekend due
to southwesterly surface flow and rising heights.
Kanofsky
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1028 PM CDT Sun Jun 22 2014
Convection along outflow boundary will move through COU with
weaker convection moving through UIN until 07Z or 08Z Monday. Some
of this convection may make it into the St Louis metro area late
tonight, but may leave the St Louis metro area tafs dry for now
as the latest HRRR model dissipates most of the convection before
it makes it into the St Louis metro area. Should be mainly just
high level convective cloud debris outside of the shower/storm
activity late tonight. Diurnal cumulus clouds will develop late
Monday morning and afternoon with showers and thunderstorms
expected mainly during the late morning and afternoon for COU, the
afternoon for UIN, and the late afternoon and early evening for
the St Louis metro area as a weak cold front approaches. Surface
winds will be mainly swly on Monday.
Specifics for KSTL: Mainly just mid-high level clouds late tonight
with most of the convection remaining north and west of STL.
Diurnal cumulus clouds will develop late Monday morning and
afternoon with the best chance of showers and storms during the
late afternoon and early evening hours. The surface wind will be
mainly light and s-swly late tonight, then increasing to around
8-9 kts by Monday afternoon from a swly direction, and
diminishing Monday night and veering around to a w-nwly direction
after fropa by late Monday night.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1102 PM CDT Sun Jun 22 2014
.UPDATE:
Issued at 937 PM CDT Sun Jun 22 2014
In the process of making some adjustment to PoPs based on latest
short-term precip trends. It appears that main convection threat
over the next few hours will be tied to outflow boundary dropping
south across western MO. This should bring an uptick of PoPs into
the likely category over mid MO over the next few hours, with this
activity then gradually waning as outflow drops further south and
ams becomes somewhat less unstable due to nocturnal cooling. This
activity should at least partially cut into precip potential over
northeast MO/west central IL due to the increase of stability of
the ams in the wake of the outflow. However, in the 09-12z time
frame, models are still indicating a weak WAA pattern which could
regenerate some elevated convection during the predawn hours (similar
to what occurred early this morning), and this should bring some
low PoPs to se sections of the CWA.
Forecast that reflects this thinking will be out shortly.
Truett
&&
.SHORT TERM: (Through Late Tonight)
Issued at 350 PM CDT Sun Jun 22 2014
A nearly stationary front was laid out near the MS river this
afternoon and is acting as the primary focus for TSRA development.
Another source for TSRA development is a MCV located along the MO-IA
border north of Kansas City that is headed east and has a tail of
TSRA extending south to near the Kansas City area thanks to a
surface outflow boundary. Otherwise, a typical partly cloudy summer
day in most areas with temps pushing 90--unless you`ve seen rain,
like Farmington sitting at 68.
The quasi-stationary front is expected to weaken in identity tonight
as well as push northeast as a warm front. The bottom line for this
will be dissipation of the TSRA during the evening with loss of
heating and weakening of moisture convergence. One thing that may
prolong this, like last night, is if individual cells can merge
together enough to form a more coherent structure. If that happens,
storms and their intensity will likely last towards midnight.
The MCV along the MO-IA border is expected to move into central IL
by late this evening, with TSRA likely during that time over the
northern CWA, around Quincy. Some breaks are expected late this
evening and a part overnight.
One final source for rain will be a shortwave TROF that will
strengthen over the central Plains tonight and will extend its
influence towards central MO by sunrise. This should lead to
increasing PoPs very late tonight in central MO and perhaps back
into northeast MO and west-central IL.
Min temps are close to persistence/MOS, which has verified well the
past few days.
TES
.LONG TERM: (Monday through Next Sunday)
Issued at 350 PM CDT Sun Jun 22 2014
The current pattern we are in will continue relatively unaltered
through late Thursday, with a flat west-east mid-level flow and
periodic effects from upper level disturbances or MCVs. This will
continue the unsettled wx and TSRA chances thru much of this period,
only being limited when available moisture becomes a factor, or
enhanced when a clear focus can be seen.
Strong chances for SHRA/TSRA are still expected on Monday,
especially afternoon, and Monday night with a more significant
shortwave TROF that will pass into a convectively favorable
atmosphere--and maintained likely PoPs as a result.
Much of Tuesday and Wednesday look to be a couple of dry days for
most areas, provided the 12z GFS is not correct with its much
stronger and slower depiction of the shortwave and associated
surface wave. Daytime max temps should be in the 80s these days.
Rain chances could return for a widespread area on Thursday with
some models depicting the return of rich and deep moisture and
another upper level shortwave.
A deep and amplified upper TROF is then expected to dig into the
western CONUS for the end of the week, more consistently depicted by
the EC. This is expected to result in temps returning closer to the
low 90s for daytime maxes with reduced PoPs.
TES
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1028 PM CDT Sun Jun 22 2014
Convection along outflow boundary will move through COU with
weaker convection moving through UIN until 07Z or 08Z Monday. Some
of this convection may make it into the St Louis metro area late
tonight, but may leave the St Louis metro area tafs dry for now
as the latest HRRR model dissipates most of the convection before
it makes it into the St Louis metro area. Should be mainly just
high level convective cloud debris outside of the shower/storm
activity late tonight. Diurnal cumulus clouds will develop late
Monday morning and afternoon with showers and thunderstorms
expected mainly during the late morning and afternoon for COU, the
afternoon for UIN, and the late afternoon and early evening for
the St Louis metro area as a weak cold front approaches. Surface
winds will be mainly swly on Monday.
Specifics for KSTL: Mainly just mid-high level clouds late tonight
with most of the convection remaining north and west of STL.
Diurnal cumulus clouds will develop late Monday morning and
afternoon with the best chance of showers and storms during the
late afternoon and early evening hours. The surface wind will be
mainly light and s-swly late tonight, then increasing to around
8-9 kts by Monday afternoon from a swly direction, and
diminishing Monday night and veering around to a w-nwly direction
after fropa by late Monday night.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
319 AM CDT MON JUN 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 319 AM CDT MON JUN 23 2014
ANOTHER MCS SHOULD DROP THROUGH THE CNTL HIGH PLAINS THIS AFTN. THE
FORECAST USES 50 PERCENT OF THE RAP MODEL AND 50 PERCENT OF THE
OTHER MODELS.
THE ONGOING MCS APPEARS TO BE TAKING ON A CYCLONIC ROTATION WITH THE
WARM SECTOR ACROSS SCNTL NEB AND THE UPPER LEVEL COLD POOL ACROSS
SWRN NEB ATTM. RADAR TRENDS SUGGEST THIS SYSTEM COULD ROTATE THROUGH
SCNTL NEB THIS MORNING AND SHOWERS AND TSTMS ARE POPPING LEFT AND
RIGHT BETWEEN KLBF AND KLXN.
FOR TONIGHT...NEBULOUS POPS ARE IN THE FCST ACROSS THE SANDHILLS AND
AREAS SOUTH. GIVEN THE INABILITY OF THE SYNOPTIC SCALE MODELS TO
PREDICT NOCTURNAL RAIN EVENTS OF LATE...THE FCST IS FORCED TO
MAINTAIN A SCATTERED POP.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 319 AM CDT MON JUN 23 2014
12Z TUESDAY AND BEYOND. NEAR DAILY PRECIPITATION CHANCES TO
HEADLINE THE EXTENDED DISCUSSION THROUGH AT LEAST SATURDAY AS THE
ACTIVE PATTERN CONTINUES.
A BRIEF PERIOD OF NORTHWEST FLOW ALOFT WILL DIRECT TWO SUBTLE
DISTURBANCES ACROSS THE CENTRAL PLAINS TUESDAY INTO WEDNESDAY. THE
FIRST OF WHICH SHOULD BE EAST OF THE CWA BY 12Z TUESDAY. THERE
REMAINS GOOD CONSENSUS HOWEVER THAT THUNDER CHANCES REMAIN THROUGH
MUCH THE DAY AS THE NEXT DISTURBANCE FOLLOWS. THE ATMOSPHERE WILL
CHARACTERIZED AS MODERATELY UNSTABLE...WITH GENERALLY 25-40 KTS OF
DEEP LAYER SHEAR. STRONG TO SEVERE STORMS ARE ANTICIPATED...BUT
POSSIBLY THE GREATER IMPACT WILL BE HEAVY RAINFALL POTENTIAL AS
THERE/S SUPPORT OF ONE OR MORE MCS/S PASSING THROUGH THE SANDHILLS
REGION. STORM MOTION WILL BE ON THE SLOW SIDE...GENERALLY LESS THAN
20KTS...AND WITH PWATS INCREASING OVER AN INCH AND A
THIRD...RAINFALL RATES OF AN INCH OR TWO AN HOUR WILL BE POSSIBLE.
UPPER LOW PRESSURE TO BUILD EAST INTO THE PACIFIC NORTHWEST
WEDNESDAY ALLOWING THE EASTWARD DEVELOPMENT OF A LOW AMPLITUDE
TRANSITORY RIDGE. PRECIPITATION CHANCES CONTINUE ON WEDNESDAY AS
THE NEXT WAVE EMBEDDED IN THE NOW QUASI-ZONAL FLOW IMPACTS THE
REGION. TIMING AND PLACEMENT OF THE BETTER PRECIPITATION CHANCES
WILL BE GENERALLY TIED TO THE LOCATION OF A LOW LEVEL FRONTAL
BOUNDARY AND HOW CONVECTION FROM THE PREVIOUS DAY PLAYS OUT. AT
THIS TIME THE MODELS ARE FAVORING NORTHERN NEBRASKA WITH THE HIGHER
POP CHANCES /40 PERCENT/ WEDNESDAY AFTERNOON...WILL FOLLOW SUIT WITH
THE FORECAST. THE AFOREMENTIONED RIDGE MAY EFFECTIVELY CAP THE
REGION ON THURSDAY AS MIDLEVEL TEMPS WARM AOA 14C...AT THIS POINT
WILL KEEP MOST OF THE CWA DRY THURSDAY WITH THE EXCEPTION BEING
THURSDAY NIGHT ACROSS OUR NORTHERN BORDER WHERE RIDGE RIDING WAVE
MAY SPARK CONVECTION. FOR LATE WEEK AND THE WEEKEND...FORECAST
CONFIDENCE IS NOT QUITE THERE YET AS THE FINER DETAILS OF HOW THE
WESTERN CONUS TROUGH WILL PLAY OUT ARE STILL AN ENIGMA. IN THE
SYNOPTIC SCALE THERE REMAINS GOOD AGREEMENT OF A FAIRLY STRONG
TROUGH ADVANCING INTO THE NORTHERN ROCKIES WITH MOST OF THE
FAVORABLE UPPER LEVEL ENERGY TARGETING THE NORTHERN PLAINS. SOLID
MOISTURE RETURN AND WARMING TEMPERATURES WILL BE IN PLACE ACROSS THE
CENTRAL PLAINS...WITH A FRONTAL PASSAGE/SFC TROUGH FOR THE WEEKEND.
STORMS...POSSIBLY SEVERE WILL ONCE AGAIN BE POSSIBLE....BUT WITH
LACKING CONSISTENCY...WILL CAP POP CHANCES AT 40 PERCENT OR LESS
THROUGH THE WEEKEND. AS FOR TEMPERATURES...A GRADUAL WARMING TREND
IS ANTICIPATED THROUGH THE END OF THE WORK WEEK...WITH HIGHS
GENERALLY IN THE 80S...LOWS WILL BE SEASONAL IN THE 50 AND 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1152 PM CDT SUN JUN 22 2014
ISOLATED THUNDERSTORMS ARE POSSIBLE IN THE VICINITY OF THE KLBF
TERMINAL THROUGH 09Z MONDAY. CIGS MAY DROP DOWN TO 7000 FT AGL IN
THE VICINITY OF THUNDERSTORMS. FOR MONDAY...CIGS AROUND 5000 FT
AGL ARE EXPECTED WITH A SMALL THREAT FOR ISOLATED THUNDERSTORMS IN
THE AFTERNOON HOURS. THE THUNDERSTORM THREAT WILL END ON MONDAY
EVENING WITH CIGS INCREASING TO 15000 FT AGL. FOR THE KVTN
TERMINAL...EXPECT BROKEN TO OVERCAST CIGS RANGING FROM 10000 TO
20000 FT AGL OVERNIGHT. CIGS WILL SCATTER OUT MONDAY
MORNING...WITH BROKEN CIGS EXPECTED MONDAY AFTERNOON AND MONDAY
EVENING WITH LEVELS AROUND 12000 FT AGL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
100 AM CDT MON JUN 23 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 301 PM CDT SUN JUN 22 2014
THE PRIMARY SHORT TERM FORECAST CONCERN CENTERS AROUND THE CHANCE OF
THUNDERSTORMS THIS AFTERNOON INTO TONIGHT. OVER THE LAST 8 HOURS
HAVE GREATLY REDUCED THUNDERSTORM CHANCES FOR THIS AFTERNOON AND
TONIGHT ACROSS OUR FORECAST AREA. THE GREATEST REDUCTION IN
THUNDERSTORM CHANCES HAS BEEN ACROSS NEBRASKA.
THERE IS MODEST TO EVEN FAIRLY GOOD INSTABILITY ACROSS THE FORECAST
AREA ESPECIALLY ACROSS KANSAS...WITH LITTLE TO NO CIN. WIND SHEAR IS
RATHER WEAK WITH DEEP LAYER 0-6 KM SHEAR OF LESS THAN 30 KTS. THE
BIG ISSUE CENTERS AROUND FORCING OR THE LIFTING MECHANISM FOR
ORGANIZED CONVECTION. FORCING MECHANISMS ACROSS THE REGION INCLUDE
AN UPPER LEVEL SHORT WAVE TROUGH OVER IOWA...A SOUTHWARD SLIPPING
SFC FRONTAL BOUNDARY ACROSS NORTHERN KANSAS...AND A VERY WEAK UPPER
WAVE CENTERED OVER THE BLACK HILLS OF SOUTH DAKOTA EXTENDING INTO
THE NEBRASKA PANHANDLE. THE SFC FRONT IS THE PRIMARY FORCING
MECHANISM CURRENTLY LOCATED OVER OUR FORECAST AREA AND IT IS
GRADUALLY SINKING SOUTH WHERE IT WILL EXIT OUR AREA BY LATER THIS
EVENING. THEREFORE...THUNDERSTORMS SEEM MOST LIKELY LATE THIS
AFTERNOON INTO EARLY THIS EVENING IN CLOSE PROXIMITY TO THE SFC
FRONT OVER NORTHERN KANSAS AND THUS HAVE KEPT POPS AROUND 50/50 IN
THESE SOUTHERN ZONES...WITH THE HIGHER POPS REALLY BEING SOUTH OF
OUR FORECAST AREA TONIGHT. SOME FORECAST MODELS GENERATE CONVECTION
ACROSS THE HIGH PLAINS TONIGHT IN ASSOCIATION WITH THE VERY WEAK
UPPER WAVE...BUT 4 OUT OF 6 MODELS HAVE THIS PRECIPITATION DIEING
OFF BEFORE REALLY REACHING OUR AREA TONIGHT. ONE OUTSIDE WRF RUN AND
THE HRRR DO BRING CONVECTION FROM WESTERN PORTIONS OF NEBRASKA AND
KANSAS INTO OUR FORECAST AREA LATE TONIGHT WHILE MOST MODELS DO NOT.
WILL GO WITH THE MAJORITY GIVEN THERE IS NOT MUCH OF A LOW LEVEL JET
TO HELP SUSTAIN CONVECTION TONIGHT ACROSS OUR FORECAST AREA. ANY
THUNDERSTORMS THAT CAN FORM THIS AFTERNOON OR EVENING ACROSS KANSAS
COULD BECOME SEVERE GIVEN THE HIGHER INSTABILITY ACROSS OUR SOUTHERN
ZONES.
MONDAY...MOST FORECAST MODELS INDICATE THAT WE WILL BE IN BETWEEN
WEAK SHORT WAVE STORM SYSTEMS AND LIKELY DRY. TEMPERATURES WILL BE
MILD WITH A LIGHT NORTHEAST WIND KEEPING THINGS A BIT COOLER THAN
TODAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 301 PM CDT SUN JUN 22 2014
THE WEATHER PATTERN REMAINS UNSETTLED DURING THE EXTENDED PERIODS
WITH INTERMITTENT CHANCES FOR THUNDERSTORMS. AN UPPER LOW PRESSURE
SYSTEM WILL BE TRANSLATING SOUTHEAST FM CANADA TO THE UPPER MIDWEST
REGION AT THE ONSET OF THE EXTENDED WITH THE FLOW ALOFT
TRANSITIONING WEST NORTHWEST FOR A TIME AS ANOTHER TROUGH DIGS INTO
THE PACIFIC NORTHWEST REGION. A SERIES OF WAVES EMBEDDED IN THE
FLOW WILL AID IN TSTM DEVELOPMENT WITH TIMING/PLACEMENT DEPENDENT
UPON WAVE TIMING AND BOUNDARY LOCATIONS AND BOUNDARY LOCATION WILL
BE DEPENDENT UPON HOW CONVECTION UNFOLDS THE PREVIOUS DAY. IT IS
DIFFICULT TO PINPOINT DETAILS ATTM AND WITH THE PROGRESSIVE PATTERN
JUST CANNOT RULE OUT TSTM CHCS NEARLY EVERY DAY. CONVECTION MAY
DEVELOP ALONG THE HIGH PLAINS AND ROLL EASTWARD...OR MAY INITIATE
ALONG A BOUNDARY WITHIN THE AREA.
SREF INSTABILITY PROGS INDICATE THE GREATER INSTABILITY MONDAY NIGHT
WILL RESIDE ALONG THE HIGH PLAINS REGION...WHICH WILL BEGIN TO
SPREAD EASTWARD ON TUESDAY...WITH MUCAPES INCREASING TO NEAR OR JUST
ABOVE 1000 J/KG. WITH THE MORE MARGINAL INSTABILITY ON
TUESDAY...NOT LOOKING FOR MUCH SEVERE WX JUST YET WITH INSTABILITY
FURTHER INCREASING TUESDAY NIGHT INTO MID WEEK WITH RETURN
FLOW...STRENGTHENING NOCTURNAL LLVL JET AND WAA/UPPER RIDGING AHEAD
OF UPPER TROUGH IN THE PACIFIC NW. UPPER RIDGING SETTLES OVERHEAD
FOR THE LATTER PART OF THE WORKWEEK AND MID LEVEL TEMPS INCREASE TO
AROUND 14C SO CAP MAY LIMIT CONVECTION FOR A TIME. MODELS ARE NOT
IN GREAT AGREEMENT ON THE TIMING/PROGRESSION OF THE WESTERN TROUGH
AS IT PUSHES EAST THRU THE MOUNTAINS TOWARDS THE PLAINS AND WILL NEED TO
MONITOR BUT CHCS FOR STORMS INCREASE AGAIN WITH THIS SYSTEM OVER THE
WEEKEND OR EARLY NEXT WEEK. ALL BEING SAID...INTERMITTENT CHANCES
FOR STORMS CONTINUE AND TEMPS LOOK FAIRLY SEASONAL ATTM.
&&
.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1259 AM CDT MON JUN 23 2014
VFR CONDITIONS ARE EXPECTED BEHIND A COLD FRONT WITH VARYING
AMOUNTS OF MID TO UPPER LEVEL CLOUDINESS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...WESELY
LONG TERM...FAY
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1202 AM CDT MON JUN 23 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 341 PM CDT SUN JUN 22 2014
AT 19Z...WATER VAPOR SHOWED QUASI-ZONAL FLOW ACROSS MUCH OF THE
CONUS WITH AN UPPER LEVEL LOW SPINNING OVER THE CENTRAL
SASKATCHEWAN/MANITOBA BORDER. MULTIPLE WEAK SHORTWAVES COULD BE
PICKED OUT MOVING ACROSS THE ROCKIES...FROM MONTANA DOWN THROUGH NEW
MEXICO. THE STRONGER SHORTWAVE WAS SEEN OVER WESTERN COLORADO AT MID
AFTERNOON WHICH WILL IMPACT THE FORECAST FOR TONIGHT...WITH THE
SECOND MORE DISTINCT SHORTWAVE SEEN OVER EASTERN IDAHO...WHICH WILL
IMPACT THE FORECAST FOR MONDAY. AT THE SURFACE...A COLD FRONT WAS
SITUATED FROM SOUTHWEST KANSAS INTO NORTHWEST MISSOURI. NORTH OF
THIS FRONT COLD AIR HAD ADVECTED INTO NEBRASKA...WITH MID AFTERNOON
TEMPERATURES GENERALLY IN THE 70S AND LOW 80S. DECENT LOW LEVEL
MOISTURE DID REMAIN IN PLACE...AS DEWPOINTS ACROSS THE AREA WERE
STILL IN THE UPPER 50S AND 60S. WITH THE MOISTURE IN PLACE AND STEEP
LOW LEVEL LAPSE RATES...AN EXTENSIVE CUMULUS FIELD HAD DEVELOPED
ACROSS WESTERN NEBRASKA. DESPITE DECENT SB INSTABILITY OF 1500-2500
J/KG WITH NO CAP...ANY SHOWERS AND THUNDERSTORMS HAVE HAD A PROBLEM
MAINTAINING WITH NO ADDITIONAL FORCING IN PLACE.
FOR THIS EVENING AND TONIGHT...ALTHOUGH THE HRRR IS INDICATING
STORMS DEVELOPING OVER SOUTHWEST NEBRASKA AHEAD OF THE MAIN SYSTEM
OVER THE ROCKIES...FEEL THIS ACTIVITY WILL BE WEAK WITH THE LACK OF
FORCING FROM THE SHORTWAVE AND VERY LITTLE IF ANY FORCING COMING
FROM ANY LOW LEVEL MOISTURE TRANSPORT. SO WILL FOCUS ON ACTIVITY
MOVING OUT ONTO THE PLAINS WITH THE MAIN SHORTWAVE. AS THIS SHORTWAVE
OVER WESTERN COLORADO MOVES EAST EXPECT FURTHER DEVELOPMENT OF
CONVECTION ALONG THE FOOTHILLS AND INTO THE HIGH PLAINS. THE
QUESTION WILL BE HOW FAR NORTH THE CONVECTION WILL DEVELOP. THE
LATEST FEW RUNS OF THE HRRR INDICATE ACTIVITY DEVELOPING AS FAR
NORTH AS SCOTTSBLUFF. THESE STORMS WOULD THEN MOVE SOUTHEAST ALONG A
THETA-E GRADIENT. ALTHOUGH THERE IS SUFFICIENT INSTABILITY AND DEEP
LAYER SHEAR WILL BE INCREASING...THE LOCAL AREA WILL BE ON THE
NORTHERN FRINGE OF ANY ACTIVITY AND WITH THE BETTER FORCING OVER
KANSAS EXPECT THE THREAT FOR ANY SEVERE STORMS TO STAY SOUTH OF THE
AREA.
FOR MONDAY THE SHORTWAVE TROUGH NOW OVER EASTERN IDAHO WILL MOVE
ACROSS WYOMING AND THEN ACROSS NEBRASKA FROM NORTHWEST TO SOUTHEAST.
NOT EXTREMELY CONFIDENT ON HOW MUCH COVERAGE OF SHOWERS AND
THUNDERSTORMS THERE WILL BE AS THE AIRMASS WILL BE SLIGHTLY
DRIER...WITH DEWPOINTS MAINLY IN THE 50S AND NO REAL SURGE OF DEEP
MOISTURE ALOFT. AT THE PRESENT TIME THINK ANY CONVECTION WILL BE
MORE ISOLATED TO SCATTERED IN NATURE. THE NEXT QUESTION IS WHERE THE
CONVECTION WILL ACTUALLY BE. THE NAM SHOWS QPF ACROSS MUCH OF THE
FORECAST AREA WHILE THE GFS/ECMWF ARE KEEPING IT MAINLY OVER THE
PANHANDLE AND SOUTHWEST NEBRASKA. HAVE SIDED WITH THE GFS/ECMWF FOR
TODAY AND HAVE LIMITED CHANCES FOR THE WESTERN AREAS. AS FOR HIGHS
ON MONDAY...LOOKING FOR A SLIGHTLY COOLER DAY WITH HIGHS IN THE 70S
AND LOW 80S AS COOLER AIR SLOWLY CONTINUES TO FILTER INTO THE AREA
BEHIND THE UPPER LEVEL SYSTEM OVER SOUTHERN CANADA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 341 PM CDT SUN JUN 22 2014
NORTHWEST FLOW ALOFT WILL PERSIST MONDAY NIGHT THROUGH TUESDAY
NIGHT WITH THE PASSAGE OF TWO DISTINCT DISTURBANCES. MAINTAINED 30
POPS LATE MONDAY NIGHT ACROSS WESTERN ZONES...TO 40 POPS
TUESDAY/TUESDAY NIGHT. PWAT VALUES FROM GFS INDICATE 120 TO NEAR 140
PERCENT OF NORMAL WITH DEEP LAYER SHEAR INCREASING TO 30 TO 40
KTS. THIS SUPPORTIVE OF STRONG THUNDERSTORMS TUESDAY AFTN/EVENING
WITH LOCALLY HEAVY RAINFALL DUE TO SLOW STORM MOTION NEAR 10 KTS.
SECOND DISTURBANCE FORECAST TO LIFT ACROSS LATE TUESDAY NIGHT AND
WEDNESDAY WITH 40 POPS TUESDAY NIGHT...FOLLOWED BY 40 POPS FOR
NCTRL WEDNESDAY.
MAINLY 20 TO 30 POPS THURSDAY THROUGH SATURDAY. DUE TO WEAK RIDGING
OVER THE REGION AND SWRLY FLOW TO OUR WEST WHICH MOVES IN BY
FRIDAY NIGHT...MODEL AGREEMENT IN TIMING AND LOCATION IS RATHER
POOR. TEMPERATURES HOWEVER WILL WARM FROM THE UPPER 70S TO LOWER
80S TUESDAY...MID 80S THURSDAY THROUGH SATURDAY TO AROUND 90 BY
SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1152 PM CDT SUN JUN 22 2014
ISOLATED THUNDERSTORMS ARE POSSIBLE IN THE VICINITY OF THE KLBF
TERMINAL THROUGH 09Z MONDAY. CIGS MAY DROP DOWN TO 7000 FT AGL IN
THE VICINITY OF THUNDERSTORMS. FOR MONDAY...CIGS AROUND 5000 FT
AGL ARE EXPECTED WITH A SMALL THREAT FOR ISOLATED THUNDERSTORMS IN
THE AFTERNOON HOURS. THE THUNDERSTORM THREAT WILL END ON MONDAY
EVENING WITH CIGS INCREASING TO 15000 FT AGL. FOR THE KVTN
TERMINAL...EXPECT BROKEN TO OVERCAST CIGS RANGING FROM 10000 TO
20000 FT AGL OVERNIGHT. CIGS WILL SCATTER OUT MONDAY
MORNING...WITH BROKEN CIGS EXPECTED MONDAY AFTERNOON AND MONDAY
EVENING WITH LEVELS AROUND 12000 FT AGL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BROOKS
LONG TERM...ROBERG
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
343 AM CDT MON JUN 23 2014
.SYNOPSIS...
ISSUED AT 324 AM CDT MON JUN 23 2014
REX BLOCKING OVER THE CANADIAN PRAIRIE IS FORECAST TO BREAK DOWN
ON WEDNESDAY...BUT THERE IS GOOD AGREEMENT THAT THE NORTHEAST
PACIFIC UPPER LEVEL LOW WILL BROADEN FURTHER INTO NORTHWESTERN
CONUS...AND EVENTUALLY INTO THE NORTHERN PLAINS. SCATTERED SHOWERS
AND THUNDERSTORMS WILL TRANSITION TO HIGHER CHANCES OF
THUNDERSTORMS AS SOUTHWESTERLY FLOW ALOFT MOVES OVER THE DAKOTAS
LATER THIS WEEK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT MON JUN 23 2014
SCATTERED SHOWERS AND THUNDERSTORMS ARE FORECAST TODAY WITH PEAK
HEATING...BUT THERE IS UNCERTAINTY ABOUT HOW MUCH INSTABILITY
WILL DEVELOP. THE MOST RECENT TWO HRRR RUNS HAVE INCREASED THEIR
COVERAGE OF THUNDERSTORMS EMBEDDED WITHIN RAIN SHOWERS. CAPPED THE
COVERAGE OF THUNDERSTORMS TO SCATTERED FOR TODAY AND TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 324 AM CDT MON JUN 23 2014
JUST A REMNANT OF THE PERSISTENT UPPER LOW WILL REMAIN ACROSS NORTH
DAKOTA ON TUESDAY. THIS UPPER FEATURE ACCOMPANIED BY AN ASSOCIATED
SURFACE FRONTAL BOUNDARY WILL HELP FOCUS SHOWERS AND SCATTERED
THUNDERSTORMS ACROSS THE CENTRAL AND NORTH TUESDAY AFTERNOON. TUESDAY
NIGHT ACTIVITY WILL BE MINIMAL AS THE COLD FRONT REMAINS SOUTH OF
THE STATE...BECOMING STATIONARY...TO RETURN EVENTUALLY WEDNESDAY
NIGHT AND THURSDAY AS A WARM FRONTAL BOUNDARY IN ADVANCE OF A
WESTERN UPPER TROUGH. THIS H500 TROUGH AND SURFACE WARM FRONT
WILL BE THE FOCUS FOR AN ACTIVE THUNDERSTORM PERIOD THURSDAY NIGHT
INTO FRIDAY NIGHT. MODELS SUGGEST SEVERAL MCS TYPE SYSTEMS
SPREADING THUNDERSTORMS INTO THE REGION AND WILL BE MONITORING THE
POTENTIAL FOR MODERATE TO HEAVY RAIN DURING THIS TIME FRAME. POPS
REMAIN LIKELY FRIDAY NIGHT INTO SATURDAY FOR THIS.
POPS TRAIL OFF INTO 20 TO 30S SUNDAY AFTER THE PASSAGE OF THE
SHORTWAVE TROUGH/COLD FRONT. TEMPERATURES DURING THE EXTENDED LOOK
NEAR OR SLIGHTLY BELOW NORMAL WITH HIGHS IN THE 70S TO AROUND 80.
LOWS IN THE 50S TO NEAR 60.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 324 AM CDT MON JUN 23 2014
THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS THIS
AFTERNOON...BUT CONFIDENCE IS TOO LOW TO NAIL DOWN TIMING AND
COVERAGE. THE BEST CHANCE FOR THUNDERSTORMS IS AT KMOT...WITH
KISN/KJMS TIED FOR SECOND.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SCHECK
SHORT TERM...SCHECK
LONG TERM...WAA
AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS TULSA OK
344 AM CDT MON JUN 23 2014
.DISCUSSION...
LARGE MCS ONGOING FROM TX PANHANDLE THROUGH CENTRAL OK WILL
CONTINUE TO DEVELOP SOUTH AND EASTWARD THROUGH THE MORNING. WHILE
THE EXACT EVOLUTION REMAINS TO BE SEEN...LATEST RAP DATA DEPICT A
WELL DEVELOPED MCV WHICH IS FORECAST TO SHIFT EASTWARD TODAY
WITHIN THE BASE OF THE LARGER SYNOPTIC SCALE TROUGH. THIS IS
EXPECTED TO EITHER MAINTAIN ONGOING CONVECTION AND/OR AID IN
REDEVELOPMENT LATER THIS AFTERNOON THUS HIGH PRECIP CHANCES
AREAWIDE TODAY. THE SYNOPTIC FRONT WILL PUSH INTO THE REGION
TONIGHT AND IS EXPECTED TO FOCUS ANY OVERNIGHT PRECIP TOWARD THE
SOUTHEASTERN HALF OF THE FORECAST AREA.
BEYOND TONIGHT THE AFOREMENTIONED BOUNDARY REMAINS STALLED ACROSS
THE REGION WHILE PROFILES REMAIN MOIST AND LARGELY UNCAPPED. THIS
WILL RESULT IN SEVERAL DAYS OF SCATTERED CONVECTION THROUGH MID
WEEK. TEMPS DURING THIS TIMEFRAME ARE EXPECTED TO REMAIN NEAR OR
BELOW NORMAL. THE PATTERN BEGINS TO TRANSITION TOWARD MORE
DOMINANT UPPER RIDGING BY LATE WEEK THROUGH NEXT WEEKEND...WITH A
TREND TOWARD LESSER PRECIP COVERAGE AND WARMER TEMPS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 84 67 87 70 / 80 40 20 20
FSM 84 69 86 69 / 70 60 30 20
MLC 84 68 85 69 / 80 60 40 30
BVO 83 65 87 67 / 80 30 10 10
FYV 80 65 83 66 / 60 60 20 20
BYV 81 65 83 66 / 70 60 20 20
MKO 83 67 86 68 / 70 50 30 20
MIO 83 66 86 68 / 70 40 10 10
F10 83 67 86 69 / 80 50 30 20
HHW 85 70 86 70 / 90 60 40 40
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
LONG TERM....07
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
551 AM EDT MON JUN 23 2014
.SYNOPSIS...
A MOISTENING SOUTHERLY FLOW WILL DEVELOP AHEAD OF A SLOW MOVING
COLD FRONT APPROACHING FROM THE WEST. THE COLD FRONT WILL PUSH
THROUGH THE STATE ON WEDNESDAY...FOLLOWED BY HIGH PRESSURE FOR
LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
OTHER THAN FOR PATCHY FOG...THE DAY WILL DAWN BRIGHT WITH JUST
SOME THIN HIGH CLOUDS BLEEDING ACROSS FROM DYING CONVECTION OVER
THE GR LAKES.
WITH HIGH PRESSURE NOSING DOWN FROM THE NEW ENGLAND COAST ALL THE
WAY TO THE CAROLINAS...SOUTHERLY FLOW ON THE RETURN SIDE WILL
BRING STEADILY HIGHER DEWPOINTS NORTHWARD INTO THE REGION OVER
THE NEXT COUPLE OF DAYS. AS WE HEAT UP TODAY...WE WILL SEE A
STEADY EROSION OF THE STABILITY WITH THE RAP INDICATING MID LEVEL
LAPSE RATES EXCEEDING 7C/KM BY EARLY AFTERNOON. HOWEVER CAPE IS
EXPECTED TO BE LIMITED BY MID LEVEL DRY AIR OVER CENTRAL AND
EASTERN AREAS...WITH THE BEST CHANCE OF POPPING A SHOWER OR STORM
BEING OVER MY WESTERN ZONES. MOISTURE WILL BE A BIT DEEPER
THERE...BUT EVEN SO A FAIRLY STRONG CAPPING INVERSION WILL BE HARD
TO BREAK SO ACTIVITY SHOULD NOT BE WIDESPREAD.
HIGHS TODAY LOOK TO BE PRETTY WELL CLUSTERED FROM THE UPPER 70S TO
MID 80S...STARTING TO EDGE ABOVE NORMAL FOR A CHANGE.
THE PROXIMITY OF THE WAVY FRONT ENTERING THE OHIO VALLEY TONIGHT
WILL KEEP A SMALL CHANCE OF SHOWERS AND STORMS LINGERING OVER MY
WESTERN AND NORTHWESTERN AREAS OVERNIGHT. IT WILL BE A MILD NIGHT
IN THE 60S.
&&
.SHORT TERM /TUESDAY/...
TUESDAY WILL BE WARM AND MUGGY WITH AN INCREASING THREAT FOR
CONVECTION THE DEEPER INTO THE DAY WE GET. SREF/GEFS BOTH BRING A
SURGE OF ANOMALOUSLY HIGH PWATS WITH CAPES EXPECTED EXPECTED TO
EXCEED 1000J OVER A WIDE AREA. SPC HAS PLACED US IN A SEE TEXT
AREA MENTIONING...STEEP LOW-LEVEL LAPSE RATES MAY BE ENOUGH FOR
MARGINALLY SEVERE WIND GUSTS ASSOCIATED WITH SHORT BOWING LINE
SEGMENTS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE FRONTAL SYSTEM APPROACHING FROM THE MID WEST IS FORECAST TO
BE RATHER WAVY AND COMPLEX...WITH THE POTENTIAL FOR IT TO LINGER
OVER THE REGION LONGER THAN PREVIOUSLY INDICATED. BOTH THE GFS AND
ECMWF SHOW A NEW WAVE FORMING OVER THE STATE
WEDNESDAY...AT LEAST SUPPORTING THE IDEA OF KEEPING HIGH POPS IN
THE FORECAST THROUGH THE DAY...BUT ALSO RAISING THE POSSIBILITY OF
LOCALLY HEAVY RAINS FOCUSING ALONG THE SLOW MOVING FRONTAL
BOUNDARY.
DRIER AIR FINALLY LOOKS LIKE IT WILL MAKE A RETURN FOR THURSDAY-
FRIDAY AS HIGH PRESSURE BUILDS ACROSS SOUTHERN CANADA JUST NORTH
OF THE GREAT LAKES. THE COOL PUSH DOESN`T LOOK TERRIBLY ROBUST SO
HIGHS SHOULD REMAIN CLOSE TO OR EVEN A BIT ABOVE NORMAL INTO NEXT
WEEKEND.
OPERATIONAL GFS/ECMWF DIFFER ON EVENTS FOR SATURDAY-SUNDAY
TIMEFRAME WITH THE EXPECTED HANGING AROUND OF THE BOUNDARY THAT
IS EXPECTED TO PASS ON WEDNESDAY. THE GFS CREATES QUITE A BIT OF
PRECIP FOCUSED ON THE STRONG LOW LEVEL CONVERGENCE ASSOCIATED
WITH THE SLOW MOVING FRONTAL ZONE. THE ECMWF IS LESS EXCITED ABOUT
THIS...KEEPING THE BOUNDARY WEAKER AND FURTHER SOUTH. I DIDN`T
BITE TOO HARD ON THE MORE PESSIMISTIC GFS/GEFS...KEEPING JUST
SMALL CHANCES OF PRECIP OVER THE NEXT WEEKEND.
WORTH NOTING...LAST NIGHT THE LONGER RANGE GUIDANCE WANTED TO
REALLY PUMP UP HEIGHTS OVER THE EASTERN US FOR EARLY NEXT WEEK.
THE ECMWF HAS DONE A TOTAL FLIP-FLOP ON THIS NOW BRINGING AN UPPER
LOW SLOWLY DOWN THE NEW ENGLAND COAST TO OFF NJ BY MONDAY...WITH
UPPER HEIGHTS NOT NEARLY AS HIGH AS WAS ADVERTISED. THE GEFS SHOWS
MORE RIDGING...BUT SIMILARLY SEEMS TO WANT TO BACK OFF THE IDEA OF
A BIG SURGE IN THE SUBTROPICAL RIDGE IN THE EAST.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
NOT MUCH FOG SO FAR. MAY SEE A LITTLE AS THE SUN HEATS
THINGS UP.
MAINLY LOOKING A DRY DAY TODAY WITH VFR CONDITIONS. ENJOY...AS AT
LEAST THE LATER PART OF TUESDAY INTO WED...WILL FEATURE SHOWERS
AND THUNDERSTORMS...AS A SW FLOW OF MORE HUMID AIR WORKS
IN...AHEAD OF A COLD FRONT FOR LATE WED. THERE WAS A FEW SHOWERS
YESTERDAY AFT...GIVEN STEEP LOW LVL LAPSE RATES. THIS WILL BE THE
CASE THE NEXT SEVERAL DAYS.
A SHOWER WILL BE POSSIBLE AT BFD BEFORE 06Z TUE AM...BUT STILL
THINK THE FIRST PART OF TUESDAY WILL BE MAINLY DRY IN MOST
LOCATIONS.
OUTLOOK...
TUE-WED...SHRA/TSRA. LOCAL RESTRICTIONS LIKELY.
THU-FRI...VFR. PERHAPS A SHOWER OR STORM LATE FRI.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
524 AM EDT MON JUN 23 2014
.SYNOPSIS...
A MOISTENING SOUTHERLY FLOW WILL DEVELOP AHEAD OF A SLOW MOVING
COLD FRONT APPROACHING FROM THE WEST. THE COLD FRONT WILL PUSH
THROUGH THE STATE ON WEDNESDAY...FOLLOWED BY HIGH PRESSURE FOR
LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
OTHER THAN FOR PATCHY FOG...THE DAY WILL DAWN BRIGHT WITH JUST
SOME THIN HIGH CLOUDS BLEEDING ACROSS FROM DYING CONVECTION OVER
THE GR LAKES.
WITH HIGH PRESSURE NOSING DOWN FROM THE NEW ENGLAND COAST ALL THE
WAY TO THE CAROLINAS...SOUTHERLY FLOW ON THE RETURN SIDE WILL
BRING STEADILY HIGHER DEWPOINTS NORTHWARD INTO THE REGION OVER
THE NEXT COUPLE OF DAYS. AS WE HEAT UP TODAY...WE WILL SEE A
STEADY EROSION OF THE STABILITY WITH THE RAP INDICATING MID LEVEL
LAPSE RATES EXCEEDING 7C/KM BY EARLY AFTERNOON. HOWEVER CAPE IS
EXPECTED TO BE LIMITED BY MID LEVEL DRY AIR OVER CENTRAL AND
EASTERN AREAS...WITH THE BEST CHANCE OF POPPING A SHOWER OR STORM
BEING OVER MY WESTERN ZONES. MOISTURE WILL BE A BIT DEEPER
THERE...BUT EVEN SO A FAIRLY STRONG CAPPING INVERSION WILL BE HARD
TO BREAK SO ACTIVITY SHOULD NOT BE WIDESPREAD.
HIGHS TODAY LOOK TO BE PRETTY WELL CLUSTERED FROM THE UPPER 70S TO
MID 80S...STARTING TO EDGE ABOVE NORMAL FOR A CHANGE.
THE PROXIMITY OF THE WAVY FRONT ENTERING THE OHIO VALLEY TONIGHT
WILL KEEP A SMALL CHANCE OF SHOWERS AND STORMS LINGERING OVER MY
WESTERN AND NORTHWESTERN AREAS OVERNIGHT. IT WILL BE A MILD NIGHT
IN THE 60S.
&&
.SHORT TERM /TUESDAY/...
TUESDAY WILL BE WARM AND MUGGY WITH AN INCREASING THREAT FOR CONVECTION
THE DEEPER INTO THE DAY WE GET. SREF/GEFS BOTH BRING A SURGE OF
ANOMALOUSLY HIGH PWATS WITH CAPES EXPECTED EXPECTED TO EXCEED
1000J OVER A WIDE AREA. SPC HAS PLACED US IN A SEE TEXT AREA
MENTIONING...STEEP LOW-LEVEL LAPSE RATES MAY BE ENOUGH FOR
MARGINALLY SEVERE WIND GUSTS ASSOCIATED WITH SHORT BOWING LINE
SEGMENTS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE FRONTAL SYSTEM APPROACHING FROM THE MID WEST IS FORECAST TO
BE RATHER WAVY AND COMPLEX...WITH THE POTENTIAL FOR IT TO LINGER
OVER THE REGION LONGER THAN PREVIOUSLY INDICATED. BOTH THE GFS AND
ECMWF SHOW A NEW WAVE FORMING OVER THE STATE
WEDNESDAY...AT LEAST SUPPORTING THE IDEA OF KEEPING HIGH POPS IN
THE FORECAST THROUGH THE DAY...BUT ALSO RAISING THE POSSIBILITY OF
LOCALLY HEAVY RAINS FOCUSING ALONG THE SLOW MOVING FRONTAL
BOUNDARY.
DRIER AIR FINALLY LOOKS LIKE IT WILL MAKE A RETURN FOR THURSDAY-
FRIDAY AS HIGH PRESSURE BUILDS ACROSS SOUTHERN CANADA JUST NORTH
OF THE GREAT LAKES. THE COOL PUSH DOESN`T LOOK TERRIBLY ROBUST SO
HIGHS SHOULD REMAIN CLOSE TO OR EVEN A BIT ABOVE NORMAL INTO NEXT
WEEKEND.
OPERATIONAL GFS/ECMWF DIFFER ON EVENTS FOR SATURDAY-SUNDAY
TIMEFRAME WITH THE EXPECTED HANGING AROUND OF THE BOUNDARY THAT
IS EXPECTED TO PASS ON WEDNESDAY. THE GFS CREATES QUITE A BIT OF
PRECIP FOCUSED ON THE STRONG LOW LEVEL CONVERGENCE ASSOCIATED
WITH THE SLOW MOVING FRONTAL ZONE. THE ECMWF IS LESS EXCITED ABOUT
THIS...KEEPING THE BOUNDARY WEAKER AND FURTHER SOUTH. I DIDN`T
BITE TOO HARD ON THE MORE PESSIMISTIC GFS/GEFS...KEEPING JUST
SMALL CHANCES OF PRECIP OVER THE NEXT WEEKEND.
WORTH NOTING...LAST NIGHT THE LONGER RANGE GUIDANCE WANTED TO
REALLY PUMP UP HEIGHTS OVER THE EASTERN US FOR EARLY NEXT WEEK.
THE ECMWF HAS DONE A TOTAL FLIP-FLOP ON THIS NOW BRINGING AN UPPER
LOW SLOWLY DOWN THE NEW ENGLAND COAST TO OFF NJ BY MONDAY...WITH
UPPER HEIGHTS NOT NEARLY AS HIGH AS WAS ADVERTISED. THE GEFS SHOWS
MORE RIDGING...BUT SIMILARLY SEEMS TO WANT TO BACK OFF THE IDEA OF
A BIG SURGE IN THE SUBTROPICAL RIDGE IN THE EAST.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SOME CLDS FROM NEAR UNV...SE INTO THE MDT AREA. WAS A FEW
DROPS OF RAIN AT MDT JUST BEFORE MIDNIGHT.
ANYWAY...EXPECT SOME FOG OVERNIGHT...BUT NOT AS WIDESPREAD
AS IT WAS LAST NIGHT.
EARLIER DISCUSSION BELOW.
AN ISOLATED SHOWER WILL REMAIN POSS THROUGH MID
EVE...MAINLY IN THE LAUREL HIGHLANDS. VFR CONDITIONS WILL CONTINUE
THROUGH THE EVENING HOURS...WITH SOME MVFR FOG DEVELOPING AFTER
MIDNIGHT. WINDS WILL REMAIN LIGHT.
VFR PERSISTS THROUGH MONDAY AS WINDS INCREASE TO 5-10 KTS FROM THE
SOUTH. ISOLATED SHOWERS/POSS A TSTM ACROSS THE WESTERN HALF LATER
MON AFT MAY BRING VERY LOCALIZED RESTRICTIONS.
OUTLOOK...
TUE-WED...SHRA/TSRA. LOCAL RESTRICTIONS LIKELY.
THU...VFR.
FRI...VFR TO MVFR WITH SCT AFTN -TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...MARTIN/RXR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1153 PM CDT SUN JUN 22 2014
.UPDATE...
ISSUED AT 740 PM CDT SUN JUN 22 2014
CONCERNING THE FLASH FLOOD WATCH AND HEAVY RAIN POTENTIAL.
TRENDS HAVE REALLY BEEN ON THE DECREASE FOR THE INGREDIENTS NEEDED
FOR FLASH FLOODING TONIGHT. CURRENTLY A WEAKLY CONVERGENT TROUGH
RUNS ABOUT ON I-35 THROUGH IA AND SRN MN THEN ANGLES TO NEAR KAXN
IN MN. FURTHER WEST THE STABILIZING FRONT WAS EXTENDING FROM NW OF
KFSD-KINL AND PROGRESSING SE WITH MID-50S DEWPOINTS /KABR 00Z RAOB
WITH 0.70 INCH PRECIPITABLE WATER/. INDICATIONS ARE FOR A BIT
FASTER COLD FRONTAL PUSH OVERNIGHT INTO THE MORNING HOURS WHICH
MEANS MONDAY WILL NOT HAVE ANY FLASH FLOOD THREAT. PER THE 22.23Z
RAP...THE 925 MB WINDS ARE ALL NW IN THE FORECAST AREA BY 15Z. IN
FACT...MOST WINDS ON AND WEST OF THE MISS RIVER VEER AROUND TO NW
AT 925 MB BY 08Z. THIS PROVIDES A MORE PROGRESSIVE SOLUTION TO ANY
STORM ACTIVITY TONIGHT.
CONCERNING THE STORMS EXPECTED TONIGHT...THE INSTABILITY AFTER
THE AFTERNOON STORMS HAS SEVERELY IMPACTED THE CAPE AVAILABLE FOR
HEAVY RAINFALL TONIGHT. RIGHT NOW THE FORECAST AREA IS IN THE
HUNDREDS OF J/KG OF MUCAPE AND RADAR IS SHOWING LITTLE SIGN OF ANY
ORGANIZED RAIN THREAT. THE COMPLEX NEAR ALBERT LEA MN HAS NOW
DISSIPATED. THERE IS A BIT OF FRONTOGENESIS IN MID LEVELS THAT
TRIES TO PRODUCE SOME LIFT FROM BLACK RIVER FALLS WI INTO NERN IA
OVER NEXT SEVERAL HOURS. BUT WITH LIMITED OR DIMINISHING
CAPES...ANY STORMS THAT FORM WILL STRUGGLE TO PRODUCE HEAVY RAIN.
WITH THAT SAID..THE AIR MASS STILL HAS POTENT MOISTURE /KMPX 00Z
RAOB 1.36 INCH PRECIPITABLE WATER/. IT IS JUST THAT THE
ORGANIZATION AND INSTABILITY ARE NOT THERE FOR HEAVY RAIN. IN
FACT...WILL ALSO ASSESS THE RAIN COVERAGE TONIGHT...IT LOOKS MUCH
TOO HIGH PER LATEST HRRR RUNS AND 22.21Z HOPWRF RUN FROM MPX.
BOTTOM LINE IS WE HAVE STARTED TO MESSAGE A REDUCED FLASH FLOOD
THREAT...AND THE FLASH FLOOD WATCH WILL BE CANCELLED BY 9 PM
UNLESS SOMETHING CHANGES. HAVE ALREADY REMOVED TAYLOR AND CLARK
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 334 PM CDT SUN JUN 22 2014
THE MAIN FOCUS THROUGH TOMORROW IS ON CONVECTIVE TRENDS AND
WHETHER ANY FLASH FLOODING IS STILL POSSIBLE.
AN MCV FROM OVERNIGHT HAS COME THROUGH MUCH OF THE REGION FROM
LATE THIS MORNING INTO THE EARLY AFTERNOON HOURS AND HAS KICKED UP
A BAND OF CONVECTION/RAIN OUT AHEAD OF IT. MUCH OF THE 22.12Z
GUIDANCE HAS NOT DONE A VERY GOOD JOB OF PICKING UP ON THIS
FEATURE AND STILL WANT TO DEVELOP A WIDE SWATH OF CONVECTION
ACROSS THE REGION THIS EVENING. THE HRRR HAS DONE A DECENT JOB OF
CAPTURING THIS CONVECTION AND CLEARS MOST OF THE REGION FROM THE
WEST EARLY THIS EVENING. THE MOST UNSTABLE AIR MASS APPEARS TO
STAY OUT AHEAD OF THE MCV...SO AM NOT EXPECTING MUCH IN THE WAY OF
SEVERE DEVELOPMENT BEHIND IT. CONFIDENCE IS NOT VERY HIGH WITH HOW
TONIGHT WILL PAN OUT WITH THE MAIN COLD FRONT STILL OFF TO THE
WEST...SO WILL KEEP THE FLASH FLOOD WATCH GOING FOR THE TIME
BEING AND LET THE EVENING PLAY OUT A BIT MORE BEFORE CANNING IT.
THE 22.12Z NAM/GFS/GEM DID TREND FASTER WITH PUSHING THE
PRECIPITATION/MID LEVEL TROUGH/SFC LOW OFF TO THE EAST TOMORROW
MORNING...SO HAVE TRENDED A BIT FASTER WITH ENDING THE RAIN
CHANCES TOMORROW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 334 PM CDT SUN JUN 22 2014
A BRIEF DRY PERIOD IS EXPECTED MONDAY NIGHT INTO TUESDAY MORNING
AS SUBSIDENT AIR COMES IN THE WAKE OF THE TROUGH. ANOTHER COLD
FRONT WILL DROP DOWN FROM CANADA TUESDAY AFTERNOON AND BRING THE
NEXT CHANCE OF RAIN ALONG WITH IT. SKINNY CAPE PROFILE WITH THIS
FEATURE WITH LESS THAN 1000 J/KG OF MLCAPE EXPECTED...SO NOT
THINKING THAT THIS WILL BE A SEVERE WEATHER PRODUCER AT THIS
POINT.
AFTER THAT FRONT DROPS TO THE SOUTH IT APPEARS TO STALL OUT FROM
THE HIGH PLAINS ON DOWN SOUTHEAST THROUGH THE MID MISSISSIPPI
RIVER VALLEY. CONFIDENCE NOT VERY HIGH WITH OUR PRECIPITATION
CHANCES TOWARD THE END OF THE WEEK...BUT ALSO DID NOT HAVE MUCH OF
A CHANCE TO DIG INTO THE DETAILS WITH CONVECTION ON GOING...SO
HAVE GONE WITH THE CONSENSUS OF THE MODEL BLENDS FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1153 PM CDT SUN JUN 22 2014
VFR CONDITIONS THROUGH THE PERIOD. THUNDERSTORMS FAR TO THE SOUTH
ARE PROVIDING AN OVERCAST CEILING AT HIGHER ALTITUDES. THERE MAY
BE SOME FOG IN THE VICINITY OF THE TAF SITES BUT FOR NOW HAVE LEFT
IT OUT OF THE FORECAST WITH THE THICK HIGHER CLOUD KEEPING
TEMPERATURES A BIT WARMER. THERE IS ALSO SOME CLOUD DEBRIS MOVING
AROUND THAT ARE NOT ACCOUNTED FOR IN THE TAFS BUT SHOULD ONLY BE
TRANSIENT AT THE AIRFIELDS TONIGHT.
&&
.HYDROLOGY...
ISSUED AT 334 PM CDT SUN JUN 22 2014
HEAVY RAINFALL FROM LAST WEEK HAS PRIMED THE GROUND FOR ADDITIONAL
FLOODING WITH ANY STORMS THAT MAY MOVE THROUGH. THE STORMS TODAY
HAD SOME BRIEFLY INTENSE RAINFALL RATES AT ABOUT 2 INCHES PER HOUR
THOUGH THEY ONLY LASTED FOR ABOUT A HALF HOUR. MANY AREA RIVERS
ARE STILL ELEVATED FROM THE RECENT RAINFALL AND WILL LIKELY STAY
THAT WAY THROUGH THE WEEK. CONFIDENCE IS NOT VERY HIGH AT THIS
POINT ABOUT WHETHER THE FLASH FLOOD WATCH IS STILL NECESSARY FOR
TONIGHT...BUT WANT TO MAKE SURE THAT CONDITIONS WILL BE OKAY
BEFORE DROPPING IT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BAUMGARDT
HYDROLOGY...HALBACH
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1015 AM EDT MON JUN 23 2014
.DISCUSSION...
LATEST SAT PICS SHOW A DISTINCT MOISTURE BNDRY ACRS THE FL PENINSULA
WITH CONSIDERABLE CLOUD COVER CENTRAL/NRN PENINSULA...LITTLE IF ANY
OVER THE S PENINSULA. MORNING SOUNDINGS CONFIRM THIS WITH PWAT
VALUES ARND 2.0" AT KJAX/KMLB...DECREASING TO 1.6" AT KTBW...AND TO
1.4" AT KMFL. RUC ANALYSIS SHOWS THIS AS A BAND OF DRY H85-H50 AIR
EXTENDING FROM THE NRN BAHAMAS INTO THE CENTRAL GOMEX. A FRONTAL
TROF EXTENDING FROM THE CAROLINA COAST TO BERMUDA IS KEEPING THE
AXIS OF THE H100-H70 SUBTROPICAL RIDGE SUPPRESSED OVER THE CENTRAL
BAHAMAS/GOMEX. ALOFT...A WELL DEFINED TUTT AXIS EXTENDS FROM THE NW
CARIB TO THE NRN BAHAMAS.
THE FL PENINSULA LIES ON THE DESCENDING FLANK OF THE TUTT...WHILE
THE POSITION OF THE LOW/MID LVL RIDGE AXIS WILL GENERATE A DEEP W/SW
FLOW ACRS CENTRAL FL THAT WILL TAP THE DRIER MID LVL AIR UPSTREAM.
WHILE THIS WILL LEAD TO DECREASING PWATS ACRS THE CWA...WITH SFC
DEWPOINTS IN THE L/M70S...THIS WILL ONLY DELAY THE ONSET OF DIURNAL
CONVECTION UNTIL MID AFTN. THIS...IN TURN WILL ALLOW GREATER SFC
HEATING/DESTABILIZATION.
SCT DIURNAL CONVECTION WILL FORM ALONG SEA/LAKE BREEZE BDRYS WITH
WSW H85-H50 STEERING WINDS PUSHING ACTIVITY EWD ACROSS ECFL AT 10-15
MPH. INCREASING MOISTURE FROM S TO N WILL LEAD TO HIGHER PRECIP
COVERAGE ALONG AND N OF I-4. WHILE DRY AIR ADVECTION AT MID LVLS
WILL INCREASE TSTM GUST POTENTIAL...TEMP PROFILE IS UNIMPRESSIVE
WITH LAPSE RATES THRU THE H85-H50 LYR BTWN 5.5-6.0C/KM...SVR THREAT
REMAINS LOW. WRLY WINDS AND SLOWER INLAND PENETRATION OF THE EAST
COAST SEA BREEZE WILL ALLOW MAX TEMPS TO WARM INTO THE L/M90S
AREAWIDE.
&&
.AVIATION...
THRU 23/16Z...VFR ALL SITES. BTWN 23/16Z-23/18Z...SFC WNDSHFT FM
W/SW TO E/SE AOB 12KTS ASSOCD WITH THE EAST COAST SEA BREEZE. BTWN
23/16Z-23/22Z...SCT MVFR SHRAS/IFR TSRAS ALL SITES...MORE NMRS N OF
KVRB-KOBE...LIFR TSRAS PSBL BTWN KMLB-KDAB. BTWN 23/22Z-23/24Z...
SCT SHRAS/TSRAS CONTG COASTAL SITES...MVFR CIGS/VSBYS IN -RA
INTERIOR SITES. BTWN 24/00Z-24/02Z...SHRAS/TSRAS ENDING COASTAL
SITES...BCMG VFR ALL SITES.
&&
.MARINE...
NO SIG CHANGES...LCL DATA BUOY/C-MAN NETWORK CONTINUES TO MEASURE A
LIGHT TO GENTLE SW BREEZE WITH SEAS AOB 2FT. WINDS WILL SHIFT TO THE
E/SE AOB 10KTS OVER THE NEARSHORE WATERS BY EARLY AFTN AS THE EAST
COAST SEA BREEZE DVLPS. WRLY ENVIRONMENTAL FLOW WILL KEEP IT PINNED
NEAR THE INTRACOASTAL WATERWAY THRU THE AFTN. DIURNAL CONVECTION TO
DVLP BY MID AFTN WITH STORMS MVG OFFSHORE...POTENTIAL FOR WIND GUSTS
ARND 35KTS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
RADAR/IMPACT WX.......WEITLICH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
917 AM CDT MON JUN 23 2014
.DISCUSSION...
305 AM CDT
A HANDFUL OF FORECAST CHALLENGES THIS FINAL FULL WEEK OF
JUNE...ALTHOUGH IT DOES APPEAR TO BE A MORE QUIET WEEK THAN
LAST...WITH LESS WIDESPREAD STORM/HEAVY RAINFALL CHANCES. ITEMS OF
CONCERN THIS MORNING INCLUDE RAIN AND THUNDER COVERAGE TODAY AS
WELL AS FOG POSSIBILITIES NEAR THE LAKE SHORE.
TODAY AND TONIGHT...
ONCE AGAIN THIS MORNING IT IS A MESSY MID-LEVEL PATTERN WITH
MULTIPLE SMALL SCALE IMPULSES FROM KS TO WI SEEN ON A LONG LOOP OF
SATELLITE WATER VAPOR CHANNEL. OVERALL THOUGH THESE FEATURES COMPOSE
AN UPPER SHORT WAVE TROUGH THAT WILL INCH EASTWARD LIKELY CLEARING
THE AREA BY OR DURING OVERNIGHT. QG FORCING FOR ASCENT IN ADVANCE OF
THIS TROUGH...WITHIN A MOIST AIR MASS OF PRECIPITABLE WATER OBSERVED
OF 1.50-1.75 INCHES...SHOULD SUPPORT MODEST COVERAGE OF SHOWERS
ESPECIALLY THROUGH EARLY AFTERNOON. SCATTERED/EMBEDDED THUNDER
WILL BE MOST PRONOUNCED AHEAD OF ANY OF THE AFOREMENTIONED
IMPULSES...WITH 500-1200 J/KG OF MUCAPE TO WORK WITH THROUGH THE
MORNING PER CURRENT AMDAR DATA AND RAP FORECASTS THROUGH MIDDAY.
DID OUR BEST TO ADD TEMPORAL RESOLUTION IN THE FORECAST OF HIGHER
POPS TODAY...WITH THE GREATER LIKELIHOOD SHIFTING SLOWLY EAST DURING
THE DAY. CONVECTIVE ALLOWING GUIDANCE INDICATES SOME POSSIBLY DEEPER
CONVECTION NEAR MIDDAY/EARLY AFTERNOON ACROSS THE EASTERN FORECAST
AREA...ASSOCIATED WITH INSTABILITY BECOMING MORE ROOTED IN THE
MIXED LAYER GIVEN SURFACE HEATING. WITH WEAK DEEP LAYER SHEAR
/AOB 25 KT/ AND ANY MODEST DCAPE BEING CONDITIONAL ON SOME
SUNSHINE WHICH THERE MAY NOT BE TOO MUCH OF...THINK SEVERE STORM
POTENTIAL IS SMALL AND THAT CHANCE CONFINED TO THE EASTERN
FORECAST AREA.
OBSERVATIONS AND WEBCAMS EARLY THIS MORNING ARE INDICATING THE LEAST
DENSE THE FOG HAS BEEN NEAR THE LAKE SHORE IN SEVERAL MORNINGS.
THUS ITS POSSIBLE THE ADVISORY MAY BE CANCELLED NEAR SUNRISE
DEPENDING ON HOW THINGS LOOK. A LIGHT FLOW PATTERN TODAY MAY FAVOR
A LAKE BREEZE...THOUGH SHOWERS AND POSSIBLE STORMS COULD DISRUPT
THE WIND FIELD AND LAKE FOG. IN ADDITION...LATE DAY VISIBLE
SATELLITE IMAGERY FROM SUNDAY INDICATED THE FOG OVER SOUTHERN LAKE
MI HAD BECOME MORE THIN...SO NOT EXPECTING FOG TO BE A BIG DEAL
MUCH OF TODAY ALONG THE LAKE SHORE. DEPENDING ON EXACT FRONTAL
TIMING...SOME PATCHY FOG MAY SPREAD BRIEFLY INLAND AGAIN THIS
EVENING...AND POSSIBLY INTO NORTHWEST INDIANA OVERNIGHT BEHIND
FROPA WITH THE SYNOPTIC FLOW SHIFTING NORTH-NORTHWEST.
TUESDAY THROUGH THURSDAY...
A LITTLE MORE OF A NORTHWEST PUSH ARRIVES ON TUESDAY AFTERNOON OR
EVENING BEHIND A SECONDARY COOL FRONT. ALONG THIS FEATURE ON TUESDAY
AFTERNOON THERE COULD BE ISOLATED SHOWERS/STORMS AS A JET STREAK
AND ASSOCIATED RIGHT ENTRANCE REGION MOVE OVER THE BOUNDARY DURING
PEAK HEATING. HAVE MAINTAINED THE CHANCES FOR PRECIP ONLY IN THE
NORTHERN FORECAST AREA ON TUESDAY AS THIS FEATURE APPROACHES.
SEMI-ZONAL FLOW IS FORECAST TO PERSIST THROUGH MIDWEEK WITH LITTLE
TO KEY IN ON FOR SHOWER OR STORM CHANCES. WARM AIR ADVECTION AND
POSSIBLY A SHORT WAVE DEPENDING ON WHICH LONG RANGE MODEL ONE
LOOKS AT INDICATE SOME STORM POTENTIAL LATER THURSDAY...BUT
OVERALL NOT TOO EXCITED ABOUT THIS AT THIS POINT. TEMPERATURES
LOOK TO COOL SLIGHTLY WEDNESDAY AND THURSDAY...ALTHOUGH MORE SO
NEAR THE LAKE SHORE. THIS IS ESPECIALLY TRUE ON WEDNESDAY WHICH
LOOKS TO HAVE SHORELINE HIGHS STRUGGLE TO REACH 70.
FRIDAY INTO NEXT WEEKEND...
ENERGY FROM A PERSIST GULF OF ALASKA TROUGH IS EXPECTED TO EVOLVE
INTO THE NORTHWEST U.S. AND WESTERN CANADA DURING THIS PERIOD AND IN
RESPONSE HEIGHTS WILL BUILD ACROSS THE MISSISSIPPI AND OHIO RIVER
VALLEY REGIONS. THE EC HAS TRENDED DOWN FROM THE HEIGHTS AND 850MB
TEMPS IT HAD 24 HOURS AGO...BUT STILL SUPPORTIVE OF AROUND 90
DEGREES FOR WEEKEND HIGHS IF NOT IMPACTED BY ANY CONVECTION...WHICH
THERE LOOKS TO BE AT LEAST SMALL CHANCES FOR AT THIS POINT.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* PERIODS OF SHOWERS AND BRIEF MVFR. LITTLE TSRA EXPECTED.
* LOW IFR CONDITIONS EAST OF THE TERMINALS ALONG THE LAKESHORE.
* WINDS VARIABLE BUT GENERALLY SOUTHERLY TO SOUTHWESTERLY.
LENNING
//DISCUSSION...UPDATED 12Z...
THE PCPN FORECAST REMAINS THE MAIN CONCERN WITH SOME UNCERTAINTY
CONTINUING WITH THE TSRA POTENTIAL. THE ENVIRONMENT OVER THE AREA
REMAINS VERY MOIST AND SHOULD BECOME AT LEAST WEAKLY UNSTABLE
THROUGH THE DAY. A MODERATE SHORTWAVE ALOFT HAS BEEN CONSISTENTLY
FORECAST BY THE MODELS TO CROSS THE REGION THIS AFTERNOON...AND
WILL BE ACCOMPANIED BY A WEAK COLD FRONT. FRONTAL FORCING WILL BE
LOW AS THERE WILL BE ONLY A MINOR AIRMASS CHANGE WITH THE FRONTAL
PASSAGE AND A WINDSHIFT FROM LIGHT SOUTHERLY WINDS TO LIGHT NWLY
WINDS. THERE MAY BE A FEW GUSTS TO ARND 15KT IN THE WEAK WARM
ADVECTION AHEAD OF THE FRONT...BUT WINDS SHOULD BE LESS THAN 10KT
BEHIND THE FRONT. THE LATEST GUIDANCE AND SATELLITE TRENDS
INDICATE A WEAKER SHORTWAVE ALOFT THAN PREVIOUSLY NOTED...SO HAVE
BACKED OFF A BIT ON THE TSRA POTENTIAL IN THE TAFS. STILL FEEL
THAT THE BEST TIMING WILL BE AT SOME POINT DURG THE AFTERNOON
HOURS...BUT TSRA COULD END UP BEING MORE ISOLD/EMBEDDED THAN
ORGANIZED SO HAVE GONE WITH VCTS WORDING. THIS SHOULD STILL
COINCIDE WITH THE PASSAGE OF THE SHORTWAVE ALOFT AND THE WEAK
COLD FRONT AT THE SURFACE. THE REMAINDER OF THE PERIOD SHOULD THEN
BE DRY WITH NWLY WINDS LESS THAN 10KT AND VFR CIGS/VIS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN PERIODS OF SHOWERS. MEDIUM CONFIDENCE IN MVFR.
* MEDIUM CONFIDENCE IN WIND DIRECTION...BUT HIGHER CONFIDENCE IN
STAYING RELATIVELY LIGHT...BELOW 10KT SUSTAINED.
* MEDIUM TO HIGH CONFIDENCE IN LIFR STAYING EAST OF THE TERMINALS.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH THURSDAY...VFR. WX NIL.
THURSDAY NIGHT THROUGH SATURDAY NIGHT...CHANCE TSRA. OTHERWISE
VFR.
SUNDAY...SLIGHT CHANCE TSRA. OTHERWISE VFR.
KREIN
&&
.MARINE...
315 AM CDT
BROAD HIGH PRESSURE EXTENDS FROM THE GREAT LAKES REGION ACROSS
MUCH OF THE EAST COAST. THE RESULTANT LIGHT AND VARIABLE WINDS
COMBINED WITH RESIDUAL HIGH DEWPOINT AIR OVER THE STILL VERY COLD
LAKE WATERS HAS KEPT DENSE FOG IN PLACE. THE DENSE FOG WILL
CONTINUE WHILE THE HIGH PRESSURE IS SLOWLY ERODED BY A TROUGH OF
WEAK LOW PRESSURE AS IT MOVES ACROSS THE MISSISSIPPI VALLEY
MONDAY MORNING. THE TROUGH AND AN ASSOCIATED WEAK COLD FRONT WILL
MOVE ACROSS THE LAKE LATE MONDAY NIGHT TURNING WINDS FROM LIGHT
AND VARIABLE TO WESTERLY AND NORTHWESTERLY...WHICH WILL BEGIN TO
SCOUR OUT THE FOG FROM THE LAKE. A SECONDARY COLD FRONT WILL DROP
DOWN THE LAKE TUESDAY TURNING WINDS NORTHERLY BRINGING AN END TO
ANY RESIDUAL FOG AS DRIER AIR FILTERS OVER THE LAKE. HIGH PRESSURE
WILL BUILD ACROSS THE UPPER LAKES WEDNESDAY AND THURSDAY KEEPING
CONDITIONS OVER THE LAKE RELATIVELY QUIET...BUT BY THE END OF THE
WEEK...STRENGTHENING SOUTHERLY WINDS OF 15 TO 25 KT WILL DEVELOP
OVER THE LAKE AS THE HIGH MOVES OFF TO THE EAST AND ANOTHER TROUGH
APPROACHES FROM THE WEST.
&&
.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 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
646 AM CDT MON JUN 23 2014
.DISCUSSION...
305 AM CDT
A HANDFUL OF FORECAST CHALLENGES THIS FINAL FULL WEEK OF
JUNE...ALTHOUGH IT DOES APPEAR TO BE A MORE QUIET WEEK THAN
LAST...WITH LESS WIDESPREAD STORM/HEAVY RAINFALL CHANCES. ITEMS OF
CONCERN THIS MORNING INCLUDE RAIN AND THUNDER COVERAGE TODAY AS
WELL AS FOG POSSIBILITIES NEAR THE LAKE SHORE.
TODAY AND TONIGHT...
ONCE AGAIN THIS MORNING IT IS A MESSY MID-LEVEL PATTERN WITH
MULTIPLE SMALL SCALE IMPULSES FROM KS TO WI SEEN ON A LONG LOOP OF
SATELLITE WATER VAPOR CHANNEL. OVERALL THOUGH THESE FEATURES COMPOSE
AN UPPER SHORT WAVE TROUGH THAT WILL INCH EASTWARD LIKELY CLEARING
THE AREA BY OR DURING OVERNIGHT. QG FORCING FOR ASCENT IN ADVANCE OF
THIS TROUGH...WITHIN A MOIST AIR MASS OF PRECIPITABLE WATER OBSERVED
OF 1.50-1.75 INCHES...SHOULD SUPPORT MODEST COVERAGE OF SHOWERS
ESPECIALLY THROUGH EARLY AFTERNOON. SCATTERED/EMBEDDED THUNDER
WILL BE MOST PRONOUNCED AHEAD OF ANY OF THE AFOREMENTIONED
IMPULSES...WITH 500-1200 J/KG OF MUCAPE TO WORK WITH THROUGH THE
MORNING PER CURRENT AMDAR DATA AND RAP FORECASTS THROUGH MIDDAY.
DID OUR BEST TO ADD TEMPORAL RESOLUTION IN THE FORECAST OF HIGHER
POPS TODAY...WITH THE GREATER LIKELIHOOD SHIFTING SLOWLY EAST DURING
THE DAY. CONVECTIVE ALLOWING GUIDANCE INDICATES SOME POSSIBLY DEEPER
CONVECTION NEAR MIDDAY/EARLY AFTERNOON ACROSS THE EASTERN FORECAST
AREA...ASSOCIATED WITH INSTABILITY BECOMING MORE ROOTED IN THE
MIXED LAYER GIVEN SURFACE HEATING. WITH WEAK DEEP LAYER SHEAR
/AOB 25 KT/ AND ANY MODEST DCAPE BEING CONDITIONAL ON SOME
SUNSHINE WHICH THERE MAY NOT BE TOO MUCH OF...THINK SEVERE STORM
POTENTIAL IS SMALL AND THAT CHANCE CONFINED TO THE EASTERN
FORECAST AREA.
OBSERVATIONS AND WEBCAMS EARLY THIS MORNING ARE INDICATING THE LEAST
DENSE THE FOG HAS BEEN NEAR THE LAKE SHORE IN SEVERAL MORNINGS.
THUS ITS POSSIBLE THE ADVISORY MAY BE CANCELLED NEAR SUNRISE
DEPENDING ON HOW THINGS LOOK. A LIGHT FLOW PATTERN TODAY MAY FAVOR
A LAKE BREEZE...THOUGH SHOWERS AND POSSIBLE STORMS COULD DISRUPT
THE WIND FIELD AND LAKE FOG. IN ADDITION...LATE DAY VISIBLE
SATELLITE IMAGERY FROM SUNDAY INDICATED THE FOG OVER SOUTHERN LAKE
MI HAD BECOME MORE THIN...SO NOT EXPECTING FOG TO BE A BIG DEAL
MUCH OF TODAY ALONG THE LAKE SHORE. DEPENDING ON EXACT FRONTAL
TIMING...SOME PATCHY FOG MAY SPREAD BRIEFLY INLAND AGAIN THIS
EVENING...AND POSSIBLY INTO NORTHWEST INDIANA OVERNIGHT BEHIND
FROPA WITH THE SYNOPTIC FLOW SHIFTING NORTH-NORTHWEST.
TUESDAY THROUGH THURSDAY...
A LITTLE MORE OF A NORTHWEST PUSH ARRIVES ON TUESDAY AFTERNOON OR
EVENING BEHIND A SECONDARY COOL FRONT. ALONG THIS FEATURE ON TUESDAY
AFTERNOON THERE COULD BE ISOLATED SHOWERS/STORMS AS A JET STREAK
AND ASSOCIATED RIGHT ENTRANCE REGION MOVE OVER THE BOUNDARY DURING
PEAK HEATING. HAVE MAINTAINED THE CHANCES FOR PRECIP ONLY IN THE
NORTHERN FORECAST AREA ON TUESDAY AS THIS FEATURE APPROACHES.
SEMI-ZONAL FLOW IS FORECAST TO PERSIST THROUGH MIDWEEK WITH LITTLE
TO KEY IN ON FOR SHOWER OR STORM CHANCES. WARM AIR ADVECTION AND
POSSIBLY A SHORT WAVE DEPENDING ON WHICH LONG RANGE MODEL ONE
LOOKS AT INDICATE SOME STORM POTENTIAL LATER THURSDAY...BUT
OVERALL NOT TOO EXCITED ABOUT THIS AT THIS POINT. TEMPERATURES
LOOK TO COOL SLIGHTLY WEDNESDAY AND THURSDAY...ALTHOUGH MORE SO
NEAR THE LAKE SHORE. THIS IS ESPECIALLY TRUE ON WEDNESDAY WHICH
LOOKS TO HAVE SHORELINE HIGHS STRUGGLE TO REACH 70.
FRIDAY INTO NEXT WEEKEND...
ENERGY FROM A PERSIST GULF OF ALASKA TROUGH IS EXPECTED TO EVOLVE
INTO THE NORTHWEST U.S. AND WESTERN CANADA DURING THIS PERIOD AND IN
RESPONSE HEIGHTS WILL BUILD ACROSS THE MISSISSIPPI AND OHIO RIVER
VALLEY REGIONS. THE EC HAS TRENDED DOWN FROM THE HEIGHTS AND 850MB
TEMPS IT HAD 24 HOURS AGO...BUT STILL SUPPORTIVE OF AROUND 90
DEGREES FOR WEEKEND HIGHS IF NOT IMPACTED BY ANY CONVECTION...WHICH
THERE LOOKS TO BE AT LEAST SMALL CHANCES FOR AT THIS POINT.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* SCT SHRA WITH OCNL MVFR CIGS THROUGH LATE MORNING.
* SCT SHRA WITH ISOLD TSRA THIS AFTERNOON...POSSIBLY INTO EARLY
EVENING.
KREIN
//DISCUSSION...UPDATED 12Z...
THE PCPN FORECAST REMAINS THE MAIN CONCERN WITH SOME UNCERTAINTY
CONTINUING WITH THE TSRA POTENTIAL. THE ENVIRONMENT OVER THE AREA
REMAINS VERY MOIST AND SHOULD BECOME AT LEAST WEAKLY UNSTABLE
THROUGH THE DAY. A MODERATE SHORTWAVE ALOFT HAS BEEN CONSISTENTLY
FORECAST BY THE MODELS TO CROSS THE REGION THIS AFTERNOON...AND
WILL BE ACCOMPANIED BY A WEAK COLD FRONT. FRONTAL FORCING WILL BE
LOW AS THERE WILL BE ONLY A MINOR AIRMASS CHANGE WITH THE FRONTAL
PASSAGE AND A WINDSHIFT FROM LIGHT SOUTHERLY WINDS TO LIGHT NWLY
WINDS. THERE MAY BE A FEW GUSTS TO ARND 15KT IN THE WEAK WARM
ADVECTION AHEAD OF THE FRONT...BUT WINDS SHOULD BE LESS THAN 10KT
BEHIND THE FRONT. THE LATEST GUIDANCE AND SATELLITE TRENDS
INDICATE A WEAKER SHORTWAVE ALOFT THAN PREVIOUSLY NOTED...SO HAVE
BACKED OFF A BIT ON THE TSRA POTENTIAL IN THE TAFS. STILL FEEL
THAT THE BEST TIMING WILL BE AT SOME POINT DURG THE AFTERNOON
HOURS...BUT TSRA COULD END UP BEING MORE ISOLD/EMBEDDED THAN
ORGANIZED SO HAVE GONE WITH VCTS WORDING. THIS SHOULD STILL
COINCIDE WITH THE PASSAGE OF THE SHORTWAVE ALOFT AND THE WEAK
COLD FRONT AT THE SURFACE. THE REMAINDER OF THE PERIOD SHOULD THEN
BE DRY WITH NWLY WINDS LESS THAN 10KT AND VFR CIGS/VIS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* LOW CONFIDENCE IN TSRA TIMING AND COVERAGE.
* MEDIUM TO HIGH CONFIDENCE IN SCT SHRA THROUGH MUCH OF THE DAY.
* LOW TO MEDIUM CONFIDENCE IN SHRA IMPACTS ON CIG/VIS.
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH THURSDAY...VFR. WX NIL.
THURSDAY NIGHT THROUGH SATURDAY NIGHT...CHANCE TSRA. OTHERWISE
VFR.
SUNDAY...SLIGHT CHANCE TSRA. OTHERWISE VFR.
KREIN
&&
.MARINE...
315 AM CDT
BROAD HIGH PRESSURE EXTENDS FROM THE GREAT LAKES REGION ACROSS
MUCH OF THE EAST COAST. THE RESULTANT LIGHT AND VARIABLE WINDS
COMBINED WITH RESIDUAL HIGH DEWPOINT AIR OVER THE STILL VERY COLD
LAKE WATERS HAS KEPT DENSE FOG IN PLACE. THE DENSE FOG WILL
CONTINUE WHILE THE HIGH PRESSURE IS SLOWLY ERODED BY A TROUGH OF
WEAK LOW PRESSURE AS IT MOVES ACROSS THE MISSISSIPPI VALLEY
MONDAY MORNING. THE TROUGH AND AN ASSOCIATED WEAK COLD FRONT WILL
MOVE ACROSS THE LAKE LATE MONDAY NIGHT TURNING WINDS FROM LIGHT
AND VARIABLE TO WESTERLY AND NORTHWESTERLY...WHICH WILL BEGIN TO
SCOUR OUT THE FOG FROM THE LAKE. A SECONDARY COLD FRONT WILL DROP
DOWN THE LAKE TUESDAY TURNING WINDS NORTHERLY BRINGING AN END TO
ANY RESIDUAL FOG AS DRIER AIR FILTERS OVER THE LAKE. HIGH PRESSURE
WILL BUILD ACROSS THE UPPER LAKES WEDNESDAY AND THURSDAY KEEPING
CONDITIONS OVER THE LAKE RELATIVELY QUIET...BUT BY THE END OF THE
WEEK...STRENGTHENING SOUTHERLY WINDS OF 15 TO 25 KT WILL DEVELOP
OVER THE LAKE AS THE HIGH MOVES OFF TO THE EAST AND ANOTHER TROUGH
APPROACHES FROM THE WEST.
&&
.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 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
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AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1009 AM EDT MON JUN 23 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE NORTHEAST COAST TONIGHT. A COLD
FRONT WILL SLOWLY DROP SOUTH FROM CANADA TUESDAY AND WILL STALL
OVER THE REGION ON WEDNESDAY. THE FRONT WILL SLOWLY SHIFT OFFSHORE
ON THURSDAY AND SEVERAL WEAK WAVES OF LOW PRESSURE WILL TRACK
NORTHEAST ALONG IT THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...SOME MINOR CHANGES TO ACCOUNT FOR LATEST OBSERVATIONAL
TRENDS. PRES GRADIENT WILL SUPPORT ONSHORE FLOW INCREASING
THROUGHOUT THE DAY...AND WINDS HAVE ALREADY TURNED SELY ALONG THE
COAST ATTM. SHOULDN/T SEE TOO MUCH WARMING FOR THOSE AREAS FROM
THIS POINT FORWARD TODAY. WARMING OF THE ELEVATED TERRAIN IS
SUPPORTING CU DEVELOPMENT ATTM...WITH AN ISOLD SHRA NOT OUT OF THE
QUESTION FOR THIS AFTERNOON. SPC WRF HAS SOME SHRA ACTIVITY...BUT
LATEST HRRR NOT AS BULLISH ON CONVECTIVE PRECIP. WILL KEEP POP
BELOW CHC ATTM.
PREVIOUS DISCUSSION...HIGH PRESSURE WAS FIRMLY IN CONTROL OVER
NORTHERN NEW ENGLAND EARLY THIS MORNING. THE WIND WAS CALM AREA
WIDE. EVEN MOUNT WASHINGTON WAS REPORTING A WIND SPEED OF ONLY 1
MPH. 00Z GYX SOUNDING SHOWED DRY AIR AT THE SURFACE AND A MIXED
LAYER EXTENDING ALL THE WAY TO 700 MB. ABOVE 700 MB A COUPLE OF
SUBSIDENCE INVERSIONS WERE NOTED. IT WAS THIS STABLE LAYER THAT
SERVED TO CAP THE WEAKLY UNSTABLE LOWER LEVELS AND TEND TO SQUASH
THE HIGH BASED AFTERNOON CUMULUS CLOUDS BEFORE ANY SUBSTANTIAL
SHOWERS COULD FORM.
TODAY... EXPECT HIGH PRESSURE TO MOVE OFFSHORE INTO THE GULF OF
MAINE... SETTING UP A RETURN SOUTHERLY FLOW / SEA BREEZE ACROSS THE
AREA. EXPECT TEMPERATURES TO BE A COUPLE OF DEGREES WARMER THAN
YESTERDAY... CONSIDERING THE WELL MIXED LAYER ABOVE THE SURFACE
AND SLIGHTLY WARMING TEMPERATURES BENEATH RIDGING ALOFT. THIS
TRANSLATES TO UPPER 70S TO LOW 80S EXCEPT FOR THE COASTAL AREAS
WHERE TEMPERATURES WILL BE A FEW DEGREES COOLER.
THE RETURN FLOW WILL BRING SOME SLIGHTLY GREATER MOISTURE INTO
THE REGION. ESTIMATES FROM THE 00Z GYX SOUNDING ARE THAT IT WOULD
TAKE A SURFACE DEW POINT IN THE MID 50S TO OVERCOME THE CAP ABOVE
THE 700 MB LEVEL. DO NOT EXPECT DEW POINTS TO REACH THAT LEVEL
TODAY AS RETURN FLOW IS NOT THAT STRONG... DEW POINTS ACROSS
SOUTHERN NEW ENGLAND ARE ONLY IN THE LOW 50S... AND DEEP MIXING TO
700 MB WILL MAKE IT MORE DIFFICULT TO CONCENTRATE THIS MOISTURE
RETURN IN THE LOW LEVELS ENOUGH TO GENERATE INSTABILITY.
HOWEVER... IT IS POSSIBLE THAT HEATING IN THE MOUNTAINS MAY LEAD
TO A FEW SHOWERS DEVELOPING THERE... WHERE IT WILL TAKE LESS
SURFACE HEATING TO OVERCOME THE CAP.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
SOUTHERLY FLOW CONTINUES TONIGHT... WITH BETTER MOISTURE RETURN
DEVELOPING ABOVE THE SURFACE INVERSION. COULD SEE SOME FOG IN
VALLEY LOCATIONS WHERE TEMPERATURES COOL MORE EFFICIENTLY BEFORE
THE HIGHER DEW POINT AIR MOVES IN LATER IN THE NIGHT. EXPECT LOWS
ONLY IN THE LOW TO MID 50S DEW TO THE GREATER MOISTURE.
ON TUESDAY... EXPECT TEMPERATURES ABOUT THE SAME AS MONDAY OR
MAYBE A DEGREE OR TWO WARMER. UPPER TROUGH MOVING SOUTHEAST OUT OF
HUDSON BAY WILL APPROACH THE AREA LATER IN THE DAY WITH A SURFACE
COLD FRONT ASSOCIATED WITH IT. IN ADDITION... A SHORTWAVE TROUGH
MOVING EAST OUT OF THE GREAT LAKES WILL ALSO CROSS NEW ENGLAND
DURING THE AFTERNOON. THIS WILL PROVIDE SOME COOLING ALOFT (BETTER
CHANCE OF INSTABILITY) AND LIFT AS THESE FEATURES MOVE TOWARD
NORTHERN NEW ENGLAND. IN ADDITION... THE GREATER LOW LEVEL
MOISTURE (MID TO UPPER 50S DEW POINTS) WILL ALSO SERVE TO INCREASE
INSTABILITY ESPECIALLY IN THE MOUNTAINS. SHOULD SEE A FEW SHOWERS
AND ISOLATED THUNDERSTORMS DEVELOPING BY EARLY AFTERNOON OVER THE
HIGHER TERRAIN... WITH MORE WIDESPREAD SHOWERS AND THUNDERSTORMS
MOVING INTO THE AREA LATER IN THE AFTERNOON AND INTO TUESDAY
EVENING AS THE UPPER TROUGH AND SURFACE FRONT MOVE TOWARD THE
AREA. INSTABILITY SHOULD BE TOO WEAK FOR SEVERE THUNDERSTORMS TO
BE A THREAT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MODELS ARE SIMILAR IN MOVING COLD FRONT SLOWLY SOUTH FROM CANADA
TUESDAY NIGHT. GFS IS GOING CRAZY WITH QPF AT THIS POINT WITH THE
EURO BEING MORE REALISTIC. GFS MAY BE SUFFERING FROM SOME
CONVECTIVE FEEDBACK. HOWEVER THAT SAID THE AIRMASS WILL BE VERY
MOIST WITH PWATS NEAR 2 INCHES AND SURFACE DEWPOINTS IN THE MID 60S
SO THERE IS A CHANCE FOR HEAVY RAIN ON THE ORDER OF 1 TO 3 INCHES.
THE FRONT WILL ALSO SEE SEVERAL WAVES OF LOW PRESSURE RIPPLING
NORTHEAST ALONG IT. COLD FRONT WILL FINALLY EXIT THE REGION LATE
THURSDAY OR EARLY FRIDAY. HIGH PRESSURE WILL BEGIN TO BUILD IN FRIDAY.
ANOTHER SYSTEM MAY APPROACH FROM THE SOUTHWEST LATE SATURDAY.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
SHORT TERM...VFR CONDITIONS TODAY AREA WIDE. THERE WILL BE A
BETTER CHANCE FOR FOG TONIGHT AS LOW LEVEL MOISTURE WILL BE
INCREASING. THE BEST CHANCE OF FOG WOULD BE AT LEBANON.
LONG TERM...EXPECT IFR/LIFR LATE TUESDAY AND WEDNESDAY. MVFR/IFR
NEAR THE COAST THURSDAY WITH IMPROVING CONDITIONS IN THE INTERIOR.
VFR FRIDAY. MAY SEE MVFR BY LATE SATURDAY.
&&
.MARINE...
SHORT TERM...HIGH PRESSURE OVER THE WATERS BRINGS LIGHT WINDS AND
NEARLY CALM SEAS. AS HIGH PRESSURE MOVES EAST... A SOUTHERLY FLOW
WILL GRADUALLY INCREASE ON TUESDAY.
LONG TERM...SMALL CRAFT ADVISORY MAY BE NEEDED TUESDAY NIGHT AND
WEDNESDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...LEGRO
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
627 AM EDT MON JUN 23 2014
.SYNOPSIS...
THE WEATHER WILL BE A LITTLE WARMER AND MORE HUMID TODAY WITH AN
ISOLATED STORM. THE BEST CHANCE FOR WET WEATHER WILL BE TUESDAY INTO
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
DRY WEATHER IS EXPECTED FOR THE START OF THE DAY...ALTHOUGH SOME
HIGH CLOUDS WILL REMAIN OVER EASTERN OHIO. IN ADDITION...MANY
LOCATIONS WILL HAVE SOME FOG. ANY LOCATION COULD SEE AN ISOLATED
THUNDERSTORM TODAY...ALTHOUGH THE FOCUS WILL LIKELY REMAIN OVER THE
LAUREL HIGHLANDS. A FEATURE NOT PREVIOUSLY SHOWN ON MODEL RUNS IS A
SHORTWAVE THAT COULD DEVELOP OVER WESTERN OHIO LATE THIS AFTERNOON
AND TRACK OVER NORTHWESTERN PENNSYLVANIA BY MIDNIGHT. WHILE THE NAM
MOST CLEARLY DEPICTS THIS SHORTWAVE...THE END OF THE RAP MODEL RUN
HINTS AT THIS DEVELOPMENT...AND VARIOUS HIGH RESOLUTION NMM RUNS
ALSO DEVELOP THIS PRECIPITATION DURING THE EVENING HOURS. HAVE
RAISED POPS SLIGHTLY DURING THE EVENING HOURS...DECREASING POPS
AGAIN AFTER MIDNIGHT. WITH UPPER RIDGE BUILDING IN...TEMPS WILL BE
ABOUT FIVE DEGREES WARMER TODAY THAN YESTERDAY.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
UNFORTUNATELY...THE 00Z GFS SUFFERS FROM CONVECTIVE
FEEDBACK...SPINNING UP A SURFACE LOW ALONG THE APPROACHING COLD
FRONT AND SHOWING UNREALISTIC PRECIPITATION AND VORTICITY MAXIMA. AS
A RESULT...THE 00Z GFS WAS NOT USED THROUGH THIS PORTION OF THE
FORECAST.
PRIMARY CHANGE DURING THIS PORTION OF THE FORECAST WAS TO SLOW DOWN
THE TIMING OF THE COLD FRONT. COMPARED TO MODEL RUNS FROM 24 HOURS
AGO...FRONT APPEARS TO BE ABOUT 6 HOURS SLOWER IN ITS ARRIVAL AND
PASSAGE WITH LATEST MODEL RUNS. THIS MEANS MANY LOCATIONS COULD
REMAIN DRY TUESDAY MORNING...ALTHOUGH RAIN IS STILL EXPECTED
EVERYWHERE BY TUESDAY EVENING. STRONG SHEAR VALUES REMAIN CONFINED
TO THE LAKE ERIE SHORELINE...WHICH SHOULD KEEP THE THREAT FOR SEVERE
STORMS FARTHER TO THE NORTH..BUT SOME STRONGER STORMS REMAIN
POSSIBLE WITH MODEST INSTABILITY. BIGGER CONCERN COULD POSSIBLY BE
HEAVY RAINFALL TUESDAY AFTERNOON AND NIGHT WITH PRECIPITABLE WATER
VALUES RANGING FROM 1.5 INCHES ACROSS WV/MD RIDGES TO NEARLY 2
INCHES IN EASTERN OHIO AND NORTHWESTERN PENNSYLVANIA. THESE PWAT
VALUES ARE NEAR THE 99TH PERCENTILE FOR JUNE...AND IF SHOWERS/STORM
TRAIN ALONG THE FRONT...SOME LOCATIONS COULD SEE SEVERAL ROUNDS OF
MODERATE TO HEAVY RAIN. HOWEVER...THE RELATIVELY DRY WEEKEND THAT
JUST OCCURRED SHOULD HELP TO ALLEVIATE CONCERNS.
MOST RAINFALL SHOULD FALL IN ADVANCE OF THE COLD FRONT...WHICH
SHOULD ACTUALLY PASS OVER THE REGION LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING. RAIN SHOULD HANG ON FOR A WHILE INTO WEDNESDAY
AFTERNOON ACROSS THE WV/MD RIDGES...BUT THINK THAT PRECIP CHANCES
WILL DROP QUITE A BIT WEDNESDAY AFTERNOON...WITH NEARLY ALL
LOCATIONS DRY BY WEDNESDAY NIGHT. A COUPLE OF WARM NIGHTS CAN BE
EXPECTED DUE TO THE EXTENSIVE CLOUD COVER. DAYTIME HIGHS WILL BE
SLIGHTLY ABOVE NORMAL TUESDAY AND SLIGHTLY BELOW NORMAL WEDNESDAY
BEHIND THE COLD FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
KEEPING THURSDAY DRY WITH HIGH PRESSURE IN PLACE AND RELATIVELY
LOW MOISTURE. FRONTAL BOUNDARY WILL RETURN NORTHWARD AS A WARM
FRONT THURSDAY NIGHT/FRIDAY...BRINGING HIGHER PRECIPITABLE WATER
VALUES BACK NORTHWARD. FROM HERE ON OUT...EXPECTING A DAILY CHANCE
OF SHOWERS/THUNDERSTORMS AS H500 HEIGHTS SLOWLY RISE AND WE STAY
IN A TYPICALLY WARM AND MOIST SUMMERTIME AIRMASS. DECIDED TO KEY
ON DIURNAL POPS FOR NOW...EVEN THOUGH RIPPLES IN THE WESTERLIES
MAY PROVIDE ENHANCED CHANCES. TEMPERATURES WILL FLOAT TO A BIT
ABOVE SEASONAL LEVELS WITH TIME.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ACROSS THE FORECAST AREA EXPECTED TODAY. THE MAJORITY
OF THE AFTERNOON WILL BE QUIET...BUT BY LATE AFTERNOON/EVENING
SHOWERS AND THUNDERSTORMS WILL EXPAND IN COVERAGE AS THE CAP ALOFT
ERODES AND ALLOWS FOR DEEPER CONVECTIVE DEVELOPMENT.
.OUTLOOK.../TUESDAY THROUGH SATURDAY/...
THE BEST CHANCE FOR RESTRICTIONS WILL BE TUESDAY INTO WEDNESDAY
WITH FRONTAL BOUNDARY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
753 AM EDT MON JUN 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 522 AM EDT MON JUN 23 2014
WV IMAGERY AND RUC ANALYSIS INDICATED WSW FLOW INTO THE NRN LAKES
BETWEEN A MID/UPPER LEVEL TROUGH FROM MANITOBA INTO THE NRN PLAINS
AND A RIDGE FROM THE OHIO VALLEY INTO QUEBEC. AT THE SFC...A WEAK
TROUGH EXTENDED FROM NE MN INTO WRN WI. A MORE PROMINENT COLD FRONT
STRETCHED FROM JAMES BAY TO NEAR WINNIPEG AHEAD OF HIGH PRESSURE
OVER N CNTRL CANADA. FORCING FROM A WEAK SHRTWV IN NRN WI ALONG WITH
AN AXIS OF HIGHER MOISTURE WITH PWAT VALUES TO 1.4 INCHES...WAS
ENOUGH TO SUPPORT AN AREA OF SHOWERS OVER FROM SW UPPER MI INTO E
CNTRL WI.
TODAY...EXPECT THE SHRTWV AND AREA OF PCPN ONLY SLOWLY MOVE TO THE
EAST THIS MORNING. WITH ONLY WEAK LARGE SCALE FORCING EXPECTED INTO
THE AFTERNOON AND THE POTENTIAL FOR ANOTHER WEAK SHRTWV TO MOVE INTO
THE AREA DURING INCREASED DAYTIME HEATING...THE FCST KEEPS MENTION
OF JUST SCT SHRA WITH THE GREATEST COVERAGE EXPECTED OVER CNTRL
UPPER MI. WITH TEMPS CLIMBING INTO THE MID 70S...THERE MAY BE ENOUGH
INSTABILITY FOR SOME ISOLD/SCT TSRA AS MLCAPE VALUES CLIMB INTO THE
400-800 J/KG RANGE.
TONIGHT...WITH THE LOSS OF DAYTIME HEATING...THE PCPN COVERAGE
SHOULD DIMINISH. HOWEVER...INCREASED QVECTOR CONV AHEAD OF THE MID
LEVEL TROUGH MOVING INTO THE UPPER MS VALLEY WILL SUPPORT CONTINUED
CHANCES FOR SCT SHOWERS AND A FEW TSRA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 421 AM EDT MON JUN 23 2014
ON TUESDAY MORNING...THE MODELS ARE IN GOOD AGREEMENT IN SHOWING THE
COLD FRONT MOVING OVER OR JUST SOUTH OF THE AREA. HOWEVER...THE
850MB TROUGH AXIS HANGS UP OVER LAKE SUPERIOR AS THERE IS LACK OF A
SOUTHWARD PUSH DUE TO THE GENERAL ZONAL FLOW ALOFT. THIS WILL
PROVIDE THE FOCUS FOR PRECIPITATION ON TUESDAY ESPECIALLY SINCE THE
MODELS ARE IN EXCELLENT AGREEMENT IN SHOWING BROAD SYNOPTIC SUPPORT
MOVING THRU AS THE 500MB TROUGH AXIS MOVES THROUGH. AS SUCH...THERE
WILL LIKELY BE SCATTERED SHOWERS ACROSS THE ENTIRE FORECAST AREA
THROUGH THE DAY DESPITE THE SURFACE FRONT BEING SOUTH OF THE REGION.
THE NUMERICAL GUIDANCE ALSO SHOWS MUCAPE VALUES OF 500-1500 J/KG
ACROSS THE REGION DURING THE DAY WITH MID LEVEL LAPSE RATES OF 6+
C/KM...ALLOWING FOR POSSIBLE THUNDERSTORM DEVELOPMENT. BEST CHANCES
FOR THUNDER WOULD BE ACROSS THE SOUTHERN TIER WHERE SFC TEMPS WILL
LIKELY BE IN THE LOWER-MID 70S AND IS WHERE THE BEST INSTABILITY
WILL BE LOCATED. WILL NEED TO KEEP CHANCE POPS ACROSS THE EASTERN
HALF OF THE FORECAST AREA DURING THE TUE EVENING HOURS AS WELL GIVEN
REMAINING MID LEVEL FORCING AND REMAINING DAYTIME INSTABILITY.
AT THIS TIME...WEDNESDAY IS EXPECTED TO REMAIN DRY AND COOL WITH THE
850MB TROUGH AND SFC FRONT REMAINING SOUTH OF THE AREA. STILL SOME
WEAK TROUGHINESS AT 500MB AND AS SUCH WEAK MID LEVEL Q-VECTOR
CONVERGENCE AND MOISTURE PERSISTS ACROSS THE AREA ALL DAY.
HOWEVER...GIVEN LACK OF INSTABILITY AND VERY WEAK MID LEVEL LAPSE
RATES COMBINED WITH ANTICYCLONIC LOW LEVELS WILL KEEP IT DRY FOR
NOW. WOULD NOT BE SHOCKED TO SEE ISOLATED SHOWERS BUT CHANCES ARE
NOT HIGH ENOUGH TO INCLUDE IN THE FORECAST AT TIME TIME.
IN THE EXTENDED...ZONAL FLOW THROUGH THE PERIOD WILL MAKE TIMING OF
PRECIPITATION SOMEWHAT DIFFICULT ESPECIALLY INTO THE WEEKEND.
HOWEVER...THE LONGER RANGE MODELS ARE IN DECENT AGREEMENT ON THE
BROAD SCALE FEATURES WHICH AT LEAST GIVES SOME BASIC CONFIDENCE ON
WHEN THE BETTER CHANCES FOR RAIN WILL BE. ON THURSDAY...THE ECMWF
AND GFS BOTH SHOW A COMPACT VORT MAX MOVING ACROSS THE AREA DURING
THE DAY AS THE 850MB FRONT MOVES BACK NORTH. ALTHOUGH MOISTURE WILL
BE VERY LIMITED...WILL INCLUDE CHANCE POPS FOR THE WESTERN HALF OF
THE FORECAST AREA. BEHIND THIS VORT MAX...UPPER RIDGING BUILDS
ACROSS THE AREA FOR FRIDAY WHICH SHOULD ALLOW FOR TEMPS TO RETURN TO
NORMAL AS WELL AS DRY WEATHER. RETURN FLOW BEGINS IN EARNEST FOR THE
WEEKEND WITH TEMPERATURES LIKELY TO RISE ABOVE NORMAL...AND PERHAPS
A LITTLE MORE HUMIDITY AND SUMMER LIKE WEATHER. THIS WILL ALLOW FOR
CHANCES OF SHOWERS AND STORMS EACH DAY...ALTHOUGH SUNDAY LOOKS LIKE
THE BETTER CHANCE FOR SHOWERS AND STORMS GIVEN LOWERING HEIGHTS
ACROSS THE AREA IN RESPONSE TO THE APPROACHING TROUGH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 752 AM EDT MON JUN 23 2014
A MOIST AIRMASS WITH A WEAK DISTURBANCE MOVING THROUGH THE AREA WILL
BRING SCT SHRA TODAY INTO THIS EVENING. HOWEVER...MAINLY VFR CONDITIONS ARE
EXPECTED AS MOST OF THE RAIN WILL BE LIGHT. ISOLATED THUNDERSTORMS
ARE ALSO POSSIBLE...MAINLY THIS AFTERNOON AND EVENING. HOWEVER...THE
PROBABILITY IS LOW ENOUGH TO LEAVE OUT MENTION FROM THE TAF. WITH
LIGHT WINDS AND ABUNDANT LOW LEVEL MOISTURE REMAINING...FOG IS
EXPECTED TO DEVELOP OVERNIGHT WITH VLIFR CONDITIONS POSSIBLE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 522 AM EDT MON JUN 23 2014
DENSE FOG WILL PERSIST OVER WESTERN LAKE SUPERIOR INTO THIS
AFTERNOON. OTHERWISE...MAINLY LIGHT WINDS WILL PREVAIL INTO TONIGHT.
AS A COLD FRONT MOVES THROUGH THE AREA ON TUESDAY...NORTHEAST WINDS
WILL INCREASE TO 20 KNOTS WITH WAVES BUILDING TO AROUND 4 FEET.
WINDS WILL DIMINISH TUE NIGHT INTO WED AS HIGH PRES BUILDS INTO THE
REGION. MAINLY LIGHT WINDS AT OR BELOW 15 KNOTS ARE THEN EXPECTED
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 2 PM EDT /1 PM CDT/ THIS AFTERNOON FOR
LSZ162-240>248-263>265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
929 AM CDT MON JUN 23 2014
.UPDATE...
ISSUED AT 929 AM CDT MON JUN 23 2014
AS MCS CONTINUES TO WEAKEN AND MOVE OUT CI SHIELD ALSO PROGRESSING
EWD. VISIBLE SAT PICS INDICATING POCKETS OF ELEVATED INSTABILITY
IN THE FORM OF ENHANCEMENT OF AC LIKELY ON LEFTOVER BOUNDARIES.
SHORT TERM MODELS CONTINUE TO SHOW SOME THREAT OF ISOLD SHOWERS
AND MAYBE A COUPLE TSRA THROUGH THE MORNING INTO EARLY AFTERNOON
LIKELY AS RESULT OF LOCAL CONVERGENCE ENHANCEMENT AS SUBTLE UPPER
PV ANOMALY MOVES OUT OF SRN WY. WILL HAVE TO INVESTIGATE THIS A
BIT MORE FOR THE AFTERNOON IN ORDER TO FURTHER REFINE BEST PRECIP
CHANCES. OTHERWISE TEMPS AND DEW POINTS LOOK ON TRACK FOR NOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 319 AM CDT MON JUN 23 2014
ANOTHER MCS SHOULD DROP THROUGH THE CNTL HIGH PLAINS THIS AFTN. THE
FORECAST USES 50 PERCENT OF THE RAP MODEL AND 50 PERCENT OF THE
OTHER MODELS.
THE ONGOING MCS APPEARS TO BE TAKING ON A CYCLONIC ROTATION WITH THE
WARM SECTOR ACROSS SCNTL NEB AND THE UPPER LEVEL COLD POOL ACROSS
SWRN NEB ATTM. RADAR TRENDS SUGGEST THIS SYSTEM COULD ROTATE THROUGH
SCNTL NEB THIS MORNING AND SHOWERS AND TSTMS ARE POPPING LEFT AND
RIGHT BETWEEN KLBF AND KLXN.
FOR TONIGHT...NEBULOUS POPS ARE IN THE FCST ACROSS THE SANDHILLS AND
AREAS SOUTH. GIVEN THE INABILITY OF THE SYNOPTIC SCALE MODELS TO
PREDICT NOCTURNAL RAIN EVENTS OF LATE...THE FCST IS FORCED TO
MAINTAIN A SCATTERED POP.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 319 AM CDT MON JUN 23 2014
12Z TUESDAY AND BEYOND. NEAR DAILY PRECIPITATION CHANCES TO
HEADLINE THE EXTENDED DISCUSSION THROUGH AT LEAST SATURDAY AS THE
ACTIVE PATTERN CONTINUES.
A BRIEF PERIOD OF NORTHWEST FLOW ALOFT WILL DIRECT TWO SUBTLE
DISTURBANCES ACROSS THE CENTRAL PLAINS TUESDAY INTO WEDNESDAY. THE
FIRST OF WHICH SHOULD BE EAST OF THE CWA BY 12Z TUESDAY. THERE
REMAINS GOOD CONSENSUS HOWEVER THAT THUNDER CHANCES REMAIN THROUGH
MUCH THE DAY AS THE NEXT DISTURBANCE FOLLOWS. THE ATMOSPHERE WILL
CHARACTERIZED AS MODERATELY UNSTABLE...WITH GENERALLY 25-40 KTS OF
DEEP LAYER SHEAR. STRONG TO SEVERE STORMS ARE ANTICIPATED...BUT
POSSIBLY THE GREATER IMPACT WILL BE HEAVY RAINFALL POTENTIAL AS
THERE/S SUPPORT OF ONE OR MORE MCS/S PASSING THROUGH THE SANDHILLS
REGION. STORM MOTION WILL BE ON THE SLOW SIDE...GENERALLY LESS THAN
20KTS...AND WITH PWATS INCREASING OVER AN INCH AND A
THIRD...RAINFALL RATES OF AN INCH OR TWO AN HOUR WILL BE POSSIBLE.
UPPER LOW PRESSURE TO BUILD EAST INTO THE PACIFIC NORTHWEST
WEDNESDAY ALLOWING THE EASTWARD DEVELOPMENT OF A LOW AMPLITUDE
TRANSITORY RIDGE. PRECIPITATION CHANCES CONTINUE ON WEDNESDAY AS
THE NEXT WAVE EMBEDDED IN THE NOW QUASI-ZONAL FLOW IMPACTS THE
REGION. TIMING AND PLACEMENT OF THE BETTER PRECIPITATION CHANCES
WILL BE GENERALLY TIED TO THE LOCATION OF A LOW LEVEL FRONTAL
BOUNDARY AND HOW CONVECTION FROM THE PREVIOUS DAY PLAYS OUT. AT
THIS TIME THE MODELS ARE FAVORING NORTHERN NEBRASKA WITH THE HIGHER
POP CHANCES /40 PERCENT/ WEDNESDAY AFTERNOON...WILL FOLLOW SUIT WITH
THE FORECAST. THE AFOREMENTIONED RIDGE MAY EFFECTIVELY CAP THE
REGION ON THURSDAY AS MIDLEVEL TEMPS WARM AOA 14C...AT THIS POINT
WILL KEEP MOST OF THE CWA DRY THURSDAY WITH THE EXCEPTION BEING
THURSDAY NIGHT ACROSS OUR NORTHERN BORDER WHERE RIDGE RIDING WAVE
MAY SPARK CONVECTION. FOR LATE WEEK AND THE WEEKEND...FORECAST
CONFIDENCE IS NOT QUITE THERE YET AS THE FINER DETAILS OF HOW THE
WESTERN CONUS TROUGH WILL PLAY OUT ARE STILL AN ENIGMA. IN THE
SYNOPTIC SCALE THERE REMAINS GOOD AGREEMENT OF A FAIRLY STRONG
TROUGH ADVANCING INTO THE NORTHERN ROCKIES WITH MOST OF THE
FAVORABLE UPPER LEVEL ENERGY TARGETING THE NORTHERN PLAINS. SOLID
MOISTURE RETURN AND WARMING TEMPERATURES WILL BE IN PLACE ACROSS THE
CENTRAL PLAINS...WITH A FRONTAL PASSAGE/SFC TROUGH FOR THE WEEKEND.
STORMS...POSSIBLY SEVERE WILL ONCE AGAIN BE POSSIBLE....BUT WITH
LACKING CONSISTENCY...WILL CAP POP CHANCES AT 40 PERCENT OR LESS
THROUGH THE WEEKEND. AS FOR TEMPERATURES...A GRADUAL WARMING TREND
IS ANTICIPATED THROUGH THE END OF THE WORK WEEK...WITH HIGHS
GENERALLY IN THE 80S...LOWS WILL BE SEASONAL IN THE 50 AND 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 611 AM CDT MON JUN 23 2014
VFR IS EXPECTED EAST OF HIGHWAY 83 TODAY. SCATTERED TSTM ACTIVITY
IS EXPECTED WEST OF HIGHWAY 83...MAINLY FROM 18Z ONWARD AS STORMS
DEVELOP NORTH AND MOVE SOUTH.
TONIGHT...THE FORECAST IS UNCERTAIN AS THE MODELS SUGGEST A SECOND
AREA OF TSTMS WILL DEVELOP ACROSS THE CNTL SANDHILLS AND CONTINUE
THROUGHOUT THE NIGHT. LATER FORECASTS USING THE RAP MODEL WILL
HOPEFULLY CLARIFY THIS AS THE SYNOPTIC SCALE MODELS HAVE SHOWN
POOR SKILL FORECASTING STORM DEVELOPMENT LATELY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JWS
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
612 AM CDT MON JUN 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 319 AM CDT MON JUN 23 2014
ANOTHER MCS SHOULD DROP THROUGH THE CNTL HIGH PLAINS THIS AFTN. THE
FORECAST USES 50 PERCENT OF THE RAP MODEL AND 50 PERCENT OF THE
OTHER MODELS.
THE ONGOING MCS APPEARS TO BE TAKING ON A CYCLONIC ROTATION WITH THE
WARM SECTOR ACROSS SCNTL NEB AND THE UPPER LEVEL COLD POOL ACROSS
SWRN NEB ATTM. RADAR TRENDS SUGGEST THIS SYSTEM COULD ROTATE THROUGH
SCNTL NEB THIS MORNING AND SHOWERS AND TSTMS ARE POPPING LEFT AND
RIGHT BETWEEN KLBF AND KLXN.
FOR TONIGHT...NEBULOUS POPS ARE IN THE FCST ACROSS THE SANDHILLS AND
AREAS SOUTH. GIVEN THE INABILITY OF THE SYNOPTIC SCALE MODELS TO
PREDICT NOCTURNAL RAIN EVENTS OF LATE...THE FCST IS FORCED TO
MAINTAIN A SCATTERED POP.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 319 AM CDT MON JUN 23 2014
12Z TUESDAY AND BEYOND. NEAR DAILY PRECIPITATION CHANCES TO
HEADLINE THE EXTENDED DISCUSSION THROUGH AT LEAST SATURDAY AS THE
ACTIVE PATTERN CONTINUES.
A BRIEF PERIOD OF NORTHWEST FLOW ALOFT WILL DIRECT TWO SUBTLE
DISTURBANCES ACROSS THE CENTRAL PLAINS TUESDAY INTO WEDNESDAY. THE
FIRST OF WHICH SHOULD BE EAST OF THE CWA BY 12Z TUESDAY. THERE
REMAINS GOOD CONSENSUS HOWEVER THAT THUNDER CHANCES REMAIN THROUGH
MUCH THE DAY AS THE NEXT DISTURBANCE FOLLOWS. THE ATMOSPHERE WILL
CHARACTERIZED AS MODERATELY UNSTABLE...WITH GENERALLY 25-40 KTS OF
DEEP LAYER SHEAR. STRONG TO SEVERE STORMS ARE ANTICIPATED...BUT
POSSIBLY THE GREATER IMPACT WILL BE HEAVY RAINFALL POTENTIAL AS
THERE/S SUPPORT OF ONE OR MORE MCS/S PASSING THROUGH THE SANDHILLS
REGION. STORM MOTION WILL BE ON THE SLOW SIDE...GENERALLY LESS THAN
20KTS...AND WITH PWATS INCREASING OVER AN INCH AND A
THIRD...RAINFALL RATES OF AN INCH OR TWO AN HOUR WILL BE POSSIBLE.
UPPER LOW PRESSURE TO BUILD EAST INTO THE PACIFIC NORTHWEST
WEDNESDAY ALLOWING THE EASTWARD DEVELOPMENT OF A LOW AMPLITUDE
TRANSITORY RIDGE. PRECIPITATION CHANCES CONTINUE ON WEDNESDAY AS
THE NEXT WAVE EMBEDDED IN THE NOW QUASI-ZONAL FLOW IMPACTS THE
REGION. TIMING AND PLACEMENT OF THE BETTER PRECIPITATION CHANCES
WILL BE GENERALLY TIED TO THE LOCATION OF A LOW LEVEL FRONTAL
BOUNDARY AND HOW CONVECTION FROM THE PREVIOUS DAY PLAYS OUT. AT
THIS TIME THE MODELS ARE FAVORING NORTHERN NEBRASKA WITH THE HIGHER
POP CHANCES /40 PERCENT/ WEDNESDAY AFTERNOON...WILL FOLLOW SUIT WITH
THE FORECAST. THE AFOREMENTIONED RIDGE MAY EFFECTIVELY CAP THE
REGION ON THURSDAY AS MIDLEVEL TEMPS WARM AOA 14C...AT THIS POINT
WILL KEEP MOST OF THE CWA DRY THURSDAY WITH THE EXCEPTION BEING
THURSDAY NIGHT ACROSS OUR NORTHERN BORDER WHERE RIDGE RIDING WAVE
MAY SPARK CONVECTION. FOR LATE WEEK AND THE WEEKEND...FORECAST
CONFIDENCE IS NOT QUITE THERE YET AS THE FINER DETAILS OF HOW THE
WESTERN CONUS TROUGH WILL PLAY OUT ARE STILL AN ENIGMA. IN THE
SYNOPTIC SCALE THERE REMAINS GOOD AGREEMENT OF A FAIRLY STRONG
TROUGH ADVANCING INTO THE NORTHERN ROCKIES WITH MOST OF THE
FAVORABLE UPPER LEVEL ENERGY TARGETING THE NORTHERN PLAINS. SOLID
MOISTURE RETURN AND WARMING TEMPERATURES WILL BE IN PLACE ACROSS THE
CENTRAL PLAINS...WITH A FRONTAL PASSAGE/SFC TROUGH FOR THE WEEKEND.
STORMS...POSSIBLY SEVERE WILL ONCE AGAIN BE POSSIBLE....BUT WITH
LACKING CONSISTENCY...WILL CAP POP CHANCES AT 40 PERCENT OR LESS
THROUGH THE WEEKEND. AS FOR TEMPERATURES...A GRADUAL WARMING TREND
IS ANTICIPATED THROUGH THE END OF THE WORK WEEK...WITH HIGHS
GENERALLY IN THE 80S...LOWS WILL BE SEASONAL IN THE 50 AND 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 611 AM CDT MON JUN 23 2014
VFR IS EXPECTED EAST OF HIGHWAY 83 TODAY. SCATTERED TSTM ACTIVITY
IS EXPECTED WEST OF HIGHWAY 83...MAINLY FROM 18Z ONWARD AS STORMS
DEVELOP NORTH AND MOVE SOUTH.
TONIGHT...THE FORECAST IS UNCERTAIN AS THE MODELS SUGGEST A SECOND
AREA OF TSTMS WILL DEVELOP ACROSS THE CNTL SANDHILLS AND CONTINUE
THROUGHOUT THE NIGHT. LATER FORECASTS USING THE RAP MODEL WILL
HOPEFULLY CLARIFY THIS AS THE SYNOPTIC SCALE MODELS HAVE SHOWN
POOR SKILL FORECASTING STORM DEVELOPMENT LATELY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
855 AM CDT MON JUN 23 2014
.SYNOPSIS...
ISSUED AT 324 AM CDT MON JUN 23 2014
REX BLOCKING OVER THE CANADIAN PRAIRIE IS FORECAST TO BREAK DOWN
ON WEDNESDAY...BUT THERE IS GOOD AGREEMENT THAT THE NORTHEAST
PACIFIC UPPER LEVEL LOW WILL BROADEN FURTHER INTO NORTHWESTERN
CONUS...AND EVENTUALLY INTO THE NORTHERN PLAINS. SCATTERED SHOWERS
AND THUNDERSTORMS WILL TRANSITION TO HIGHER CHANCES OF
THUNDERSTORMS AS SOUTHWESTERLY FLOW ALOFT MOVES OVER THE DAKOTAS
LATER THIS WEEK.
&&
.UPDATE...
ISSUED AT 841 AM CDT MON JUN 23 2014
CURRENT FORECAST REMAINS IN PRETTY GOOD SHAPE WITH UPPER LOW/TROF
NEAR LAKE WINNIPEG CONTINUING TO SAG TO THE SOUTHEAST WHILE COOL
FRONT WORKS ITS WAY INTO THE AREA. STILL EXPECT SHOWERS AND
THUNDERSTORMS TO DEVELOP FROM NORTH TO SOUTH TODAY AS THESE
FEATURES WORK THEIR WAY INTO THE STATE.
UPDATE ISSUED AT 639 AM CDT MON JUN 23 2014
CYCLONIC FLOW ALOFT WITH SHORTWAVE TROUGH MOVING THROUGH SOUTHWEST
NORTH DAKOTA. THIS GENERATING HIGH CLOUDS AND SOME VIRGA WITH NO
PRECIP SO FAR REACHING THE GROUND. OTHERWISE MAIN FEATURE TODAY
WILL BE THE UPPER LEVEL OW ACROSS SOUTHERN CANADA WHICH WILL MOVE
SOUTH TODAY AND TONIGHT BRINGING SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT MON JUN 23 2014
SCATTERED SHOWERS AND THUNDERSTORMS ARE FORECAST TODAY WITH PEAK
HEATING...BUT THERE IS UNCERTAINTY ABOUT HOW MUCH INSTABILITY
WILL DEVELOP. THE MOST RECENT TWO HRRR RUNS HAVE INCREASED THEIR
COVERAGE OF THUNDERSTORMS EMBEDDED WITHIN RAIN SHOWERS. CAPPED THE
COVERAGE OF THUNDERSTORMS TO SCATTERED FOR TODAY AND TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 324 AM CDT MON JUN 23 2014
JUST A REMNANT OF THE PERSISTENT UPPER LOW WILL REMAIN ACROSS NORTH
DAKOTA ON TUESDAY. THIS UPPER FEATURE ACCOMPANIED BY AN ASSOCIATED
SURFACE FRONTAL BOUNDARY WILL HELP FOCUS SHOWERS AND SCATTERED
THUNDERSTORMS ACROSS THE CENTRAL AND NORTH TUESDAY AFTERNOON. TUESDAY
NIGHT ACTIVITY WILL BE MINIMAL AS THE COLD FRONT REMAINS SOUTH OF
THE STATE...BECOMING STATIONARY...TO RETURN EVENTUALLY WEDNESDAY
NIGHT AND THURSDAY AS A WARM FRONTAL BOUNDARY IN ADVANCE OF A
WESTERN UPPER TROUGH. THIS H500 TROUGH AND SURFACE WARM FRONT
WILL BE THE FOCUS FOR AN ACTIVE THUNDERSTORM PERIOD THURSDAY NIGHT
INTO FRIDAY NIGHT. MODELS SUGGEST SEVERAL MCS TYPE SYSTEMS
SPREADING THUNDERSTORMS INTO THE REGION AND WILL BE MONITORING THE
POTENTIAL FOR MODERATE TO HEAVY RAIN DURING THIS TIME FRAME. POPS
REMAIN LIKELY FRIDAY NIGHT INTO SATURDAY FOR THIS.
POPS TRAIL OFF INTO 20 TO 30S SUNDAY AFTER THE PASSAGE OF THE
SHORTWAVE TROUGH/COLD FRONT. TEMPERATURES DURING THE EXTENDED LOOK
NEAR OR SLIGHTLY BELOW NORMAL WITH HIGHS IN THE 70S TO AROUND 80.
LOWS IN THE 50S TO NEAR 60.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 639 AM CDT MON JUN 23 2014
THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS THIS
AFTERNOON...BUT CONFIDENCE IS TOO LOW TO NAIL DOWN TIMING AND
COVERAGE. THE BEST CHANCE FOR THUNDERSTORMS IS AT KMOT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SYNOPSIS...SCHECK
SHORT TERM...SCHECK
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
647 AM CDT MON JUN 23 2014
.SYNOPSIS...
ISSUED AT 324 AM CDT MON JUN 23 2014
REX BLOCKING OVER THE CANADIAN PRAIRIE IS FORECAST TO BREAK DOWN
ON WEDNESDAY...BUT THERE IS GOOD AGREEMENT THAT THE NORTHEAST
PACIFIC UPPER LEVEL LOW WILL BROADEN FURTHER INTO NORTHWESTERN
CONUS...AND EVENTUALLY INTO THE NORTHERN PLAINS. SCATTERED SHOWERS
AND THUNDERSTORMS WILL TRANSITION TO HIGHER CHANCES OF
THUNDERSTORMS AS SOUTHWESTERLY FLOW ALOFT MOVES OVER THE DAKOTAS
LATER THIS WEEK.
&&
.UPDATE...
ISSUED AT 639 AM CDT MON JUN 23 2014
CYCLONIC FLOW ALOFT WITH SHORTWAVE TROUGH MOVING THROUGH SOUTHWEST
NORTH DAKOTA. THIS GENERATING HIGH CLOUDS AND SOME VIRGA WITH NO
PRECIP SO FAR REACHING THE GROUND. OTHERWISE MAIN FEATURE TODAY
WILL BE THE UPPER LEVEL OW ACROSS SOUTHERN CANADA WHICH WILL MOVE
SOUTH TODAY AND TONIGHT BRINGING SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT MON JUN 23 2014
SCATTERED SHOWERS AND THUNDERSTORMS ARE FORECAST TODAY WITH PEAK
HEATING...BUT THERE IS UNCERTAINTY ABOUT HOW MUCH INSTABILITY
WILL DEVELOP. THE MOST RECENT TWO HRRR RUNS HAVE INCREASED THEIR
COVERAGE OF THUNDERSTORMS EMBEDDED WITHIN RAIN SHOWERS. CAPPED THE
COVERAGE OF THUNDERSTORMS TO SCATTERED FOR TODAY AND TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 324 AM CDT MON JUN 23 2014
JUST A REMNANT OF THE PERSISTENT UPPER LOW WILL REMAIN ACROSS NORTH
DAKOTA ON TUESDAY. THIS UPPER FEATURE ACCOMPANIED BY AN ASSOCIATED
SURFACE FRONTAL BOUNDARY WILL HELP FOCUS SHOWERS AND SCATTERED
THUNDERSTORMS ACROSS THE CENTRAL AND NORTH TUESDAY AFTERNOON. TUESDAY
NIGHT ACTIVITY WILL BE MINIMAL AS THE COLD FRONT REMAINS SOUTH OF
THE STATE...BECOMING STATIONARY...TO RETURN EVENTUALLY WEDNESDAY
NIGHT AND THURSDAY AS A WARM FRONTAL BOUNDARY IN ADVANCE OF A
WESTERN UPPER TROUGH. THIS H500 TROUGH AND SURFACE WARM FRONT
WILL BE THE FOCUS FOR AN ACTIVE THUNDERSTORM PERIOD THURSDAY NIGHT
INTO FRIDAY NIGHT. MODELS SUGGEST SEVERAL MCS TYPE SYSTEMS
SPREADING THUNDERSTORMS INTO THE REGION AND WILL BE MONITORING THE
POTENTIAL FOR MODERATE TO HEAVY RAIN DURING THIS TIME FRAME. POPS
REMAIN LIKELY FRIDAY NIGHT INTO SATURDAY FOR THIS.
POPS TRAIL OFF INTO 20 TO 30S SUNDAY AFTER THE PASSAGE OF THE
SHORTWAVE TROUGH/COLD FRONT. TEMPERATURES DURING THE EXTENDED LOOK
NEAR OR SLIGHTLY BELOW NORMAL WITH HIGHS IN THE 70S TO AROUND 80.
LOWS IN THE 50S TO NEAR 60.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 639 AM CDT MON JUN 23 2014
THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS THIS
AFTERNOON...BUT CONFIDENCE IS TOO LOW TO NAIL DOWN TIMING AND
COVERAGE. THE BEST CHANCE FOR THUNDERSTORMS IS AT KMOT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SYNOPSIS...SCHECK
SHORT TERM...SCHECK
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
939 AM EDT MON JUN 23 2014
.SYNOPSIS...
A WARM FRONT WILL MOVE ACROSS THE REGION THIS AFTERNOON. A COLD
FRONT WILL MOVE ACROSS NORTHERN OHIO AND NORTHWEST PENNSYLVANIA
TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WARM FRONT CONTINUES TO PUSH NORTHEAST TOWARD THE AREA AND WAS
CURRENTLY LOCATED OVER SOUTHWEST OHIO. SOME SHOWER AND
THUNDERSTORM ACTIVITY WAS OVER NORTHERN INDIANA AND SOUTHERN
MICHIGAN AT THIS TIME. THIS ACTIVITY WILL MOVE NORTHEAST INTO
MICHIGAN WITH TIME.
LATEST HRRR GUIDANCE SHOWS LITTLE THREAT EARLY THIS AFTERNOON FOR
SHOWERS AND THUNDERSTORMS TO DEVELOP OVER THE WESTERN PORTIONS OF
THE FORECAST AREA. HOWEVER...INCREASING DEW POINTS WERE TAKING
PLACE OVER THE WEST ALONG WITH ABUNDANT SUNSHINE. CAPE IS ALSO
INCREASING AS WELL. CUMULUS CLOUDS ARE BEGINNING TO FORM SO WILL
LEAVE A MENTION OF AT LEAST A SLIGHT CHANCE FOR SHOWERS AND
THUNDERSTORMS IN THE WEST AND THEN PROGRESS IT EAST AS THE
AFTERNOON OCCURS.
SO FAR...TEMPERATURES LOOK REASONABLE SO NO ADJUSTMENTS THERE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
A COLD FRONT WILL SLOWLY APPROACH THE FORECAST AREA ON TUESDAY.
WITH MUCH OF THE FORECAST AREA IN THE WARM SECTOR SCATTERED
THUNDERSTORMS ARE NOT OUT OF THE QUESTION AT ANY TIME. THE 00Z RUN
OF THE MODELS INDICATED THE COLD FRONT WILL PUSH ACROSS THE FORECAST
AREA TUESDAY NIGHT. I WILL BEGIN TO INCREASE THE PROBABILITY OF
PRECIPITATION CHANCES TUESDAY AFTERNOON THROUGH TUESDAY NIGHT. THE
GFS IS TRYING TO SHOW A WAVE DEVELOP ON THE FRONT ON TUESDAY. THIS
SCENARIO MAY BE OVER DONE AND I AM LEANING MORE TOWARDS THE NAM
SOLUTION. THE MODELS INDICATE A SECONDARY TROF WEDNESDAY
MORNING...SO I WILL HOLD ON TO A LOW CHANCE OF PRECIPITATION
WEDNESDAY.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
FOLLOWED WPC THROUGH THE LONG TERM PERIOD WHICH FAVORS CLOSER TO THE
ECMWF. GENERALLY AM EXPECTING AN UPPER RIDGE FROM THE TENNESSEE
VALLEY INTO THE OHIO VALLEY WITH HIGH PRESSURE ACROSS THE AREA OR TO
THE SOUTHEAST. TEMPS SEASONAL TO SLIGHTLY ABOVE. WITH CHANCE OR
SLIGHT CHANCE POPS THROUGH THE PERIOD.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
WARM FRONT TO OUR WEST AND SOUTH WILL MOVE EAST REACHING NEAR A
TOL-MFD-CMH LINE BY 00Z. NO CHANGES IN EXPECTATIONS IN THAT WITH
THE FRONT MOVING INTO THE AREA...EXPECT SHOWERS AND THUNDERSTORMS
TO DEVELOP THIS AFTERNOON. ALSO TONIGHT WITH MORE MOISTURE IN THE
AREA TOOK VISIBILITIES DOWN TO AT LEAST MVFR IN HAZE/FOG WITH SHOWERS.
OUTLOOK...NON VFR POSSIBLE MON NIGHT THRU FRI IN SCT SHOWERS AND
THUNDERSTORMS AS WELL AS POSSIBLE MORNING FOG/MIST.
&&
.MARINE...
HIGH PRESSURE MOVING EAST OF THE LAKES WILL SUPPORT A SOUTHEAST
FLOW TODAY INTO TONIGHT AHEAD OF A WARM FRONT. THE WARM FRONT WILL
MOVE ONTO THE WESTERN BASIN THIS EVENING AND BISECT THE LAKE TUESDAY
MORNING BEFORE MOVING EAST IN THE AFTERNOON. WINDS WILL TURN
SOUTHWEST AFTER THE WARM FRONT PASSES. A COLD FRONT WILL FOLLOW
TUESDAY NIGHT...DROPPING SOUTHEAST OF THE LAKE BY WEDNESDAY MORNING.
WINDS WILL TURN NORTHWEST BEHIND THE COLD FRONT. HIGH PRESSURE WILL
BUILD ACROSS THE LAKE THURSDAY...MOVING EAST ON FRIDAY. WINDS SHOULD
REMAIN GENERALLY LIGHT THROUGH THE PERIOD OUTSIDE OF ANY CONVECTIVE
ACTIVITY SO AM EXPECTING TO REMAIN WELL BELOW SMALL CRAFT LEVELS
THROUGHOUT THE FORECAST.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GARNET
NEAR TERM...LOMBARDY
SHORT TERM...GARNET
LONG TERM...TK
AVIATION...TK
MARINE...TK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
934 AM EDT MON JUN 23 2014
.SYNOPSIS...
CONVECTION CHANCES INCREASE SLOWLY THROUGH TUESDAY AS A COLD FRONT
APPROACHES AND ARRIVES WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A FEW SHOWERS EXITING THE FORECAST AREA UP INTO THE WEST VIRGINIA
NORTHERN PANHANDLE THIS MORNING. A QUASI STATIONARY WARM FRONT SITS TO
OUR WEST ACROSS CENTRAL KY AND OH. ATMOSPHERE IS CURRENTLY WEAKLY
UNSTABLE...AND WITH A LACK OF SIGNIFICANT TRIGGER THEN CHANCES FOR
CONVECTIVE INITIATION LOW TO START THE PERIOD. EXPECT TERRAIN TO
BE MAIN DRIVER AS TO WHERE WE SEE CONVECTIVE DEVELOPMENT TODAY AND
CURRENT HRRR RUNS SEEM TO SUPPORT THIS TREND. MORE MOISTURE DUE TO
ARRIVE LATE THIS AFTERNOON AND TONIGHT WITH PW VALUES INCREASING
TO ABOUT 1.7 INCHES BY TUESDAY MORNING. SLIGHT RAMP UP IN
POPS...ESPECIALLY OVER THE EASTERN MOUNTAINS TO START...THEN
PROGRESSING IN FROM THE WEST AS FRONT MAKES CLOSER APPROACH LOOKS
LIKE A GOOD FORECAST TREND AND THIS COVERED IN CURRENT PACKAGE. NO
SIGNIFICANT CHANGES PLANNED.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
A VERY WARM AND HUMID AIRMASS...AND A VIGOROUS LEAD SHORT WAVE AHEAD
OF AN APPROACHING COLD FRONT...WILL ACT TO BRING WIDESPREAD SHOWERS
AND THUNDERSTORMS MAINLY TUESDAY AFTERNOON AND TUESDAY NIGHT. MODELS
AGREE PRETTY WELL ON THE TIMING OF THE LEAD WAVE AND GOOD PROSPECTS
FOR RAIN. TEMPERATURES WILL NOT BE AS HIGH TUESDAY DUE TO THE CLOUDS
AND SHOWERS...BUT SHOULD STILL REACH THE LOWER TO MID 80S...AND IT
WILL REMAIN QUITE HUMID. TEMPS TUESDAY NIGHT WILL BE WARM WITH
TEMPERATURES STRUGGLING TO DROP BELOW 70.
AS FAR AS THE FRONT IS CONCERNED...MODELS DIFFER ON WHETHER THE
FRONT IS STRONG ENOUGH TO ACTUALLY MOVE EASTWARD ACROSS THE AREA
BEHIND THE SHORT WAVE...AS FLOW ALOFT TURNS MORE WESTERLY OR
NORTHWESTERLY. THE GFS AND CMC MODELS MANAGE TO DRIVE THE FRONT EAST
OF THE AREA LATER WEDNESDAY...WITH THE NAM AND EURO MODELS SLOWLY
DISSIPATING THE FRONT AS IT MOVE INTO THE AREA WEDNESDAY. IT
WILL...IN ANY CASE...LAG BEHIND THE MAIN SHORT WAVE WHICH DEPARTS
WEDNESDAY MORNING. DESPITE MUCH OF THE UPPER DYNAMICS DEPARTING WITH
THE SHORT WAVE...AND WHETHER THE FRONT MAKES IT OR
DISSIPATES...THERE WILL BE A WARM AND HUMID AIRMASS AHEAD OF THE
FRONT TO CONTINUE A CHANCE OF SHOWERS AND STORMS WEDNESDAY.
THEREAFTER...ENOUGH DRIER AIR ALOFT FINALLY MOVES IN FOR THURSDAY AND
MUCH OF FRIDAY TO MAKE MOST OF THE AREA RAIN FREE. WHETHER THE FRONT
MAKES IT OR NOT...THERE WILL NOT BE MUCH OF A TEMPERATURE DIFFERENCE
FOR HIGHS..WITH TEMPS STILL REACHING INTO THE 80S.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
A SOMEWHAT TYPICAL LATE-JUNE PATTERN WILL CONTINUE IN THE EXTENDED
PERIOD...CHARACTERIZED BY WARM AND MUGGY DAYS WITH AT LEAST A SLIGHT
CHANCE OF A SHOWER AND/OR THUNDERSTORM EVERY DAY. HIGHER CHANCES OF
PRECIP ARE CENTERED ON TWO DISTURBANCES...ONE ON FRIDAY AND THE
OTHER NEAR WEEKEND/S END INTO SUNDAY NIGHT/EARLY MON. AFOREMENTIONED
TEMPERATURES WILL BE NEAR SEASONAL...WITH NO REAL HEAT WAVES OR COOL
PERIODS FORESEEN.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
WILL BE GETTING INTO SLIGHTLY BETTER CHANCES FOR SHOWERS AND
STORMS TODAY...BUT NONE HIGH ENOUGH TO WARRANT TSRA IN THE
PREVAILING. HAVE ALSO TRIED TO USE THE VCTS/CB SPARINGLY AS WELL.
OTHERWISE...LOOKING AT 4-5KFT CU DECK FORMING TODAY...WITH
MOUNTAIN CONVECTION BEGINNING EARLIER IN THE AFTERNOON THAN
LOWLAND AREAS...WHERE FORMATION IS EXPECTED TO BE AFTER 20Z. BY
NOT GOING WITH ANY PREVAILING TSRA...AN AMD OR TOW MAY BE NEEDED
AS CONVECTION BEGINS TO SHOW ITS HAND.
FOG TONIGHT IS IN QUESTION DUE TO EXPECTED CLOUD COVER. HAVE KEPT
IT MODEST WITH THIS TAF ISSUANCE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND COVERAGE OF SHOWERS AND STORMS MAY
NEED PREVAILING OR TEMPO IN THE TAF.
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 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H M M
CKB CONSISTENCY H H H H H H H H H H M H
AFTER 12Z TUESDAY...
IFR POSSIBLE IN IN THUNDERSTORMS TUESDAY INTO WEDNESDAY AND
STRATUS/FOG AT NIGHT FOR SITES RECEIVING RAIN.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...KMC
SHORT TERM...JMV
LONG TERM...50
AVIATION...26
AREA FORECAST DISCUSSION
NWS TULSA OK
615 AM CDT MON JUN 23 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
COMPLEX OF THUNDERSTORMS WILL MOVE ACROSS SOUTHEAST OK AND
POSSIBLY INTO WEST CENTRAL ARKANSAS EARLY THIS MORNING...WITH MORE
SCATTERED ACTIVITY ELSEWHERE. EXPECT NUMEROUS SHOWERS AND
THUNDERSTORMS TO RE-DEVELOP BY AFTERNOON IN MOIST AND UNSTABLE
AIRMASS...MOSTLY ENDING A LITTLE AFTER 00Z. PERIODS OF MVFR
CONDITIONS EXPECTED WITH SHOWERS AND THUNDERSTORMS.
&&
.PREV DISCUSSION... /ISSUED 344 AM CDT MON JUN 23 2014/
DISCUSSION...
LARGE MCS ONGOING FROM TX PANHANDLE THROUGH CENTRAL OK WILL
CONTINUE TO DEVELOP SOUTH AND EASTWARD THROUGH THE MORNING. WHILE
THE EXACT EVOLUTION REMAINS TO BE SEEN...LATEST RAP DATA DEPICT A
WELL DEVELOPED MCV WHICH IS FORECAST TO SHIFT EASTWARD TODAY
WITHIN THE BASE OF THE LARGER SYNOPTIC SCALE TROUGH. THIS IS
EXPECTED TO EITHER MAINTAIN ONGOING CONVECTION AND/OR AID IN
REDEVELOPMENT LATER THIS AFTERNOON THUS HIGH PRECIP CHANCES
AREAWIDE TODAY. THE SYNOPTIC FRONT WILL PUSH INTO THE REGION
TONIGHT AND IS EXPECTED TO FOCUS ANY OVERNIGHT PRECIP TOWARD THE
SOUTHEASTERN HALF OF THE FORECAST AREA.
BEYOND TONIGHT THE AFOREMENTIONED BOUNDARY REMAINS STALLED ACROSS
THE REGION WHILE PROFILES REMAIN MOIST AND LARGELY UNCAPPED. THIS
WILL RESULT IN SEVERAL DAYS OF SCATTERED CONVECTION THROUGH MID
WEEK. TEMPS DURING THIS TIMEFRAME ARE EXPECTED TO REMAIN NEAR OR
BELOW NORMAL. THE PATTERN BEGINS TO TRANSITION TOWARD MORE
DOMINANT UPPER RIDGING BY LATE WEEK THROUGH NEXT WEEKEND...WITH A
TREND TOWARD LESSER PRECIP COVERAGE AND WARMER TEMPS.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...14
LONG TERM....07
AVIATION...14
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1059 AM EDT MON JUN 23 2014
.SYNOPSIS...
A MOISTENING SOUTHERLY FLOW WILL DEVELOP AHEAD OF A SLOW MOVING
COLD FRONT APPROACHING FROM THE WEST. THE COLD FRONT WILL PUSH
THROUGH THE STATE ON WEDNESDAY...FOLLOWED BY HIGH PRESSURE FOR
LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
GOOD FIELD OF CUMULUS FRACTUS/HUMULUS THIS MORNING AS THE BOUNDARY
LAYER MOISTURE AND PATCHY FOG LIFTED. AS THIS TRIES TO BURN OFF
AND THIN...SOME HIGH CLOUDS TO WEST WILL DRIFT OVER THE REGION.
STILL MOSTLY SUNNY IN SOUTH IN EASTERN AREAS THOUGH SATELLITE DOES
IMPLY THIN CIRRUS OVER MORE NORTHERN AREAS.
BACKED OFF A BIT ON THE CONVECTION IN WEST. MODELS CONTINUE TO
SHOW THE FRONT TO OUR WEST SLOWING DOWN. 13Z RAP SHOWS WEAKER AND
MORE ISOLATED CONVECTION.
OVERNIGHT BEST CHANCE OF ANY SHOWERS WOULD BE OVER THE WESTERN
MOUNTAINS. BUT ONLY CHANCE AND SLIGHT CHANCE AT THIS TIME.
&&
.SHORT TERM /TUESDAY/...
THEME FOR TUESDAY SEEMS SLOWER FRONT AND MOISTURE SURGE INTO PA...09Z
SREF LESS ROBUST WITH QPF/POPS IN WESTERN PA AND MORE OPTIMISTIC
OF MOSTLY RAIN FREE DAY IN SOUTHEASTERN PA. COULD BE A MORE CLOUDY
DAY. THIS IS DUE TO SLOWER PROGRESSION OF FRONT AND PW PLUME TO
OUR WEST.
THIS SLOWER...DRIER THEME IS RELATED TO STRONG AND SLOW TO ERODE
SURFACE RIDGE AND 500 HPA RIDGE. HARD FOR FRONTS TO PUSH INTO
RIDGES THIS TIME OF YEAR.
THE SREF SHOWS LIKELY POPS AS DOES FORECAST IN WESTERN AND
NORTHWESTERN AREAS TUESDAY. BUT ONLY SLIGHT CHANCE IN SOUTHEAST.
MODELS CONTINUE TO WANT TO DEFER HIGHER RAINFALL PROBS UNTIL
WEDNESDAY AS RIDGE SHOULD SLOWLY YIELD.
UNLESS YOUR BAILING HAY THIS WEEK...WE NEED RAIN WITH THIS SYSTEM
AS THE GROWING RIDGE LATER THIS WEEK AND NEXT COULD PUT US INTO A
MORE AIR MASS FORCED CONVECTIVE REGIME.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE FRONTAL SYSTEM APPROACHING FROM THE MID WEST IS FORECAST TO
BE RATHER WAVY AND COMPLEX...WITH THE POTENTIAL FOR IT TO LINGER
OVER THE REGION LONGER THAN PREVIOUSLY INDICATED. BOTH THE GFS AND
ECMWF SHOW A NEW WAVE FORMING OVER THE STATE
WEDNESDAY...AT LEAST SUPPORTING THE IDEA OF KEEPING HIGH POPS IN
THE FORECAST THROUGH THE DAY...BUT ALSO RAISING THE POSSIBILITY OF
LOCALLY HEAVY RAINS FOCUSING ALONG THE SLOW MOVING FRONTAL
BOUNDARY.
DRIER AIR FINALLY LOOKS LIKE IT WILL MAKE A RETURN FOR THURSDAY-
FRIDAY AS HIGH PRESSURE BUILDS ACROSS SOUTHERN CANADA JUST NORTH
OF THE GREAT LAKES. THE COOL PUSH DOESN`T LOOK TERRIBLY ROBUST SO
HIGHS SHOULD REMAIN CLOSE TO OR EVEN A BIT ABOVE NORMAL INTO NEXT
WEEKEND.
OPERATIONAL GFS/ECMWF DIFFER ON EVENTS FOR SATURDAY-SUNDAY
TIMEFRAME WITH THE EXPECTED HANGING AROUND OF THE BOUNDARY THAT
IS EXPECTED TO PASS ON WEDNESDAY. THE GFS CREATES QUITE A BIT OF
PRECIP FOCUSED ON THE STRONG LOW LEVEL CONVERGENCE ASSOCIATED
WITH THE SLOW MOVING FRONTAL ZONE. THE ECMWF IS LESS EXCITED ABOUT
THIS...KEEPING THE BOUNDARY WEAKER AND FURTHER SOUTH. I DIDN`T
BITE TOO HARD ON THE MORE PESSIMISTIC GFS/GEFS...KEEPING JUST
SMALL CHANCES OF PRECIP OVER THE NEXT WEEKEND.
WORTH NOTING...LAST NIGHT THE LONGER RANGE GUIDANCE WANTED TO
REALLY PUMP UP HEIGHTS OVER THE EASTERN US FOR EARLY NEXT WEEK.
THE ECMWF HAS DONE A TOTAL FLIP-FLOP ON THIS NOW BRINGING AN UPPER
LOW SLOWLY DOWN THE NEW ENGLAND COAST TO OFF NJ BY MONDAY...WITH
UPPER HEIGHTS NOT NEARLY AS HIGH AS WAS ADVERTISED. THE GEFS SHOWS
MORE RIDGING...BUT SIMILARLY SEEMS TO WANT TO BACK OFF THE IDEA OF
A BIG SURGE IN THE SUBTROPICAL RIDGE IN THE EAST.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
HAD FOG FOR A SHORT TIME AT UNIV. NOW AT LNS.
OTHERWISE...MAINLY LOOKING A DRY DAY TODAY WITH VFR CONDITIONS.
ENJOY...AS AT LEAST THE LATER PART OF TUESDAY INTO WED...WILL
FEATURE SHOWERS AND THUNDERSTORMS...AS A SW FLOW OF MORE HUMID AIR
WORKS IN...AHEAD OF A COLD FRONT FOR LATE WED. THERE WAS A FEW
SHOWERS YESTERDAY AFT...GIVEN STEEP LOW LVL LAPSE RATES. THIS WILL
BE THE CASE THE NEXT SEVERAL DAYS.
A SHOWER WILL BE POSSIBLE AT BFD AND JST BEFORE 12Z TUE AM...BUT
STILL THINK THE FIRST PART OF TUESDAY WILL BE MAINLY DRY IN MOST
LOCATIONS.
OUTLOOK...
TUE-WED...SHRA/TSRA. LOCAL RESTRICTIONS LIKELY.
THU-FRI...VFR. PERHAPS A SHOWER OR STORM LATE FRI.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...GRUMM
SHORT TERM...GRUMM/LA CORTE
LONG TERM...LA CORTE
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
718 AM EDT MON JUN 23 2014
.SYNOPSIS...
A MOISTENING SOUTHERLY FLOW WILL DEVELOP AHEAD OF A SLOW MOVING
COLD FRONT APPROACHING FROM THE WEST. THE COLD FRONT WILL PUSH
THROUGH THE STATE ON WEDNESDAY...FOLLOWED BY HIGH PRESSURE FOR
LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
OTHER THAN FOR PATCHY FOG...THE DAY WILL DAWN BRIGHT WITH JUST
SOME THIN HIGH CLOUDS BLEEDING ACROSS FROM DYING CONVECTION OVER
THE GR LAKES.
WITH HIGH PRESSURE NOSING DOWN FROM THE NEW ENGLAND COAST ALL THE
WAY TO THE CAROLINAS...SOUTHERLY FLOW ON THE RETURN SIDE WILL
BRING STEADILY HIGHER DEWPOINTS NORTHWARD INTO THE REGION OVER
THE NEXT COUPLE OF DAYS. AS WE HEAT UP TODAY...WE WILL SEE A
STEADY EROSION OF THE STABILITY WITH THE RAP INDICATING MID LEVEL
LAPSE RATES EXCEEDING 7C/KM BY EARLY AFTERNOON. HOWEVER CAPE IS
EXPECTED TO BE LIMITED BY MID LEVEL DRY AIR OVER CENTRAL AND
EASTERN AREAS...WITH THE BEST CHANCE OF POPPING A SHOWER OR STORM
BEING OVER MY WESTERN ZONES. MOISTURE WILL BE A BIT DEEPER
THERE...BUT EVEN SO A FAIRLY STRONG CAPPING INVERSION WILL BE HARD
TO BREAK SO ACTIVITY SHOULD NOT BE WIDESPREAD.
HIGHS TODAY LOOK TO BE PRETTY WELL CLUSTERED FROM THE UPPER 70S TO
MID 80S...STARTING TO EDGE ABOVE NORMAL FOR A CHANGE.
THE PROXIMITY OF THE WAVY FRONT ENTERING THE OHIO VALLEY TONIGHT
WILL KEEP A SMALL CHANCE OF SHOWERS AND STORMS LINGERING OVER MY
WESTERN AND NORTHWESTERN AREAS OVERNIGHT. IT WILL BE A MILD NIGHT
IN THE 60S.
&&
.SHORT TERM /TUESDAY/...
TUESDAY WILL BE WARM AND MUGGY WITH AN INCREASING THREAT FOR
CONVECTION THE DEEPER INTO THE DAY WE GET. SREF/GEFS BOTH BRING A
SURGE OF ANOMALOUSLY HIGH PWATS WITH CAPES EXPECTED EXPECTED TO
EXCEED 1000J OVER A WIDE AREA. SPC HAS PLACED US IN A SEE TEXT
AREA MENTIONING...STEEP LOW-LEVEL LAPSE RATES MAY BE ENOUGH FOR
MARGINALLY SEVERE WIND GUSTS ASSOCIATED WITH SHORT BOWING LINE
SEGMENTS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE FRONTAL SYSTEM APPROACHING FROM THE MID WEST IS FORECAST TO
BE RATHER WAVY AND COMPLEX...WITH THE POTENTIAL FOR IT TO LINGER
OVER THE REGION LONGER THAN PREVIOUSLY INDICATED. BOTH THE GFS AND
ECMWF SHOW A NEW WAVE FORMING OVER THE STATE
WEDNESDAY...AT LEAST SUPPORTING THE IDEA OF KEEPING HIGH POPS IN
THE FORECAST THROUGH THE DAY...BUT ALSO RAISING THE POSSIBILITY OF
LOCALLY HEAVY RAINS FOCUSING ALONG THE SLOW MOVING FRONTAL
BOUNDARY.
DRIER AIR FINALLY LOOKS LIKE IT WILL MAKE A RETURN FOR THURSDAY-
FRIDAY AS HIGH PRESSURE BUILDS ACROSS SOUTHERN CANADA JUST NORTH
OF THE GREAT LAKES. THE COOL PUSH DOESN`T LOOK TERRIBLY ROBUST SO
HIGHS SHOULD REMAIN CLOSE TO OR EVEN A BIT ABOVE NORMAL INTO NEXT
WEEKEND.
OPERATIONAL GFS/ECMWF DIFFER ON EVENTS FOR SATURDAY-SUNDAY
TIMEFRAME WITH THE EXPECTED HANGING AROUND OF THE BOUNDARY THAT
IS EXPECTED TO PASS ON WEDNESDAY. THE GFS CREATES QUITE A BIT OF
PRECIP FOCUSED ON THE STRONG LOW LEVEL CONVERGENCE ASSOCIATED
WITH THE SLOW MOVING FRONTAL ZONE. THE ECMWF IS LESS EXCITED ABOUT
THIS...KEEPING THE BOUNDARY WEAKER AND FURTHER SOUTH. I DIDN`T
BITE TOO HARD ON THE MORE PESSIMISTIC GFS/GEFS...KEEPING JUST
SMALL CHANCES OF PRECIP OVER THE NEXT WEEKEND.
WORTH NOTING...LAST NIGHT THE LONGER RANGE GUIDANCE WANTED TO
REALLY PUMP UP HEIGHTS OVER THE EASTERN US FOR EARLY NEXT WEEK.
THE ECMWF HAS DONE A TOTAL FLIP-FLOP ON THIS NOW BRINGING AN UPPER
LOW SLOWLY DOWN THE NEW ENGLAND COAST TO OFF NJ BY MONDAY...WITH
UPPER HEIGHTS NOT NEARLY AS HIGH AS WAS ADVERTISED. THE GEFS SHOWS
MORE RIDGING...BUT SIMILARLY SEEMS TO WANT TO BACK OFF THE IDEA OF
A BIG SURGE IN THE SUBTROPICAL RIDGE IN THE EAST.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
HAD FOG FOR A SHORT TIME AT UNV. NOW AT LNS.
OTHERWISE...MAINLY LOOKING A DRY DAY TODAY WITH VFR CONDITIONS.
ENJOY...AS AT LEAST THE LATER PART OF TUESDAY INTO WED...WILL
FEATURE SHOWERS AND THUNDERSTORMS...AS A SW FLOW OF MORE HUMID AIR
WORKS IN...AHEAD OF A COLD FRONT FOR LATE WED. THERE WAS A FEW
SHOWERS YESTERDAY AFT...GIVEN STEEP LOW LVL LAPSE RATES. THIS WILL
BE THE CASE THE NEXT SEVERAL DAYS.
A SHOWER WILL BE POSSIBLE AT BFD AND JST BEFORE 12Z TUE AM...BUT
STILL THINK THE FIRST PART OF TUESDAY WILL BE MAINLY DRY IN MOST
LOCATIONS.
OUTLOOK...
TUE-WED...SHRA/TSRA. LOCAL RESTRICTIONS LIKELY.
THU-FRI...VFR. PERHAPS A SHOWER OR STORM LATE FRI.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
930 AM CDT MON JUN 23 2014
.UPDATE...
SEE MORNING UPDATE.
&&
.DISCUSSION...
A STRONG OUTFLOW BOUNDARY IS HEADING SOUTH AND CONVECTION IS
GETTING CLOSE TO THE NORTHERN PART OF THE CWA. SHORT TERM GUIDANCE
STILL SUGGESTS WEAKENING OF THIS SYSTEM BUT THE RAP 13 AND TEXAS
TECH 3 KM BECOMING MORE BULLISH WITH POPS OVER THE NW THIRD OF
THE CWA. RAISED POPS TO CHANCE OVER THE NW ZONES. 12Z CRP SOUNDING
HAS A PW VALUE OF 2.06 INCHES WITH SOME DRY AIR AT 700 MB. THE
CONVECTIVE TEMPS ARE IN THE MID 80S WHICH IS MORE THAN REACHABLE.
SHORT TERM GUIDANCE SUGGESTS CONVECTION WILL WANE THIS AFTN AS
SOME OF THE DRIER AIR ALOFT MIXES TO THE SURFACE. WILL RE-EVALUATE
THAT TREND AFTER 17Z. 43
&&
.PREV DISCUSSION... /ISSUED 648 AM CDT MON JUN 23 2014/
DISCUSSION...
UPDATED AVIATION SECTION.
AVIATION...
LATEST RADAR COMPOSITES SHOW BAND OF STORMS SITUATED OVER NORTH
TEXAS...NEAR THE DFW METROPLEX. LINE OF STORMS WAS MOVING
SOUTHEAST AROUND 45 MPH. INFRARED SATELLITE SHOWING WARMING CLOUD
TOPS AND OVERALL WEAKENING OF THIS CONVECTIVE COMPLEX. AVAILABLE
MESO MODELS ARE NOT HANDLING THIS SYSTEM VERY WELL...BUT THESE
ALSO SHOW A DISSIPATION OF THE LINE GOING FORWARD. TAFS ARE
WRITTEN WITH THE IDEA THAT THIS DISSIPATING TREND WILL
CONTINUE...BUT NOT COMPLETELY CERTAIN IT WILL OCCUR GIVEN FAIRLY
UNSTABLE AIRMASS DOWNSTREAM. FOR THIS REASON HAVE GONE WITH A VCTS
FOR CLL...UTS AND CXO BASED ON TIMING OF CURRENT LINE BUT BASED ON
LOW PROBABILITY IT WILL SURVIVE AS A LINE. FARTHER SOUTH AND
EAST...EVEN LESS LIKELY LINE WILL MAKE IT...AND WILL CONTINUE WITH
NO MENTION OF PRECIP THERE IN THE TAFS. OTHERWISE EXPECT A
DECREASE IN CONVECTION TONIGHT...WITH JUST SOME PATCHY MVFR LATE
TONIGHT FOR IAH ON NORTH AND NORTHWEST.
PREV DISCUSSION... /ISSUED 415 AM CDT MON JUN 23 2014/
DISCUSSION...
REGIONAL SATELLITE IMAGERY AND RADAR SHOW MATURE SQUALL LINE
PUSHING THROUGH OK/TX AND RED RIVER REGION. CLOSER TO HOUSTON
MAINLY OBSERVING SPOTTY SHOWERS BUT NOT MUCH PRECIP HITTING THE
GROUND. SQUALL LINE SHOULD CONTINUE TO PUSH SOUTH TOWARDS THE AREA
THIS MORNING WITH STRONG COLD POOL BEHIND IT. RAPID REFRESH AND
WRF RUNS SHOW THE SQUALL LINE BREAKING UP BEFORE REACHING COLLEGE
STATION. KEPT THE FORECAST IN LINE WITH THIS THINKING FOR THE
MORNING BUT CONCERNED LINE COULD PUSH FARTHER SOUTH THAN EXPECTED
SINCE THERE IS LITTLE SUBSIDENCE AND DRY AIR TO IMPEDE ITS
PROGRESS. FORECAST HOLDS WITH 20 POPS AS STILL POSSIBLE FOR ISO
CONVECTION TO DEVELOP DURING THE HEAT OF THE DAY.
WATER VAPOR IMAGERY AND 00Z 500MB ANALYSIS SHOW TROUGHING OVER
MUCH OF TX. UPPER RIDGE IS NOT ALL THAT STRONG AND LIKELY SPLIT
BETWEEN NORTHERN MEXICO AND THE C GULF. GLOBAL MODELS ALL SUPPORT
TROUGHING OVER TX THROUGH THE END OF THE WEEK. MODELS ALSO SHOW A
SURGE IN TROPICAL MOISTURE LATE TUE INTO WED. GIVEN PERCIP WATER
VALUES OF NEAR 2 INCHES ACROSS MUCH OF THE AREA FOR WED/THUR
DECIDED TO GO WITH 50/60 POPS EACH OF THOSE DAYS. TROPICAL
MOISTURE WILL BE SUPPORTIVE OF 1-2 INCH AN HOUR RAINRATES IN
STRONGER STORMS SO LOCALLY HEAVY RAINFALL A CONCERN. THIS COULD
RESULT IN URBAN FLOODING AND RAPID INCREASES IN BAYOUS. AREAWIDE
RAINFALL TOTALS OF 1 TO 2 INCHES OF RAIN WILL BE POSSIBLE FOR THE
LATER HALF OF THE WEEK. THE TRICK TO THE FORECAST WILL BE WHERE
THE ISOLATED 3 TO 5 INCH RAINFALL AMOUNTS SET UP WHICH COULD LEAD
TO FLOODING IMPACTS.
UPPER LEVEL RIDGING DOES TRY TO STRENGTHEN DEPENDING ON THE MODEL.
THE ECMWF SEEMS TO BE MORE ROBUST WITH THE RIDGE SUNDAY INTO NEXT
MONDAY. MEANWHILE THE GFS MAINTAINS A SHEAR AXIS OVER THE NW GULF.
RIGHT NOW WILL STILL CARRY SOME LOWER POPS. THINK FRI/SAT WILL BE
DRIER BUT 40 POPS STILL DECENT CHANCES. WILL ALSO KEEP 20 POPS IN
THE FORECAST FOR SUN/MON AS THERE STILL SHOULD BE PLENTY OF DEEP
MOISTURE IN PLACE AND RIDGING STRENGTH WILL STILL BE RELATIVELY
UNKNOWN.
TEMPERATURES SHOULD REMAIN NEAR NORMAL FOR THE COMING WEEK MAYBE A
DEGREE OR TWO COOLER WITH THUNDERSTORM CHANCES. THIS MEANS UPPER
80S TO LOW 90S WITH MIN TEMPS IN THE MID 70S. STILL COULD GET SOME
RAIN COOLED LOW 70S OR UPPER 60S BUT DIFFICULT TO FORECAST THOSE
OCCURRENCES SINCE IT WILL DEPEND ON THE CONVECTION. THE NICE
THING ABOUT THIS FORECAST IS THAT TEMPS SHOULD REMAIN BELOW 95F
THROUGH ALMOST THE END OF JUNE. CLIMATE FACTOID...CLL/IAH/HOU HAVE
YET TO REACH 95F OR HIGHER THIS YEAR FOR A MAX TEMP.
39
MARINE...
LIGHT TO MODERATE ONSHORE FLOW WILL CONTINUE THE NEXT FEW DAYS
WITH SUSTAINED 10 METER WINDS GENERALLY ONSHORE AROUND 10 TO 15
KNOTS THROUGH TUESDAY. GRADIENT IS FORECAST TO TIGHTEN SOMEWHAT
MID TO LATE WEEK WITH SMALL CRAFT EXERCISE CAUTION WINDS A
POSSIBILITY BY WED OR THU. WITH PERSISTENT SE FLOW AND LONG FETCH
SEAS ARE EXPECTED TO GRADUALLY BUILD THROUGH THE WEEK...WITH 6 TO
9 FOOT SEAS A GOOD BET BY THURSDAY AND FRIDAY. 46
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 93 74 90 74 88 / 50 20 40 20 60
HOUSTON (IAH) 92 76 90 75 88 / 30 20 40 20 60
GALVESTON (GLS) 89 80 88 80 87 / 20 20 30 40 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
655 AM CDT MON JUN 23 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 308 AM CDT MON JUN 23 2014
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY AND THEN
AGAIN FROM TUESDAY INTO WEDNESDAY.
SURFACE ANALYSIS THIS MORNING SHOWS A VERY WEAK AND ILL DEFINED
PATTERN ACROSS THE UPPER MIDWEST. THERE IS A WEAK BOUNDARY WORKING
EAST ACROSS MINNESOTA WHERE THE WINDS SWITCH AROUND TO THE WEST
AND DEW POINTS BEGIN TO SLOWLY DECREASE. IT APPEARS THE FLOW ABOVE
THE SURFACE IS COMING AROUND TO THE WEST/NORTHWEST AHEAD OF THE
SURFACE BOUNDARY WITH 925 MB VWP WINDS FROM KDMX AND KMPX ALREADY
AROUND TO THE WEST/NORTHWEST.
THE 23.00Z NAM AND GFS ALONG WITH THE 23.06Z RAP ALL TRY TO
GENERATE A WEAK SURFACE WAVE OVER MISSOURI AND MOVE IT NORTHEAST
THIS MORNING INTO EASTERN WISCONSIN ALONG THE LOW LEVEL WIND SHIFT
BOUNDARY DEPICTED BY THE VWP WINDS. THE LOW LEVEL MOISTURE
CONVERGENCE MAY INCREASE FOR A SHORT WHILE THIS MORNING ON THE
NORTHWEST SIDE OF THIS LOW TO POSSIBLY HELP GENERATE A FEW SHOWERS
ACROSS THE EASTERN PART OF THE FORECAST AREA. WILL CARRY SOME LOW
RAIN CHANCES ACROSS THE EAST TO COVER THIS POSSIBILITY THROUGH
ABOUT THE MIDDLE OF THE AFTERNOON.
THE NEXT CHANCE OF RAIN WILL THEN COME TUESDAY AS A SHORT WAVE
TROUGH DROPS OUT OF SOUTHERN CANADA INTO THE UPPER MIDWEST. THIS
WAVE DOES NOT LOOK TO BE VERY STRONG BUT SHOULD STILL BRING SOME
WEAK PV ADVECTION IN THE 500-300 MB LAYER ACROSS NORTHERN
MINNESOTA AND WISCONSIN. ONLY WEAK MOISTURE CONVERGENCE ALONG THE
FRONT AND WITH BETWEEN 500 AND 1000 J/KG OF ML CAPE...IT SHOULD BE
ENOUGH TO GENERATE SOME SCATTERED ACTIVITY WITH THE BULK OF THIS
OCCURRING IN THE AFTERNOON. WITH THIS BOUNDARY STILL IN THE AREA
TUESDAY NIGHT...SOME OF THIS ACTIVITY COULD PERSIST PAST DARK
NORTHEAST OF THE I94 CORRIDOR WITH THE COVERAGE DIMINISHING AS THE
CAPE DECREASES.
ANOTHER SHORT WAVE TROUGH IS EXPECTED TO APPROACH FROM THE WEST
WEDNESDAY. THE WEAK PV ADVECTION FROM THIS WAVE SHOULD ONLY
ADVANCE INTO WESTERN MINNESOTA AND IOWA BY LATE IN THE DAY.
HOWEVER...THE WARM AIR ADVECTION AHEAD OF THIS WAVE SHOULD ALLOW
1-3 UBAR/S OF ISENTROPIC UP GLIDE ON THE 300K SURFACE TO START
SPREADING IN THROUGH THE DAY AND THIS COULD AGAIN BE ENOUGH TO
GENERATE SOME SCATTERED ACTIVITY AS THE ML CAPE INCREASES TO
500-1000 J/KG.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 308 AM CDT MON JUN 23 2014
THE LONGER RANGE MODELS REMAIN CONSISTENT IN SHOWING A TEMPORARY
CHANGE IN THE UPPER AIR FLOW AS A LONG WAVE TROUGH DIGS IN OVER
THE INTERMOUNTAIN WEST EARLY IN THIS PERIOD. HOWEVER...THE LATEST
TRENDS ARE FOR THIS TROUGH TO NOT BE A FAR SOUTH AS THEY NOW
INDICATE AN UPPER LEVEL LOW FORMING OVER CENTRAL CANADA OVER THE
WEEKEND. THIS ALLOWS A SOUTHWEST FLOW ALOFT TO REMAIN OVER THE
UPPER MIDWEST TO CLOSE OUT THE WEEK AND THEN THE LONG WAVE TROUGH
SWINGS THROUGH WITH A POSITIVE TILT TO IT. AT THE SURFACE...HIGH
PRESSURE SHOULD BE SOUTH OF HUDSONS BAY TO HELP FUNNEL MOISTURE
BACK INTO THE UPPER MIDWEST. THE COMBINATION OF THIS MOISTURE FEED
AND SHORT WAVE TROUGHS IN THE SOUTHWEST FLOW AND THEN THE LONG
WAVE TROUGH ITSELF WILL KEEP THE RAIN CHANCES GOING THROUGH THE
PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 655 AM CDT MON JUN 23 2014
LIFR CONDITIONS IN DENSE FOG WILL OCCUR AT KRST THROUGH 13Z THEN
A GRADUAL IMPROVEMENT IS EXPECTED THROUGH 14Z AS MIXING INCREASES.
LOW STRATUS WILL PERSIST AT KLSE THROUGH 14Z WITH CEILINGS AT 600
FT. CLOUD BASES WILL GRADUALLY INCREASE THIS MORNING AND THE
OVERCAST SHOULD BECOME MORE BROKEN THROUGH THE MID MORNING HOURS.
VFR CONDITIONS ARE EXPECTED BY 15Z WITH BROKEN TO SCATTERED
CUMULUS. A FEW RAIN SHOWERS AND POSSIBLE TODAY AT THE TAF SITE BUT
THEY ARE NOT EXPECTED TO CAUSE SIGNIFICANT VISIBILITY
RESTRICTIONS. VFR CONDITIONS ARE EXPECTED LATE THIS AFTERNOON INTO
THE OVERNIGHT HOURS AS WEAK HIGH PRESSURE BUILDS IN.
&&
.HYDROLOGY...
ISSUED AT 308 AM CDT MON JUN 23 2014
RIVER FLOOD WARNINGS HAVE BEEN PAIRED BACK TO ALMOST JUST THE
MISSISSIPPI RIVER. GIVEN THAT ADDITIONAL HEAVY RAIN DID NOT FALL
AND IS NOT EXPECTED OVER THE NEXT SEVERAL DAYS...THE FLOODING WILL
BECOME CONFINED TO JUST THE MISSISSIPPI. MANY LOCATIONS ALONG THE
MISSISSIPPI ARE EXPECTED TO BE NEAR OR ABOVE FLOOD STAGE THROUGH
THE WEEK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...WETENKAMP
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS TUCSON AZ
245 PM MST MON JUN 23 2014
.SYNOPSIS...A FEW SHOWERS AND THUNDERSTORMS WILL OCCUR ACROSS FAR
SOUTHEASTERN SECTIONS EARLY THIS EVENING. OTHERWISE...DRY CONDITIONS
WILL PREVAIL INTO EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL BE NEAR
TO A FEW DEGREES ABOVE AVERAGE THIS WEEK FOLLOWED BY EVEN HOTTER
TEMPERATURES BY EARLY NEXT WEEK.
&&
.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 30-45 DBZ ECHOES IN THE
VICINITY OF THE CHIRICAHUA MOUNTAINS IN ERN COCHISE COUNTY AT 2140Z.
SOME LIGHTNING STRIKES WERE DETECTED JUST EAST OF THE CHIRICAHUA
MTNS NEAR THE NEW MEXICO BORDER. OTHERWISE...CLEAR SKIES PREVAILED
ACROSS MUCH OF PIMA/SRN PINAL COUNTIES...AND SCATTERED CUMULOFORM
CLOUDS WERE MOSTLY EAST AND SOUTH OF TUCSON. 23/19Z HRRR WAS SIMILAR
TO PREVIOUS SOLUTIONS IN DEPICTING WEAK PRECIP ECHOES TO OCCUR
ACROSS ABOUT THE ERN HALF OF COCHISE COUNTY THRU ABOUT 24/03Z.
BELIEVE THERE IS JUST ENOUGH LOWER AND MID-LEVEL MOISTURE TO
MAINTAIN A SLIGHT CHANCE OF SHOWERS/TSTMS ACROSS THE CHIRICAHUA
MOUNTAINS EARLY THIS EVENING. VERY LITTLE RAINFALL IS EXPECTED FROM
THIS ACTIVITY. THE NEAR-SURFACE ENVIRONMENT IS TOO DRY TO SUPPORT
THE DEPICTION/MENTION OF MEASURABLE PRECIP AT LOWER ELEVATIONS OF
COCHISE COUNTY. THEREAFTER...CLEAR SKIES OR MOSTLY CLEAR SKIES WILL
PREVAIL LATER THIS EVENING AND THE REST OF TONIGHT.
HIGH PRESSURE ALOFT CENTERED WEST OF NRN BAJA CALIFORNIA GENERALLY
NEAR 28N/128W WITH RIDGE AXIS EXTENDING EWD ACROSS SONORA MEXICO
WILL REMAIN QUASI-STATIONARY THRU WED. THIS PATTERN WILL PRODUCE
CLEAR SKIES OR MOSTLY CLEAR SKIES...WITH ANY THUNDERSTORMS EXPECTED
TO REMAIN SE OF THE AREA ACROSS NERN SONORA/NWRN CHIHUAHUA.
A LOW PRESSURE TROUGH WILL ENTER THE PACIFIC NW WED NIGHT. THIS
SYSTEM IS THEN PROGGED TO MOVE SEWD ACROSS THE GREAT BASIN
THUR...AND CONTINUE EWD INTO THE NRN/CENTRAL ROCKIES FRI. THE 23/12Z
GFS/ECMWF/CANADIAN WERE IN DECENT AGREEMENT WITH THIS SYSTEM. THERE
MAY BE SOME ENHANCED WIND SPEEDS FRI AFTERNOON...PARTICULARLY IN THE
SAFFORD VALLEY GIVEN THE ORIENTATION OF THE MID-LEVEL GRADIENT.
HOWEVER...WIND SPEEDS AT THIS TIME ARE PROJECTED TO REMAIN WELL
BELOW WIND ADVISORY CRITERIA. A VERY DRY REGIME WILL THEN CONTINUE
SAT UNDER LIGHT WLY/NWLY FLOW ALOFT.
THEREAFTER...GFS/ECMWF WERE SIMILAR WITH DEPICTING A BROAD AREA OF
HIGH PRESSURE ALOFT EXTENDING FROM THE ERN PACIFIC EWD INTO TEXAS
SUN. HIGH PRESSURE ALOFT IS THEN PROGGED TO BECOME CENTERED
ESSENTIALLY OVER NWRN NEW MEXICO MON. THIS PATTERN YIELDED A LIGHT
GENERALLY ELY MID-LEVEL FLOW REGIME ACROSS SE AZ. HOWEVER...BOTH
MODELS DEPICTED PRECIP-FREE CONDITIONS ACROSS THIS FORECAST
AREA...WITH ANY MEASURABLE PRECIP WELL EAST TO SOUTHEAST FROM ERN
NEW MEXICO INTO EAST CENTRAL SONORA. THUS...FOR THIS FORECAST
PACKAGE...HAVE MAINTAINED DRY CONDITIONS NEXT MON.
HOWEVER...THE ECMWF THEN PRODUCED FAIRLY ROBUST QPF/S JUST EAST TO
SOUTHEAST OF THE AREA NEXT TUE (JULY 1) FOLLOWED BY MEASURABLE
PRECIP ACROSS MUCH OF THE AREA NEXT WED (JULY 2). THESE DAYS ARE
BEYOND THE SCOPE OF THIS FORECAST PACKAGE. AT ANY RATE...THE
SYNOPTIC SCALE PATTERN APPEARS TO BE BECOMING MORE CONDUCIVE FOR THE
DEEPER IMPORT OF MOISTURE INTO SE AZ BY ABOUT THE MIDDLE OF NEXT
WEEK...AT LEAST FROM A MEDIUM RANGE MODEL PERSPECTIVE.
HIGH TEMPS TUE-SAT WILL BE AT NORMAL VALUES OR AVERAGE JUST A FEW
DEGS ABOVE SEASONAL NORMALS. NO COOLING OF SIGNIFICANCE IS EXPECTED
FRI AS PREVIOUSLY THOUGHT. THEREAFTER...WARMER TEMPERATURES ARE
FORECAST TO OCCUR SUN-MON DUE TO INCREASED HEIGHTS/THICKNESSES IN
RESPONSE TO THE AMPLIFICATION OF THE UPPER RIDGE ACROSS THE AREA.
&&
.AVIATION...VALID THRU 25/00Z.
ISOLATED THUNDERSTORMS WILL OCCUR MAINLY EAST OF A WILLCOX TO KDUG
LINE IN THE ERN HALF OF COCHISE COUNTY EARLY THIS EVENING.
OTHERWISE...A FEW TO SCATTERED CLOUDS GENERALLY AT 10-15K FT AGL
INTO THIS EVENING AND AGAIN TUESDAY AFTERNOON. EXPECT CLEAR SKIES
ACROSS MUCH OF THE AREA LATE TONIGHT AND TUESDAY MORNING. SURFACE
WINDS INTO THIS EVENING AND TUESDAY AFTERNOON WILL BE SWLY TO NWLY
AT 12-18 KTS WITH GUSTS TO NEAR 25 KTS. OTHERWISE...SURFACE WINDS
WILL BE LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...A FEW SHOWERS AND THUNDERSTORMS PRODUCING VERY
LITTLE RAINFALL WILL OCCUR ACROSS ABOUT THE EASTERN HALF OF COCHISE
COUNTY EARLY THIS EVENING. OTHERWISE...DRY CONDITIONS WILL PREVAIL
INTO EARLY NEXT WEEK. NORMAL DIURNAL WIND TRENDS WILL OCCUR THROUGH
MUCH OF THE FORECAST PERIOD...WITH OCCASIONAL GUSTS DURING THE
AFTERNOON AND EARLY EVENING HOURS DUE TO DAYTIME HEATING.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
AREA FORECAST DISCUSSION
NWS TUCSON AZ
240 PM MST MON JUN 23 2014
.SYNOPSIS...A FEW SHOWERS AND THUNDERSTORMS WILL OCCUR ACROSS FAR
SOUTHEASTERN SECTIONS EARLY THIS EVENING. OTHERWISE...DRY CONDITIONS
WILL PREVAIL INTO EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL BE NEAR
TO A FEW DEGREES ABOVE AVERAGE THIS WEEK FOLLOWED BY EVEN HOTTER
TEMPERATURES BY EARLY NEXT WEEK.
&&
.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 30-35 DBZ ECHOES NEAR
THE CHIRICAHUA MOUNTAINS IN ERN COCHISE COUNTY AT 2115Z. OTHERWISE...
CLEAR SKIES PREVAILED ACROSS MUCH OF PIMA/SRN PINAL COUNTIES...AND
SCATTERED CUMULOFORM CLOUDS WERE MOSTLY EAST AND SOUTH OF TUCSON.
23/19Z HRRR WAS SIMILAR TO PREVIOUS SOLUTIONS IN DEPICTING WEAK
PRECIP ECHOES TO OCCUR ACROSS ABOUT THE ERN HALF OF COCHISE COUNTY
THRU ABOUT 24/03Z. BELIEVE THERE IS JUST ENOUGH LOWER AND MID-LEVEL
MOISTURE TO MAINTAIN A SLIGHT CHANCE OF SHOWERS/TSTMS ACROSS THE
CHIRICAHUA MOUNTAINS EARLY THIS EVENING. VERY LITTLE RAINFALL IS
EXPECTED FROM THIS ACTIVITY. THE NEAR-SURFACE ENVIRONMENT IS TOO DRY
TO SUPPORT THE DEPICTION/MENTION OF SHOWERS/TSTMS AT LOWER
ELEVATIONS OF COCHISE COUNTY. THEREAFTER...CLEAR SKIES OR MOSTLY
CLEAR SKIES WILL PREVAIL LATER THIS EVENING AND THE REST OF TONIGHT.
HIGH PRESSURE ALOFT CENTERED WEST OF NRN BAJA CALIFORNIA GENERALLY
NEAR 28N/128W WITH RIDGE AXIS EXTENDING EWD ACROSS SONORA MEXICO
WILL REMAIN QUASI-STATIONARY THRU WED. THIS PATTERN WILL PRODUCE
CLEAR SKIES OR MOSTLY CLEAR SKIES...WITH ANY THUNDERSTORMS EXPECTED
TO REMAIN SE OF THE AREA ACROSS NERN SONORA/NWRN CHIHUAHUA.
A LOW PRESSURE TROUGH WILL ENTER THE PACIFIC NW WED NIGHT. THIS
SYSTEM IS THEN PROGGED TO MOVE SEWD ACROSS THE GREAT BASIN
THUR...AND CONTINUE EWD INTO THE NRN/CENTRAL ROCKIES FRI. THE 23/12Z
GFS/ECMWF/CANADIAN WERE IN DECENT AGREEMENT WITH THIS SYSTEM. THERE
MAY BE SOME ENHANCED WIND SPEEDS FRI AFTERNOON...PARTICULARLY IN THE
SAFFORD VALLEY GIVEN THE ORIENTATION OF THE MID-LEVEL GRADIENT.
HOWEVER...WIND SPEEDS AT THIS TIME ARE PROJECTED TO REMAIN WELL
BELOW WIND ADVISORY CRITERIA. A VERY DRY REGIME WILL THEN CONTINUE
SAT UNDER LIGHT WLY/NWLY FLOW ALOFT.
THEREAFTER...GFS/ECMWF WERE SIMILAR WITH DEPICTING A BROAD AREA OF
HIGH PRESSURE ALOFT EXTENDING FROM THE ERN PACIFIC EWD INTO TEXAS
SUN. HIGH PRESSURE ALOFT IS THEN PROGGED TO BECOME CENTERED
ESSENTIALLY OVER NWRN NEW MEXICO MON. THIS PATTERN YIELDED A LIGHT
GENERALLY ELY MID-LEVEL FLOW REGIME ACROSS SE AZ. HOWEVER...BOTH
MODELS DEPICTED PRECIP-FREE CONDITIONS ACROSS THIS FORECAST
AREA...WITH ANY MEASURABLE PRECIP WELL EAST TO SOUTHEAST FROM ERN
NEW MEXICO INTO EAST CENTRAL SONORA. THUS...FOR THIS FORECAST
PACKAGE...HAVE MAINTAINED DRY CONDITIONS NEXT MON.
HOWEVER...THE ECMWF THEN PRODUCED FAIRLY ROBUST QPF/S JUST EAST TO
SOUTHEAST OF THE AREA NEXT TUE (JULY 1) FOLLOWED BY MEASURABLE
PRECIP ACROSS MUCH OF THE AREA NEXT WED (JULY 2). THESE DAYS ARE
BEYOND THE SCOPE OF THIS FORECAST PACKAGE. AT ANY RATE...THE
SYNOPTIC SCALE PATTERN APPEARS TO BE BECOMING MORE CONDUCIVE FOR THE
DEEPER IMPORT OF MOISTURE INTO SE AZ BY ABOUT THE MIDDLE OF NEXT
WEEK...AT LEAST FROM A MEDIUM RANGE MODEL PERSPECTIVE.
HIGH TEMPS TUE-SAT WILL BE AT NORMAL VALUES OR AVERAGE JUST A FEW
DEGS ABOVE SEASONAL NORMALS. NO COOLING OF SIGNIFICANCE IS EXPECTED
FRI AS PREVIOUSLY THOUGHT. THEREAFTER...WARMER TEMPERATURES ARE
FORECAST TO OCCUR SUN-MON DUE TO INCREASED HEIGHTS/THICKNESSES IN
RESPONSE TO THE AMPLIFICATION OF THE UPPER RIDGE ACROSS THE AREA.
&&
.AVIATION...VALID THRU 25/00Z.
ISOLATED THUNDERSTORMS WILL OCCUR MAINLY EAST OF A WILLCOX TO KDUG
LINE IN THE ERN HALF OF COCHISE COUNTY EARLY THIS EVENING.
OTHERWISE...A FEW TO SCATTERED CLOUDS GENERALLY AT 10-15K FT AGL
INTO THIS EVENING AND AGAIN TUESDAY AFTERNOON. EXPECT CLEAR SKIES
ACROSS MUCH OF THE AREA LATE TONIGHT AND TUESDAY MORNING. SURFACE
WINDS INTO THIS EVENING AND TUESDAY AFTERNOON WILL BE SWLY TO NWLY
AT 12-18 KTS WITH GUSTS TO NEAR 25 KTS. OTHERWISE...SURFACE WINDS
WILL BE LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...A FEW SHOWERS AND THUNDERSTORMS PRODUCING VERY
LITTLE RAINFALL WILL OCCUR ACROSS ABOUT THE EASTERN HALF OF COCHISE
COUNTY EARLY THIS EVENING. OTHERWISE...DRY CONDITIONS WILL PREVAIL
INTO EARLY NEXT WEEK. NORMAL DIURNAL WIND TRENDS WILL OCCUR THROUGH
MUCH OF THE FORECAST PERIOD...WITH OCCASIONAL GUSTS DURING THE
AFTERNOON AND EARLY EVENING HOURS DUE TO DAYTIME HEATING.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
256 PM CDT MON JUN 23 2014
.DISCUSSION...
1147 AM CDT
STILL EXPECTING AN INCREASE IN THE COVERAGE OF SHOWERS AND
ISOLATED TO SCATTERED THUNDERSTORMS THROUGH THE AFTERNOON HOURS.
MOST OF THE CONVECTIVE ACTIVITY THIS MORNING WAS LOCATED SOUTHEAST
OF THE AREA. THIS WAS IN THE REGION OF BETTER SURFACE HEATING AND
HIGHER DEWPOINTS. A BROAD AREA OF MOISTURE CONVERGENCE IS NOW
MOVING TOWARD NORTHERN IL AND NORTHWEST INDIANA AS DEPICTED BOTH
BY THE LATEST RAP FORECASTS AS WELL AS THE SPC MESOANALYSIS. THIS
AFTERNOON...SHOWERS ARE EXPECTED TO DEVELOP IN THIS REGION OF
INCREASING MOISTURE...AHEAD OF AN APPROACHING FRONTAL ZONE AND
UNDER THE WEAK MID TO UPPER SHORTWAVES SPINNING THROUGH THE UPPER
TROUGH. THE RADAR MOSAIC AT THE NOON HOUR WAS STARTING TO HINT AT
THIS DEVELOPMENT...AND THE VISIBILE SATELLITE CHANNEL WAS SHOWING
SIGNS OF CYCLONIC CIRCULATION THAT WOULD FURTHER ENHANCE
CONVERGENCE. MILD AIR ALOFT AND THE LACK OF STRONG WINDS AT UPPER
LEVELS ARE RESULTING IN TALL SKINNY SOUNDINGS WITH LITTLE DEEP
LAYER SHEAR...SO LOCALLY HEAVY RAIN COULD BE A PROBLEM BUT
WIDESPREAD ORGANIZED SEVERE STORMS ARE NOT A LARGE CONCERN.
THE MOST FAVORABLE AXIS FOR DEVELOPMENT THEN SHIFTS SOUTH AND
EAST OF THE IMMEDIATE CHICAGO METRO AREA BY LATE EVENING.
LENNING
//PREV DISCUSSION...
305 AM CDT
A HANDFUL OF FORECAST CHALLENGES THIS FINAL FULL WEEK OF
JUNE...ALTHOUGH IT DOES APPEAR TO BE A MORE QUIET WEEK THAN
LAST...WITH LESS WIDESPREAD STORM/HEAVY RAINFALL CHANCES. ITEMS OF
CONCERN THIS MORNING INCLUDE RAIN AND THUNDER COVERAGE TODAY AS
WELL AS FOG POSSIBILITIES NEAR THE LAKE SHORE.
TODAY AND TONIGHT...
ONCE AGAIN THIS MORNING IT IS A MESSY MID-LEVEL PATTERN WITH
MULTIPLE SMALL SCALE IMPULSES FROM KS TO WI SEEN ON A LONG LOOP OF
SATELLITE WATER VAPOR CHANNEL. OVERALL THOUGH THESE FEATURES COMPOSE
AN UPPER SHORT WAVE TROUGH THAT WILL INCH EASTWARD LIKELY CLEARING
THE AREA BY OR DURING OVERNIGHT. QG FORCING FOR ASCENT IN ADVANCE OF
THIS TROUGH...WITHIN A MOIST AIR MASS OF PRECIPITABLE WATER OBSERVED
OF 1.50-1.75 INCHES...SHOULD SUPPORT MODEST COVERAGE OF SHOWERS
ESPECIALLY THROUGH EARLY AFTERNOON. SCATTERED/EMBEDDED THUNDER
WILL BE MOST PRONOUNCED AHEAD OF ANY OF THE AFOREMENTIONED
IMPULSES...WITH 500-1200 J/KG OF MUCAPE TO WORK WITH THROUGH THE
MORNING PER CURRENT AMDAR DATA AND RAP FORECASTS THROUGH MIDDAY.
DID OUR BEST TO ADD TEMPORAL RESOLUTION IN THE FORECAST OF HIGHER
POPS TODAY...WITH THE GREATER LIKELIHOOD SHIFTING SLOWLY EAST DURING
THE DAY. CONVECTIVE ALLOWING GUIDANCE INDICATES SOME POSSIBLY DEEPER
CONVECTION NEAR MIDDAY/EARLY AFTERNOON ACROSS THE EASTERN FORECAST
AREA...ASSOCIATED WITH INSTABILITY BECOMING MORE ROOTED IN THE
MIXED LAYER GIVEN SURFACE HEATING. WITH WEAK DEEP LAYER SHEAR
/AOB 25 KT/ AND ANY MODEST DCAPE BEING CONDITIONAL ON SOME
SUNSHINE WHICH THERE MAY NOT BE TOO MUCH OF...THINK SEVERE STORM
POTENTIAL IS SMALL AND THAT CHANCE CONFINED TO THE EASTERN
FORECAST AREA.
OBSERVATIONS AND WEBCAMS EARLY THIS MORNING ARE INDICATING THE LEAST
DENSE THE FOG HAS BEEN NEAR THE LAKE SHORE IN SEVERAL MORNINGS.
THUS ITS POSSIBLE THE ADVISORY MAY BE CANCELLED NEAR SUNRISE
DEPENDING ON HOW THINGS LOOK. A LIGHT FLOW PATTERN TODAY MAY FAVOR
A LAKE BREEZE...THOUGH SHOWERS AND POSSIBLE STORMS COULD DISRUPT
THE WIND FIELD AND LAKE FOG. IN ADDITION...LATE DAY VISIBLE
SATELLITE IMAGERY FROM SUNDAY INDICATED THE FOG OVER SOUTHERN LAKE
MI HAD BECOME MORE THIN...SO NOT EXPECTING FOG TO BE A BIG DEAL
MUCH OF TODAY ALONG THE LAKE SHORE. DEPENDING ON EXACT FRONTAL
TIMING...SOME PATCHY FOG MAY SPREAD BRIEFLY INLAND AGAIN THIS
EVENING...AND POSSIBLY INTO NORTHWEST INDIANA OVERNIGHT BEHIND
FROPA WITH THE SYNOPTIC FLOW SHIFTING NORTH-NORTHWEST.
TUESDAY THROUGH THURSDAY...
A LITTLE MORE OF A NORTHWEST PUSH ARRIVES ON TUESDAY AFTERNOON OR
EVENING BEHIND A SECONDARY COOL FRONT. ALONG THIS FEATURE ON TUESDAY
AFTERNOON THERE COULD BE ISOLATED SHOWERS/STORMS AS A JET STREAK
AND ASSOCIATED RIGHT ENTRANCE REGION MOVE OVER THE BOUNDARY DURING
PEAK HEATING. HAVE MAINTAINED THE CHANCES FOR PRECIP ONLY IN THE
NORTHERN FORECAST AREA ON TUESDAY AS THIS FEATURE APPROACHES.
SEMI-ZONAL FLOW IS FORECAST TO PERSIST THROUGH MIDWEEK WITH LITTLE
TO KEY IN ON FOR SHOWER OR STORM CHANCES. WARM AIR ADVECTION AND
POSSIBLY A SHORT WAVE DEPENDING ON WHICH LONG RANGE MODEL ONE
LOOKS AT INDICATE SOME STORM POTENTIAL LATER THURSDAY...BUT
OVERALL NOT TOO EXCITED ABOUT THIS AT THIS POINT. TEMPERATURES
LOOK TO COOL SLIGHTLY WEDNESDAY AND THURSDAY...ALTHOUGH MORE SO
NEAR THE LAKE SHORE. THIS IS ESPECIALLY TRUE ON WEDNESDAY WHICH
LOOKS TO HAVE SHORELINE HIGHS STRUGGLE TO REACH 70.
FRIDAY INTO NEXT WEEKEND...
ENERGY FROM A PERSIST GULF OF ALASKA TROUGH IS EXPECTED TO EVOLVE
INTO THE NORTHWEST U.S. AND WESTERN CANADA DURING THIS PERIOD AND IN
RESPONSE HEIGHTS WILL BUILD ACROSS THE MISSISSIPPI AND OHIO RIVER
VALLEY REGIONS. THE EC HAS TRENDED DOWN FROM THE HEIGHTS AND 850MB
TEMPS IT HAD 24 HOURS AGO...BUT STILL SUPPORTIVE OF AROUND 90
DEGREES FOR WEEKEND HIGHS IF NOT IMPACTED BY ANY CONVECTION...WHICH
THERE LOOKS TO BE AT LEAST SMALL CHANCES FOR AT THIS POINT.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* INCREASING TSRA COVERAGE SOUTH AND EAST OF THE TERMINALS. MAINLY
SHRA WITH ISOLATED TSRA AT THE TERMINALS.
* UNCERTAIN WIND DIRECTION...WESTERLY IN THE IMMEDIATE TERM BUT
FAVORING SOUTHWESTERLY AHEAD OF AN APPROACHING FRONT...THEN
VEERING WESTERLY AGAIN TONIGHT. SPEEDS GENERALLY UNDER 10 KTS.
* PATCHY MVFR CIGS BUT TRENDING MOSTLY VFR. MVFR VSBYS IN SHOWERS.
LENNING
//DISCUSSION...UPDATED 20Z...
THUNDERSTORM ACTIVITY HAS INCREASED ACROSS EAST CENTRAL ILLINIOS
INTO NORTHWEST INDIANA WHICH IS POSING PROBLEMS FOR INBOUND AND
OUTBOUD FLIGHTS...BUT MAINLY JUST SHOWERS WITH ISOLATED TSRA ARE
EXPECTED AROUND THE TERMINAL AREAS. CEILINGS HAD LOWERED TO MVFR
RANGE BRIEFLY BUT NOW ARE HEADING BACK UP...AND VSBY CONDITIONS
GENERALLY ARE EXPECTED TO REMAIN VFR EXCEPT FOR BRIEF PERIODS
NEAR THE HEAVIER SHOWERS. THE PEAK COVERAGE STILL IS EXPECTED
TOWARD MID TO LATE AFTERNOON...WITH THE BEST FOCUS BEGINNING TO
SHIFT EAST BY LATE EVENING. WINDS WILL REMAIN LIGHT OUT OF THE
SOUTHWEST AND THEN WEST AS A FRONT CROSSES THE AREA TONIGHT.
TUESDAY LOOKS MOSTLY DRY...WITH AN AFTERNOON LAKE BREEZE LIKELY
DEVELOPING IN THE LIGHT PRESSURE GRADIENT.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN SHRA COVERAGE...AND MEDIUM TO HIGH
CONFIDENCE THAT MOST TSRA STAYS SOUTH AND EAST OF THE TERMINALS.
* MEDIUM TO HIGH CONFIDENCE IN VFR CIGS/VSBYS AWAY FROM SHOWERS.
* LOW CONFIDENCE IN WIND DIRECTION...BUT HIGHER CONFIDENCE IN SPEEDS.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH THURSDAY...VFR. WX NIL.
THURSDAY NIGHT THROUGH SATURDAY NIGHT...CHANCE TSRA. OTHERWISE
VFR.
SUNDAY...SLIGHT CHANCE TSRA. OTHERWISE VFR.
KREIN
&&
.MARINE...
223 PM CDT
WEBCAMS AND SATELLITE IMAGERY BOTH SUGGEST DENSE FOG IS STILL OVER
THE LAKE...SO WILL KEEP THE DENSE FOG ADVISORY GOING. THERE IS A
LITTLE CONCERN THAT THE FOG MAY CONTINUE THROUGH TONIGHT...BUT DO
NOT HAVE ENOUGH CONFIDENCE TO EXTEND THE ADVISORY NOW.
A LOW PRESSURE TROUGH AND COLD FRONT WILL MOVE OVER THE LAKE TONIGHT
AND WINDS WILL NW TO W BEHIND THE FRONT. THE BAGGY TROUGH REMAINS
OVERHEAD TOMORROW AND EXPECTING ONSHORE FLOW DEVELOP ACROSS THE LAKE
IN THE AFTERNOON. A SECOND COLD FRONT SINKS DOWN THE LAKE IN THE
EVENING WITH WINDS BECOMING NORTH 10-15 KT BEHIND IT. WINDS REMAIN
LIGHT OUT OF THE N TO NE AS HIGH PRESSURE BUILDS OVER THE LAKE
WEDNESDAY NIGHT. THE LIGHT WINDS THEN VEER TO EAST THURSDAY NIGHT
AS THE HIGH SHIFTS EAST. THE GRADIENT TIGHTENS LATE THIS WEEK INTO
NEXT WEEK AHEAD OF THE NEXT STORM SYSTEM WITH SOUTH WINDS GUSTING TO
AROUND 20 KT SUNDAY.
JEE
&&
.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 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
224 PM CDT MON JUN 23 2014
.DISCUSSION...
1147 AM CDT
STILL EXPECTING AN INCREASE IN THE COVERAGE OF SHOWERS AND
ISOLATED TO SCATTERED THUNDERSTORMS THROUGH THE AFTERNOON HOURS.
MOST OF THE CONVECTIVE ACTIVITY THIS MORNING WAS LOCATED SOUTHEAST
OF THE AREA. THIS WAS IN THE REGION OF BETTER SURFACE HEATING AND
HIGHER DEWPOINTS. A BROAD AREA OF MOISTURE CONVERGENCE IS NOW
MOVING TOWARD NORTHERN IL AND NORTHWEST INDIANA AS DEPICTED BOTH
BY THE LATEST RAP FORECASTS AS WELL AS THE SPC MESOANALYSIS. THIS
AFTERNOON...SHOWERS ARE EXPECTED TO DEVELOP IN THIS REGION OF
INCREASING MOISTURE...AHEAD OF AN APPROACHING FRONTAL ZONE AND
UNDER THE WEAK MID TO UPPER SHORTWAVES SPINNING THROUGH THE UPPER
TROUGH. THE RADAR MOSAIC AT THE NOON HOUR WAS STARTING TO HINT AT
THIS DEVELOPMENT...AND THE VISIBILE SATELLITE CHANNEL WAS SHOWING
SIGNS OF CYCLONIC CIRCULATION THAT WOULD FURTHER ENHANCE
CONVERGENCE. MILD AIR ALOFT AND THE LACK OF STRONG WINDS AT UPPER
LEVELS ARE RESULTING IN TALL SKINNY SOUNDINGS WITH LITTLE DEEP
LAYER SHEAR...SO LOCALLY HEAVY RAIN COULD BE A PROBLEM BUT
WIDESPREAD ORGANIZED SEVERE STORMS ARE NOT A LARGE CONCERN.
THE MOST FAVORABLE AXIS FOR DEVELOPMENT THEN SHIFTS SOUTH AND
EAST OF THE IMMEDIATE CHICAGO METRO AREA BY LATE EVENING.
LENNING
//PREV DISCUSSION...
305 AM CDT
A HANDFUL OF FORECAST CHALLENGES THIS FINAL FULL WEEK OF
JUNE...ALTHOUGH IT DOES APPEAR TO BE A MORE QUIET WEEK THAN
LAST...WITH LESS WIDESPREAD STORM/HEAVY RAINFALL CHANCES. ITEMS OF
CONCERN THIS MORNING INCLUDE RAIN AND THUNDER COVERAGE TODAY AS
WELL AS FOG POSSIBILITIES NEAR THE LAKE SHORE.
TODAY AND TONIGHT...
ONCE AGAIN THIS MORNING IT IS A MESSY MID-LEVEL PATTERN WITH
MULTIPLE SMALL SCALE IMPULSES FROM KS TO WI SEEN ON A LONG LOOP OF
SATELLITE WATER VAPOR CHANNEL. OVERALL THOUGH THESE FEATURES COMPOSE
AN UPPER SHORT WAVE TROUGH THAT WILL INCH EASTWARD LIKELY CLEARING
THE AREA BY OR DURING OVERNIGHT. QG FORCING FOR ASCENT IN ADVANCE OF
THIS TROUGH...WITHIN A MOIST AIR MASS OF PRECIPITABLE WATER OBSERVED
OF 1.50-1.75 INCHES...SHOULD SUPPORT MODEST COVERAGE OF SHOWERS
ESPECIALLY THROUGH EARLY AFTERNOON. SCATTERED/EMBEDDED THUNDER
WILL BE MOST PRONOUNCED AHEAD OF ANY OF THE AFOREMENTIONED
IMPULSES...WITH 500-1200 J/KG OF MUCAPE TO WORK WITH THROUGH THE
MORNING PER CURRENT AMDAR DATA AND RAP FORECASTS THROUGH MIDDAY.
DID OUR BEST TO ADD TEMPORAL RESOLUTION IN THE FORECAST OF HIGHER
POPS TODAY...WITH THE GREATER LIKELIHOOD SHIFTING SLOWLY EAST DURING
THE DAY. CONVECTIVE ALLOWING GUIDANCE INDICATES SOME POSSIBLY DEEPER
CONVECTION NEAR MIDDAY/EARLY AFTERNOON ACROSS THE EASTERN FORECAST
AREA...ASSOCIATED WITH INSTABILITY BECOMING MORE ROOTED IN THE
MIXED LAYER GIVEN SURFACE HEATING. WITH WEAK DEEP LAYER SHEAR
/AOB 25 KT/ AND ANY MODEST DCAPE BEING CONDITIONAL ON SOME
SUNSHINE WHICH THERE MAY NOT BE TOO MUCH OF...THINK SEVERE STORM
POTENTIAL IS SMALL AND THAT CHANCE CONFINED TO THE EASTERN
FORECAST AREA.
OBSERVATIONS AND WEBCAMS EARLY THIS MORNING ARE INDICATING THE LEAST
DENSE THE FOG HAS BEEN NEAR THE LAKE SHORE IN SEVERAL MORNINGS.
THUS ITS POSSIBLE THE ADVISORY MAY BE CANCELLED NEAR SUNRISE
DEPENDING ON HOW THINGS LOOK. A LIGHT FLOW PATTERN TODAY MAY FAVOR
A LAKE BREEZE...THOUGH SHOWERS AND POSSIBLE STORMS COULD DISRUPT
THE WIND FIELD AND LAKE FOG. IN ADDITION...LATE DAY VISIBLE
SATELLITE IMAGERY FROM SUNDAY INDICATED THE FOG OVER SOUTHERN LAKE
MI HAD BECOME MORE THIN...SO NOT EXPECTING FOG TO BE A BIG DEAL
MUCH OF TODAY ALONG THE LAKE SHORE. DEPENDING ON EXACT FRONTAL
TIMING...SOME PATCHY FOG MAY SPREAD BRIEFLY INLAND AGAIN THIS
EVENING...AND POSSIBLY INTO NORTHWEST INDIANA OVERNIGHT BEHIND
FROPA WITH THE SYNOPTIC FLOW SHIFTING NORTH-NORTHWEST.
TUESDAY THROUGH THURSDAY...
A LITTLE MORE OF A NORTHWEST PUSH ARRIVES ON TUESDAY AFTERNOON OR
EVENING BEHIND A SECONDARY COOL FRONT. ALONG THIS FEATURE ON TUESDAY
AFTERNOON THERE COULD BE ISOLATED SHOWERS/STORMS AS A JET STREAK
AND ASSOCIATED RIGHT ENTRANCE REGION MOVE OVER THE BOUNDARY DURING
PEAK HEATING. HAVE MAINTAINED THE CHANCES FOR PRECIP ONLY IN THE
NORTHERN FORECAST AREA ON TUESDAY AS THIS FEATURE APPROACHES.
SEMI-ZONAL FLOW IS FORECAST TO PERSIST THROUGH MIDWEEK WITH LITTLE
TO KEY IN ON FOR SHOWER OR STORM CHANCES. WARM AIR ADVECTION AND
POSSIBLY A SHORT WAVE DEPENDING ON WHICH LONG RANGE MODEL ONE
LOOKS AT INDICATE SOME STORM POTENTIAL LATER THURSDAY...BUT
OVERALL NOT TOO EXCITED ABOUT THIS AT THIS POINT. TEMPERATURES
LOOK TO COOL SLIGHTLY WEDNESDAY AND THURSDAY...ALTHOUGH MORE SO
NEAR THE LAKE SHORE. THIS IS ESPECIALLY TRUE ON WEDNESDAY WHICH
LOOKS TO HAVE SHORELINE HIGHS STRUGGLE TO REACH 70.
FRIDAY INTO NEXT WEEKEND...
ENERGY FROM A PERSIST GULF OF ALASKA TROUGH IS EXPECTED TO EVOLVE
INTO THE NORTHWEST U.S. AND WESTERN CANADA DURING THIS PERIOD AND IN
RESPONSE HEIGHTS WILL BUILD ACROSS THE MISSISSIPPI AND OHIO RIVER
VALLEY REGIONS. THE EC HAS TRENDED DOWN FROM THE HEIGHTS AND 850MB
TEMPS IT HAD 24 HOURS AGO...BUT STILL SUPPORTIVE OF AROUND 90
DEGREES FOR WEEKEND HIGHS IF NOT IMPACTED BY ANY CONVECTION...WHICH
THERE LOOKS TO BE AT LEAST SMALL CHANCES FOR AT THIS POINT.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* INCREASING COVERAGE OF SHOWERS WITH ISOLATED TSRA THIS AFTERNOON
AND EVENING.
* SHORT PERIODS OF MVFR VSBYS IN HEAVIER ACTIVITY.
* WINDS LIGHT FROM THE SOUTH...GRADUALLY VEERING NORTHWEST.
* LAKE BREEZE LIKELY TOMORROW AFTERNOON.
LENNING
//DISCUSSION...UPDATED 18Z...
THUNDERSTORM ACTIVITY INCREASING ACROSS EAST CENTRAL ILLINIOS
INTO NORTHWEST INDIANA MAY POSE PROBLEMS FOR INBOUND AND OUTBOUD
FLIGHTS...BUT MAINLY JUST SHOWERS WITH ISOLATED TSRA ARE EXPECTED
AROUND THE TERMINAL AREAS. CEILINGS LOWERING TO MVFR RANGE MAY
PROMPT A TAF AMENDMENT A BIT SOONER THAN EXPECTED...THOUGH VSBY
CONDITIONS GENERALLY ARE EXPECTED TO BE VFR EXCEPT FOR BRIEF
PERIODS NEAR THE HEAVIER SHOWERS. THE PEAK COVERAGE IS EXPECTED
TOWARD MID TO LATE AFTERNOON...WITH THE BEST FOCUS BEGINNING TO
SHIFT EAST BY LATE EVENING. WINDS WILL REMAIN LIGHT OUT OF THE
SOUTH BEFORE GRADUALLY VEERING SOUTHWEST AND THEN WEST AS A FRONT
CROSSES THE AREA TONIGHT. TUESDAY LOOKS MOSTLY DRY...WITH AN
AFTERNOON LAKE BREEZE LIKELY DEVELOPING IN THE LIGHT PRESSURE
GRADIENT.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM TO LOW CONFIDENCE ON CEILINGS STAYING ABOVE MVFR...BUT
HIGHER ON VSBYS STAYING VFR.
* MEDIUM TO HIGH CONFIDENCE OF SHOWERS THIS AFTERNOON AND EVENING.
* MEDIUM CONFIDENCE ON WIND DIRECTION TRENDS...HIGHER ON SPEED TRENDS.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH THURSDAY...VFR. WX NIL.
THURSDAY NIGHT THROUGH SATURDAY NIGHT...CHANCE TSRA. OTHERWISE
VFR.
SUNDAY...SLIGHT CHANCE TSRA. OTHERWISE VFR.
KREIN
&&
.MARINE...
223 PM CDT
WEBCAMS AND SATELLITE IMAGERY BOTH SUGGEST DENSE FOG IS STILL OVER
THE LAKE...SO WILL KEEP THE DENSE FOG ADVISORY GOING. THERE IS A
LITTLE CONCERN THAT THE FOG MAY CONTINUE THROUGH TONIGHT...BUT DO
NOT HAVE ENOUGH CONFIDENCE TO EXTEND THE ADVISORY NOW.
A LOW PRESSURE TROUGH AND COLD FRONT WILL MOVE OVER THE LAKE TONIGHT
AND WINDS WILL NW TO W BEHIND THE FRONT. THE BAGGY TROUGH REMAINS
OVERHEAD TOMORROW AND EXPECTING ONSHORE FLOW DEVELOP ACROSS THE LAKE
IN THE AFTERNOON. A SECOND COLD FRONT SINKS DOWN THE LAKE IN THE
EVENING WITH WINDS BECOMING NORTH 10-15 KT BEHIND IT. WINDS REMAIN
LIGHT OUT OF THE N TO NE AS HIGH PRESSURE BUILDS OVER THE LAKE
WEDNESDAY NIGHT. THE LIGHT WINDS THEN VEER TO EAST THURSDAY NIGHT
AS THE HIGH SHIFTS EAST. THE GRADIENT TIGHTENS LATE THIS WEEK INTO
NEXT WEEK AHEAD OF THE NEXT STORM SYSTEM WITH SOUTH WINDS GUSTING TO
AROUND 20 KT SUNDAY.
JEE
&&
.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 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
115 PM CDT MON JUN 23 2014
.DISCUSSION...
1147 AM CDT
STILL EXPECTING AN INCREASE IN THE COVERAGE OF SHOWERS AND
ISOLATED TO SCATTERED THUNDERSTORMS THROUGH THE AFTERNOON HOURS.
MOST OF THE CONVECTIVE ACTIVITY THIS MORNING WAS LOCATED SOUTHEAST
OF THE AREA. THIS WAS IN THE REGION OF BETTER SURFACE HEATING AND
HIGHER DEWPOINTS. A BROAD AREA OF MOISTURE CONVERGENCE IS NOW
MOVING TOWARD NORTHERN IL AND NORTHWEST INDIANA AS DEPICTED BOTH
BY THE LATEST RAP FORECASTS AS WELL AS THE SPC MESOANALYSIS. THIS
AFTERNOON...SHOWERS ARE EXPECTED TO DEVELOP IN THIS REGION OF
INCREASING MOISTURE...AHEAD OF AN APPROACHING FRONTAL ZONE AND
UNDER THE WEAK MID TO UPPER SHORTWAVES SPINNING THROUGH THE UPPER
TROUGH. THE RADAR MOSAIC AT THE NOON HOUR WAS STARTING TO HINT AT
THIS DEVELOPMENT...AND THE VISIBILE SATELLITE CHANNEL WAS SHOWING
SIGNS OF CYCLONIC CIRCULATION THAT WOULD FURTHER ENHANCE
CONVERGENCE. MILD AIR ALOFT AND THE LACK OF STRONG WINDS AT UPPER
LEVELS ARE RESULTING IN TALL SKINNY SOUNDINGS WITH LITTLE DEEP
LAYER SHEAR...SO LOCALLY HEAVY RAIN COULD BE A PROBLEM BUT
WIDESPREAD ORGANIZED SEVERE STORMS ARE NOT A LARGE CONCERN.
THE MOST FAVORABLE AXIS FOR DEVELOPMENT THEN SHIFTS SOUTH AND
EAST OF THE IMMEDIATE CHICAGO METRO AREA BY LATE EVENING.
LENNING
//PREV DISCUSSION...
305 AM CDT
A HANDFUL OF FORECAST CHALLENGES THIS FINAL FULL WEEK OF
JUNE...ALTHOUGH IT DOES APPEAR TO BE A MORE QUIET WEEK THAN
LAST...WITH LESS WIDESPREAD STORM/HEAVY RAINFALL CHANCES. ITEMS OF
CONCERN THIS MORNING INCLUDE RAIN AND THUNDER COVERAGE TODAY AS
WELL AS FOG POSSIBILITIES NEAR THE LAKE SHORE.
TODAY AND TONIGHT...
ONCE AGAIN THIS MORNING IT IS A MESSY MID-LEVEL PATTERN WITH
MULTIPLE SMALL SCALE IMPULSES FROM KS TO WI SEEN ON A LONG LOOP OF
SATELLITE WATER VAPOR CHANNEL. OVERALL THOUGH THESE FEATURES COMPOSE
AN UPPER SHORT WAVE TROUGH THAT WILL INCH EASTWARD LIKELY CLEARING
THE AREA BY OR DURING OVERNIGHT. QG FORCING FOR ASCENT IN ADVANCE OF
THIS TROUGH...WITHIN A MOIST AIR MASS OF PRECIPITABLE WATER OBSERVED
OF 1.50-1.75 INCHES...SHOULD SUPPORT MODEST COVERAGE OF SHOWERS
ESPECIALLY THROUGH EARLY AFTERNOON. SCATTERED/EMBEDDED THUNDER
WILL BE MOST PRONOUNCED AHEAD OF ANY OF THE AFOREMENTIONED
IMPULSES...WITH 500-1200 J/KG OF MUCAPE TO WORK WITH THROUGH THE
MORNING PER CURRENT AMDAR DATA AND RAP FORECASTS THROUGH MIDDAY.
DID OUR BEST TO ADD TEMPORAL RESOLUTION IN THE FORECAST OF HIGHER
POPS TODAY...WITH THE GREATER LIKELIHOOD SHIFTING SLOWLY EAST DURING
THE DAY. CONVECTIVE ALLOWING GUIDANCE INDICATES SOME POSSIBLY DEEPER
CONVECTION NEAR MIDDAY/EARLY AFTERNOON ACROSS THE EASTERN FORECAST
AREA...ASSOCIATED WITH INSTABILITY BECOMING MORE ROOTED IN THE
MIXED LAYER GIVEN SURFACE HEATING. WITH WEAK DEEP LAYER SHEAR
/AOB 25 KT/ AND ANY MODEST DCAPE BEING CONDITIONAL ON SOME
SUNSHINE WHICH THERE MAY NOT BE TOO MUCH OF...THINK SEVERE STORM
POTENTIAL IS SMALL AND THAT CHANCE CONFINED TO THE EASTERN
FORECAST AREA.
OBSERVATIONS AND WEBCAMS EARLY THIS MORNING ARE INDICATING THE LEAST
DENSE THE FOG HAS BEEN NEAR THE LAKE SHORE IN SEVERAL MORNINGS.
THUS ITS POSSIBLE THE ADVISORY MAY BE CANCELLED NEAR SUNRISE
DEPENDING ON HOW THINGS LOOK. A LIGHT FLOW PATTERN TODAY MAY FAVOR
A LAKE BREEZE...THOUGH SHOWERS AND POSSIBLE STORMS COULD DISRUPT
THE WIND FIELD AND LAKE FOG. IN ADDITION...LATE DAY VISIBLE
SATELLITE IMAGERY FROM SUNDAY INDICATED THE FOG OVER SOUTHERN LAKE
MI HAD BECOME MORE THIN...SO NOT EXPECTING FOG TO BE A BIG DEAL
MUCH OF TODAY ALONG THE LAKE SHORE. DEPENDING ON EXACT FRONTAL
TIMING...SOME PATCHY FOG MAY SPREAD BRIEFLY INLAND AGAIN THIS
EVENING...AND POSSIBLY INTO NORTHWEST INDIANA OVERNIGHT BEHIND
FROPA WITH THE SYNOPTIC FLOW SHIFTING NORTH-NORTHWEST.
TUESDAY THROUGH THURSDAY...
A LITTLE MORE OF A NORTHWEST PUSH ARRIVES ON TUESDAY AFTERNOON OR
EVENING BEHIND A SECONDARY COOL FRONT. ALONG THIS FEATURE ON TUESDAY
AFTERNOON THERE COULD BE ISOLATED SHOWERS/STORMS AS A JET STREAK
AND ASSOCIATED RIGHT ENTRANCE REGION MOVE OVER THE BOUNDARY DURING
PEAK HEATING. HAVE MAINTAINED THE CHANCES FOR PRECIP ONLY IN THE
NORTHERN FORECAST AREA ON TUESDAY AS THIS FEATURE APPROACHES.
SEMI-ZONAL FLOW IS FORECAST TO PERSIST THROUGH MIDWEEK WITH LITTLE
TO KEY IN ON FOR SHOWER OR STORM CHANCES. WARM AIR ADVECTION AND
POSSIBLY A SHORT WAVE DEPENDING ON WHICH LONG RANGE MODEL ONE
LOOKS AT INDICATE SOME STORM POTENTIAL LATER THURSDAY...BUT
OVERALL NOT TOO EXCITED ABOUT THIS AT THIS POINT. TEMPERATURES
LOOK TO COOL SLIGHTLY WEDNESDAY AND THURSDAY...ALTHOUGH MORE SO
NEAR THE LAKE SHORE. THIS IS ESPECIALLY TRUE ON WEDNESDAY WHICH
LOOKS TO HAVE SHORELINE HIGHS STRUGGLE TO REACH 70.
FRIDAY INTO NEXT WEEKEND...
ENERGY FROM A PERSIST GULF OF ALASKA TROUGH IS EXPECTED TO EVOLVE
INTO THE NORTHWEST U.S. AND WESTERN CANADA DURING THIS PERIOD AND IN
RESPONSE HEIGHTS WILL BUILD ACROSS THE MISSISSIPPI AND OHIO RIVER
VALLEY REGIONS. THE EC HAS TRENDED DOWN FROM THE HEIGHTS AND 850MB
TEMPS IT HAD 24 HOURS AGO...BUT STILL SUPPORTIVE OF AROUND 90
DEGREES FOR WEEKEND HIGHS IF NOT IMPACTED BY ANY CONVECTION...WHICH
THERE LOOKS TO BE AT LEAST SMALL CHANCES FOR AT THIS POINT.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* INCREASING COVERAGE OF SHOWERS WITH ISOLATED TSRA THIS AFTERNOON
AND EVENING.
* SHORT PERIODS OF MVFR VSBYS IN HEAVIER ACTIVITY.
* WINDS LIGHT FROM THE SOUTH...GRADUALLY VEERING NORTHWEST.
* LAKE BREEZE LIKELY TOMORROW AFTERNOON.
LENNING
//DISCUSSION...UPDATED 18Z...
THUNDERSTORM ACTIVITY INCREASING ACROSS EAST CENTRAL ILLINIOS
INTO NORTHWEST INDIANA MAY POSE PROBLEMS FOR INBOUND AND OUTBOUD
FLIGHTS...BUT MAINLY JUST SHOWERS WITH ISOLATED TSRA ARE EXPECTED
AROUND THE TERMINAL AREAS. CEILINGS LOWERING TO MVFR RANGE MAY
PROMPT A TAF AMENDMENT A BIT SOONER THAN EXPECTED...THOUGH VSBY
CONDITIONS GENERALLY ARE EXPECTED TO BE VFR EXCEPT FOR BRIEF
PERIODS NEAR THE HEAVIER SHOWERS. THE PEAK COVERAGE IS EXPECTED
TOWARD MID TO LATE AFTERNOON...WITH THE BEST FOCUS BEGINNING TO
SHIFT EAST BY LATE EVENING. WINDS WILL REMAIN LIGHT OUT OF THE
SOUTH BEFORE GRADUALLY VEERING SOUTHWEST AND THEN WEST AS A FRONT
CROSSES THE AREA TONIGHT. TUESDAY LOOKS MOSTLY DRY...WITH AN
AFTERNOON LAKE BREEZE LIKELY DEVELOPING IN THE LIGHT PRESSURE
GRADIENT.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM TO LOW CONFIDENCE ON CEILINGS STAYING ABOVE MVFR...BUT
HIGHER ON VSBYS STAYING VFR.
* MEDIUM TO HIGH CONFIDENCE OF SHOWERS THIS AFTERNOON AND EVENING.
* MEDIUM CONFIDENCE ON WIND DIRECTION TRENDS...HIGHER ON SPEED TRENDS.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH THURSDAY...VFR. WX NIL.
THURSDAY NIGHT THROUGH SATURDAY NIGHT...CHANCE TSRA. OTHERWISE
VFR.
SUNDAY...SLIGHT CHANCE TSRA. OTHERWISE VFR.
KREIN
&&
.MARINE...
315 AM CDT
BROAD HIGH PRESSURE EXTENDS FROM THE GREAT LAKES REGION ACROSS
MUCH OF THE EAST COAST. THE RESULTANT LIGHT AND VARIABLE WINDS
COMBINED WITH RESIDUAL HIGH DEWPOINT AIR OVER THE STILL VERY COLD
LAKE WATERS HAS KEPT DENSE FOG IN PLACE. THE DENSE FOG WILL
CONTINUE WHILE THE HIGH PRESSURE IS SLOWLY ERODED BY A TROUGH OF
WEAK LOW PRESSURE AS IT MOVES ACROSS THE MISSISSIPPI VALLEY
MONDAY MORNING. THE TROUGH AND AN ASSOCIATED WEAK COLD FRONT WILL
MOVE ACROSS THE LAKE LATE MONDAY NIGHT TURNING WINDS FROM LIGHT
AND VARIABLE TO WESTERLY AND NORTHWESTERLY...WHICH WILL BEGIN TO
SCOUR OUT THE FOG FROM THE LAKE. A SECONDARY COLD FRONT WILL DROP
DOWN THE LAKE TUESDAY TURNING WINDS NORTHERLY BRINGING AN END TO
ANY RESIDUAL FOG AS DRIER AIR FILTERS OVER THE LAKE. HIGH PRESSURE
WILL BUILD ACROSS THE UPPER LAKES WEDNESDAY AND THURSDAY KEEPING
CONDITIONS OVER THE LAKE RELATIVELY QUIET...BUT BY THE END OF THE
WEEK...STRENGTHENING SOUTHERLY WINDS OF 15 TO 25 KT WILL DEVELOP
OVER THE LAKE AS THE HIGH MOVES OFF TO THE EAST AND ANOTHER TROUGH
APPROACHES FROM THE WEST.
&&
.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 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1213 PM CDT MON JUN 23 2014
.DISCUSSION...
1147 AM CDT
STILL EXPECTING AN INCREASE IN THE COVERAGE OF SHOWERS AND
ISOLATED TO SCATTERED THUNDERSTORMS THROUGH THE AFTERNOON HOURS.
MOST OF THE CONVECTIVE ACTIVITY THIS MORNING WAS LOCATED SOUTHEAST
OF THE AREA. THIS WAS IN THE REGION OF BETTER SURFACE HEATING AND
HIGHER DEWPOINTS. A BROAD AREA OF MOISTURE CONVERGENCE IS NOW
MOVING TOWARD NORTHERN IL AND NORTHWEST INDIANA AS DEPICTED BOTH
BY THE LATEST RAP FORECASTS AS WELL AS THE SPC MESOANALYSIS. THIS
AFTERNOON...SHOWERS ARE EXPECTED TO DEVELOP IN THIS REGION OF
INCREASING MOISTURE...AHEAD OF AN APPROACHING FRONTAL ZONE AND
UNDER THE WEAK MID TO UPPER SHORTWAVES SPINNING THROUGH THE UPPER
TROUGH. THE RADAR MOSAIC AT THE NOON HOUR WAS STARTING TO HINT AT
THIS DEVELOPMENT...AND THE VISIBILE SATELLITE CHANNEL WAS SHOWING
SIGNS OF CYCLONIC CIRCULATION THAT WOULD FURTHER ENHANCE
CONVERGENCE. MILD AIR ALOFT AND THE LACK OF STRONG WINDS AT UPPER
LEVELS ARE RESULTING IN TALL SKINNY SOUNDINGS WITH LITTLE DEEP
LAYER SHEAR...SO LOCALLY HEAVY RAIN COULD BE A PROBLEM BUT
WIDESPREAD ORGANIZED SEVERE STORMS ARE NOT A LARGE CONCERN.
THE MOST FAVORABLE AXIS FOR DEVELOPMENT THEN SHIFTS SOUTH AND
EAST OF THE IMMEDIATE CHICAGO METRO AREA BY LATE EVENING.
LENNING
&&
.PREV DISCUSSION...
305 AM CDT
A HANDFUL OF FORECAST CHALLENGES THIS FINAL FULL WEEK OF
JUNE...ALTHOUGH IT DOES APPEAR TO BE A MORE QUIET WEEK THAN
LAST...WITH LESS WIDESPREAD STORM/HEAVY RAINFALL CHANCES. ITEMS OF
CONCERN THIS MORNING INCLUDE RAIN AND THUNDER COVERAGE TODAY AS
WELL AS FOG POSSIBILITIES NEAR THE LAKE SHORE.
TODAY AND TONIGHT...
ONCE AGAIN THIS MORNING IT IS A MESSY MID-LEVEL PATTERN WITH
MULTIPLE SMALL SCALE IMPULSES FROM KS TO WI SEEN ON A LONG LOOP OF
SATELLITE WATER VAPOR CHANNEL. OVERALL THOUGH THESE FEATURES COMPOSE
AN UPPER SHORT WAVE TROUGH THAT WILL INCH EASTWARD LIKELY CLEARING
THE AREA BY OR DURING OVERNIGHT. QG FORCING FOR ASCENT IN ADVANCE OF
THIS TROUGH...WITHIN A MOIST AIR MASS OF PRECIPITABLE WATER OBSERVED
OF 1.50-1.75 INCHES...SHOULD SUPPORT MODEST COVERAGE OF SHOWERS
ESPECIALLY THROUGH EARLY AFTERNOON. SCATTERED/EMBEDDED THUNDER
WILL BE MOST PRONOUNCED AHEAD OF ANY OF THE AFOREMENTIONED
IMPULSES...WITH 500-1200 J/KG OF MUCAPE TO WORK WITH THROUGH THE
MORNING PER CURRENT AMDAR DATA AND RAP FORECASTS THROUGH MIDDAY.
DID OUR BEST TO ADD TEMPORAL RESOLUTION IN THE FORECAST OF HIGHER
POPS TODAY...WITH THE GREATER LIKELIHOOD SHIFTING SLOWLY EAST DURING
THE DAY. CONVECTIVE ALLOWING GUIDANCE INDICATES SOME POSSIBLY DEEPER
CONVECTION NEAR MIDDAY/EARLY AFTERNOON ACROSS THE EASTERN FORECAST
AREA...ASSOCIATED WITH INSTABILITY BECOMING MORE ROOTED IN THE
MIXED LAYER GIVEN SURFACE HEATING. WITH WEAK DEEP LAYER SHEAR
/AOB 25 KT/ AND ANY MODEST DCAPE BEING CONDITIONAL ON SOME
SUNSHINE WHICH THERE MAY NOT BE TOO MUCH OF...THINK SEVERE STORM
POTENTIAL IS SMALL AND THAT CHANCE CONFINED TO THE EASTERN
FORECAST AREA.
OBSERVATIONS AND WEBCAMS EARLY THIS MORNING ARE INDICATING THE LEAST
DENSE THE FOG HAS BEEN NEAR THE LAKE SHORE IN SEVERAL MORNINGS.
THUS ITS POSSIBLE THE ADVISORY MAY BE CANCELLED NEAR SUNRISE
DEPENDING ON HOW THINGS LOOK. A LIGHT FLOW PATTERN TODAY MAY FAVOR
A LAKE BREEZE...THOUGH SHOWERS AND POSSIBLE STORMS COULD DISRUPT
THE WIND FIELD AND LAKE FOG. IN ADDITION...LATE DAY VISIBLE
SATELLITE IMAGERY FROM SUNDAY INDICATED THE FOG OVER SOUTHERN LAKE
MI HAD BECOME MORE THIN...SO NOT EXPECTING FOG TO BE A BIG DEAL
MUCH OF TODAY ALONG THE LAKE SHORE. DEPENDING ON EXACT FRONTAL
TIMING...SOME PATCHY FOG MAY SPREAD BRIEFLY INLAND AGAIN THIS
EVENING...AND POSSIBLY INTO NORTHWEST INDIANA OVERNIGHT BEHIND
FROPA WITH THE SYNOPTIC FLOW SHIFTING NORTH-NORTHWEST.
TUESDAY THROUGH THURSDAY...
A LITTLE MORE OF A NORTHWEST PUSH ARRIVES ON TUESDAY AFTERNOON OR
EVENING BEHIND A SECONDARY COOL FRONT. ALONG THIS FEATURE ON TUESDAY
AFTERNOON THERE COULD BE ISOLATED SHOWERS/STORMS AS A JET STREAK
AND ASSOCIATED RIGHT ENTRANCE REGION MOVE OVER THE BOUNDARY DURING
PEAK HEATING. HAVE MAINTAINED THE CHANCES FOR PRECIP ONLY IN THE
NORTHERN FORECAST AREA ON TUESDAY AS THIS FEATURE APPROACHES.
SEMI-ZONAL FLOW IS FORECAST TO PERSIST THROUGH MIDWEEK WITH LITTLE
TO KEY IN ON FOR SHOWER OR STORM CHANCES. WARM AIR ADVECTION AND
POSSIBLY A SHORT WAVE DEPENDING ON WHICH LONG RANGE MODEL ONE
LOOKS AT INDICATE SOME STORM POTENTIAL LATER THURSDAY...BUT
OVERALL NOT TOO EXCITED ABOUT THIS AT THIS POINT. TEMPERATURES
LOOK TO COOL SLIGHTLY WEDNESDAY AND THURSDAY...ALTHOUGH MORE SO
NEAR THE LAKE SHORE. THIS IS ESPECIALLY TRUE ON WEDNESDAY WHICH
LOOKS TO HAVE SHORELINE HIGHS STRUGGLE TO REACH 70.
FRIDAY INTO NEXT WEEKEND...
ENERGY FROM A PERSIST GULF OF ALASKA TROUGH IS EXPECTED TO EVOLVE
INTO THE NORTHWEST U.S. AND WESTERN CANADA DURING THIS PERIOD AND IN
RESPONSE HEIGHTS WILL BUILD ACROSS THE MISSISSIPPI AND OHIO RIVER
VALLEY REGIONS. THE EC HAS TRENDED DOWN FROM THE HEIGHTS AND 850MB
TEMPS IT HAD 24 HOURS AGO...BUT STILL SUPPORTIVE OF AROUND 90
DEGREES FOR WEEKEND HIGHS IF NOT IMPACTED BY ANY CONVECTION...WHICH
THERE LOOKS TO BE AT LEAST SMALL CHANCES FOR AT THIS POINT.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* INCREASING SHRA COVERAGE EXPECTED THROUGH MID AFTERNOON...WITH
ISOLATED TSRA.
* POSSIBLE MVFR CIGS/VSBYS IN HEAVIER SHOWERS BUT GENERALLY VFR.
* VARIABLE WINDS...SOUTHERLY TO SOUTHWESTERLY...VEERING WEST LATE.
LENNING
//DISCUSSION...UPDATED 12Z...
THE PCPN FORECAST REMAINS THE MAIN CONCERN WITH SOME UNCERTAINTY
CONTINUING WITH THE TSRA POTENTIAL. THE ENVIRONMENT OVER THE AREA
REMAINS VERY MOIST AND SHOULD BECOME AT LEAST WEAKLY UNSTABLE
THROUGH THE DAY. A MODERATE SHORTWAVE ALOFT HAS BEEN CONSISTENTLY
FORECAST BY THE MODELS TO CROSS THE REGION THIS AFTERNOON...AND
WILL BE ACCOMPANIED BY A WEAK COLD FRONT. FRONTAL FORCING WILL BE
LOW AS THERE WILL BE ONLY A MINOR AIRMASS CHANGE WITH THE FRONTAL
PASSAGE AND A WINDSHIFT FROM LIGHT SOUTHERLY WINDS TO LIGHT NWLY
WINDS. THERE MAY BE A FEW GUSTS TO ARND 15KT IN THE WEAK WARM
ADVECTION AHEAD OF THE FRONT...BUT WINDS SHOULD BE LESS THAN 10KT
BEHIND THE FRONT. THE LATEST GUIDANCE AND SATELLITE TRENDS
INDICATE A WEAKER SHORTWAVE ALOFT THAN PREVIOUSLY NOTED...SO HAVE
BACKED OFF A BIT ON THE TSRA POTENTIAL IN THE TAFS. STILL FEEL
THAT THE BEST TIMING WILL BE AT SOME POINT DURG THE AFTERNOON
HOURS...BUT TSRA COULD END UP BEING MORE ISOLD/EMBEDDED THAN
ORGANIZED SO HAVE GONE WITH VCTS WORDING. THIS SHOULD STILL
COINCIDE WITH THE PASSAGE OF THE SHORTWAVE ALOFT AND THE WEAK
COLD FRONT AT THE SURFACE. THE REMAINDER OF THE PERIOD SHOULD THEN
BE DRY WITH NWLY WINDS LESS THAN 10KT AND VFR CIGS/VIS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE OF INCREASING SHRA COVERAGE AND ONLY ISOLATED
TSRA.
* MEDIUM CONFIDENCE ON WIND DIRECTION TRENDS...HIGHER CONFIDENCE
ON SPEED TRENDS.
* HIGH TO MEDIUM CONFIDENCE OF PREVAILING VFR WITH BRIEF MVFR.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH THURSDAY...VFR. WX NIL.
THURSDAY NIGHT THROUGH SATURDAY NIGHT...CHANCE TSRA. OTHERWISE
VFR.
SUNDAY...SLIGHT CHANCE TSRA. OTHERWISE VFR.
KREIN
&&
.MARINE...
315 AM CDT
BROAD HIGH PRESSURE EXTENDS FROM THE GREAT LAKES REGION ACROSS
MUCH OF THE EAST COAST. THE RESULTANT LIGHT AND VARIABLE WINDS
COMBINED WITH RESIDUAL HIGH DEWPOINT AIR OVER THE STILL VERY COLD
LAKE WATERS HAS KEPT DENSE FOG IN PLACE. THE DENSE FOG WILL
CONTINUE WHILE THE HIGH PRESSURE IS SLOWLY ERODED BY A TROUGH OF
WEAK LOW PRESSURE AS IT MOVES ACROSS THE MISSISSIPPI VALLEY
MONDAY MORNING. THE TROUGH AND AN ASSOCIATED WEAK COLD FRONT WILL
MOVE ACROSS THE LAKE LATE MONDAY NIGHT TURNING WINDS FROM LIGHT
AND VARIABLE TO WESTERLY AND NORTHWESTERLY...WHICH WILL BEGIN TO
SCOUR OUT THE FOG FROM THE LAKE. A SECONDARY COLD FRONT WILL DROP
DOWN THE LAKE TUESDAY TURNING WINDS NORTHERLY BRINGING AN END TO
ANY RESIDUAL FOG AS DRIER AIR FILTERS OVER THE LAKE. HIGH PRESSURE
WILL BUILD ACROSS THE UPPER LAKES WEDNESDAY AND THURSDAY KEEPING
CONDITIONS OVER THE LAKE RELATIVELY QUIET...BUT BY THE END OF THE
WEEK...STRENGTHENING SOUTHERLY WINDS OF 15 TO 25 KT WILL DEVELOP
OVER THE LAKE AS THE HIGH MOVES OFF TO THE EAST AND ANOTHER TROUGH
APPROACHES FROM THE WEST.
&&
.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 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1109 AM CDT MON JUN 23 2014
.DISCUSSION...
305 AM CDT
A HANDFUL OF FORECAST CHALLENGES THIS FINAL FULL WEEK OF
JUNE...ALTHOUGH IT DOES APPEAR TO BE A MORE QUIET WEEK THAN
LAST...WITH LESS WIDESPREAD STORM/HEAVY RAINFALL CHANCES. ITEMS OF
CONCERN THIS MORNING INCLUDE RAIN AND THUNDER COVERAGE TODAY AS
WELL AS FOG POSSIBILITIES NEAR THE LAKE SHORE.
TODAY AND TONIGHT...
ONCE AGAIN THIS MORNING IT IS A MESSY MID-LEVEL PATTERN WITH
MULTIPLE SMALL SCALE IMPULSES FROM KS TO WI SEEN ON A LONG LOOP OF
SATELLITE WATER VAPOR CHANNEL. OVERALL THOUGH THESE FEATURES COMPOSE
AN UPPER SHORT WAVE TROUGH THAT WILL INCH EASTWARD LIKELY CLEARING
THE AREA BY OR DURING OVERNIGHT. QG FORCING FOR ASCENT IN ADVANCE OF
THIS TROUGH...WITHIN A MOIST AIR MASS OF PRECIPITABLE WATER OBSERVED
OF 1.50-1.75 INCHES...SHOULD SUPPORT MODEST COVERAGE OF SHOWERS
ESPECIALLY THROUGH EARLY AFTERNOON. SCATTERED/EMBEDDED THUNDER
WILL BE MOST PRONOUNCED AHEAD OF ANY OF THE AFOREMENTIONED
IMPULSES...WITH 500-1200 J/KG OF MUCAPE TO WORK WITH THROUGH THE
MORNING PER CURRENT AMDAR DATA AND RAP FORECASTS THROUGH MIDDAY.
DID OUR BEST TO ADD TEMPORAL RESOLUTION IN THE FORECAST OF HIGHER
POPS TODAY...WITH THE GREATER LIKELIHOOD SHIFTING SLOWLY EAST DURING
THE DAY. CONVECTIVE ALLOWING GUIDANCE INDICATES SOME POSSIBLY DEEPER
CONVECTION NEAR MIDDAY/EARLY AFTERNOON ACROSS THE EASTERN FORECAST
AREA...ASSOCIATED WITH INSTABILITY BECOMING MORE ROOTED IN THE
MIXED LAYER GIVEN SURFACE HEATING. WITH WEAK DEEP LAYER SHEAR
/AOB 25 KT/ AND ANY MODEST DCAPE BEING CONDITIONAL ON SOME
SUNSHINE WHICH THERE MAY NOT BE TOO MUCH OF...THINK SEVERE STORM
POTENTIAL IS SMALL AND THAT CHANCE CONFINED TO THE EASTERN
FORECAST AREA.
OBSERVATIONS AND WEBCAMS EARLY THIS MORNING ARE INDICATING THE LEAST
DENSE THE FOG HAS BEEN NEAR THE LAKE SHORE IN SEVERAL MORNINGS.
THUS ITS POSSIBLE THE ADVISORY MAY BE CANCELLED NEAR SUNRISE
DEPENDING ON HOW THINGS LOOK. A LIGHT FLOW PATTERN TODAY MAY FAVOR
A LAKE BREEZE...THOUGH SHOWERS AND POSSIBLE STORMS COULD DISRUPT
THE WIND FIELD AND LAKE FOG. IN ADDITION...LATE DAY VISIBLE
SATELLITE IMAGERY FROM SUNDAY INDICATED THE FOG OVER SOUTHERN LAKE
MI HAD BECOME MORE THIN...SO NOT EXPECTING FOG TO BE A BIG DEAL
MUCH OF TODAY ALONG THE LAKE SHORE. DEPENDING ON EXACT FRONTAL
TIMING...SOME PATCHY FOG MAY SPREAD BRIEFLY INLAND AGAIN THIS
EVENING...AND POSSIBLY INTO NORTHWEST INDIANA OVERNIGHT BEHIND
FROPA WITH THE SYNOPTIC FLOW SHIFTING NORTH-NORTHWEST.
TUESDAY THROUGH THURSDAY...
A LITTLE MORE OF A NORTHWEST PUSH ARRIVES ON TUESDAY AFTERNOON OR
EVENING BEHIND A SECONDARY COOL FRONT. ALONG THIS FEATURE ON TUESDAY
AFTERNOON THERE COULD BE ISOLATED SHOWERS/STORMS AS A JET STREAK
AND ASSOCIATED RIGHT ENTRANCE REGION MOVE OVER THE BOUNDARY DURING
PEAK HEATING. HAVE MAINTAINED THE CHANCES FOR PRECIP ONLY IN THE
NORTHERN FORECAST AREA ON TUESDAY AS THIS FEATURE APPROACHES.
SEMI-ZONAL FLOW IS FORECAST TO PERSIST THROUGH MIDWEEK WITH LITTLE
TO KEY IN ON FOR SHOWER OR STORM CHANCES. WARM AIR ADVECTION AND
POSSIBLY A SHORT WAVE DEPENDING ON WHICH LONG RANGE MODEL ONE
LOOKS AT INDICATE SOME STORM POTENTIAL LATER THURSDAY...BUT
OVERALL NOT TOO EXCITED ABOUT THIS AT THIS POINT. TEMPERATURES
LOOK TO COOL SLIGHTLY WEDNESDAY AND THURSDAY...ALTHOUGH MORE SO
NEAR THE LAKE SHORE. THIS IS ESPECIALLY TRUE ON WEDNESDAY WHICH
LOOKS TO HAVE SHORELINE HIGHS STRUGGLE TO REACH 70.
FRIDAY INTO NEXT WEEKEND...
ENERGY FROM A PERSIST GULF OF ALASKA TROUGH IS EXPECTED TO EVOLVE
INTO THE NORTHWEST U.S. AND WESTERN CANADA DURING THIS PERIOD AND IN
RESPONSE HEIGHTS WILL BUILD ACROSS THE MISSISSIPPI AND OHIO RIVER
VALLEY REGIONS. THE EC HAS TRENDED DOWN FROM THE HEIGHTS AND 850MB
TEMPS IT HAD 24 HOURS AGO...BUT STILL SUPPORTIVE OF AROUND 90
DEGREES FOR WEEKEND HIGHS IF NOT IMPACTED BY ANY CONVECTION...WHICH
THERE LOOKS TO BE AT LEAST SMALL CHANCES FOR AT THIS POINT.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* INCREASING SHRA COVERAGE EXPECTED THROUGH MID AFTERNOON...WITH
ISOLATED TSRA.
* POSSIBLE MVFR CIGS/VSBYS IN HEAVIER SHOWERS BUT GENERALLY VFR.
* VARIABLE WINDS...SOUTHERLY TO SOUTHWESTERLY...VEERING WEST LATE.
LENNING
//DISCUSSION...UPDATED 12Z...
THE PCPN FORECAST REMAINS THE MAIN CONCERN WITH SOME UNCERTAINTY
CONTINUING WITH THE TSRA POTENTIAL. THE ENVIRONMENT OVER THE AREA
REMAINS VERY MOIST AND SHOULD BECOME AT LEAST WEAKLY UNSTABLE
THROUGH THE DAY. A MODERATE SHORTWAVE ALOFT HAS BEEN CONSISTENTLY
FORECAST BY THE MODELS TO CROSS THE REGION THIS AFTERNOON...AND
WILL BE ACCOMPANIED BY A WEAK COLD FRONT. FRONTAL FORCING WILL BE
LOW AS THERE WILL BE ONLY A MINOR AIRMASS CHANGE WITH THE FRONTAL
PASSAGE AND A WINDSHIFT FROM LIGHT SOUTHERLY WINDS TO LIGHT NWLY
WINDS. THERE MAY BE A FEW GUSTS TO ARND 15KT IN THE WEAK WARM
ADVECTION AHEAD OF THE FRONT...BUT WINDS SHOULD BE LESS THAN 10KT
BEHIND THE FRONT. THE LATEST GUIDANCE AND SATELLITE TRENDS
INDICATE A WEAKER SHORTWAVE ALOFT THAN PREVIOUSLY NOTED...SO HAVE
BACKED OFF A BIT ON THE TSRA POTENTIAL IN THE TAFS. STILL FEEL
THAT THE BEST TIMING WILL BE AT SOME POINT DURG THE AFTERNOON
HOURS...BUT TSRA COULD END UP BEING MORE ISOLD/EMBEDDED THAN
ORGANIZED SO HAVE GONE WITH VCTS WORDING. THIS SHOULD STILL
COINCIDE WITH THE PASSAGE OF THE SHORTWAVE ALOFT AND THE WEAK
COLD FRONT AT THE SURFACE. THE REMAINDER OF THE PERIOD SHOULD THEN
BE DRY WITH NWLY WINDS LESS THAN 10KT AND VFR CIGS/VIS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE OF INCREASING SHRA COVERAGE AND ONLY ISOLATED
TSRA.
* MEDIUM CONFIDENCE ON WIND DIRECTION TRENDS...HIGHER CONFIDENCE
ON SPEED TRENDS.
* HIGH TO MEDIUM CONFIDENCE OF PREVAILING VFR WITH BRIEF MVFR.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH THURSDAY...VFR. WX NIL.
THURSDAY NIGHT THROUGH SATURDAY NIGHT...CHANCE TSRA. OTHERWISE
VFR.
SUNDAY...SLIGHT CHANCE TSRA. OTHERWISE VFR.
KREIN
&&
.MARINE...
315 AM CDT
BROAD HIGH PRESSURE EXTENDS FROM THE GREAT LAKES REGION ACROSS
MUCH OF THE EAST COAST. THE RESULTANT LIGHT AND VARIABLE WINDS
COMBINED WITH RESIDUAL HIGH DEWPOINT AIR OVER THE STILL VERY COLD
LAKE WATERS HAS KEPT DENSE FOG IN PLACE. THE DENSE FOG WILL
CONTINUE WHILE THE HIGH PRESSURE IS SLOWLY ERODED BY A TROUGH OF
WEAK LOW PRESSURE AS IT MOVES ACROSS THE MISSISSIPPI VALLEY
MONDAY MORNING. THE TROUGH AND AN ASSOCIATED WEAK COLD FRONT WILL
MOVE ACROSS THE LAKE LATE MONDAY NIGHT TURNING WINDS FROM LIGHT
AND VARIABLE TO WESTERLY AND NORTHWESTERLY...WHICH WILL BEGIN TO
SCOUR OUT THE FOG FROM THE LAKE. A SECONDARY COLD FRONT WILL DROP
DOWN THE LAKE TUESDAY TURNING WINDS NORTHERLY BRINGING AN END TO
ANY RESIDUAL FOG AS DRIER AIR FILTERS OVER THE LAKE. HIGH PRESSURE
WILL BUILD ACROSS THE UPPER LAKES WEDNESDAY AND THURSDAY KEEPING
CONDITIONS OVER THE LAKE RELATIVELY QUIET...BUT BY THE END OF THE
WEEK...STRENGTHENING SOUTHERLY WINDS OF 15 TO 25 KT WILL DEVELOP
OVER THE LAKE AS THE HIGH MOVES OFF TO THE EAST AND ANOTHER TROUGH
APPROACHES FROM THE WEST.
&&
.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 PM MONDAY.
&&
$$
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...UPDATED
NWS DODGE CITY KS
346 PM CDT Mon Jun 23 2014
...Updated for Long Term...
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 300 PM CDT MON JUN 23 2014
Another MCS night likely across far western Kansas. There is isolated
weak thunderstorms developing across south central Kansas this afternoon
as well. Have the highest pops along and west of Garden City to Liberal,
although the most recent HRRR propagates the MCS farther east. Something
to watch and update ESTF grids based on reality rather than model output
solutions. There could be some severe weather across far western Kansas
as meso analyzed SBCAPES are near 2000 J/kg and 30 kt effective bulk
shear. Most probable threat is hail and winds along with heavy rainfall
as pwats remain just below the 75th percentile for a normal distribution.
Overnight minimums will be in the 60sF.
Another MCS likely tomorrow. Attempted to add some diurnal pop variability
with a minimum towards 18Z and maximum at the end of my period. Some
uncertainty in storm placement as convective allowing models are different
than the global models. Broad bushed pops at this point as pwats remain
high and the overall synoptic pattern is that which is conducive for
MCS`s. There could be some marginal severe weather again as instability is
moderate and bulk shear is more marginal. Highs in the 80sF.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 344 PM CDT MON JUN 23 2014
For Tuesday night, a weak upper level shortwave trough will be
moving across western Kansas with numerous showers and thunderstorms
expected as an MCS. At this time with weak wind shear and
instability the chances for severe do not look that promising. Have
upped precip chances. Overnight lows will be in the mid 60s.
On Wednesday, more widely scattered thunderstorms are possible with
moderate instability mainly by late afternoon. The upper level winds
again look weak with severe thunderstorms not a good bet. Highs will
be in the mid to upper 80s.
For the period Thursday into next Monday, the best chance for more
scattered thunderstorms looks to be on Thursday with another weak
upper level wave. A stronger wave moves from the Pacific Northwest
and into the Northern Plains by the Weekend with the best chance for
thunderstorms mainly far north across I-70. Lows will be mild in the
upper 60s to lower 70s, with highs warming slowly from the upper 80s
into the low to mid 90s by the Weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1200 PM CDT MON JUN 23 2014
VFR mainly expected. Some local MVFR here in KDDC, but this won`t last
long. CB`s likely to impact KGCK this evening with fairly strong outflow
winds as main aviation impact.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 63 85 65 87 / 20 40 50 30
GCK 62 85 64 87 / 50 40 50 20
EHA 62 84 64 89 / 50 40 50 30
LBL 63 87 64 88 / 50 40 50 30
HYS 63 82 64 85 / 20 20 40 30
P28 65 86 68 86 / 10 30 40 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Sugden
LONG TERM...Kruse
AVIATION...Sugden
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
300 PM CDT Mon Jun 23 2014
...Update to short term...
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 300 PM CDT MON JUN 23 2014
Another MCS night likely across far western Kansas. There is isolated
weak thunderstorms developing across south central Kansas this afternoon
as well. Have the highest pops along and west of Garden City to Liberal,
although the most recent HRRR propagates the MCS farther east. Something
to watch and update ESTF grids based on reality rather than model output
solutions. There could be some severe weather across far western Kansas
as meso analyzed SBCAPES are near 2000 J/kg and 30 kt effective bulk
shear. Most probable threat is hail and winds along with heavy rainfall
as pwats remain just below the 75th percentile for a normal distribution.
Overnight minimums will be in the 60sF.
Another MCS likely tomorrow. Attempted to add some diurnal pop variability
with a minimum towards 18Z and maximum at the end of my period. Some
uncertainty in storm placement as convective allowing models are different
than the global models. Broad bushed pops at this point as pwats remain
high and the overall synoptic pattern is that which is conducive for
MCS`s. There could be some marginal severe weather again as instability is
moderate and bulk shear is more marginal. Highs in the 80sF.
.LONG TERM...(Tuesday through Sunday)
ISSUED AT 323 AM CDT MON JUN 23 2014
The overall wet pattern, with nightly mesoscale convective systems
(MCS), will continue through Wednesday Night. This pattern will not
break until we see more pronounced ridging develop over the
Rockies...which is expected by Thursday with height rises ahead of a
West Coast trough/Pacific jet. Lower-mid tropospheric temperatures
will warm substantially as a result. This will force the overall
convective activity into the Northern High Plains as a general rule
Thursday and Friday...and probably into Saturday as well. There is
still quite a bit of difference between the ECMWF and the GFS
regarding the strength and evolution of the polar jet as it
penetrates the central CONUS. The ECMWF is a bit further south with
the jet core, which would keep western Kansas in play for severe
thunderstorm risk, whereas the GFS would keep western Kansas dry
amidst warm mid level temperatures with the jet core centered across
the Dakotas. Surface temperatures will slowly increase through the
period, too, with lower 90s back in the forecast by late week and
next weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1200 PM CDT MON JUN 23 2014
VFR mainly expected. Some local MVFR here in KDDC, but this won`t last
long. CB`s likely to impact KGCK this evening with fairly strong outflow
winds as main aviation impact.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 63 85 65 87 / 20 40 40 30
GCK 62 85 65 87 / 50 40 50 20
EHA 62 84 64 90 / 50 40 50 20
LBL 63 87 65 89 / 50 40 50 20
HYS 63 82 66 87 / 20 20 30 30
P28 65 86 68 88 / 10 30 30 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Sugden
LONG TERM...Umscheid
AVIATION...Sugden
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
349 PM EDT MON JUN 23 2014
.SHORT TERM...THIS AFTERNOON AND TONIGHT
AT 19Z THE SURFACE WARM FRONT WAS DRAPED ROUGHLY ALONG THE MICHIGAN
STATE BORDER PER REGIONAL OBSERVATIONS. NORTH OF THE FRONT, SHOWERS
ASSOCIATED WITH THIS MORNING`S MCV CONTINUE EXITING EAST. THIS LIGHT
PRECIP AND ASSOCIATED CLOUD COVER HAS KEPT TEMPERATURES CONFINED TO
THE LOW/MID 70S THROUGH MID-AFTERNOON. SOUTH OF THE WARM FRONT,
TEMPERATURES IN THE MID 80S AND DEWPOINTS NEAR 70 ARE CONTRIBUTING
TO A MODERATE TO STRONGLY UNSTABLE ENVIRONMENT CHARACTERIZED BY A
WEAK/UNIDIRECTIONAL AMBIENT WIND FIELD. WITHIN SAID WARM SECTOR,
WIDESPREAD MULTICELL CONVECTION IS ONGOING WITH ONLY ISOLATED SEVERE
REPORTS THUS FAR. HOWEVER, SUFFICIENT BOUNDARY LAYER RECOVERY SOUTH
OF THE WARM FRONT, MOST LIKELY SOUTH OF I-94, WILL HAVE THE
POTENTIAL TO CONTRIBUTE TO A WELL-MIXED ENVIRONMENT THROUGH THE
LOWEST 5KFT PER THE LATEST RAP FORECAST SOUNDINGS. THIS, IN THE
PRESENCE OF LOCALLY ENHANCED SHEAR INVOF THE WARM FRONT, WILL
PRESENT A LOW-END CHANCE FOR BRIEF ORGANIZED UPDRAFTS CAPABLE OF
PRODUCING A MARGINAL DIABATICALLY-INDUCED SEVERE WIND THREAT UNTIL
DIURNAL HEATING IS LOST LATER THIS EVENING.
THUNDERSTORM POTENTIAL WILL PERSIST THROUGH THE NIGHT AS THE AREA
BECOMES INCREASINGLY ENTRENCHED IN THE WARM SECTOR. ONE LINE OF
THUNDERSTORMS HAS DEVELOPED ALONG A LINE FROM SOUTH BEND TO TERRE
HAUTE ALONG THE LEAD EDGE OF THE MID-LEVEL MOISTURE TRANSPORT AXIS.
IN ADDITION, MORE UPSTREAM DEVELOPMENT HAS BEGUN JUST SOUTH OF
CHICAGO IN ASSOCIATION WITH AN MCV EVIDENT IN AFTERNOON VISIBLE
IMAGERY. THIS ACTIVITY WILL SPREAD EAST THROUGH MIDNIGHT, WITH THE
LAST ROUND LIKELY AFFECTING THE METRO AREA SOMETIME AROUND 02-03Z.
THE PRIMARY THREATS WITH LATE EVENING/EARLY NIGHT ACTIVITY WILL BE
HEAVY RAIN DUE TO POTENTIAL TRAINING AND PWATS OF 1.6" TO 1.8" ALONG
WITH LIGHTNING. SEVERE WIND POTENTIAL WILL DIMINISH WITH TIME AS THE
SUN ANGLE DECREASES. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
WILL REMAIN POSSIBLE THROUGH TONIGHT AS THE MID-LEVEL THERMAL
GRADIENT RESPONDS TO AN ENCROACHING NORTHERN STREAM WAVE. THE
AGEOSTROPHIC RESPONSE SHOULD BE JUST ENOUGH TO KEEP ACTIVITY
BUBBLING WITHIN THE MOISTURE AXIS THROUGH THE NOCTURNAL PERIOD. LOWS
IN THE WARM SECTOR WILL STRUGGLE TO FALL BELOW 70 DEGREES.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
GENERALLY ILL-DEFINED FORCING IN A MOIST ENVIRONMENT /PW 1.5-2
INCHES/ POSES CHALLENGES FOR DETERMINING POPS TUESDAY...BUT TRIED TO
KEY IN ON SOME FEATURES WITH THIS PACKAGE. WEAK SURFACE CIRCULATION
WILL BE LOCATED NEAR CENTRAL LAKE HURON AT 12Z TUESDAY AND MOVING
NORTHEAST...LIKELY ACCOMPANIED BY AN AREA OF SHOWERS/T-STORMS. A
WEAK SURFACE TROUGH WILL EXTEND SOUTHWARD FROM THIS LOW...BISECTING
LOWER MICHIGAN. MEANWHILE...A SHORTWAVE CURRENTLY NOTED ON WATER
VAPOR OVER OKLAHOMA WILL PROGRESS NORTHEASTWARD...REACHING IN/OH BY
00Z WEDNESDAY. WEAK AREA OF MIDLEVEL DEFORMATION NORTH OF THIS WAVE
MAY PROVIDE SOME LIFT OVER SE MI...ALONG WITH RIGHT ENTRANCE REGION
FORCING FROM 70KT JET OVER NORTHERN LOWER. HAVE HIGHLIGHTED THIS
FORCING BY UPGRADING THE SOUTHEAST THIRD OF THE CWA TO ENTRY-LEVEL
LIKELY POPS FROM 15-21Z. ALSO LOWERED HIGHS A COUPLE DEGREES OVER
THE SOUTH TO ACCOUNT FOR EXPECTED ACTIVITY. OTHERWISE...SHOWER/STORM
ACTIVITY IS POSSIBLE IN THE MORNING ALONG THE SURFACE TROUGH. SEVERE
POTENTIAL DOES NOT LOOK TOO OVERWHELMING...ESPECIALLY IF MORNING
ACTIVITY HAMPERS DESTABILIZATION. MIDLEVEL LAPSE RATES ARE NOT
TOTALLY IMPRESSIVE AT 6-6.5 K/KM. IF PRECIP HOLDS OFF UNTIL LATER
AND SOME MORE RESPECTABLE INSTABILITY DEVELOPS...BULK SHEAR
INCREASING TO AROUND 30 KT COULD RESULT IN SOME BETTER ORGANIZED
ACTIVITY...BUT CONFIDENCE IS LOW IN THAT SCENARIO. LOCALLY HEAVY
RAIN WILL BE POSSIBLE GIVEN THE MOIST ENVIRONMENT...ESPECIALLY IN
ANY MORE ORGANIZED ACTIVITY. THE SOUTHWARD PUSH OF THE EAST/WEST
ORIENTED COLD FRONT SHOULD SPELL AN END TO MOST POPS AFTER
00Z...THOUGH IT IS NOT A VERY AGRESSIVE FRONTAL PUSH...SO LOW TEMPS
TUESDAY NIGHT SHOULD REMAIN IN THE 60S.
LOWER THETA-E AIR WILL CONTINUE TO FILTER IN ON WEDNESDAY AS SURFACE
ANTICYCLONE OVER ONTARIO ATTEMPTS TO EXPAND SOUTHWARD INTO LOWER MI.
THIS WILL BE COMPLICATED BY THE PASSAGE OF A MIDLEVEL SHORTWAVE
DURING THE DAY. MODEL SOUNDINGS SHOW A DECIDED LACK OF MIDLEVEL
MOISTURE HOWEVER...SO KEPT THE FORECAST DRY. GFS IS SHOWING MOISTURE
TRAPPED UNDER AN INVERSION AROUND 900MB FOR MOST OF THE DAY...SO
HAVE KEPT A DECENT AMOUNT OF CLOUD COVER AROUND UNTIL THE AFTERNOON.
HIGHS WILL BE A BIT COOLER THAN TUESDAY IN THE MID-70S TO NEAR 80.
THE HIGH WILL HAVE MORE SUCCESS BUILDING IN WEDNESDAY NIGHT AS DRIER
AIR CONTINUES TO FILTER IN...SO EXPECTING CLEARING SKIES AND LOWS
MAINLY IN THE 50S.
HIGH PRESSURE BUILDS SOUTHWARD INTO THE GREAT LAKES ON THURSDAY AND
WILL SLOWLY DRIFT EASTWARD THROUGH FRIDAY. THIS HIGH WILL ALLOW
DRY CONDITIONS TO STICK AROUND FOR THE END OF THE WEEK BEFORE A LOW
PRESSURE SYSTEM MOVES NORTHWARD TOWARDS SOUTHEAST MICHIGAN LATE
SATURDAY AND INTO SUNDAY. THE LOW WILL BRING RAIN SHOWERS AND
POSSIBLY THUNDERSTORMS TO THE AREA THROUGH THE FIRST PART OF NEXT WEEK. HIGH
TEMPERATURES ARE EXPECTED TO REMAIN STEADY THROUGH THE END OF THE
WEEK IN THE MID TO UPPER 70S BEFORE RISING INTO THE LOW TO MID 80S
FOR THE WEEKEND. LOW TEMPERATURES WILL REMAIN STEADY IN THE LOW TO
MID 60S THROUGH THE EXTENDED PERIOD.
&&
.MARINE...
ACTIVE STRETCH OF WEATHER WILL PERSIST INTO MID WEEK FOR THE EASTERN
GREAT LAKES AS A PAIR OF FRONTS WORK THROUGH THE AREA. THE FIRST
FRONT IS DRAPED ALONG A LINE FROM LAKE ONTARIO AND LAKE
ERIE...SOUTHWEST INTO THE OHIO VALLEY AND WILL PRODUCE SHOWERS AND
THUNDERSTORMS THROUGH TUESDAY. THIS WILL VEER WINDS FROM SOUTHERLY
TO WESTERLY. A SECOND COLD FRONT WILL DROP SOUTHWARD OUT OF CANADA
THROUGH THE EASTERN LAKES TUESDAY AND WEDNESDAY AND WILL USHER
NORTHERLY WINDS DOWN THROUGH LAKE HURON. A WEAK PRESSURE GRADIENT
WILL KEEP WINDS LIGHT THROUGH THE PERIOD...GENERALLY LESS THAN 15
KNOTS...WHICH IN TURN WILL KEEP THE WAVES IN CHECK.
&&
.AVIATION...ISSUED 1253 PM EDT MON JUN 23 2014
//DISCUSSION...
LOW VFR CONDITIONS AND LIGHT SHOWERS HAVE OVERSPREAD THE AREA EARLY
THIS AFTERNOON. SHOWERS AND A FEW EMBEDDED TSTORMS WILL PERSIST FOR
THE NEXT FEW HOURS BEFORE TAPERING EXITING TO THE EAST. AN ISOLATED
SHOWER OR THUNDERSTORM WILL THEN BE POSSIBLE INTO THE EVENING, WITH
THE NEXT ORGANIZED BATCH OF ACTIVITY EXPECTED TO MOVE THROUGH
BETWEEN 01Z-05Z. LOW CONFIDENCE IN COVERAGE FOR TONIGHT SO ELECTED
TO REDUCE PREVAILING -SHRA TO A PROB30 GROUP.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE IN CEILINGS BELOW 5KFT
* LOW CONFIDENCE IN TSTORMS AFFECTING KDTW
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...JVC
LONG TERM....DRK/RK
MARINE.......DRK
AVIATION.....JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
112 PM EDT MON JUN 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 522 AM EDT MON JUN 23 2014
WV IMAGERY AND RUC ANALYSIS INDICATED WSW FLOW INTO THE NRN LAKES
BETWEEN A MID/UPPER LEVEL TROUGH FROM MANITOBA INTO THE NRN PLAINS
AND A RIDGE FROM THE OHIO VALLEY INTO QUEBEC. AT THE SFC...A WEAK
TROUGH EXTENDED FROM NE MN INTO WRN WI. A MORE PROMINENT COLD FRONT
STRETCHED FROM JAMES BAY TO NEAR WINNIPEG AHEAD OF HIGH PRESSURE
OVER N CNTRL CANADA. FORCING FROM A WEAK SHRTWV IN NRN WI ALONG WITH
AN AXIS OF HIGHER MOISTURE WITH PWAT VALUES TO 1.4 INCHES...WAS
ENOUGH TO SUPPORT AN AREA OF SHOWERS OVER FROM SW UPPER MI INTO E
CNTRL WI.
TODAY...EXPECT THE SHRTWV AND AREA OF PCPN ONLY SLOWLY MOVE TO THE
EAST THIS MORNING. WITH ONLY WEAK LARGE SCALE FORCING EXPECTED INTO
THE AFTERNOON AND THE POTENTIAL FOR ANOTHER WEAK SHRTWV TO MOVE INTO
THE AREA DURING INCREASED DAYTIME HEATING...THE FCST KEEPS MENTION
OF JUST SCT SHRA WITH THE GREATEST COVERAGE EXPECTED OVER CNTRL
UPPER MI. WITH TEMPS CLIMBING INTO THE MID 70S...THERE MAY BE ENOUGH
INSTABILITY FOR SOME ISOLD/SCT TSRA AS MLCAPE VALUES CLIMB INTO THE
400-800 J/KG RANGE.
TONIGHT...WITH THE LOSS OF DAYTIME HEATING...THE PCPN COVERAGE
SHOULD DIMINISH. HOWEVER...INCREASED QVECTOR CONV AHEAD OF THE MID
LEVEL TROUGH MOVING INTO THE UPPER MS VALLEY WILL SUPPORT CONTINUED
CHANCES FOR SCT SHOWERS AND A FEW TSRA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 421 AM EDT MON JUN 23 2014
ON TUESDAY MORNING...THE MODELS ARE IN GOOD AGREEMENT IN SHOWING THE
COLD FRONT MOVING OVER OR JUST SOUTH OF THE AREA. HOWEVER...THE
850MB TROUGH AXIS HANGS UP OVER LAKE SUPERIOR AS THERE IS LACK OF A
SOUTHWARD PUSH DUE TO THE GENERAL ZONAL FLOW ALOFT. THIS WILL
PROVIDE THE FOCUS FOR PRECIPITATION ON TUESDAY ESPECIALLY SINCE THE
MODELS ARE IN EXCELLENT AGREEMENT IN SHOWING BROAD SYNOPTIC SUPPORT
MOVING THRU AS THE 500MB TROUGH AXIS MOVES THROUGH. AS SUCH...THERE
WILL LIKELY BE SCATTERED SHOWERS ACROSS THE ENTIRE FORECAST AREA
THROUGH THE DAY DESPITE THE SURFACE FRONT BEING SOUTH OF THE REGION.
THE NUMERICAL GUIDANCE ALSO SHOWS MUCAPE VALUES OF 500-1500 J/KG
ACROSS THE REGION DURING THE DAY WITH MID LEVEL LAPSE RATES OF 6+
C/KM...ALLOWING FOR POSSIBLE THUNDERSTORM DEVELOPMENT. BEST CHANCES
FOR THUNDER WOULD BE ACROSS THE SOUTHERN TIER WHERE SFC TEMPS WILL
LIKELY BE IN THE LOWER-MID 70S AND IS WHERE THE BEST INSTABILITY
WILL BE LOCATED. WILL NEED TO KEEP CHANCE POPS ACROSS THE EASTERN
HALF OF THE FORECAST AREA DURING THE TUE EVENING HOURS AS WELL GIVEN
REMAINING MID LEVEL FORCING AND REMAINING DAYTIME INSTABILITY.
AT THIS TIME...WEDNESDAY IS EXPECTED TO REMAIN DRY AND COOL WITH THE
850MB TROUGH AND SFC FRONT REMAINING SOUTH OF THE AREA. STILL SOME
WEAK TROUGHINESS AT 500MB AND AS SUCH WEAK MID LEVEL Q-VECTOR
CONVERGENCE AND MOISTURE PERSISTS ACROSS THE AREA ALL DAY.
HOWEVER...GIVEN LACK OF INSTABILITY AND VERY WEAK MID LEVEL LAPSE
RATES COMBINED WITH ANTICYCLONIC LOW LEVELS WILL KEEP IT DRY FOR
NOW. WOULD NOT BE SHOCKED TO SEE ISOLATED SHOWERS BUT CHANCES ARE
NOT HIGH ENOUGH TO INCLUDE IN THE FORECAST AT TIME TIME.
IN THE EXTENDED...ZONAL FLOW THROUGH THE PERIOD WILL MAKE TIMING OF
PRECIPITATION SOMEWHAT DIFFICULT ESPECIALLY INTO THE WEEKEND.
HOWEVER...THE LONGER RANGE MODELS ARE IN DECENT AGREEMENT ON THE
BROAD SCALE FEATURES WHICH AT LEAST GIVES SOME BASIC CONFIDENCE ON
WHEN THE BETTER CHANCES FOR RAIN WILL BE. ON THURSDAY...THE ECMWF
AND GFS BOTH SHOW A COMPACT VORT MAX MOVING ACROSS THE AREA DURING
THE DAY AS THE 850MB FRONT MOVES BACK NORTH. ALTHOUGH MOISTURE WILL
BE VERY LIMITED...WILL INCLUDE CHANCE POPS FOR THE WESTERN HALF OF
THE FORECAST AREA. BEHIND THIS VORT MAX...UPPER RIDGING BUILDS
ACROSS THE AREA FOR FRIDAY WHICH SHOULD ALLOW FOR TEMPS TO RETURN TO
NORMAL AS WELL AS DRY WEATHER. RETURN FLOW BEGINS IN EARNEST FOR THE
WEEKEND WITH TEMPERATURES LIKELY TO RISE ABOVE NORMAL...AND PERHAPS
A LITTLE MORE HUMIDITY AND SUMMER LIKE WEATHER. THIS WILL ALLOW FOR
CHANCES OF SHOWERS AND STORMS EACH DAY...ALTHOUGH SUNDAY LOOKS LIKE
THE BETTER CHANCE FOR SHOWERS AND STORMS GIVEN LOWERING HEIGHTS
ACROSS THE AREA IN RESPONSE TO THE APPROACHING TROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 111 PM EDT MON JUN 23 2014
VFR CONDITIONS ARE EXPECTED INTO THIS EVENING. WITH LIGHT WINDS AND
ABUNDANT LOW LEVEL MOISTURE REMAINING...FOG IS EXPECTED TO DEVELOP
TONIGHT WITH VLIFR CONDITIONS EXPECTED AT ALL SITES. WITH NORTH
WINDS TUE MORNING...A SLOW IMRPOVEMENT TO LIFR CONDITIONS ARE
EXPECTED WITH MOIST UPSLOPE FLOW CONTINUING TUE MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 522 AM EDT MON JUN 23 2014
DENSE FOG WILL PERSIST OVER WESTERN LAKE SUPERIOR INTO THIS
AFTERNOON. OTHERWISE...MAINLY LIGHT WINDS WILL PREVAIL INTO TONIGHT.
AS A COLD FRONT MOVES THROUGH THE AREA ON TUESDAY...NORTHEAST WINDS
WILL INCREASE TO 20 KNOTS WITH WAVES BUILDING TO AROUND 4 FEET.
WINDS WILL DIMINISH TUE NIGHT INTO WED AS HIGH PRES BUILDS INTO THE
REGION. MAINLY LIGHT WINDS AT OR BELOW 15 KNOTS ARE THEN EXPECTED
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 8 PM EDT /7 PM CDT/ TUESDAY FOR LSZ162-
240>248-263>265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1247 PM CDT MON JUN 23 2014
.UPDATE...
ISSUED AT 1148 AM CDT MON JUN 23 2014
UPDATE TO FURTHER REFINE PRECIP CHANCES THROUGH THE AFTERNOON.
WITH VERY SUBTLE FORCING AND LOW LEVEL MOISTURE LIMITED...COVERAGE
SHOULD ALSO BE LIMITED. BROAD AREA OF SC HAS DEVELOPED ACROSS THE
PORTIONS OF THE SANDHILLS WHICH MAY HAVE A LIMITING FACTOR ON HOW
FAST TEMPS RISE THIS AFTERNOON. BELIEVE MODELS PICKING UP ON THIS
AREA AS LOCATION OF SHRA/TSRA BUT LITTLE VERTICAL DEVELOPMENT
NOTED ON VISIBLE SAT PICS AT THIS TIME...AND MID LEVEL LAPSE RATES
ARE NOT CONDUCIVE YET FOR THAT. HIGHER TERRAIN FURTHER WEST SHOULD
BE THE INITIATION FOR TSRA DEVELOPMENT LATER THIS AFTERNOON AND
CONFIDENCE IS LOW THAT MUCH WILL ENTER THE FORECAST AREA UNTIL
LATER THIS EVENING...AFTER A MORE ORGANIZED CONVECTIVE SYSTEM
EMERGES FROM NERN CO AND MOVES EWD.
UPDATE ISSUED AT 929 AM CDT MON JUN 23 2014
AS MCS CONTINUES TO WEAKEN AND MOVE OUT CI SHIELD ALSO PROGRESSING
EWD. VISIBLE SAT PICS INDICATING POCKETS OF ELEVATED INSTABILITY
IN THE FORM OF ENHANCEMENT OF AC LIKELY ON LEFTOVER BOUNDARIES.
SHORT TERM MODELS CONTINUE TO SHOW SOME THREAT OF ISOLD SHOWERS
AND MAYBE A COUPLE TSRA THROUGH THE MORNING INTO EARLY AFTERNOON
LIKELY AS RESULT OF LOCAL CONVERGENCE ENHANCEMENT AS SUBTLE UPPER
PV ANOMALY MOVES OUT OF SRN WY. WILL HAVE TO INVESTIGATE THIS A
BIT MORE FOR THE AFTERNOON IN ORDER TO FURTHER REFINE BEST PRECIP
CHANCES. OTHERWISE TEMPS AND DEW POINTS LOOK ON TRACK FOR NOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 319 AM CDT MON JUN 23 2014
ANOTHER MCS SHOULD DROP THROUGH THE CNTL HIGH PLAINS THIS AFTN. THE
FORECAST USES 50 PERCENT OF THE RAP MODEL AND 50 PERCENT OF THE
OTHER MODELS.
THE ONGOING MCS APPEARS TO BE TAKING ON A CYCLONIC ROTATION WITH THE
WARM SECTOR ACROSS SCNTL NEB AND THE UPPER LEVEL COLD POOL ACROSS
SWRN NEB ATTM. RADAR TRENDS SUGGEST THIS SYSTEM COULD ROTATE THROUGH
SCNTL NEB THIS MORNING AND SHOWERS AND TSTMS ARE POPPING LEFT AND
RIGHT BETWEEN KLBF AND KLXN.
FOR TONIGHT...NEBULOUS POPS ARE IN THE FCST ACROSS THE SANDHILLS AND
AREAS SOUTH. GIVEN THE INABILITY OF THE SYNOPTIC SCALE MODELS TO
PREDICT NOCTURNAL RAIN EVENTS OF LATE...THE FCST IS FORCED TO
MAINTAIN A SCATTERED POP.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 319 AM CDT MON JUN 23 2014
12Z TUESDAY AND BEYOND. NEAR DAILY PRECIPITATION CHANCES TO
HEADLINE THE EXTENDED DISCUSSION THROUGH AT LEAST SATURDAY AS THE
ACTIVE PATTERN CONTINUES.
A BRIEF PERIOD OF NORTHWEST FLOW ALOFT WILL DIRECT TWO SUBTLE
DISTURBANCES ACROSS THE CENTRAL PLAINS TUESDAY INTO WEDNESDAY. THE
FIRST OF WHICH SHOULD BE EAST OF THE CWA BY 12Z TUESDAY. THERE
REMAINS GOOD CONSENSUS HOWEVER THAT THUNDER CHANCES REMAIN THROUGH
MUCH THE DAY AS THE NEXT DISTURBANCE FOLLOWS. THE ATMOSPHERE WILL
CHARACTERIZED AS MODERATELY UNSTABLE...WITH GENERALLY 25-40 KTS OF
DEEP LAYER SHEAR. STRONG TO SEVERE STORMS ARE ANTICIPATED...BUT
POSSIBLY THE GREATER IMPACT WILL BE HEAVY RAINFALL POTENTIAL AS
THERE/S SUPPORT OF ONE OR MORE MCS/S PASSING THROUGH THE SANDHILLS
REGION. STORM MOTION WILL BE ON THE SLOW SIDE...GENERALLY LESS THAN
20KTS...AND WITH PWATS INCREASING OVER AN INCH AND A
THIRD...RAINFALL RATES OF AN INCH OR TWO AN HOUR WILL BE POSSIBLE.
UPPER LOW PRESSURE TO BUILD EAST INTO THE PACIFIC NORTHWEST
WEDNESDAY ALLOWING THE EASTWARD DEVELOPMENT OF A LOW AMPLITUDE
TRANSITORY RIDGE. PRECIPITATION CHANCES CONTINUE ON WEDNESDAY AS
THE NEXT WAVE EMBEDDED IN THE NOW QUASI-ZONAL FLOW IMPACTS THE
REGION. TIMING AND PLACEMENT OF THE BETTER PRECIPITATION CHANCES
WILL BE GENERALLY TIED TO THE LOCATION OF A LOW LEVEL FRONTAL
BOUNDARY AND HOW CONVECTION FROM THE PREVIOUS DAY PLAYS OUT. AT
THIS TIME THE MODELS ARE FAVORING NORTHERN NEBRASKA WITH THE HIGHER
POP CHANCES /40 PERCENT/ WEDNESDAY AFTERNOON...WILL FOLLOW SUIT WITH
THE FORECAST. THE AFOREMENTIONED RIDGE MAY EFFECTIVELY CAP THE
REGION ON THURSDAY AS MIDLEVEL TEMPS WARM AOA 14C...AT THIS POINT
WILL KEEP MOST OF THE CWA DRY THURSDAY WITH THE EXCEPTION BEING
THURSDAY NIGHT ACROSS OUR NORTHERN BORDER WHERE RIDGE RIDING WAVE
MAY SPARK CONVECTION. FOR LATE WEEK AND THE WEEKEND...FORECAST
CONFIDENCE IS NOT QUITE THERE YET AS THE FINER DETAILS OF HOW THE
WESTERN CONUS TROUGH WILL PLAY OUT ARE STILL AN ENIGMA. IN THE
SYNOPTIC SCALE THERE REMAINS GOOD AGREEMENT OF A FAIRLY STRONG
TROUGH ADVANCING INTO THE NORTHERN ROCKIES WITH MOST OF THE
FAVORABLE UPPER LEVEL ENERGY TARGETING THE NORTHERN PLAINS. SOLID
MOISTURE RETURN AND WARMING TEMPERATURES WILL BE IN PLACE ACROSS THE
CENTRAL PLAINS...WITH A FRONTAL PASSAGE/SFC TROUGH FOR THE WEEKEND.
STORMS...POSSIBLY SEVERE WILL ONCE AGAIN BE POSSIBLE....BUT WITH
LACKING CONSISTENCY...WILL CAP POP CHANCES AT 40 PERCENT OR LESS
THROUGH THE WEEKEND. AS FOR TEMPERATURES...A GRADUAL WARMING TREND
IS ANTICIPATED THROUGH THE END OF THE WORK WEEK...WITH HIGHS
GENERALLY IN THE 80S...LOWS WILL BE SEASONAL IN THE 50 AND 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1246 PM CDT MON JUN 23 2014
GENERALLY VFR CONDITIONS FOR BOTH TAF SITES THROUGH THE PERIOD.
THE USUAL CONVEATS EXISTS HOWEVER IN THE SUMMER CONVECTIVE SEASON
WITH THE POSSIBILITY OF ISOLATED TSRA IN THE AREA. SHORT RANGE
MODELS INCLUDING CAMS SUCH AS THE HRRR...CONTINUE TO INDICATE
ISOLATED TSRA POTENTIAL MOVING FROM THE WRN SANDHILLS SEWD THIS
AFTERNOON...MUCH LIKE YDAY. CURRENT CLOUD COVER ACROSS THE
PANHANDLE INTO THE WRN SANDHILLS SUGGESTS BROAD CONVERGENCE
THERE...BUT NOTHING FOCUSED AND THIS IS CONFIRMED IN SPC/LAPS MESO
GUIDANCE. HAVE LEFT ANY MENTION OUT FOR THE AFTERNOON OF TAFS DUE
TO LOW CONFIDENCE IN ANY PARTICULAR MODEL SOLUTION...AND LIMITED
COVERAGE SHOULD SOMETHING DEVELOP.
OF GREATER INTEREST WOULD BE THE EVOLUTION OF A CONVECTIVE SYSTEM
MOVING OUT OF THE CO FRONT RANGE LATER THIS EVENING AND POSSIBLY
AFFECTING THE KLBF TAF IN THE 05-12Z TIME FRAME. AGAIN HAVE LEFT
MENTION OF PRECIP OUT FOR NOW AS MOST SHORT TERM MODELS TAKE THE
SYSTEM INTO NWRN KS...THOUGH A MID LEVEL CIG WILL BE POSSIBLE WITH
SUCH A SOLUTION.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JWS
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...JWS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1149 AM CDT MON JUN 23 2014
.UPDATE...
ISSUED AT 1148 AM CDT MON JUN 23 2014
UPDATE TO FURTHER REFINE PRECIP CHANCES THROUGH THE AFTERNOON.
WITH VERY SUBTLE FORCING AND LOW LEVEL MOISTURE LIMITED...COVERAGE
SHOULD ALSO BE LIMITED. BROAD AREA OF SC HAS DEVELOPED ACROSS THE
PORTIONS OF THE SANDHILLS WHICH MAY HAVE A LIMITING FACTOR ON HOW
FAST TEMPS RISE THIS AFTERNOON. BELIEVE MODELS PICKING UP ON THIS
AREA AS LOCATION OF SHRA/TSRA BUT LITTLE VERTICAL DEVELOPMENT
NOTED ON VISIBLE SAT PICS AT THIS TIME...AND MID LEVEL LAPSE RATES
ARE NOT CONDUCIVE YET FOR THAT. HIGHER TERRAIN FURTHER WEST SHOULD
BE THE INITIATION FOR TSRA DEVELOPMENT LATER THIS AFTERNOON AND
CONFIDENCE IS LOW THAT MUCH WILL ENTER THE FORECAST AREA UNTIL
LATER THIS EVENING...AFTER A MORE ORGANIZED CONVECTIVE SYSTEM
EMERGES FROM NERN CO AND MOVES EWD.
UPDATE ISSUED AT 929 AM CDT MON JUN 23 2014
AS MCS CONTINUES TO WEAKEN AND MOVE OUT CI SHIELD ALSO PROGRESSING
EWD. VISIBLE SAT PICS INDICATING POCKETS OF ELEVATED INSTABILITY
IN THE FORM OF ENHANCEMENT OF AC LIKELY ON LEFTOVER BOUNDARIES.
SHORT TERM MODELS CONTINUE TO SHOW SOME THREAT OF ISOLD SHOWERS
AND MAYBE A COUPLE TSRA THROUGH THE MORNING INTO EARLY AFTERNOON
LIKELY AS RESULT OF LOCAL CONVERGENCE ENHANCEMENT AS SUBTLE UPPER
PV ANOMALY MOVES OUT OF SRN WY. WILL HAVE TO INVESTIGATE THIS A
BIT MORE FOR THE AFTERNOON IN ORDER TO FURTHER REFINE BEST PRECIP
CHANCES. OTHERWISE TEMPS AND DEW POINTS LOOK ON TRACK FOR NOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 319 AM CDT MON JUN 23 2014
ANOTHER MCS SHOULD DROP THROUGH THE CNTL HIGH PLAINS THIS AFTN. THE
FORECAST USES 50 PERCENT OF THE RAP MODEL AND 50 PERCENT OF THE
OTHER MODELS.
THE ONGOING MCS APPEARS TO BE TAKING ON A CYCLONIC ROTATION WITH THE
WARM SECTOR ACROSS SCNTL NEB AND THE UPPER LEVEL COLD POOL ACROSS
SWRN NEB ATTM. RADAR TRENDS SUGGEST THIS SYSTEM COULD ROTATE THROUGH
SCNTL NEB THIS MORNING AND SHOWERS AND TSTMS ARE POPPING LEFT AND
RIGHT BETWEEN KLBF AND KLXN.
FOR TONIGHT...NEBULOUS POPS ARE IN THE FCST ACROSS THE SANDHILLS AND
AREAS SOUTH. GIVEN THE INABILITY OF THE SYNOPTIC SCALE MODELS TO
PREDICT NOCTURNAL RAIN EVENTS OF LATE...THE FCST IS FORCED TO
MAINTAIN A SCATTERED POP.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 319 AM CDT MON JUN 23 2014
12Z TUESDAY AND BEYOND. NEAR DAILY PRECIPITATION CHANCES TO
HEADLINE THE EXTENDED DISCUSSION THROUGH AT LEAST SATURDAY AS THE
ACTIVE PATTERN CONTINUES.
A BRIEF PERIOD OF NORTHWEST FLOW ALOFT WILL DIRECT TWO SUBTLE
DISTURBANCES ACROSS THE CENTRAL PLAINS TUESDAY INTO WEDNESDAY. THE
FIRST OF WHICH SHOULD BE EAST OF THE CWA BY 12Z TUESDAY. THERE
REMAINS GOOD CONSENSUS HOWEVER THAT THUNDER CHANCES REMAIN THROUGH
MUCH THE DAY AS THE NEXT DISTURBANCE FOLLOWS. THE ATMOSPHERE WILL
CHARACTERIZED AS MODERATELY UNSTABLE...WITH GENERALLY 25-40 KTS OF
DEEP LAYER SHEAR. STRONG TO SEVERE STORMS ARE ANTICIPATED...BUT
POSSIBLY THE GREATER IMPACT WILL BE HEAVY RAINFALL POTENTIAL AS
THERE/S SUPPORT OF ONE OR MORE MCS/S PASSING THROUGH THE SANDHILLS
REGION. STORM MOTION WILL BE ON THE SLOW SIDE...GENERALLY LESS THAN
20KTS...AND WITH PWATS INCREASING OVER AN INCH AND A
THIRD...RAINFALL RATES OF AN INCH OR TWO AN HOUR WILL BE POSSIBLE.
UPPER LOW PRESSURE TO BUILD EAST INTO THE PACIFIC NORTHWEST
WEDNESDAY ALLOWING THE EASTWARD DEVELOPMENT OF A LOW AMPLITUDE
TRANSITORY RIDGE. PRECIPITATION CHANCES CONTINUE ON WEDNESDAY AS
THE NEXT WAVE EMBEDDED IN THE NOW QUASI-ZONAL FLOW IMPACTS THE
REGION. TIMING AND PLACEMENT OF THE BETTER PRECIPITATION CHANCES
WILL BE GENERALLY TIED TO THE LOCATION OF A LOW LEVEL FRONTAL
BOUNDARY AND HOW CONVECTION FROM THE PREVIOUS DAY PLAYS OUT. AT
THIS TIME THE MODELS ARE FAVORING NORTHERN NEBRASKA WITH THE HIGHER
POP CHANCES /40 PERCENT/ WEDNESDAY AFTERNOON...WILL FOLLOW SUIT WITH
THE FORECAST. THE AFOREMENTIONED RIDGE MAY EFFECTIVELY CAP THE
REGION ON THURSDAY AS MIDLEVEL TEMPS WARM AOA 14C...AT THIS POINT
WILL KEEP MOST OF THE CWA DRY THURSDAY WITH THE EXCEPTION BEING
THURSDAY NIGHT ACROSS OUR NORTHERN BORDER WHERE RIDGE RIDING WAVE
MAY SPARK CONVECTION. FOR LATE WEEK AND THE WEEKEND...FORECAST
CONFIDENCE IS NOT QUITE THERE YET AS THE FINER DETAILS OF HOW THE
WESTERN CONUS TROUGH WILL PLAY OUT ARE STILL AN ENIGMA. IN THE
SYNOPTIC SCALE THERE REMAINS GOOD AGREEMENT OF A FAIRLY STRONG
TROUGH ADVANCING INTO THE NORTHERN ROCKIES WITH MOST OF THE
FAVORABLE UPPER LEVEL ENERGY TARGETING THE NORTHERN PLAINS. SOLID
MOISTURE RETURN AND WARMING TEMPERATURES WILL BE IN PLACE ACROSS THE
CENTRAL PLAINS...WITH A FRONTAL PASSAGE/SFC TROUGH FOR THE WEEKEND.
STORMS...POSSIBLY SEVERE WILL ONCE AGAIN BE POSSIBLE....BUT WITH
LACKING CONSISTENCY...WILL CAP POP CHANCES AT 40 PERCENT OR LESS
THROUGH THE WEEKEND. AS FOR TEMPERATURES...A GRADUAL WARMING TREND
IS ANTICIPATED THROUGH THE END OF THE WORK WEEK...WITH HIGHS
GENERALLY IN THE 80S...LOWS WILL BE SEASONAL IN THE 50 AND 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 611 AM CDT MON JUN 23 2014
VFR IS EXPECTED EAST OF HIGHWAY 83 TODAY. SCATTERED TSTM ACTIVITY
IS EXPECTED WEST OF HIGHWAY 83...MAINLY FROM 18Z ONWARD AS STORMS
DEVELOP NORTH AND MOVE SOUTH.
TONIGHT...THE FORECAST IS UNCERTAIN AS THE MODELS SUGGEST A SECOND
AREA OF TSTMS WILL DEVELOP ACROSS THE CNTL SANDHILLS AND CONTINUE
THROUGHOUT THE NIGHT. LATER FORECASTS USING THE RAP MODEL WILL
HOPEFULLY CLARIFY THIS AS THE SYNOPTIC SCALE MODELS HAVE SHOWN
POOR SKILL FORECASTING STORM DEVELOPMENT LATELY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JWS
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1241 PM CDT MON JUN 23 2014
.SYNOPSIS...
ISSUED AT 324 AM CDT MON JUN 23 2014
REX BLOCKING OVER THE CANADIAN PRAIRIE IS FORECAST TO BREAK DOWN
ON WEDNESDAY...BUT THERE IS GOOD AGREEMENT THAT THE NORTHEAST
PACIFIC UPPER LEVEL LOW WILL BROADEN FURTHER INTO NORTHWESTERN
CONUS...AND EVENTUALLY INTO THE NORTHERN PLAINS. SCATTERED SHOWERS
AND THUNDERSTORMS WILL TRANSITION TO HIGHER CHANCES OF
THUNDERSTORMS AS SOUTHWESTERLY FLOW ALOFT MOVES OVER THE DAKOTAS
LATER THIS WEEK.
&&
.UPDATE...
ISSUED AT 1231 PM CDT MON JUN 23 2014
SHOWERS CONTINUE TO DEVELOP OVER NORTHERN NORTH DAKOTA IN CYCLONIC
FLOW. FOR EARLY AFTERNOON UPDATE HAVE BUMPED UP POPS OVER THE
NORTHERN TIER AS COVERAGE CONTINUES TO INCREASE AND HAVE PULLED
POPS SOUTH A BIT FURTHER. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 841 AM CDT MON JUN 23 2014
CURRENT FORECAST REMAINS IN PRETTY GOOD SHAPE WITH UPPER LOW/TROF
NEAR LAKE WINNIPEG CONTINUING TO SAG TO THE SOUTHEAST WHILE COOL
FRONT WORKS ITS WAY INTO THE AREA. STILL EXPECT SHOWERS AND
THUNDERSTORMS TO DEVELOP FROM NORTH TO SOUTH TODAY AS THESE
FEATURES WORK THEIR WAY INTO THE STATE.
UPDATE ISSUED AT 639 AM CDT MON JUN 23 2014
CYCLONIC FLOW ALOFT WITH SHORTWAVE TROUGH MOVING THROUGH SOUTHWEST
NORTH DAKOTA. THIS GENERATING HIGH CLOUDS AND SOME VIRGA WITH NO
PRECIP SO FAR REACHING THE GROUND. OTHERWISE MAIN FEATURE TODAY
WILL BE THE UPPER LEVEL OW ACROSS SOUTHERN CANADA WHICH WILL MOVE
SOUTH TODAY AND TONIGHT BRINGING SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT MON JUN 23 2014
SCATTERED SHOWERS AND THUNDERSTORMS ARE FORECAST TODAY WITH PEAK
HEATING...BUT THERE IS UNCERTAINTY ABOUT HOW MUCH INSTABILITY
WILL DEVELOP. THE MOST RECENT TWO HRRR RUNS HAVE INCREASED THEIR
COVERAGE OF THUNDERSTORMS EMBEDDED WITHIN RAIN SHOWERS. CAPPED THE
COVERAGE OF THUNDERSTORMS TO SCATTERED FOR TODAY AND TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 324 AM CDT MON JUN 23 2014
JUST A REMNANT OF THE PERSISTENT UPPER LOW WILL REMAIN ACROSS NORTH
DAKOTA ON TUESDAY. THIS UPPER FEATURE ACCOMPANIED BY AN ASSOCIATED
SURFACE FRONTAL BOUNDARY WILL HELP FOCUS SHOWERS AND SCATTERED
THUNDERSTORMS ACROSS THE CENTRAL AND NORTH TUESDAY AFTERNOON. TUESDAY
NIGHT ACTIVITY WILL BE MINIMAL AS THE COLD FRONT REMAINS SOUTH OF
THE STATE...BECOMING STATIONARY...TO RETURN EVENTUALLY WEDNESDAY
NIGHT AND THURSDAY AS A WARM FRONTAL BOUNDARY IN ADVANCE OF A
WESTERN UPPER TROUGH. THIS H500 TROUGH AND SURFACE WARM FRONT
WILL BE THE FOCUS FOR AN ACTIVE THUNDERSTORM PERIOD THURSDAY NIGHT
INTO FRIDAY NIGHT. MODELS SUGGEST SEVERAL MCS TYPE SYSTEMS
SPREADING THUNDERSTORMS INTO THE REGION AND WILL BE MONITORING THE
POTENTIAL FOR MODERATE TO HEAVY RAIN DURING THIS TIME FRAME. POPS
REMAIN LIKELY FRIDAY NIGHT INTO SATURDAY FOR THIS.
POPS TRAIL OFF INTO 20 TO 30S SUNDAY AFTER THE PASSAGE OF THE
SHORTWAVE TROUGH/COLD FRONT. TEMPERATURES DURING THE EXTENDED LOOK
NEAR OR SLIGHTLY BELOW NORMAL WITH HIGHS IN THE 70S TO AROUND 80.
LOWS IN THE 50S TO NEAR 60.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1231 PM CDT MON JUN 23 2014
SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE TO SPREAD FROM NORTH
TO SOUTH OVER THE AREA TODAY...BRINGING LCL MVFR CIGS.
TONIGHT...SOME AREAS OF FOG MAY DEVELOP PARTICULARLY OVER NORTHERN
NORTH DAKOTA WHERE AREAS OF IFR CONDITIONS ARE EXPECTED AFFECTING
THE KISN AND KMOT TERMINALS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SYNOPSIS...SCHECK
SHORT TERM...SCHECK
LONG TERM...WAA
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
402 PM EDT MON JUN 23 2014
.SYNOPSIS...
MUGGY AIR DOMINATES. CONVECTION COVERAGE INCREASES TUESDAY
AFTERNOON AND TUESDAY NIGHT...AS A COLD FRONT APPROACHES. FRONT
CREEPS THROUGH DURING WEDNESDAY. DRIER AND MORE STABLE AIR EXPECTED
THURSDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
DECENT FIELD OF CUMULUS ACROSS THE FORECAST AREA THIS AFTERNOON
WITH CLOUDS EXPANDING IN AREAL COVERAGE. CLOUDS HAVE BEEN CAPPED
SO FAR...BUT THERE MAY BE ENOUGH UPDRAFT STRENGTH TO KICK OFF A
FEW SHOWERS...ESPECIALLY OVER THE MOUNTAINS. KEEPING ISOLD
ACTIVITY GOING FOR NOW...AND WILL ALLOW FOR A CONTINUATION OF
ISOLD POPS INTO THIS EVENING. LATEST RUC HINTS AT A WEAK SHORTWAVE
AT THE MID LEVELS OVER NORTHERN WV WHICH STILL MAY ACT AS A
TRIGGER INTO THE EVENING HOURS.
MOISTURE INCREASES LATE TONIGHT AS QUASI STATIONARY FRONT SLIDES
SLOWLY EASTWARD FROM CENTRAL KY. CONTINUED TREND OF RAMPING UP
POPS LATE IN THE PERIOD.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
PRECIPITABLE WATER MAXES OUT 1.8 TO 2 INCHES OVERNIGHT TUESDAY NIGHT
BEFORE LOWERING WEDNESDAY AFTERNOON AND EVENING. THE MAIN MID LEVEL
SUPPORT LIFTS NORTHEAST THROUGH NORTHERN OHIO INTO WESTERN NEW YORK
BY 12Z WEDNESDAY. WEAKER 500 MB SUPPORT...WITH THE WEAKENING TROF
SWINGS THROUGH OUR CWA AFTER 06Z WEDNESDAY. SO MID LEVEL SUPPORT
ARRIVES WELL AFTER MAXIMUM HEATING.
WAS A BIT SLOWER TUESDAY EVENING...TRYING TO INCREASE POPS ACROSS
SOUTHERN AND EASTERN COUNTIES. STILL QUESTIONABLE ON COVERAGE ACROSS
EXTREME SOUTHERN WEST VIRGINIA INTO SOUTHWEST VIRGINIA OVERNIGHT
TUESDAY NIGHT.
WILL HOLD SOME HIGHER LIKELY POPS LONGER WEDNESDAY MORNING IN MANY
COUNTIES FROM I-79 EAST. THOUGH...ON WEDNESDAY THE COVERAGE OF
THUNDER FORECAST TO BE LESS WITH ABUNDANT CLOUDS EXPECTED.
700 MB STEERING FLOW IS ABOUT 20 KNOTS ON BOTH SIDE OF THIS TROF.
YET...WILL CONSIDER ADDING A HAZARD TO THE HAZARDOUS WEATHER
POTENTIAL TO A PORTION OF OUR CWA...FOR KEEPING AN EYE ON RAIN
AMOUNTS AND SMALL STREAM FLASH FLOODING.
THERE MAY BE SOME FOG DEVELOPING FOR 06Z TO 12Z THURSDAY...BUT
CLOUDS AND LOW STRATUS MAY HINDER THICK SURFACE FOG. SO DID NOT
INCLUDE THICK FOG IN WEATHER GRIDS AT THIS DISTANCE.
BASED ON FORECAST SOUNDINGS...REMOVED POPS ON THURSDAY AND THURSDAY
NIGHT...BUT NOT SURE HOW MUCH THE SURFACE DEW POINT WILL LOWER.
HAVE 60 TO 65 DEW POINTS FORECAST NOW IN THE AFTERNOON.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ANOTHER WEAKENING MID LEVEL TROF EXPECTED TO BE LIFTING NORTHEAST IN
THE LOWER OHIO VALLEY INTO THE MIDWEST ON FRIDAY INTO SATURDAY.
STILL QUESTIONABLE ABOUT THE COVERAGE OF CONVECTION ASSOCIATED WITH
IT...SO NO LIKELY POPS. WAS SLOWER TRYING TO INCREASE POPS ACROSS
NORTHERN AND EASTERN COUNTIES ON FRIDAY.
OVERALL THOUGH...500 MB HEIGHTS WILL BE BUILDING FOR THOSE LAST FEW
DAYS OF JUNE. AS A RESULT...WENT A FEW DEGREES HIGHER THAN WPC
MAXIMUM TEMPERATURE GUIDANCE FOR SUNDAY AND MONDAY.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
FIELD OF CU NOTED ON THIS AFTERNOONS SATELLITE IMAGERY WILL
CONTINUE TO EXPAND IN AREAL COVERAGE. DAYTIME HEATING MAY BE
ENOUGH TO CAUSE A FEW UPDRAFTS TO BREAK THE CAP TO ALLOW FOR ISOLD
CONVECTION. OTHERWISE VFR CONDITIONS EXPECTED THROUGH THIS
EVENING. SOME BL DECOUPLING WILL ALLOW FOR SOME FOG DEVELOPMENT
ALONG RIVERS AND IN VALLEYS. EXPECT COVERAGE AND DENSITY OF FOG TO
BE DOWN FROM PAST SEVERAL NIGHTS DUE TO INCREASE IN CLOUDS AND
GRADIENT FLOW. CAN NOT RULE OUT DEVELOPMENT ENTIRELY THOUGH.
INCREASING MOISTURE BY 12Z TIME FRAME WITH FRONT INCHING CLOSER FROM
THE WEST WILL HELP LEAD TO AN UPSWING IN CONVECTION TOWARD END OF
PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND COVERAGE OF SHOWERS AND STORMS MAY
NEED PREVAILING OR TEMPO IN THE TAF.
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 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
CRW CONSISTENCY H H H H H H H H H H H M
HTS CONSISTENCY H H H H H H H H H H H M
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H M M M H L
PKB CONSISTENCY H H H H H H H H H H H M
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z TUESDAY...
IFR POSSIBLE IN SHOWERS/THUNDERSTORMS WEDNESDAY WITH STRATUS/FOG AT
WEDNESDAY NIGHT INTO THURSDAY MORNING FOR SITES RECEIVING RAIN.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KMC/KTB
NEAR TERM...KMC
SHORT TERM...KTB
LONG TERM...KTB
AVIATION...KMC/KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
152 PM EDT MON JUN 23 2014
.SYNOPSIS...
CONVECTION CHANCES INCREASE SLOWLY THROUGH TUESDAY AS A COLD FRONT
APPROACHES AND ARRIVES WEDNESDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
DECENT FIELD OF CUMULUS ACROSS THE FORECAST AREA THIS AFTERNOON
WITH CLOUDS EXPANDING IN AREAL COVERAGE. CLOUDS HAVE BEEN CAPPED
SO FAR...BUT THERE MAY BE ENOUGH UPDRAFT STRENGTH TO KICK OFF A
FEW SHOWERS...ESPECIALLY OVER THE MOUNTAINS. KEEPING ISOLD
ACTIVITY GOING FOR NOW...AND WILL ALLOW FOR A CONTINUATION OF
ISOLD POPS INTO THIS EVENING. LATEST RUC HINTS AT A WEAK SHORTWAVE
AT THE MID LEVELS OVER NORTHERN WV WHICH STILL MAY ACT AS A
TRIGGER INTO THE EVENING HOURS.
MOISTURE INCREASES LATE TONIGHT AS QUASI STATIONARY FRONT SLIDES
SLOWLY EASTWARD FROM CENTRAL KY. CONTINUED TREND OF RAMPING UP
POPS LATE IN THE PERIOD.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
A VERY WARM AND HUMID AIRMASS...AND A VIGOROUS LEAD SHORT WAVE AHEAD
OF AN APPROACHING COLD FRONT...WILL ACT TO BRING WIDESPREAD SHOWERS
AND THUNDERSTORMS MAINLY TUESDAY AFTERNOON AND TUESDAY NIGHT. MODELS
AGREE PRETTY WELL ON THE TIMING OF THE LEAD WAVE AND GOOD PROSPECTS
FOR RAIN. TEMPERATURES WILL NOT BE AS HIGH TUESDAY DUE TO THE CLOUDS
AND SHOWERS...BUT SHOULD STILL REACH THE LOWER TO MID 80S...AND IT
WILL REMAIN QUITE HUMID. TEMPS TUESDAY NIGHT WILL BE WARM WITH
TEMPERATURES STRUGGLING TO DROP BELOW 70.
AS FAR AS THE FRONT IS CONCERNED...MODELS DIFFER ON WHETHER THE
FRONT IS STRONG ENOUGH TO ACTUALLY MOVE EASTWARD ACROSS THE AREA
BEHIND THE SHORT WAVE...AS FLOW ALOFT TURNS MORE WESTERLY OR
NORTHWESTERLY. THE GFS AND CMC MODELS MANAGE TO DRIVE THE FRONT EAST
OF THE AREA LATER WEDNESDAY...WITH THE NAM AND EURO MODELS SLOWLY
DISSIPATING THE FRONT AS IT MOVE INTO THE AREA WEDNESDAY. IT
WILL...IN ANY CASE...LAG BEHIND THE MAIN SHORT WAVE WHICH DEPARTS
WEDNESDAY MORNING. DESPITE MUCH OF THE UPPER DYNAMICS DEPARTING WITH
THE SHORT WAVE...AND WHETHER THE FRONT MAKES IT OR
DISSIPATES...THERE WILL BE A WARM AND HUMID AIRMASS AHEAD OF THE
FRONT TO CONTINUE A CHANCE OF SHOWERS AND STORMS WEDNESDAY.
THEREAFTER...ENOUGH DRIER AIR ALOFT FINALLY MOVES IN FOR THURSDAY AND
MUCH OF FRIDAY TO MAKE MOST OF THE AREA RAIN FREE. WHETHER THE FRONT
MAKES IT OR NOT...THERE WILL NOT BE MUCH OF A TEMPERATURE DIFFERENCE
FOR HIGHS..WITH TEMPS STILL REACHING INTO THE 80S.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
A SOMEWHAT TYPICAL LATE-JUNE PATTERN WILL CONTINUE IN THE EXTENDED
PERIOD...CHARACTERIZED BY WARM AND MUGGY DAYS WITH AT LEAST A SLIGHT
CHANCE OF A SHOWER AND/OR THUNDERSTORM EVERY DAY. HIGHER CHANCES OF
PRECIP ARE CENTERED ON TWO DISTURBANCES...ONE ON FRIDAY AND THE
OTHER NEAR WEEKEND/S END INTO SUNDAY NIGHT/EARLY MON. AFOREMENTIONED
TEMPERATURES WILL BE NEAR SEASONAL...WITH NO REAL HEAT WAVES OR COOL
PERIODS FORESEEN.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
FIELD OF CU NOTED ON THIS AFTERNOONS SATELLITE IMAGERY WILL
CONTINUE TO EXPAND IN AREAL COVERAGE. DAYTIME HEATING MAY BE
ENOUGH TO CAUSE A FEW UPDRAFTS TO BREAK THE CAP TO ALLOW FOR ISOLD
CONVECTION. OTHERWISE VFR CONDITIONS EXPECTED THROUGH THIS
EVENING. SOME BL DECOUPLING WILL ALLOW FOR SOME FOG DEVELOPMENT
ALONG RIVERS AND IN VALLEYS. EXPECT COVERAGE AND DENSITY OF FOG TO
BE DOWN FROM PAST SEVERAL NIGHTS DUE TO INCREASE IN CLOUDS AND
GRADIENT FLOW. CAN NOT RULE OUT DEVELOPMENT ENTIRELY THOUGH. INCREASING
MOISTURE BY 12Z TIME FRAME WITH FRONT INCHING CLOSER FROM THE WEST
WILL HELP LEAD TO AN UPSWING IN CONVECTION TOWARD END OF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND COVERAGE OF SHOWERS AND STORMS MAY
NEED PREVAILING OR TEMPO IN THE TAF.
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 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H M M M
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H M M M L
PKB CONSISTENCY H H H H H H M M M M M M
CKB CONSISTENCY H H H H H H M H H H H H
AFTER 18Z TUESDAY...
IFR POSSIBLE IN IN THUNDERSTORMS WEDNESDAY WITH STRATUS/FOG AT
NIGHT FOR SITES RECEIVING RAIN.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...KMC
SHORT TERM...JMV
LONG TERM...50
AVIATION...KMC
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
102 PM CDT MON JUN 23 2014
.DISCUSSION...
18Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
WIDELY SCATTERED SHOWERS...WITH LOCALLY HEAVY RAIN...AND EMBEDDED
ISOLATED THUNDERSTORMS WEST OF METRO MOVING UP AHEAD OUT A LINE
OF SHOWERS CREATED UPON NORTH CENTRAL TEXAS CONVECTIVE OUTFLOW NOW
PASSING OVER THE NORTHERN TERMINAL AIR SPACE OF KCLL AND KUTS.
SHORT TERM FORECAST CALLS FOR VCSH WITH TEMPO THUNDER...IFR CONDITIONS
WITHIN HEAVIEST RAIN OR STORM CELLS. CURRENTLY...BULK OF LIGHTNING
CONCENTRATED OVER THE NORTHERN FORT BEND AND WESTERN HARRIS COUNTIES.
LEAVING VCSH IN THROUGH EARLY EVENING TO ACCOUNT FOR THE POSSIBLE
PASSAGE OF A WEAK SHORTWAVE DISTURBANCE. MODELS HAVE BEEN OF NO
GUIDANCE SO CONFIDENCE IS EXTREMELY LOW WITH THIS PACKAGE. AS OF
NOW...WITH LITTLE TO NO CHANGE IN THE LARGE SCALE ENVIRONMENT...THE
ONLY LULL WILL BE TONIGHT (DUE TO THE RECENT WORK OVER AND LACK OF
HEATING) WITH AN ANTICIPATED RETURN OF SHOWER/ISOL THUNDER ACTIVITY
TOMORROW MORNING AS TEMPERATURES WARM INTO THE MIDDLE 80S. 31
&&
.PREV DISCUSSION... /ISSUED 1141 AM CDT MON JUN 23 2014/
UPDATE...
INCREASED POPS TODAY.
DISCUSSION...
CONVECTION HOLDING TOGETHER AND EXPANDING IN COVERAGE. HAVE RAISED
POPS TO LIKELY OVER THE NW TWO-THIRDS OF THE AREA. RAP 13
PERFORMING WELL AND HAVE LEANED TOWARD IT`S SOLUTION FOR THE
REMAINDER OF THE DAY. OF INTEREST...THE RAP BRINGS A STRONG S/WV
OVER THE CENTRAL PLAINS INTO NORTH TEXAS THIS EVENING AND BRINGS
ANOTHER ROUND OF SHRA/TSRA INTO THE NORTHERN HALF OF THE CWA. THE
NAM 12 SUPPORTS THIS SCENARIO AS WELL. 43
PREV DISCUSSION... /ISSUED 930 AM CDT MON JUN 23 2014/
UPDATE...
SEE MORNING UPDATE.
DISCUSSION...
A STRONG OUTFLOW BOUNDARY IS HEADING SOUTH AND CONVECTION IS
GETTING CLOSE TO THE NORTHERN PART OF THE CWA. SHORT TERM GUIDANCE
STILL SUGGESTS WEAKENING OF THIS SYSTEM BUT THE RAP 13 AND TEXAS
TECH 3 KM BECOMING MORE BULLISH WITH POPS OVER THE NW THIRD OF
THE CWA. RAISED POPS TO CHANCE OVER THE NW ZONES. 12Z CRP SOUNDING
HAS A PW VALUE OF 2.06 INCHES WITH SOME DRY AIR AT 700 MB. THE
CONVECTIVE TEMPS ARE IN THE MID 80S WHICH IS MORE THAN REACHABLE.
SHORT TERM GUIDANCE SUGGESTS CONVECTION WILL WANE THIS AFTN AS
SOME OF THE DRIER AIR ALOFT MIXES TO THE SURFACE. WILL RE-EVALUATE
THAT TREND AFTER 17Z. 43
PREV DISCUSSION... /ISSUED 648 AM CDT MON JUN 23 2014/
DISCUSSION...
UPDATED AVIATION SECTION.
AVIATION...
LATEST RADAR COMPOSITES SHOW BAND OF STORMS SITUATED OVER NORTH
TEXAS...NEAR THE DFW METROPLEX. LINE OF STORMS WAS MOVING
SOUTHEAST AROUND 45 MPH. INFRARED SATELLITE SHOWING WARMING CLOUD
TOPS AND OVERALL WEAKENING OF THIS CONVECTIVE COMPLEX. AVAILABLE
MESO MODELS ARE NOT HANDLING THIS SYSTEM VERY WELL...BUT THESE
ALSO SHOW A DISSIPATION OF THE LINE GOING FORWARD. TAFS ARE
WRITTEN WITH THE IDEA THAT THIS DISSIPATING TREND WILL
CONTINUE...BUT NOT COMPLETELY CERTAIN IT WILL OCCUR GIVEN FAIRLY
UNSTABLE AIRMASS DOWNSTREAM. FOR THIS REASON HAVE GONE WITH A VCTS
FOR CLL...UTS AND CXO BASED ON TIMING OF CURRENT LINE BUT BASED ON
LOW PROBABILITY IT WILL SURVIVE AS A LINE. FARTHER SOUTH AND
EAST...EVEN LESS LIKELY LINE WILL MAKE IT...AND WILL CONTINUE WITH
NO MENTION OF PRECIP THERE IN THE TAFS. OTHERWISE EXPECT A
DECREASE IN CONVECTION TONIGHT...WITH JUST SOME PATCHY MVFR LATE
TONIGHT FOR IAH ON NORTH AND NORTHWEST.
PREV DISCUSSION... /ISSUED 415 AM CDT MON JUN 23 2014/
DISCUSSION...
REGIONAL SATELLITE IMAGERY AND RADAR SHOW MATURE SQUALL LINE
PUSHING THROUGH OK/TX AND RED RIVER REGION. CLOSER TO HOUSTON
MAINLY OBSERVING SPOTTY SHOWERS BUT NOT MUCH PRECIP HITTING THE
GROUND. SQUALL LINE SHOULD CONTINUE TO PUSH SOUTH TOWARDS THE AREA
THIS MORNING WITH STRONG COLD POOL BEHIND IT. RAPID REFRESH AND
WRF RUNS SHOW THE SQUALL LINE BREAKING UP BEFORE REACHING COLLEGE
STATION. KEPT THE FORECAST IN LINE WITH THIS THINKING FOR THE
MORNING BUT CONCERNED LINE COULD PUSH FARTHER SOUTH THAN EXPECTED
SINCE THERE IS LITTLE SUBSIDENCE AND DRY AIR TO IMPEDE ITS
PROGRESS. FORECAST HOLDS WITH 20 POPS AS STILL POSSIBLE FOR ISO
CONVECTION TO DEVELOP DURING THE HEAT OF THE DAY.
WATER VAPOR IMAGERY AND 00Z 500MB ANALYSIS SHOW TROUGHING OVER
MUCH OF TX. UPPER RIDGE IS NOT ALL THAT STRONG AND LIKELY SPLIT
BETWEEN NORTHERN MEXICO AND THE C GULF. GLOBAL MODELS ALL SUPPORT
TROUGHING OVER TX THROUGH THE END OF THE WEEK. MODELS ALSO SHOW A
SURGE IN TROPICAL MOISTURE LATE TUE INTO WED. GIVEN PERCIP WATER
VALUES OF NEAR 2 INCHES ACROSS MUCH OF THE AREA FOR WED/THUR
DECIDED TO GO WITH 50/60 POPS EACH OF THOSE DAYS. TROPICAL
MOISTURE WILL BE SUPPORTIVE OF 1-2 INCH AN HOUR RAINRATES IN
STRONGER STORMS SO LOCALLY HEAVY RAINFALL A CONCERN. THIS COULD
RESULT IN URBAN FLOODING AND RAPID INCREASES IN BAYOUS. AREAWIDE
RAINFALL TOTALS OF 1 TO 2 INCHES OF RAIN WILL BE POSSIBLE FOR THE
LATER HALF OF THE WEEK. THE TRICK TO THE FORECAST WILL BE WHERE
THE ISOLATED 3 TO 5 INCH RAINFALL AMOUNTS SET UP WHICH COULD LEAD
TO FLOODING IMPACTS.
UPPER LEVEL RIDGING DOES TRY TO STRENGTHEN DEPENDING ON THE MODEL.
THE ECMWF SEEMS TO BE MORE ROBUST WITH THE RIDGE SUNDAY INTO NEXT
MONDAY. MEANWHILE THE GFS MAINTAINS A SHEAR AXIS OVER THE NW GULF.
RIGHT NOW WILL STILL CARRY SOME LOWER POPS. THINK FRI/SAT WILL BE
DRIER BUT 40 POPS STILL DECENT CHANCES. WILL ALSO KEEP 20 POPS IN
THE FORECAST FOR SUN/MON AS THERE STILL SHOULD BE PLENTY OF DEEP
MOISTURE IN PLACE AND RIDGING STRENGTH WILL STILL BE RELATIVELY
UNKNOWN.
TEMPERATURES SHOULD REMAIN NEAR NORMAL FOR THE COMING WEEK MAYBE A
DEGREE OR TWO COOLER WITH THUNDERSTORM CHANCES. THIS MEANS UPPER
80S TO LOW 90S WITH MIN TEMPS IN THE MID 70S. STILL COULD GET SOME
RAIN COOLED LOW 70S OR UPPER 60S BUT DIFFICULT TO FORECAST THOSE
OCCURRENCES SINCE IT WILL DEPEND ON THE CONVECTION. THE NICE
THING ABOUT THIS FORECAST IS THAT TEMPS SHOULD REMAIN BELOW 95F
THROUGH ALMOST THE END OF JUNE. CLIMATE FACTOID...CLL/IAH/HOU HAVE
YET TO REACH 95F OR HIGHER THIS YEAR FOR A MAX TEMP.
39
MARINE...
LIGHT TO MODERATE ONSHORE FLOW WILL CONTINUE THE NEXT FEW DAYS
WITH SUSTAINED 10 METER WINDS GENERALLY ONSHORE AROUND 10 TO 15
KNOTS THROUGH TUESDAY. GRADIENT IS FORECAST TO TIGHTEN SOMEWHAT
MID TO LATE WEEK WITH SMALL CRAFT EXERCISE CAUTION WINDS A
POSSIBILITY BY WED OR THU. WITH PERSISTENT SE FLOW AND LONG FETCH
SEAS ARE EXPECTED TO GRADUALLY BUILD THROUGH THE WEEK...WITH 6 TO
9 FOOT SEAS A GOOD BET BY THURSDAY AND FRIDAY. 46
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 74 90 74 88 74 / 30 40 20 60 20
HOUSTON (IAH) 76 90 75 88 75 / 20 40 20 60 30
GALVESTON (GLS) 80 88 80 87 80 / 20 30 40 50 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...31
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1227 PM CDT MON JUN 23 2014
.AVIATION...
A COLD FRONT THAT EXTENDED SOUTHEAST OF A MCKINNEY /KTKI/ TO
BRECKENRIDGE /KBKD/ LINE AT 17Z WILL CONTINUE TO MOVE SOUTHEAST
AND SHOULD BE MOVING THROUGH THE METROPLEX TAF SITES AROUND
18Z...SO HAVE STARTED OFF THE WINDS AS NORTHWEST AT 10 KNOTS.
WINDS SHOULD COME BACK AROUND TO THE SOUTHEAST AT 10 KNOTS OR LESS
BEFORE SUNSET /01Z/.
SOME BRIEF MVFR CEILINGS MAY MOVE INTO THE METROPLEX TAF SITES
THIS AFTERNOON...SO HAVE PLACED A TEMPO BKN025 IN FOR THE 18-20Z
PERIOD. WITH LIGHT WINDS OVERNIGHT AND A WET GROUND...SOME LIGHT
FOG MAY DEVELOP TOWARD DAYBREAK. THUS HAVE PLACED 5SM BR IN THE
METROPLEX TAFS FOR THE 12-15Z PERIOD. THIS WILL LIKELY BE ADDED
TO WACO/S TAF WITH THE 21Z UPDATE.
SCATTERED ELEVATED SHOWERS/THUNDERSTORMS COULD POP UP LATE
AFTERNOON INTO THIS EVENING...BUT THE CHANCES AT THE INDIVIDUAL
TAF SITES IS TOO LOW TO MENTION AT THIS TIME. LIKEWISE THERE WILL
BE A CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY BUT THE CHANCES
AT THE INDIVIDUAL TAF SITES ARE NOT HIGH ENOUGH TO INCLUDE IN THE
TAFS AT THIS TIME.
58
&&
.UPDATE...
THIS MORNINGS MCS CONTINUES TO WEAKEN OVER THE SOUTHERN COUNTIES
OF THE CWA. THE MOVEMENT OF THE REMAINING SHOWERS AND STORMS IS TO
THE EAST AND SOUTHEAST. AN OUTFLOW BOUNDARY CAN BE SEEN ON THE
KGRK RADAR PUSHING AHEAD OF THE LEADING EDGE INTO THE HILL COUNTRY
AND SOUTHEAST TEXAS. THIS OUTFLOW BOUNDARY WILL LIKELY NOT BE A
FACTOR FOR AFTERNOON CONVECTION IN OUR CWA WITH THE BOUNDARY
LOCATED SOUTH OF THE REGION AND THE MEAN STEERING FLOW TO THE
SOUTHEAST. HOWEVER...ANOTHER BOUNDARY/FRONT CAN BE SEEN ON THE
KFWS RADAR AND SURFACE OBS ACROSS OKLAHOMA AND NORTHWEST TEXAS...
MOVING INTO THE NORTHWESTERN PORTIONS OF THE CWA. THE WINDS AT
BOWIE HAVE COME AROUND TO THE NORTH AND OTHER SITES ALONG THE RED
RIVER HAVE SHIFTED TO THE WEST. BOTH THE HRRR AND RAP ARE
DEVELOPING CONVECTION ALONG THIS BOUNDARY EARLY THIS AFTERNOON
WITH THE FOCUS FOR CONVECTION SLOWLY MOVING SOUTH THROUGH THE
AFTERNOON HOURS.
DESPITE THE PRESENCE OF THE BOUNDARY IN OUR NORTHWESTERN
COUNTIES...THE AFTERNOON FORECAST IS STILL MUDDLED BY THIS
MORNING/S MCS. SURFACE TEMPERATURES ACROSS MOST OF THE REGION ARE
COOL IN THE UPPER 60S AND LOWER 70S. ANALYSIS OF AMDAR SOUNDINGS
SHOW THE TEMPERATURES JUST ABOVE THE SURFACE HAVE RAPIDLY WARMED
IN THE WAKE OF THE MCS DUE TO SUBSIDENCE ON THE BACK SIDE. A
RECENT AMDAR SOUNDING FROM DFW AT 1555Z SHOWS TEMPERATURES AT 900
MB HAVE WARMED 9 DEGREES CELSIUS SINCE THE RAIN STARTED. IN
ADDITION...THE LOWER LEVELS OF THE ATMOSPHERE HAVE SIGNFICANTLY
DRIED UP TO ABOUT 600 MB. IN ORDER TO BREAK THE CAP THAT HAS
DEVELOPED IN THE WAKE OF THE MCS...SURFACE TEMPERATURES WOULD HAVE
TO WARM INTO THE MID AND UPPER 90S AND THAT IS NOT GOING TO HAPPEN
TODAY. WHAT WE WILL LIKELY SEE IS ISOLATED TO SCATTERED ELEVATED
CONVECTION DEVELOP WITH HELP FROM A SHORTWAVE MOVING NORTHWEST TO
SOUTHEAST ACROSS PRIMARILY THE NORTHERN HALF OF THE REGION THIS
AFTERNOON. IF THE ELEVATED CONVECTION IS ABLE TO SATURATE THE
LOWER LEVELS OF THE ATMOSPHERE OVER TIME /AND THUS EFFECTIVELY
COOL THE TEMPERATURES AROUND 900-800 MB/...IT IS POSSIBLE WE COULD
HAVE SURFACE BASED CONVECTION LATER THIS AFTERNOON...IN PARTICULAR
AROUND ANY BOUNDARIES OR THE FRONT. HOWEVER...CONFIDENCE IN
SURFACE BASED CONVECTION IS RELATIVELY LOW FOR THE REMAINDER OF
THE DAY. IN ANTICIPATION OF ELEVATED CONVECTION FOR THE REMAINDER
OF THE DAY...TAILORED POPS TO 30 PERCENT IN THE EAST AND 40
PERCENT IN THE WEST. THE MODELS ARE INDICATING MUCH OF THE
CONVECTION MAY OCCUR WEST OF INTERSTATE 35 WHERE THE CLOUDS ARE
ALREADY THINNING OUT...SURFACE TEMPERATURES WILL BE THE WARMEST
AND INSTABILITY WILL THUS BE THE HIGHEST IN THE AREA. WITH ANY
STORMS TODAY...GUSTY WINDS...LIGHTNING...AND HEAVY RAINFALL WILL
BE THE MAIN THREATS. STORM MOTION TODAY IS EXPECTED TO BE FASTER
THAN THE LAST FEW DAYS WHICH SHOULD HELP MITIGATE ANY FLASH FLOOD
THREAT THIS AFTERNOON BUT WITH A CONTINUED THREAT FOR HEAVY
RAIN...WILL NEED TO CLOSELY MONITOR RADAR TRENDS.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 414 AM CDT MON JUN 23 2014/
THE PRIMARY WEATHER FEATURE OF INTEREST EARLY THIS MORNING WAS A
SQUALL LINE LOCATED FROM NORMAN TO WICHITA FALLS TO LUBBOCK AS OF
4 AM CDT. THIS SQUALL LINE WAS A BIT WEAKER THAN IT WAS AROUND
MIDNIGHT...HOWEVER ITS RADAR REFLECTIVITY STRUCTURE CONTINUED TO
SHOW A WELL ORGANIZED LINEAR MCS WITH FAIRLY UPRIGHT UPDRAFTS AND
STRONG CONVECTION ALONG THE LEADING EDGE OF ITS OUTFLOW BOUNDARY.
THIS STRUCTURE LIKELY MEANS THAT THIS SQUALL LINE WILL NOT FALL
APART OR SLOW DOWN MUCH AS IT CONTINUES SOUTHEAST OVER NORTH TEXAS
EARLY THIS MORNING. THE PORTION OF THE SQUALL LINE THAT WILL
LIKELY REACH OUR NORTHWESTERN CWA FIRST WAS STILL SEVERE WARNED BY
WFO OUN AT THE TIME OF THIS DISCUSSION. KFDR RADAR OBSERVED A
50-54 KT INBOUND VELOCITY AT AROUND 100 FT AGL WITHIN THIS
WARNING. THE SQUALL LINE MAY CONTINUE TO WEAKEN A BIT AS IT MOVES
TOWARDS NORTH TEXAS...BUT STRONG TO DAMAGING WIND GUSTS WILL
CERTAINLY BE A POSSIBILITY WITHIN THIS LINE THIS MORNING. AT THIS
TIME...THE SQUALL LINE WAS ON TRACK TO MOVE THROUGH THE DFW
METROPLEX FROM APPROXIMATELY 6 AM TO 8 AM. THIS TIMING MAY CHANGE
AS INTENSITY CHANGES WITHIN THE LINE OF STORMS...HOWEVER IMPACTS
TO THE MORNING RUSH HOUR COMMUTE LOOK LIKELY AT THIS TIME.
ASIDE FROM STRONG WIND GUSTS...LOCALLY HEAVY RAINFALL IS EXPECTED
TO BE A PROBLEM AS WELL. LOCALIZED FLOODING IS CONTINGENT UPON THE
SPEED OF THE STORMS AND THE SQUALL LINE IN GENERAL THIS MORNING.
THE TEXAS TECH WRF INDICATES THAT THE SQUALL LINE...OR ITS
REMNANTS...WILL PUSH THROUGH THE ENTIRE CWA FROM 12 TO 18Z. IF
THIS SCENARIO PANS OUT...LOCALIZED FLOODING IS LESS LIKELY BECAUSE
STORMS WILL BE MOVING THROUGH THE AREA TOO QUICKLY. MANY OTHER
HIGH-RESOLUTION GUIDANCE MEMBERS WEAKEN THE SQUALL LINE TO THE
POINT THAT IT DROPS A NEARLY STATIONARY BOUNDARY NEAR OR JUST
SOUTH OF INTERSTATE 20 BY LATE THIS MORNING. IF THIS OCCURS...IT`S
ONLY GOING TO HAPPEN BECAUSE THE SQUALL LINE SLOWS DOWN
CONSIDERABLY FROM ITS CURRENT PACE. ANY ONGOING RAIN SHOWER AND
THUNDERSTORM ACTIVITY IN THIS SCENARIO WOULD BE MORE LIKELY TO
PRODUCE LOCALIZED FLOODING AS STORMS WILL SIMPLY BE MOVING SLOWER.
EITHER WAY...LOCALLY HEAVY RAIN WILL OCCUR WITH ANY THUNDERSTORM
ACTIVITY ALONG THE SQUALL LINE BECAUSE MODELS INDICATE THAT PWATS
ONLY INCREASE OUT AHEAD OF THE SQUALL LINE ACROSS NORTH TEXAS THIS
MORNING. WITH LITTLE AIRCRAFT ACTIVITY (FOR AMDAR SOUNDINGS)
OVERNIGHT...ITS DIFFICULT TO ESTABLISH IF THIS IS REALISTIC OR
NOT. HOWEVER LOOKING AT THE GOES SOUNDER OUTPUT...THERE IS A PLUME
OF 2 INCH (OBSERVED AS 50 MM) PWATS LOCATED JUST SOUTH OF THE DFW
AREA...CONTINUING SOUTH OVER CENTRAL TEXAS. HOW FAR NORTH OR EAST
THIS PLUME EXTENDS IS UNKNOWN BECAUSE THE SATELLITE CAN NOT SEE
THROUGH THICK UPPER LEVEL CLOUDS OVER THESE AREAS. THE FACT THAT 2
INCH PWATS ARE OBSERVED TO THE SOUTHWEST OF WHERE MODELS DEPICT 2
INCH PWATS THIS MORNING (GENERALLY NORTH OF I-20 AND EAST OF I-35)
IS A GOOD SIGN THAT THE MODELS PROBABLY HAVE THIS RIGHT.
AS A RESULT...WENT AHEAD WITH A MENTION OF HEAVY RAINFALL IN THE
WORDED FORECAST THIS MORNING...HIGHLIGHTING AREAS NORTH OF
INTERSTATE 20 AS HAVING THE HIGHEST CHANCE AT SEEING LOCALLY HEAVY
RAINS. IN REALITY...WE WILL JUST HAVE TO WATCH AND SEE HOW THE
SQUALL LINE EVOLVES BECAUSE WHERE EVER THE STRONGEST THUNDERSTORM
ACTIVITY GOES...THE HEAVY RAIN WILL FOLLOW SUIT. THE IMPACTS WERE
NOT EXPECTED TO BE WIDESPREAD ENOUGH TO RESULT IN LARGE SCALE
FLOODING...SO NO FLOOD WATCH WILL BE ISSUED WITH THIS FORECAST
PACKAGE. WILL MONITOR STORMS AND HANDLE LOCALIZED FLOODING
TACTICALLY VIA WARNINGS...GRAPHICS AND SOCIAL MEDIA
DISSEMINATION.
FOR THIS AFTERNOON...NEW THUNDERSTORM CHANCES REALLY DEPEND ON
WHAT HAPPENS WITH OUR SQUALL LINE THIS MORNING. MANY MODELS SHOW A
GOOD QPF SIGNAL IN LINE WITH THE SQUALL LINE...BUT MOST
UNFORTUNATELY FAIL TO CARRY THE DYNAMICS OF THE SQUALL LINE INTO
THE MODEL MASS FIELDS. FOR INSTANCE...NOT ONE OPERATIONAL MODEL
BOTHERS TO BRING A WIND SHIFT LINE INTO THE CWA WITH THE SQUALL
LINE QPF BLOB THIS MORNING. THESE MODELS ALSO FAIL TO SUFFICIENTLY
STABILIZE/COOL THE LOWER TROPOSPHERE BEHIND THE SQUALL LINE. THIS
PRESENTS A BIG FORECAST PROBLEM AS BOTH OF THESE FACTORS WILL
PLAY A HUGE ROLE IN THUNDERSTORM CHANCES FOR THIS AFTERNOON. THE
TEXAS TECH WRF AND THE 4 KM NAM BOTH AT LEAST INDICATED SOME
RESPONSE IN THE LOW-LEVEL WIND FIELD...SO THESE MODELS WERE
WEIGHED MORE HEAVILY FOR THIS AFTERNOON`S THUNDERSTORM FORECAST.
AN 08Z OBJECTIVE SURFACE ANALYSIS INDICATED A THETA-E DROP OF
AROUND 11 KELVIN BEHIND THE SQUALL LINE THIS MORNING. AS FAR AS
COLD POOLS GO BEHIND SQUALL LINES...THIS IS NOT SUPER
IMPRESSIVE...BUT WILL NOT SIMPLY DISSIPATE WITH A FEW HOURS OF
DAYTIME HEATING EITHER. AS A RESULT...WHEREVER THE SQUALL LINE
LEAVES AN OUTFLOW BOUNDARY THIS MORNING...IT IS LIKELY TO HANG
AROUND AND MAINTAIN SOME IDENTITY FOR THIS AFTERNOON. AT THIS
TIME...USING THE TEXAS TECH WRF`S SURFACE WIND FIELD AS A PROXY
FOR THE OUTFLOW BOUNDARY`S LOCATION THIS AFTERNOON...THINK IT WILL
END UP SOUTH OF INTERSTATE 20. AS A RESULT...WENT AHEAD AND
LOWERED POPS FOR LOCATIONS NORTH OF THE INTERSTATE FOR THIS
AFTERNOON FROM THE PREVIOUS FORECAST. IF THE SQUALL LINE ACTUALLY
MOVES ALL THE WAY THROUGH CENTRAL TEXAS BY 18Z AS THE TEXAS TECH
WRF REFLECTIVITY SUGGESTS...IT MAY COMPLETELY SHUT DOWN
THUNDERSTORM CHANCES FOR THE CWA FOR THIS AFTERNOON.
AS IT STANDS...HAVE 30 TO 40 POPS IN THE FORECAST SOUTH OF
INTERSTATE 20 AND WEST OF INTERSTATE 35 FOR THIS AFTERNOON
REPRESENTING THE MAXIMUM POPS ACROSS THE CWA. HIGHLIGHTED AREAS
WEST OF INTERSTATE 35 BECAUSE MOST MODELS INDICATE THAT A WEAK
SHORTWAVE TROUGH CURRENTLY LOCATED ALONG THE ARIZONA/MEXICO BORDER
WILL MOVE EAST AND PROVIDE SOME FORCING FOR ASCENT OVER WEST-
CENTRAL TEXAS BY 00Z TODAY. IF THERE REALLY IS AN OUTFLOW BOUNDARY
STALLED OUT IN PLACE HERE...THE WEAK FORCING FOR ASCENT FROM THIS
TROUGH COMBINED WITH THE BOUNDARY SHOULD BE AN IDEAL PLACE FOR NEW
THUNDERSTORMS TO DEVELOP BY LATE THIS AFTERNOON. AS MENTIONED
ABOVE...IF THE OUTFLOW BOUNDARY IS ELSEWHERE BY THIS
AFTERNOON...POPS WILL NEED TO BE ADJUSTED ACCORDINGLY.
THE 4 KM NAM INDICATES THAT THIS BOUNDARY IS VERY IMPORTANT FOR
THIS AFTERNOON STORMS AS IT BLOWS UP SEVERAL CLUSTERS OF VERY
STRONG LOOKING CONVECTION ALONG THIS BOUNDARY BY 00Z. THE NSSL
WRF ON THE OTHER HAND INDICATES THAT THE OUTFLOW BOUNDARY WILL NOT
BE AS IMPORTANT AS AN MCV WITH REGARDS TO AFTERNOON THUNDERSTORM
CHANCES. THIS MODEL KEEPS WELL DEFINED MCV IN PLACE OVER EAST
CENTRAL OKLAHOMA THIS AFTERNOON AND CONCENTRATES THUNDERSTORM
ACTIVITY THERE INSTEAD OF ALONG THE OUTFLOW BOUNDARY OVER
NORTH/CENTRAL TEXAS. IT IS DIFFICULT TO KNOW WHAT WILL BE
IMPORTANT UNTIL THIS MORNINGS SQUALL LINE DISSIPATES AND WE CAN
REEVALUATE WHAT THE THERMODYNAMIC AND KINEMATIC ENVIRONMENT LOOKS
LIKE AT THAT TIME.
FOR TONIGHT...MOST MODELS INDICATE THAT OUR OUTFLOW BOUNDARY WILL
LIFT NORTH TO THE RED RIVER AND BECOME THE FOCUS FOR NEW
THUNDERSTORM ACTIVITY OVERNIGHT. WENT AHEAD AND KEPT HIGHER POPS
OVER THE NORTHERN CWA FOR TONIGHT AS A RESULT. IF THE OUTFLOW
BOUNDARY MAINTAINS ANY IDENTITY THROUGHOUT THE AFTERNOON HOURS OF
THE DAY...IT WILL PROBABLY SERVE TO ENHANCE THE SLOPE OF LOW-
LEVEL ISENTROPIC SURFACES PERPENDICULAR TO LOW-LEVEL WINDS
RESULTING IN ENHANCED LIFT. THE NORTHERN CWA SHOULD BENEFIT FROM
THIS ENHANCED LOW-LEVEL LIFT MORE SO THAN THE SOUTH.
TUESDAY THROUGH THURSDAY...MORE MODELS ARE SHOWING THAT A COL IN
THE UPPER LEVEL FLOW FIELD WILL SET UP OVER NORTH TEXAS DURING
THIS TIME FRAME. AS A RESULT...KEPT BROAD BRUSHED POPS IN PLACE
FOR ALL AREAS. HAVE SLIGHTLY HIGHER POPS ADVERTISED DURING THE
AFTERNOON HOURS OF THE DAY EACH DAY AS ANY HEATING COMBINED WITH
ANY WEAK UPPER TROUGH ALOFT WILL ENHANCE STORM CHANCES THROUGH
THIS PERIOD. WITH VERY WEAK FLOW FORECAST TO EXIST OVER THE
CWA...MESOSCALE FEATURES WILL CONTINUE TO DOMINATE THE DAILY
WEATHER PATTERN. MESOSCALE FEATURES...BY PHYSICAL DEFINITION...
CANNOT BE FORECAST MORE THAN ABOUT 12 HOURS OUT AT BEST...SO DID
NOT PUT A WHOLE LOT OF DETAIL IN PRECIPITATION CHANCES THROUGH THIS
PERIOD AS A RESULT. FOR PLANNING PURPOSES...JUST KEEP IN MIND THAT
THE LARGE SCALE PATTERN IS SUPPORTIVE OF SCATTERED SHOWERS AND
STORMS EACH DAY. THE FORECAST WILL CHANGE DEPENDING ON THE
MESOSCALE FEATURES AS THEY ARE RESOLVED...INCREASING RAIN CHANCES
FOR SOME AREAS WHILE LOWERING THEM FOR OTHERS. JUST LOOKING AT THE
PATTERN...LOCALLY HEAVY RAINFALL AND CLOUD TO GROUND LIGHTNING
WILL BE THE PRIMARY HAZARDS. LOCALLY STRONG WIND GUSTS CAN NOT BE
RULED OUT FOR ANY STORMS THAT OCCUR DURING THE PEAK HEATING HOURS
OF THE DAY.
FRIDAY THROUGH SUNDAY...WENT AHEAD AND TOOK RAIN CHANCES OUT FOR
MOST LOCATIONS DURING THIS PERIOD. THE 00Z ECMWF STOPPED
ADVERTISING THAT STALLED OUT UPPER LOW OVER NEW MEXICO THAT IT HAD
BEEN SHOWING FOR THE PAST 24 HOURS. IT NOW SHOWS WEAK RIDGING
ALOFT OVER THE CWA FOR NEXT WEEKEND WITH IS MORE IN LINE WITH WHAT
THE GFS HAS BEEN SHOWING FOR DAYS. THINGS COULD CHANGE OF COURSE
AS THE RELEVANT FEATURES REMAIN WELL OUT OVER THE OPEN WATERS OF
THE PACIFIC. AT THIS TIME...SINCE MOST GUIDANCE AS ADVERTISING
RIDGING ALOFT...DECIDED TO OPT WITH A DRY FORECAST AND ABOVE
NORMAL TEMPERATURES.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 84 75 90 75 88 / 30 40 40 30 40
WACO, TX 86 73 89 73 87 / 100 20 40 30 50
PARIS, TX 84 71 85 71 85 / 30 50 40 30 40
DENTON, TX 83 72 89 72 87 / 30 50 40 30 40
MCKINNEY, TX 83 73 89 73 87 / 30 50 40 30 40
DALLAS, TX 85 75 89 75 87 / 30 40 40 30 40
TERRELL, TX 84 76 91 73 88 / 30 30 40 30 40
CORSICANA, TX 87 74 88 73 86 / 30 30 40 30 50
TEMPLE, TX 87 73 89 73 87 / 100 20 40 30 50
MINERAL WELLS, TX 84 71 88 71 87 / 40 50 40 30 40
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
58/82
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1141 AM CDT MON JUN 23 2014
.UPDATE...
INCREASED POPS TODAY.
&&
.DISCUSSION...
CONVECTION HOLDING TOGETHER AND EXPANDING IN COVERAGE. HAVE RAISED
POPS TO LIKELY OVER THE NW TWO-THIRDS OF THE AREA. RAP 13
PERFORMING WELL AND HAVE LEANED TOWARD IT`S SOLUTION FOR THE
REMAINDER OF THE DAY. OF INTEREST...THE RAP BRINGS A STRONG S/WV
OVER THE CENTRAL PLAINS INTO NORTH TEXAS THIS EVENING AND BRINGS
ANOTHER ROUND OF SHRA/TSRA INTO THE NORTHERN HALF OF THE CWA. THE
NAM 12 SUPPORTS THIS SCENARIO AS WELL. 43
&&
.PREV DISCUSSION... /ISSUED 930 AM CDT MON JUN 23 2014/
UPDATE...
SEE MORNING UPDATE.
DISCUSSION...
A STRONG OUTFLOW BOUNDARY IS HEADING SOUTH AND CONVECTION IS
GETTING CLOSE TO THE NORTHERN PART OF THE CWA. SHORT TERM GUIDANCE
STILL SUGGESTS WEAKENING OF THIS SYSTEM BUT THE RAP 13 AND TEXAS
TECH 3 KM BECOMING MORE BULLISH WITH POPS OVER THE NW THIRD OF
THE CWA. RAISED POPS TO CHANCE OVER THE NW ZONES. 12Z CRP SOUNDING
HAS A PW VALUE OF 2.06 INCHES WITH SOME DRY AIR AT 700 MB. THE
CONVECTIVE TEMPS ARE IN THE MID 80S WHICH IS MORE THAN REACHABLE.
SHORT TERM GUIDANCE SUGGESTS CONVECTION WILL WANE THIS AFTN AS
SOME OF THE DRIER AIR ALOFT MIXES TO THE SURFACE. WILL RE-EVALUATE
THAT TREND AFTER 17Z. 43
PREV DISCUSSION... /ISSUED 648 AM CDT MON JUN 23 2014/
DISCUSSION...
UPDATED AVIATION SECTION.
AVIATION...
LATEST RADAR COMPOSITES SHOW BAND OF STORMS SITUATED OVER NORTH
TEXAS...NEAR THE DFW METROPLEX. LINE OF STORMS WAS MOVING
SOUTHEAST AROUND 45 MPH. INFRARED SATELLITE SHOWING WARMING CLOUD
TOPS AND OVERALL WEAKENING OF THIS CONVECTIVE COMPLEX. AVAILABLE
MESO MODELS ARE NOT HANDLING THIS SYSTEM VERY WELL...BUT THESE
ALSO SHOW A DISSIPATION OF THE LINE GOING FORWARD. TAFS ARE
WRITTEN WITH THE IDEA THAT THIS DISSIPATING TREND WILL
CONTINUE...BUT NOT COMPLETELY CERTAIN IT WILL OCCUR GIVEN FAIRLY
UNSTABLE AIRMASS DOWNSTREAM. FOR THIS REASON HAVE GONE WITH A VCTS
FOR CLL...UTS AND CXO BASED ON TIMING OF CURRENT LINE BUT BASED ON
LOW PROBABILITY IT WILL SURVIVE AS A LINE. FARTHER SOUTH AND
EAST...EVEN LESS LIKELY LINE WILL MAKE IT...AND WILL CONTINUE WITH
NO MENTION OF PRECIP THERE IN THE TAFS. OTHERWISE EXPECT A
DECREASE IN CONVECTION TONIGHT...WITH JUST SOME PATCHY MVFR LATE
TONIGHT FOR IAH ON NORTH AND NORTHWEST.
PREV DISCUSSION... /ISSUED 415 AM CDT MON JUN 23 2014/
DISCUSSION...
REGIONAL SATELLITE IMAGERY AND RADAR SHOW MATURE SQUALL LINE
PUSHING THROUGH OK/TX AND RED RIVER REGION. CLOSER TO HOUSTON
MAINLY OBSERVING SPOTTY SHOWERS BUT NOT MUCH PRECIP HITTING THE
GROUND. SQUALL LINE SHOULD CONTINUE TO PUSH SOUTH TOWARDS THE AREA
THIS MORNING WITH STRONG COLD POOL BEHIND IT. RAPID REFRESH AND
WRF RUNS SHOW THE SQUALL LINE BREAKING UP BEFORE REACHING COLLEGE
STATION. KEPT THE FORECAST IN LINE WITH THIS THINKING FOR THE
MORNING BUT CONCERNED LINE COULD PUSH FARTHER SOUTH THAN EXPECTED
SINCE THERE IS LITTLE SUBSIDENCE AND DRY AIR TO IMPEDE ITS
PROGRESS. FORECAST HOLDS WITH 20 POPS AS STILL POSSIBLE FOR ISO
CONVECTION TO DEVELOP DURING THE HEAT OF THE DAY.
WATER VAPOR IMAGERY AND 00Z 500MB ANALYSIS SHOW TROUGHING OVER
MUCH OF TX. UPPER RIDGE IS NOT ALL THAT STRONG AND LIKELY SPLIT
BETWEEN NORTHERN MEXICO AND THE C GULF. GLOBAL MODELS ALL SUPPORT
TROUGHING OVER TX THROUGH THE END OF THE WEEK. MODELS ALSO SHOW A
SURGE IN TROPICAL MOISTURE LATE TUE INTO WED. GIVEN PERCIP WATER
VALUES OF NEAR 2 INCHES ACROSS MUCH OF THE AREA FOR WED/THUR
DECIDED TO GO WITH 50/60 POPS EACH OF THOSE DAYS. TROPICAL
MOISTURE WILL BE SUPPORTIVE OF 1-2 INCH AN HOUR RAINRATES IN
STRONGER STORMS SO LOCALLY HEAVY RAINFALL A CONCERN. THIS COULD
RESULT IN URBAN FLOODING AND RAPID INCREASES IN BAYOUS. AREAWIDE
RAINFALL TOTALS OF 1 TO 2 INCHES OF RAIN WILL BE POSSIBLE FOR THE
LATER HALF OF THE WEEK. THE TRICK TO THE FORECAST WILL BE WHERE
THE ISOLATED 3 TO 5 INCH RAINFALL AMOUNTS SET UP WHICH COULD LEAD
TO FLOODING IMPACTS.
UPPER LEVEL RIDGING DOES TRY TO STRENGTHEN DEPENDING ON THE MODEL.
THE ECMWF SEEMS TO BE MORE ROBUST WITH THE RIDGE SUNDAY INTO NEXT
MONDAY. MEANWHILE THE GFS MAINTAINS A SHEAR AXIS OVER THE NW GULF.
RIGHT NOW WILL STILL CARRY SOME LOWER POPS. THINK FRI/SAT WILL BE
DRIER BUT 40 POPS STILL DECENT CHANCES. WILL ALSO KEEP 20 POPS IN
THE FORECAST FOR SUN/MON AS THERE STILL SHOULD BE PLENTY OF DEEP
MOISTURE IN PLACE AND RIDGING STRENGTH WILL STILL BE RELATIVELY
UNKNOWN.
TEMPERATURES SHOULD REMAIN NEAR NORMAL FOR THE COMING WEEK MAYBE A
DEGREE OR TWO COOLER WITH THUNDERSTORM CHANCES. THIS MEANS UPPER
80S TO LOW 90S WITH MIN TEMPS IN THE MID 70S. STILL COULD GET SOME
RAIN COOLED LOW 70S OR UPPER 60S BUT DIFFICULT TO FORECAST THOSE
OCCURRENCES SINCE IT WILL DEPEND ON THE CONVECTION. THE NICE
THING ABOUT THIS FORECAST IS THAT TEMPS SHOULD REMAIN BELOW 95F
THROUGH ALMOST THE END OF JUNE. CLIMATE FACTOID...CLL/IAH/HOU HAVE
YET TO REACH 95F OR HIGHER THIS YEAR FOR A MAX TEMP.
39
MARINE...
LIGHT TO MODERATE ONSHORE FLOW WILL CONTINUE THE NEXT FEW DAYS
WITH SUSTAINED 10 METER WINDS GENERALLY ONSHORE AROUND 10 TO 15
KNOTS THROUGH TUESDAY. GRADIENT IS FORECAST TO TIGHTEN SOMEWHAT
MID TO LATE WEEK WITH SMALL CRAFT EXERCISE CAUTION WINDS A
POSSIBILITY BY WED OR THU. WITH PERSISTENT SE FLOW AND LONG FETCH
SEAS ARE EXPECTED TO GRADUALLY BUILD THROUGH THE WEEK...WITH 6 TO
9 FOOT SEAS A GOOD BET BY THURSDAY AND FRIDAY. 46
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 93 74 90 74 88 / 60 30 40 20 60
HOUSTON (IAH) 92 76 90 75 88 / 60 20 40 20 60
GALVESTON (GLS) 89 80 88 80 87 / 20 20 30 40 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1124 AM CDT MON JUN 23 2014
.UPDATE...
THIS MORNINGS MCS CONTINUES TO WEAKEN OVER THE SOUTHERN COUNTIES
OF THE CWA. THE MOVEMENT OF THE REMAINING SHOWERS AND STORMS IS TO
THE EAST AND SOUTHEAST. AN OUTFLOW BOUNDARY CAN BE SEEN ON THE
KGRK RADAR PUSHING AHEAD OF THE LEADING EDGE INTO THE HILL COUNTRY
AND SOUTHEAST TEXAS. THIS OUTFLOW BOUNDARY WILL LIKELY NOT BE A
FACTOR FOR AFTERNOON CONVECTION IN OUR CWA WITH THE BOUNDARY
LOCATED SOUTH OF THE REGION AND THE MEAN STEERING FLOW TO THE
SOUTHEAST. HOWEVER...ANOTHER BOUNDARY/FRONT CAN BE SEEN ON THE
KFWS RADAR AND SURFACE OBS ACROSS OKLAHOMA AND NORTHWEST TEXAS...
MOVING INTO THE NORTHWESTERN PORTIONS OF THE CWA. THE WINDS AT
BOWIE HAVE COME AROUND TO THE NORTH AND OTHER SITES ALONG THE RED
RIVER HAVE SHIFTED TO THE WEST. BOTH THE HRRR AND RAP ARE
DEVELOPING CONVECTION ALONG THIS BOUNDARY EARLY THIS AFTERNOON
WITH THE FOCUS FOR CONVECTION SLOWLY MOVING SOUTH THROUGH THE
AFTERNOON HOURS.
DESPITE THE PRESENCE OF THE BOUNDARY IN OUR NORTHWESTERN
COUNTIES...THE AFTERNOON FORECAST IS STILL MUDDLED BY THIS
MORNING/S MCS. SURFACE TEMPERATURES ACROSS MOST OF THE REGION ARE
COOL IN THE UPPER 60S AND LOWER 70S. ANALYSIS OF AMDAR SOUNDINGS
SHOW THE TEMPERATURES JUST ABOVE THE SURFACE HAVE RAPIDLY WARMED
IN THE WAKE OF THE MCS DUE TO SUBSIDENCE ON THE BACK SIDE. A
RECENT AMDAR SOUNDING FROM DFW AT 1555Z SHOWS TEMPERATURES AT 900
MB HAVE WARMED 9 DEGREES CELSIUS SINCE THE RAIN STARTED. IN
ADDITION...THE LOWER LEVELS OF THE ATMOSPHERE HAVE SIGNFICANTLY
DRIED UP TO ABOUT 600 MB. IN ORDER TO BREAK THE CAP THAT HAS
DEVELOPED IN THE WAKE OF THE MCS...SURFACE TEMPERATURES WOULD HAVE
TO WARM INTO THE MID AND UPPER 90S AND THAT IS NOT GOING TO HAPPEN
TODAY. WHAT WE WILL LIKELY SEE IS ISOLATED TO SCATTERED ELEVATED
CONVECTION DEVELOP WITH HELP FROM A SHORTWAVE MOVING NORTHWEST TO
SOUTHEAST ACROSS PRIMARILY THE NORTHERN HALF OF THE REGION THIS
AFTERNOON. IF THE ELEVATED CONVECTION IS ABLE TO SATURATE THE
LOWER LEVELS OF THE ATMOSPHERE OVER TIME /AND THUS EFFECTIVELY
COOL THE TEMPERATURES AROUND 900-800 MB/...IT IS POSSIBLE WE COULD
HAVE SURFACE BASED CONVECTION LATER THIS AFTERNOON...IN PARTICULAR
AROUND ANY BOUNDARIES OR THE FRONT. HOWEVER...CONFIDENCE IN
SURFACE BASED CONVECTION IS RELATIVELY LOW FOR THE REMAINDER OF
THE DAY. IN ANTICIPATION OF ELEVATED CONVECTION FOR THE REMAINDER
OF THE DAY...TAILORED POPS TO 30 PERCENT IN THE EAST AND 40
PERCENT IN THE WEST. THE MODELS ARE INDICATING MUCH OF THE
CONVECTION MAY OCCUR WEST OF INTERSTATE 35 WHERE THE CLOUDS ARE
ALREADY THINNING OUT...SURFACE TEMPERATURES WILL BE THE WARMEST
AND INSTABILITY WILL THUS BE THE HIGHEST IN THE AREA. WITH ANY
STORMS TODAY...GUSTY WINDS...LIGHTNING...AND HEAVY RAINFALL WILL
BE THE MAIN THREATS. STORM MOTION TODAY IS EXPECTED TO BE FASTER
THAN THE LAST FEW DAYS WHICH SHOULD HELP MITIGATE ANY FLASH FLOOD
THREAT THIS AFTERNOON BUT WITH A CONTINUED THREAT FOR HEAVY
RAIN...WILL NEED TO CLOSELY MONITOR RADAR TRENDS.
82/JLD
&&
.AVIATION...
/ISSUED 616 AM CDT MON JUN 23 2014/
SQUALL LINE IS CURRENTLY MOVING OVER THE METROPLEX TERMINAL
LOCATIONS...AND WIND GUSTS OF 35 KT TO 50 KT WILL BE POSSIBLE
THROUGH 13Z. THUNDERSTORMS WILL REACH WACO BY 15Z BUT SHOULD BE IN
A WEAKENED STATE BY THEN. NORTHWEST WINDS WITH THE OUTFLOW
BOUNDARY WILL SHIFT BACK AROUND TO THE SOUTH LATER THIS MORNING.
ADDITIONAL CONVECTION IS POSSIBLE AGAIN TONIGHT...BUT WE WILL GET
A GOOD LOOK AT FUTURE MODEL DATA BEFORE PINPOINTING SPECIFIC
TIMES FOR TS IN AREA FORECASTS.
30
&&
.PREV DISCUSSION... /ISSUED 414 AM CDT MON JUN 23 2014/
THE PRIMARY WEATHER FEATURE OF INTEREST EARLY THIS MORNING WAS A
SQUALL LINE LOCATED FROM NORMAN TO WICHITA FALLS TO LUBBOCK AS OF
4 AM CDT. THIS SQUALL LINE WAS A BIT WEAKER THAN IT WAS AROUND
MIDNIGHT...HOWEVER ITS RADAR REFLECTIVITY STRUCTURE CONTINUED TO
SHOW A WELL ORGANIZED LINEAR MCS WITH FAIRLY UPRIGHT UPDRAFTS AND
STRONG CONVECTION ALONG THE LEADING EDGE OF ITS OUTFLOW BOUNDARY.
THIS STRUCTURE LIKELY MEANS THAT THIS SQUALL LINE WILL NOT FALL
APART OR SLOW DOWN MUCH AS IT CONTINUES SOUTHEAST OVER NORTH TEXAS
EARLY THIS MORNING. THE PORTION OF THE SQUALL LINE THAT WILL
LIKELY REACH OUR NORTHWESTERN CWA FIRST WAS STILL SEVERE WARNED BY
WFO OUN AT THE TIME OF THIS DISCUSSION. KFDR RADAR OBSERVED A
50-54 KT INBOUND VELOCITY AT AROUND 100 FT AGL WITHIN THIS
WARNING. THE SQUALL LINE MAY CONTINUE TO WEAKEN A BIT AS IT MOVES
TOWARDS NORTH TEXAS...BUT STRONG TO DAMAGING WIND GUSTS WILL
CERTAINLY BE A POSSIBILITY WITHIN THIS LINE THIS MORNING. AT THIS
TIME...THE SQUALL LINE WAS ON TRACK TO MOVE THROUGH THE DFW
METROPLEX FROM APPROXIMATELY 6 AM TO 8 AM. THIS TIMING MAY CHANGE
AS INTENSITY CHANGES WITHIN THE LINE OF STORMS...HOWEVER IMPACTS
TO THE MORNING RUSH HOUR COMMUTE LOOK LIKELY AT THIS TIME.
ASIDE FROM STRONG WIND GUSTS...LOCALLY HEAVY RAINFALL IS EXPECTED
TO BE A PROBLEM AS WELL. LOCALIZED FLOODING IS CONTINGENT UPON THE
SPEED OF THE STORMS AND THE SQUALL LINE IN GENERAL THIS MORNING.
THE TEXAS TECH WRF INDICATES THAT THE SQUALL LINE...OR ITS
REMNANTS...WILL PUSH THROUGH THE ENTIRE CWA FROM 12 TO 18Z. IF
THIS SCENARIO PANS OUT...LOCALIZED FLOODING IS LESS LIKELY BECAUSE
STORMS WILL BE MOVING THROUGH THE AREA TOO QUICKLY. MANY OTHER
HIGH-RESOLUTION GUIDANCE MEMBERS WEAKEN THE SQUALL LINE TO THE
POINT THAT IT DROPS A NEARLY STATIONARY BOUNDARY NEAR OR JUST
SOUTH OF INTERSTATE 20 BY LATE THIS MORNING. IF THIS OCCURS...IT`S
ONLY GOING TO HAPPEN BECAUSE THE SQUALL LINE SLOWS DOWN
CONSIDERABLY FROM ITS CURRENT PACE. ANY ONGOING RAIN SHOWER AND
THUNDERSTORM ACTIVITY IN THIS SCENARIO WOULD BE MORE LIKELY TO
PRODUCE LOCALIZED FLOODING AS STORMS WILL SIMPLY BE MOVING SLOWER.
EITHER WAY...LOCALLY HEAVY RAIN WILL OCCUR WITH ANY THUNDERSTORM
ACTIVITY ALONG THE SQUALL LINE BECAUSE MODELS INDICATE THAT PWATS
ONLY INCREASE OUT AHEAD OF THE SQUALL LINE ACROSS NORTH TEXAS THIS
MORNING. WITH LITTLE AIRCRAFT ACTIVITY (FOR AMDAR SOUNDINGS)
OVERNIGHT...ITS DIFFICULT TO ESTABLISH IF THIS IS REALISTIC OR
NOT. HOWEVER LOOKING AT THE GOES SOUNDER OUTPUT...THERE IS A PLUME
OF 2 INCH (OBSERVED AS 50 MM) PWATS LOCATED JUST SOUTH OF THE DFW
AREA...CONTINUING SOUTH OVER CENTRAL TEXAS. HOW FAR NORTH OR EAST
THIS PLUME EXTENDS IS UNKNOWN BECAUSE THE SATELLITE CAN NOT SEE
THROUGH THICK UPPER LEVEL CLOUDS OVER THESE AREAS. THE FACT THAT 2
INCH PWATS ARE OBSERVED TO THE SOUTHWEST OF WHERE MODELS DEPICT 2
INCH PWATS THIS MORNING (GENERALLY NORTH OF I-20 AND EAST OF I-35)
IS A GOOD SIGN THAT THE MODELS PROBABLY HAVE THIS RIGHT.
AS A RESULT...WENT AHEAD WITH A MENTION OF HEAVY RAINFALL IN THE
WORDED FORECAST THIS MORNING...HIGHLIGHTING AREAS NORTH OF
INTERSTATE 20 AS HAVING THE HIGHEST CHANCE AT SEEING LOCALLY HEAVY
RAINS. IN REALITY...WE WILL JUST HAVE TO WATCH AND SEE HOW THE
SQUALL LINE EVOLVES BECAUSE WHERE EVER THE STRONGEST THUNDERSTORM
ACTIVITY GOES...THE HEAVY RAIN WILL FOLLOW SUIT. THE IMPACTS WERE
NOT EXPECTED TO BE WIDESPREAD ENOUGH TO RESULT IN LARGE SCALE
FLOODING...SO NO FLOOD WATCH WILL BE ISSUED WITH THIS FORECAST
PACKAGE. WILL MONITOR STORMS AND HANDLE LOCALIZED FLOODING
TACTICALLY VIA WARNINGS...GRAPHICS AND SOCIAL MEDIA
DISSEMINATION.
FOR THIS AFTERNOON...NEW THUNDERSTORM CHANCES REALLY DEPEND ON
WHAT HAPPENS WITH OUR SQUALL LINE THIS MORNING. MANY MODELS SHOW A
GOOD QPF SIGNAL IN LINE WITH THE SQUALL LINE...BUT MOST
UNFORTUNATELY FAIL TO CARRY THE DYNAMICS OF THE SQUALL LINE INTO
THE MODEL MASS FIELDS. FOR INSTANCE...NOT ONE OPERATIONAL MODEL
BOTHERS TO BRING A WIND SHIFT LINE INTO THE CWA WITH THE SQUALL
LINE QPF BLOB THIS MORNING. THESE MODELS ALSO FAIL TO SUFFICIENTLY
STABILIZE/COOL THE LOWER TROPOSPHERE BEHIND THE SQUALL LINE. THIS
PRESENTS A BIG FORECAST PROBLEM AS BOTH OF THESE FACTORS WILL
PLAY A HUGE ROLE IN THUNDERSTORM CHANCES FOR THIS AFTERNOON. THE
TEXAS TECH WRF AND THE 4 KM NAM BOTH AT LEAST INDICATED SOME
RESPONSE IN THE LOW-LEVEL WIND FIELD...SO THESE MODELS WERE
WEIGHED MORE HEAVILY FOR THIS AFTERNOON`S THUNDERSTORM FORECAST.
AN 08Z OBJECTIVE SURFACE ANALYSIS INDICATED A THETA-E DROP OF
AROUND 11 KELVIN BEHIND THE SQUALL LINE THIS MORNING. AS FAR AS
COLD POOLS GO BEHIND SQUALL LINES...THIS IS NOT SUPER
IMPRESSIVE...BUT WILL NOT SIMPLY DISSIPATE WITH A FEW HOURS OF
DAYTIME HEATING EITHER. AS A RESULT...WHEREVER THE SQUALL LINE
LEAVES AN OUTFLOW BOUNDARY THIS MORNING...IT IS LIKELY TO HANG
AROUND AND MAINTAIN SOME IDENTITY FOR THIS AFTERNOON. AT THIS
TIME...USING THE TEXAS TECH WRF`S SURFACE WIND FIELD AS A PROXY
FOR THE OUTFLOW BOUNDARY`S LOCATION THIS AFTERNOON...THINK IT WILL
END UP SOUTH OF INTERSTATE 20. AS A RESULT...WENT AHEAD AND
LOWERED POPS FOR LOCATIONS NORTH OF THE INTERSTATE FOR THIS
AFTERNOON FROM THE PREVIOUS FORECAST. IF THE SQUALL LINE ACTUALLY
MOVES ALL THE WAY THROUGH CENTRAL TEXAS BY 18Z AS THE TEXAS TECH
WRF REFLECTIVITY SUGGESTS...IT MAY COMPLETELY SHUT DOWN
THUNDERSTORM CHANCES FOR THE CWA FOR THIS AFTERNOON.
AS IT STANDS...HAVE 30 TO 40 POPS IN THE FORECAST SOUTH OF
INTERSTATE 20 AND WEST OF INTERSTATE 35 FOR THIS AFTERNOON
REPRESENTING THE MAXIMUM POPS ACROSS THE CWA. HIGHLIGHTED AREAS
WEST OF INTERSTATE 35 BECAUSE MOST MODELS INDICATE THAT A WEAK
SHORTWAVE TROUGH CURRENTLY LOCATED ALONG THE ARIZONA/MEXICO BORDER
WILL MOVE EAST AND PROVIDE SOME FORCING FOR ASCENT OVER WEST-
CENTRAL TEXAS BY 00Z TODAY. IF THERE REALLY IS AN OUTFLOW BOUNDARY
STALLED OUT IN PLACE HERE...THE WEAK FORCING FOR ASCENT FROM THIS
TROUGH COMBINED WITH THE BOUNDARY SHOULD BE AN IDEAL PLACE FOR NEW
THUNDERSTORMS TO DEVELOP BY LATE THIS AFTERNOON. AS MENTIONED
ABOVE...IF THE OUTFLOW BOUNDARY IS ELSEWHERE BY THIS
AFTERNOON...POPS WILL NEED TO BE ADJUSTED ACCORDINGLY.
THE 4 KM NAM INDICATES THAT THIS BOUNDARY IS VERY IMPORTANT FOR
THIS AFTERNOON STORMS AS IT BLOWS UP SEVERAL CLUSTERS OF VERY
STRONG LOOKING CONVECTION ALONG THIS BOUNDARY BY 00Z. THE NSSL
WRF ON THE OTHER HAND INDICATES THAT THE OUTFLOW BOUNDARY WILL NOT
BE AS IMPORTANT AS AN MCV WITH REGARDS TO AFTERNOON THUNDERSTORM
CHANCES. THIS MODEL KEEPS WELL DEFINED MCV IN PLACE OVER EAST
CENTRAL OKLAHOMA THIS AFTERNOON AND CONCENTRATES THUNDERSTORM
ACTIVITY THERE INSTEAD OF ALONG THE OUTFLOW BOUNDARY OVER
NORTH/CENTRAL TEXAS. IT IS DIFFICULT TO KNOW WHAT WILL BE
IMPORTANT UNTIL THIS MORNINGS SQUALL LINE DISSIPATES AND WE CAN
REEVALUATE WHAT THE THERMODYNAMIC AND KINEMATIC ENVIRONMENT LOOKS
LIKE AT THAT TIME.
FOR TONIGHT...MOST MODELS INDICATE THAT OUR OUTFLOW BOUNDARY WILL
LIFT NORTH TO THE RED RIVER AND BECOME THE FOCUS FOR NEW
THUNDERSTORM ACTIVITY OVERNIGHT. WENT AHEAD AND KEPT HIGHER POPS
OVER THE NORTHERN CWA FOR TONIGHT AS A RESULT. IF THE OUTFLOW
BOUNDARY MAINTAINS ANY IDENTITY THROUGHOUT THE AFTERNOON HOURS OF
THE DAY...IT WILL PROBABLY SERVE TO ENHANCE THE SLOPE OF LOW-
LEVEL ISENTROPIC SURFACES PERPENDICULAR TO LOW-LEVEL WINDS
RESULTING IN ENHANCED LIFT. THE NORTHERN CWA SHOULD BENEFIT FROM
THIS ENHANCED LOW-LEVEL LIFT MORE SO THAN THE SOUTH.
TUESDAY THROUGH THURSDAY...MORE MODELS ARE SHOWING THAT A COL IN
THE UPPER LEVEL FLOW FIELD WILL SET UP OVER NORTH TEXAS DURING
THIS TIME FRAME. AS A RESULT...KEPT BROAD BRUSHED POPS IN PLACE
FOR ALL AREAS. HAVE SLIGHTLY HIGHER POPS ADVERTISED DURING THE
AFTERNOON HOURS OF THE DAY EACH DAY AS ANY HEATING COMBINED WITH
ANY WEAK UPPER TROUGH ALOFT WILL ENHANCE STORM CHANCES THROUGH
THIS PERIOD. WITH VERY WEAK FLOW FORECAST TO EXIST OVER THE
CWA...MESOSCALE FEATURES WILL CONTINUE TO DOMINATE THE DAILY
WEATHER PATTERN. MESOSCALE FEATURES...BY PHYSICAL DEFINITION...
CANNOT BE FORECAST MORE THAN ABOUT 12 HOURS OUT AT BEST...SO DID
NOT PUT A WHOLE LOT OF DETAIL IN PRECIPITATION CHANCES THROUGH THIS
PERIOD AS A RESULT. FOR PLANNING PURPOSES...JUST KEEP IN MIND THAT
THE LARGE SCALE PATTERN IS SUPPORTIVE OF SCATTERED SHOWERS AND
STORMS EACH DAY. THE FORECAST WILL CHANGE DEPENDING ON THE
MESOSCALE FEATURES AS THEY ARE RESOLVED...INCREASING RAIN CHANCES
FOR SOME AREAS WHILE LOWERING THEM FOR OTHERS. JUST LOOKING AT THE
PATTERN...LOCALLY HEAVY RAINFALL AND CLOUD TO GROUND LIGHTNING
WILL BE THE PRIMARY HAZARDS. LOCALLY STRONG WIND GUSTS CAN NOT BE
RULED OUT FOR ANY STORMS THAT OCCUR DURING THE PEAK HEATING HOURS
OF THE DAY.
FRIDAY THROUGH SUNDAY...WENT AHEAD AND TOOK RAIN CHANCES OUT FOR
MOST LOCATIONS DURING THIS PERIOD. THE 00Z ECMWF STOPPED
ADVERTISING THAT STALLED OUT UPPER LOW OVER NEW MEXICO THAT IT HAD
BEEN SHOWING FOR THE PAST 24 HOURS. IT NOW SHOWS WEAK RIDGING
ALOFT OVER THE CWA FOR NEXT WEEKEND WITH IS MORE IN LINE WITH WHAT
THE GFS HAS BEEN SHOWING FOR DAYS. THINGS COULD CHANGE OF COURSE
AS THE RELEVANT FEATURES REMAIN WELL OUT OVER THE OPEN WATERS OF
THE PACIFIC. AT THIS TIME...SINCE MOST GUIDANCE AS ADVERTISING
RIDGING ALOFT...DECIDED TO OPT WITH A DRY FORECAST AND ABOVE
NORMAL TEMPERATURES.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 84 75 90 75 88 / 30 40 40 30 40
WACO, TX 86 73 89 73 87 / 100 20 40 30 50
PARIS, TX 84 71 85 71 85 / 30 50 40 30 40
DENTON, TX 83 72 89 72 87 / 30 50 40 30 40
MCKINNEY, TX 83 73 89 73 87 / 30 50 40 30 40
DALLAS, TX 85 75 89 75 87 / 30 40 40 30 40
TERRELL, TX 84 76 91 73 88 / 30 30 40 30 40
CORSICANA, TX 87 74 88 73 86 / 30 30 40 30 50
TEMPLE, TX 87 73 89 73 87 / 100 20 40 30 50
MINERAL WELLS, TX 84 71 88 71 87 / 40 50 40 30 40
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
58/82
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
313 PM CDT MON JUN 23 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 313 PM CDT MON JUN 23 2014
THE MAIN FOCUS INTO TOMORROW IS WITH HOW LONG THE ISOLATED
CONVECTION WILL HOLD ON FOR THIS AFTERNOON/EVENING AND THEN WITH
THE PRECIPITATION CHANCES TOMORROW.
CLOUD COVER HAS BEEN SLOW TO ERODE TODAY AS A COLD FRONT
APPROACHES FROM THE WEST AND A MID LEVEL TROUGH PROPAGATES
NORTHEAST FROM IOWA INTO THE WESTERN GREAT LAKES. SOME ISOLATED
CONVECTION HAS INITIATED ALONG A COLD FRONT IN SOUTHEAST
MINNESOTA WHERE MLCAPE IS AROUND 500-1000 J/KG. THE COMBINATION
OF THE APPROACHING MID LEVEL SHORT WAVE TROUGH AND THE SLOW MOVING
SURFACE BOUNDARY HAS LEAD TO SOME FUNNEL CLOUDS FORMING CLOSER TO
THE TWIN CITIES. THIS DEVELOPMENT WILL REMAIN POSSIBLE FOR A FEW
HOURS HERE BEFORE THE SUN STARTS TO SET AND SB/MLCAPE STARTS TO
DROP OFF. THE PAST FEW RUNS OF THE HRRR HAVE DEVELOPED SOME SMALL
COLD POOLS WITH THIS CONVECTION AND TRIES TO KEEP IT GOING THROUGH
THE EARLY EVENING HOURS ACROSS WESTERN WISCONSIN. THINKING THAT
THESE SOLUTIONS ARE A BIT OVERDONE AS IT HAS SURFACE TEMPERATURES
GETTING INTO THE 90S...BUT WILL KEEP SOME PRECIPITATION CHANCES
GOING INTO THE EVENING AHEAD OF THIS FRONT.
THE FOCUS THEN GOES INTO TOMORROW AS A MID LEVEL TROUGH CURRENTLY
OVER SOUTHERN MANITOBA DROPS DOWN INTO THE REGION. THE STRONGEST
500-300MB PV ADVECTION RUNS FROM SOUTHERN MINNESOTA THROUGH
CENTRAL WISCONSIN AS THE SURFACE COLD FRONT DRIFTS DOWN INTO THE
REGION. THE THINKING IS THAT THE HIGHEST CHANCES FOR ANY
SHOWERS/STORMS SHOULD BE ALONG THIS CORRIDOR. THE 23.12Z GUIDANCE
ALL SUGGEST THAT MLCAPE SHOULD REMAIN FAIRLY TAME AT 500-1000 J/KG
AHEAD OF THE FRONT WITH LITTLE TO NO DEEP SHEAR TO WORK WITH...SO
SUSPECT THAT ANY CONVECTION WILL REMAIN OF THE PULSE NATURE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 313 PM CDT MON JUN 23 2014
WITH THIS COLD FRONT TO THE SOUTH OF THE REGION THROUGH THE REST
OF THE WORK WEEK...TEMPERATURES WILL BE SEASONAL OR JUST BELOW
SEASONAL UNTIL IT GETS KICKED BACK TO THE NORTH AS A WARM FRONT BY
NEXT WEEKEND. UNTIL THEN...CONFIDENCE IN PRECIPITATION CHANCES IS
NOT VERY HIGH AS MUCH OF IT WILL DEPEND ON WHETHER ANY CONVECTIVE
SYSTEMS TRACK ALONG THE BOUNDARY TO THE SOUTH AND WE SEE THE
NORTHERN OVERHANG OF IT. THE 23.12Z GFS/ECMWF HAVE ZONAL FLOW
OVER THE REGION FOR WEDNESDAY YET HAS SOME CONVECTION DEVELOPING
ALONG THE COLD FRONT/TROUGH THAT THEY HAVE ANALYZED ACROSS THE
AREA. THE 23.12Z NAM...MEANWHILE...HAS THE REGION MAINLY DRY
EXCEPT FOR A PORTION OF THE FRONT IN CENTRAL IOWA WHERE IT BUILDS
SURFACE DEW POINTS INTO THE MID 70S AND TAKES MLCAPE UP TOO HIGH.
SO...THERE IS NOT A LOT OF CONFIDENCE IN THE PRECIPITATION CHANCES
THROUGH THE END OF THE WEEK BUT AT LEAST EXPECT THAT THE RAINS WILL
NOT BE ALL DAY DEALS AND JUST SOME PERIODS WHERE THIS CONVECTION
IS POSSIBLE.
A PATTERN CHANGE TAKES PLACE FOR NEXT WEEKEND AS A DEEPER MID
LEVEL TROUGH DEVELOPS ACROSS THE HIGH PLAINS. THIS FEATURE STALLS
OUT AND A NUMBER OF SHORT WAVE TROUGHS ROUND THE SOUTHEASTERN
PERIPHERY OF IT ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. THIS
COULD LEAD TO A MORE ACTIVE PERIOD SEVERE WEATHER-WISE WITH
STRONG 500MB WINDS OVERHEAD TO GO ALONG WITH AN UNSTABLE AIR MASS.
DETAILS WILL FALL OUT THROUGH THE WEEK...BUT THIS APPEARS TO BE
THE TIME FRAME TO WATCH FOR POTENTIAL SEVERE WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1235 PM CDT MON JUN 23 2014
A COLD FRONT EXTENDS FROM RHINELANDER WI /KRHI/ TO AUSTIN MN
/KAUM/. MANY OF THE MESO MODELS CONTINUE TO SUGGEST THAT SOME
SCATTERED SHOWERS AND STORMS MAY DEVELOP ALONG THIS FRONT DURING
THE AFTERNOON. THESE CHANCES WERE TOO LOW AT THIS TIME TO INCLUDE
IN THE TAFS. WITH THE LOSS OF DIURNAL HEATING EXPECT SKIES TO
BECOME SCATTERED AFTER 23.23Z.
&&
.HYDROLOGY...
ISSUED AT 313 PM CDT MON JUN 23 2014
WHILE THERE ARE CHANCES FOR PRECIPITATION THROUGH THIS WEEK...THE
CHANCES FOR HEAVY RAINFALL ARE LOW WITH MOST OF THE BETTER
MOISTURE TRANSPORT STAYING SOUTH OF THE REGION. HOWEVER...THERE
STILL IS A LOT OF WATER COMING DOWN THE RIVERS FROM CENTRAL
MINNESOTA WHERE HEAVY RAIN FELL LAST WEEK. EXPECT AREA
RIVERS...ESPECIALLY THE MAIN STEMS...TO STAY UP THROUGH THE WEEK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BOYNE
HYDROLOGY...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1235 PM CDT MON JUN 23 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 308 AM CDT MON JUN 23 2014
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY AND THEN
AGAIN FROM TUESDAY INTO WEDNESDAY.
SURFACE ANALYSIS THIS MORNING SHOWS A VERY WEAK AND ILL DEFINED
PATTERN ACROSS THE UPPER MIDWEST. THERE IS A WEAK BOUNDARY WORKING
EAST ACROSS MINNESOTA WHERE THE WINDS SWITCH AROUND TO THE WEST
AND DEW POINTS BEGIN TO SLOWLY DECREASE. IT APPEARS THE FLOW ABOVE
THE SURFACE IS COMING AROUND TO THE WEST/NORTHWEST AHEAD OF THE
SURFACE BOUNDARY WITH 925 MB VWP WINDS FROM KDMX AND KMPX ALREADY
AROUND TO THE WEST/NORTHWEST.
THE 23.00Z NAM AND GFS ALONG WITH THE 23.06Z RAP ALL TRY TO
GENERATE A WEAK SURFACE WAVE OVER MISSOURI AND MOVE IT NORTHEAST
THIS MORNING INTO EASTERN WISCONSIN ALONG THE LOW LEVEL WIND SHIFT
BOUNDARY DEPICTED BY THE VWP WINDS. THE LOW LEVEL MOISTURE
CONVERGENCE MAY INCREASE FOR A SHORT WHILE THIS MORNING ON THE
NORTHWEST SIDE OF THIS LOW TO POSSIBLY HELP GENERATE A FEW SHOWERS
ACROSS THE EASTERN PART OF THE FORECAST AREA. WILL CARRY SOME LOW
RAIN CHANCES ACROSS THE EAST TO COVER THIS POSSIBILITY THROUGH
ABOUT THE MIDDLE OF THE AFTERNOON.
THE NEXT CHANCE OF RAIN WILL THEN COME TUESDAY AS A SHORT WAVE
TROUGH DROPS OUT OF SOUTHERN CANADA INTO THE UPPER MIDWEST. THIS
WAVE DOES NOT LOOK TO BE VERY STRONG BUT SHOULD STILL BRING SOME
WEAK PV ADVECTION IN THE 500-300 MB LAYER ACROSS NORTHERN
MINNESOTA AND WISCONSIN. ONLY WEAK MOISTURE CONVERGENCE ALONG THE
FRONT AND WITH BETWEEN 500 AND 1000 J/KG OF ML CAPE...IT SHOULD BE
ENOUGH TO GENERATE SOME SCATTERED ACTIVITY WITH THE BULK OF THIS
OCCURRING IN THE AFTERNOON. WITH THIS BOUNDARY STILL IN THE AREA
TUESDAY NIGHT...SOME OF THIS ACTIVITY COULD PERSIST PAST DARK
NORTHEAST OF THE I94 CORRIDOR WITH THE COVERAGE DIMINISHING AS THE
CAPE DECREASES.
ANOTHER SHORT WAVE TROUGH IS EXPECTED TO APPROACH FROM THE WEST
WEDNESDAY. THE WEAK PV ADVECTION FROM THIS WAVE SHOULD ONLY
ADVANCE INTO WESTERN MINNESOTA AND IOWA BY LATE IN THE DAY.
HOWEVER...THE WARM AIR ADVECTION AHEAD OF THIS WAVE SHOULD ALLOW
1-3 UBAR/S OF ISENTROPIC UP GLIDE ON THE 300K SURFACE TO START
SPREADING IN THROUGH THE DAY AND THIS COULD AGAIN BE ENOUGH TO
GENERATE SOME SCATTERED ACTIVITY AS THE ML CAPE INCREASES TO
500-1000 J/KG.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 308 AM CDT MON JUN 23 2014
THE LONGER RANGE MODELS REMAIN CONSISTENT IN SHOWING A TEMPORARY
CHANGE IN THE UPPER AIR FLOW AS A LONG WAVE TROUGH DIGS IN OVER
THE INTERMOUNTAIN WEST EARLY IN THIS PERIOD. HOWEVER...THE LATEST
TRENDS ARE FOR THIS TROUGH TO NOT BE A FAR SOUTH AS THEY NOW
INDICATE AN UPPER LEVEL LOW FORMING OVER CENTRAL CANADA OVER THE
WEEKEND. THIS ALLOWS A SOUTHWEST FLOW ALOFT TO REMAIN OVER THE
UPPER MIDWEST TO CLOSE OUT THE WEEK AND THEN THE LONG WAVE TROUGH
SWINGS THROUGH WITH A POSITIVE TILT TO IT. AT THE SURFACE...HIGH
PRESSURE SHOULD BE SOUTH OF HUDSONS BAY TO HELP FUNNEL MOISTURE
BACK INTO THE UPPER MIDWEST. THE COMBINATION OF THIS MOISTURE FEED
AND SHORT WAVE TROUGHS IN THE SOUTHWEST FLOW AND THEN THE LONG
WAVE TROUGH ITSELF WILL KEEP THE RAIN CHANCES GOING THROUGH THE
PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1235 PM CDT MON JUN 23 2014
A COLD FRONT EXTENDS FROM RHINELAND WI /KRHI/ TO AUSTIN MN /KAUM/.
MANY OF THE MESO MODELS CONTINUE TO SUGGEST THAT SOME SCATTERED
SHOWERS AND STORMS MAY DEVELOP ALONG THIS FRONT DURING THE
AFTERNOON. THESE CHANCES WERE TOO LOW AT THIS TIME TO INCLUDE IN
THE TAFS. WITH THE LOSS OF DIURNAL HEATING EXPECT SKIES TO BECOME
SCATTERED AFTER 23.23Z.
&&
.HYDROLOGY...
ISSUED AT 308 AM CDT MON JUN 23 2014
RIVER FLOOD WARNINGS HAVE BEEN PAIRED BACK TO ALMOST JUST THE
MISSISSIPPI RIVER. GIVEN THAT ADDITIONAL HEAVY RAIN DID NOT FALL
AND IS NOT EXPECTED OVER THE NEXT SEVERAL DAYS...THE FLOODING WILL
BECOME CONFINED TO JUST THE MISSISSIPPI. MANY LOCATIONS ALONG THE
MISSISSIPPI ARE EXPECTED TO BE NEAR OR ABOVE FLOOD STAGE THROUGH
THE WEEK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...BOYNE
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
247 PM MDT MON JUN 23 2014
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 245 PM MDT MON JUN 23 2014
DEEPER CUMULUS HAVE STARTED TO DEVELOP OVER THE PAST HOUR IN THE
CONVERGENCE ALONG THE SOUTHERN LARAMIE RANGE...BUT SO FAR NOT A
WHOLE LOT OF UPSCALE GROWTH AS THESE CELLS HAVE MOVED INTO THE
PLAINS. DEW POINTS ARE CURRENTLY IN THE UPPER 40S TO MID 50S TO THE
EAST OF THE LARAMIE RANGE. THE MODELS CONTINUE TO INDICATE AN
ENVIRONMENT CONDUCIVE FOR SOME STRONG TO SEVERE STORMS IN AREAS NEAR
THE COLORADO BORDER THROUGH THIS EVENING. SPC MESOANALYSIS SHOWS
MLCAPES OF 1000-1250 J/KG STRETCHING ALONG INTERSTATE 80 OVER THE
PLAINS COMBINED WITH 35-40 KT OF BULK SHEAR. THE HRRR MODEL HAS A
LONE STORM MOVING EASTWARD ALONG THE COLORADO BORDER THROUGH THE
LATE AFTN. SO VERY SIMILAR TO YESTERDAY...WE CONTINUE TO EXPECT A
MARGINAL SEVERE THREAT OVER LARAMIE COUNTY AND EXTENDING EASTWARD INTO
THE SOUTHERN PANHANDLE. KEPT A SLIGHT CHANCE OF TSTMS GOING THROUGH
THE NIGHT WITH A WEAK SHORTWAVE MOVING OVERHEAD...WHICH IS CURRENTLY
ACROSS SOUTHWESTERN WY.
THE REMAINDER OF THE SHORT TERM WILL FEATURE GRADUALLY INCREASING
TEMPS AND INSTABILITY. FLOW ALOFT IS STILL WEST TO NORTHWESTERLY ON
TUES WITH THE MID LEVEL RIDGE AXIS TO THE WEST OF THE CWA. DEW POINTS
INCH UP SLIGHTLY...SO CAPE VALUES WILL INCREASE OVER TODAY WITH THE
GFS SHOWING AROUND 1500 J/KG ALONG INTERSTATE 80. INSTABILITY DROPS
OFF TO 750 J/KG ACROSS CONVERSE/NIOBRARA COUNTIES AND INTO THE
NORTHERN NEBRASKA PANHANDLE. BEST CHANCE OF SEVERE STORMS WILL LIKELY
BE OVER AREAS TO THE SOUTH OF A WHEATLAND TO SCOTTSBLUFF LINE.
TEMPS ON TUES WILL BE A COUPLE DEGREES WARMER THAN THIS AFTN. THE
BEST POTENTIAL FOR MORE WIDESPREAD SEVERE STORMS IS STILL LOOKING LIKE
WED. A SFC LOW DEVELOPS OVER NORTH-CENTRAL WY DURING THE AFTN AND
WITH PERSISTENT SOUTHEAST WINDS...ADDITIONAL MOISTURE ADVECTION HAS
OCCURRED OVER THE PLAINS. DEW POINTS BY WED AFTN ARE INTO THE UPPER
50S AND LOW 60S ALMOST EVERYWHERE TO THE EAST OF THE LARAMIE RANGE
WITH CAPE VALUES OF 1500-2000. ALTHOUGH FLOW ALOFT WILL BE WEAKER
THAN THE PRECEDING DAYS DUE TO THE PROXIMITY OF THE RIDGE
AXIS...THERE IS STILL AROUND 40 KT OF DEEP LAYER SHEAR. ITS A BIT
EARLY TO PINPOINT THE AREA OVER THE PLAINS THAN HAS THE BEST
POTENTIAL FOR SEVERE STORMS...BUT IT WOULD SEEM TO BE OVER THE NORTHERN
HALF...WHICH IS CLOSEST TO A WEAK SHORTWAVE THAN MOVES INTO WESTERN
SOUTH DAKOTA DURING THE EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 225 PM MDT MON JUN 23 2014
MINOR MODEL DIFFERENCES NOTED IN THE MEDIUM RANGE PERIOD. WEAK UPPER
RIDGE OVER THE PLAINS YIELDS TO A BROADER UPPER TROUGH BY THE WEEKEND.
THE SOUTHWESTERLY FLOW ALOFT VEERS TO WESTERLY. SURFACE PATTERN WILL
BE FAIRLY WEAK WITH A RIDGE WEST OF THE MOUNTAINS AND TROUGH ACROSS
THE PLAINS. LOW LEVEL CONVERGENCE AND MOISTURE COMBINED WITH PASSING
WEAK DISTURBANCES WILL KEEP WIDELY SCATTERED SHOWERS AND TSTORMS
IN THE FORECAST THURSDAY THROUGH SATURDAY. SEVERE THREAT WILL BE
MINIMAL GIVEN WEAK SHEAR...BUT CANNOT RULE OUT ISOLATED STRONG
CONVECTION FOR THE PLAINS. UPPER TROUGH LIFTS NORTHEAST THROUGH
THE NORTHERN GREAT PLAINS AND UPPER MIDWEST SUNDAY AND MONDAY WITH
DRIER WEST-NORTHWEST FLOW PATTERN. TEMPERATURES WILL AVERAGE ABOVE
SEASONAL NORMALS WITH HIGHS IN THE 80S FOR LOWER ELEVATIONS WITH
60S AND 70S FOR THE HIGH COUNTRY. LOWS WILL BE IN THE 40S AND 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1145 AM MDT MON JUN 23 2014
EXPECT ANOTHER ACTIVE AFTERNOON OF TSTORM ACTIVITY...WITH BEST
CHANCES ALONG AND EAST OF THE LARAMIE RANGE. VFR CONDITIONS WILL
PREVAIL WITH THE EXCEPTION OF MVFR INVOF TSTORMS. THERE IS A
SLIGHT RISK FOR GUSTY OUTFLOW WINDS TO 50 KT...HAIL AND HEAVY
RAIN FROM CHEYENNE TO SIDNEY. THE CONVECTION WILL LIKELY LINGER
THROUGH 03Z IN SOUTHEAST WY AND 06Z FOR THE NEB PANHANDLE. WITH
MOIST BOUNDARY LAYER AND LIGHT WINDS...THERE IS THE POTENTIAL FOR
MVFR CONDITIONS ACROSS THE PLAINS.
&&
.FIRE WEATHER...
ISSUED AT 245 PM MDT MON JUN 23 2014
MINIMAL FIRE WEATHER CONCERNS THROUGH MIDWEEK. SCATTERED SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE EACH AFTERNOON AND EVENING
THROUGH THURSDAY. THE COVERAGE WILL BE HIGHEST AND THE BEST CHANCE
OF WETTING RAINS WILL EXIST TO THE EAST OF THE LARAMIE RANGE.
TEMPERATURES WILL BEGIN TO INCREASE ON WEDNESDAY AND THURSDAY SUCH
THAT MINIMUM AFTERNOON HUMIDITY VALUES WILL DROP TO AROUND 15
PERCENT WEST OF THE LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...JAMSKI
AVIATION...JAMSKI
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1153 AM MDT MON JUN 23 2014
.UPDATE...
ISSUED AT 1112 AM MDT MON JUN 23 2014
MOIST AIRMASS IS IN PLACE ACROSS THE PLAINS THIS MORNING WITH
SCATTERED AREAS OF LOW CLOUDS. MODELS SHOW SFC WINDS VEERING TO
THE EAST BY THIS AFTN WHICH INCREASES THE BULK SHEAR TO 45-50 KT
OFF THE RUC BY THIS AFTN. AFTN INSTABILITY IS SIMILAR TO YESTERDAY
WITH THE HIGHEST VALUES (1000-1500 J/KG) IN AREAS ALONG THE
COLORADO BORDER. SPC EXTENDED THE SLIGHT RISK NORTHWARD INTO THE
SOUTHERN PANHANDLE AND LARAMIE COUNTY WITH THE MORNING UPDATE.
COULD VERY WELL BE A REPEAT OF YESTERDAY WITH A FEW MARGINALLY SEVERE
STORMS ALONG THE COLORADO BORDER...BUT MORE NUMEROUS ACROSS
NORTHEASTERN COLORADO.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 440 AM MDT MON JUN 23 2014
CURRENT IR SATELLITE LOOP SHOWS MOSTLY CLEAR SKIES OVER THE
FORECAST AREA WITH SOUTHEAST WYOMING IN BETWEEN UPPER LEVEL SHORT
WAVE ACTIVITY EARLY THIS MORNING. THE NEXT SHORTWAVE IS CURRENTLY
MOVING SOUTHEAST ACROSS NORTHEAST WYOMING WITH SHOWERS REDEVELOPING
ALONG A LINE FROM NEWCASTLE NORTHWARD TOWARDS DEVILS TOWER. MOST
MODELS HAVE BEEN TOO AGGRESSIVE WITH THIS SHORTWAVE...SHOWING IT
DIGGING SOUTHWARD ACROSS THE AREA TONIGHT...BUT THAT HAS YET TO
HAPPEN. THE NAM SEEMS TO BE INITIALIZING THE BEST...SO WILL MAINLY
FOLLOW THE 00Z AND 06Z RUNS OVER THE NEXT 24 HOURS. THE NAM SHOWS
BANDS OF RAIN SHOWERS DEVELOPING OVER CONVERSE AND NIOBRARA
COUNTIES EARLY THIS MORNING AS THE SHORTWAVE DISTURBANCE PUSHES
ACROSS EASTERN WYOMING AND INTO THE WESTERN DAKOTAS. THIS SEEMS
MORE REALISTIC GIVEN CURRENT OBS ACROSS THE AREA. THE NAM ALSO
SHOWS MOST OF THE AFTERNOON SHOWERS AND TSTORMS TODAY FURTHER TO
THE SOUTH NEAR THE COLORADO BORDER...BUT THIS IS ALSO CONSISTENT
WITH THE OTHER MODELS WHICH SHOW A SIMILAR SOLUTION. LOWERED POP
UP NORTH TO AROUND 30 PERCENT AFTER MID TO LATE MORNING...AND
INCREASED AREAS ALONG AND JUST NORTH OF THE I80 CORRIDOR IN THE
AFTERNOON. EXPECT SIMILAR CONDITIONS TODAY WITH COOLER THAN NORMAL
DAYTIME TEMPERATURES BUT ALSO PLENTY OF INSTABILITY...ESPECIALLY
WITH THE CLEARING SKIES EARLY THIS MORNING WHICH WILL ALLOW
MAXIMUM SURFACE HEATING TODAY. STILL EXPECT A SOMEWHAT HIGHER
SEVERE WEATHER THREAT TODAY COMPARED TO YESTERDAY...BUT THERE IS
CONCERN OVER CURRENT MODEL SOUNDINGS WHICH SHOW HIGHER LI/S AND
LOWER CAPE VALUES LATE IN THE AFTERNOON DUE TO MID TO UPPER LEVEL
WARMING. CAPE VALUES STILL AROUND 1500 TO 2500 J/KG EARLY IN THE
AFTERNOON BUT QUICKLY LOWER THROUGH MID AFTERNOON...MEANING EITHER
CONVECTION WILL START PRETTY EARLY TODAY OR IT WILL BE LIMITED IN
COVERAGE THROUGH THIS AFTERNOON. BELIEVE EARLIER CONVECTION
INITIATION IS MORE LIKELY GIVEN CURRENT PROFILES...WITH ACTIVITY
TRANSITIONING TO RAIN SHOWERS BY LATE IN THE AFTERNOON.
THUNDERSTORMS WILL BE MULTI CELLULAR IN NATURE WITH TRAINING ALONG
OUTFLOW BOUNDARIES AND SOME PROPAGATION EXPECTED...DUE TO DECENT
40 TO 50 KNOT DEEP LAYER SHEAR. LOCALLY HEAVY RAINFALL AND FLASH
FLOODING IS POSSIBLE AS WELL.
ON TUESDAY...MODELS NOW SHOW WEST TO NORTHWEST FLOW ALOFT
CONTINUING OVER THE AREA WITH A WEAK RIDGE AXIS REMAINING TO THE
EAST. YESTERDAY...MODELS INDICATED SOUTHWEST FLOW TAKING OVER...SO
THIS IS A BIT OF A CHANGE IN SOLUTIONS. THEREFORE...LOWERED
TEMPERATURES A FEW DEGREES WITH HIGHS IN THE 70S ACROSS MOST OF
THE AREA TO NEAR 80 OVER FAR WESTERN CARBON COUNTY. WARMER AIR
WILL LIKELY MAKE IT INTO CARBON COUNTY...BUT THE REST OF THE AREA
WILL BE COOLER THAN NORMAL WITH ANOTHER ROUND OF SCATTERED TO
NUMEROUS SHOWERS AND TSTORMS. INCREASED POP BETWEEN 40 TO 55
PERCENT ALONG AND EAST OF THE LARAMIE RANGE. CAN NOT RULE OUT
ANOTHER ROUND OF SEVERE THUNDERSTORMS EAST OF THE LARAMIE RANGE AS
WELL...ESPECIALLY WITH SOME COOLER AIR ALOFT MOVING BACK INTO THE
FORECAST AREA WHICH WILL RESULT IN HIGHER CAPE VALUES AND LI/S
BELOW -5C.
CONDITIONS WILL BEGIN TO IMPROVE ON WEDNESDAY AS DRIER AIR MOVES
INTO CENTRAL WYOMING...GREATLY LIMITING TSTORM DEVELOPMENT. IN
FACT...THE 00Z GFS SHOWS THIS DRIER AIR MOVING TOWARDS THE
NEBRASKA BORDER BY MIDDAY WITH DEW POINTS LOWERING INTO THE MID TO
UPPER 30S BY MID AFTERNOON. BELIEVE THIS IS TOO AGGRESSIVE AND IS
PRETTY TYPICAL OF THE GFS WITH LLVL MOISTURE PRESENT AND WEAK
WESTERLY FLOW. KEPT SHOWERS AND TSTORMS IN THE FORECAST WITH POP
BETWEEN 20 TO 30 PERCENT ACROSS MOST LOCATIONS. TEMPERATURES WILL
INCREASE TO AROUND NORMAL WITH HIGHS IN THE 80S OUTSIDE OF THE
MOUNTAINS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 440 AM MDT MON JUN 23 2014
WARM AND UNSETTLED CONDITIONS WILL CONTINUE THURSDAY AND FRIDAY
AS AN UPPER TROF ALONG THE WEST COAST MOVES EAST DURING THAT TIME.
CHANCES FOR MAINLY LATE DAY CONVECTION WILL REMAIN THROUGH FRIDAY
AS WEAK IMPULSES PASS BY AHEAD OF THIS SYSTEM. THE MAIN UPPER TROF
AXIS WILL THEN PASS ACROSS THE REGION LATE FRIDAY AND LEAVE A
RATHER DRY ZONAL FLOW IN ITS WAKE FOR SATURDAY AND SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1145 AM MDT MON JUN 23 2014
EXPECT ANOTHER ACTIVE AFTERNOON OF TSTORM ACTIVITY...WITH BEST
CHANCES ALONG AND EAST OF THE LARAMIE RANGE. VFR CONDITIONS WILL
PREVAIL WITH THE EXCEPTION OF MVFR INVOF TSTORMS. THERE IS A
SLIGHT RISK FOR GUSTY OUTFLOW WINDS TO 50 KT...HAIL AND HEAVY
RAIN FROM CHEYENNE TO SIDNEY. THE CONVECTION WILL LIKELY LINGER
THROUGH 03Z IN SOUTHEAST WY AND 06Z FOR THE NEB PANHANDLE. WITH
MOIST BOUNDARY LAYER AND LIGHT WINDS...THERE IS THE POTENTIAL FOR
MVFR CONDITIONS ACROSS THE PLAINS.
&&
.FIRE WEATHER...
ISSUED AT 219 AM MDT MON JUN 23 2014
NO FIRE WEATHER CONCERNS ANTICIPATED THIS WEEK WITH MINIMUM
DAYTIME HUMIDITIES ABOVE 20 PERCENT ACROSS MOST AREAS...AND EVEN
ABOVE 40 PERCENT ACROSS THE HIGH PLAINS THROUGH THE MIDDLE OF THE
WEEK. IN ADDITION...SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH
WEDNESDAY BRINGING A GOOD CHANCE OF WETTING RAINS TO MOST AREAS
EAST OF THE LARAMIE VALLEY. SOME DRIER AIR WILL PUSH INTO
SOUTHEAST WYOMING BY LATE THIS WEEK...BUT DO NOT EXPECT CRITICAL
FIRE WEATHER CONDITIONS AT THIS TIME.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...FINCH
SHORT TERM...TJT
LONG TERM...EMANUEL
AVIATION...JAMSKI
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1120 AM MDT MON JUN 23 2014
.UPDATE...
ISSUED AT 1112 AM MDT MON JUN 23 2014
MOIST AIRMASS IS IN PLACE ACROSS THE PLAINS THIS MORNING WITH
SCATTERED AREAS OF LOW CLOUDS. MODELS SHOW SFC WINDS VEERING TO
THE EAST BY THIS AFTN WHICH INCREASES THE BULK SHEAR TO 45-50 KTS
OFF THE RUC BY THIS AFTN. AFTN INSTABILITY IS SIMILAR TO YESTERDAY
WITH THE HIGHEST VALUES (1000-1500 J/KG) IN AREAS ALONG THE
COLORADO BORDER. SPC EXTENDED THE SLIGHT RISK NORTHWARD INTO THE
SOUTHERN PANHANDLE AND LARAMIE COUNTY WITH THE MORNING UPDATE.
COULD VERY WELL BE A REPEAT OF YESTERDAY WITH A FEW MARGINALLY SVR
STORMS ALONG THE COLORADO BORDER...BUT MORE NUMEROUS ACROSS
NORTHEASTERN COLORADO.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 440 AM MDT MON JUN 23 2014
CURRENT IR SATELLITE LOOP SHOWS MOSTLY CLEAR SKIES OVER THE
FORECAST AREA WITH SOUTHEAST WYOMING IN BETWEEN UPPER LEVEL SHORT
WAVE ACTIVITY EARLY THIS MORNING. THE NEXT SHORTWAVE IS CURRENTLY
MOVING SOUTHEAST ACROSS NORTHEAST WYOMING WITH SHOWERS REDEVELOPING
ALONG A LINE FROM NEWCASTLE NORTHWARD TOWARDS DEVILS TOWER. MOST
MODELS HAVE BEEN TOO AGGRESSIVE WITH THIS SHORTWAVE...SHOWING IT
DIGGING SOUTHWARD ACROSS THE AREA TONIGHT...BUT THAT HAS YET TO
HAPPEN. THE NAM SEEMS TO BE INITIALIZING THE BEST...SO WILL MAINLY
FOLLOW THE 00Z AND 06Z RUNS OVER THE NEXT 24 HOURS. THE NAM SHOWS
BANDS OF RAIN SHOWERS DEVELOPING OVER CONVERSE AND NIOBRARA
COUNTIES EARLY THIS MORNING AS THE SHORTWAVE DISTURBANCE PUSHES
ACROSS EASTERN WYOMING AND INTO THE WESTERN DAKOTAS. THIS SEEMS
MORE REALISTIC GIVEN CURRENT OBS ACROSS THE AREA. THE NAM ALSO
SHOWS MOST OF THE AFTERNOON SHOWERS AND TSTORMS TODAY FURTHER TO
THE SOUTH NEAR THE COLORADO BORDER...BUT THIS IS ALSO CONSISTENT
WITH THE OTHER MODELS WHICH SHOW A SIMILAR SOLUTION. LOWERED POP
UP NORTH TO AROUND 30 PERCENT AFTER MID TO LATE MORNING...AND
INCREASED AREAS ALONG AND JUST NORTH OF THE I80 CORRIDOR IN THE
AFTERNOON. EXPECT SIMILAR CONDITIONS TODAY WITH COOLER THAN NORMAL
DAYTIME TEMPERATURES BUT ALSO PLENTY OF INSTABILITY...ESPECIALLY
WITH THE CLEARING SKIES EARLY THIS MORNING WHICH WILL ALLOW
MAXIMUM SURFACE HEATING TODAY. STILL EXPECT A SOMEWHAT HIGHER
SEVERE WEATHER THREAT TODAY COMPARED TO YESTERDAY...BUT THERE IS
CONCERN OVER CURRENT MODEL SOUNDINGS WHICH SHOW HIGHER LI/S AND
LOWER CAPE VALUES LATE IN THE AFTERNOON DUE TO MID TO UPPER LEVEL
WARMING. CAPE VALUES STILL AROUND 1500 TO 2500 J/KG EARLY IN THE
AFTERNOON BUT QUICKLY LOWER THROUGH MID AFTERNOON...MEANING EITHER
CONVECTION WILL START PRETTY EARLY TODAY OR IT WILL BE LIMITED IN
COVERAGE THROUGH THIS AFTERNOON. BELIEVE EARLIER CONVECTION
INITIATION IS MORE LIKELY GIVEN CURRENT PROFILES...WITH ACTIVITY
TRANSITIONING TO RAIN SHOWERS BY LATE IN THE AFTERNOON.
THUNDERSTORMS WILL BE MULTICELLULAR IN NATURE WITH TRAINING ALONG
OUTFLOW BOUNDARIES AND SOME PROPAGATION EXPECTED...DUE TO DECENT
40 TO 50 KNOT DEEP LAYER SHEAR. LOCALLY HEAVY RAINFALL AND FLASH
FLOODING IS POSSIBLE AS WELL.
ON TUESDAY...MODELS NOW SHOW WEST TO NORTHWEST FLOW ALOFT
CONTINUING OVER THE AREA WITH A WEAK RIDGE AXIS REMAINING TO THE
EAST. YESTERDAY...MODELS INDICATED SOUTHWEST FLOW TAKING OVER...SO
THIS IS A BIT OF A CHANGE IN SOLUTIONS. THEREFORE...LOWERED
TEMPERATURES A FEW DEGREES WITH HIGHS IN THE 70S ACROSS MOST OF
THE AREA TO NEAR 80 OVER FAR WESTERN CARBON COUNTY. WARMER AIR
WILL LIKELY MAKE IT INTO CARBON COUNTY...BUT THE REST OF THE AREA
WILL BE COOLER THAN NORMAL WITH ANOTHER ROUND OF SCATTERED TO
NUMEROUS SHOWERS AND TSTORMS. INCREASED POP BETWEEN 40 TO 55
PERCENT ALONG AND EAST OF THE LARAMIE RANGE. CAN NOT RULE OUT
ANOTHER ROUND OF SEVERE THUNDERSTORMS EAST OF THE LARAMIE RANGE AS
WELL...ESPECIALLY WITH SOME COOLER AIR ALOFT MOVING BACK INTO THE
FORECAST AREA WHICH WILL RESULT IN HIGHER CAPE VALUES AND LI/S
BELOW -5C.
CONDITIONS WILL BEGIN TO IMPROVE ON WEDNESDAY AS DRIER AIR MOVES
INTO CENTRAL WYOMING...GREATLY LIMITING TSTORM DEVELOPMENT. IN
FACT...THE 00Z GFS SHOWS THIS DRIER AIR MOVING TOWARDS THE
NEBRASKA BORDER BY MIDDAY WITH DEWPOINTS LOWERING INTO THE MID TO
UPPER 30S BY MID AFTERNOON. BELIEVE THIS IS TOO AGGRESSIVE AND IS
PRETTY TYPICAL OF THE GFS WITH LLVL MOISTURE PRESENT AND WEAK
WESTERLY FLOW. KEPT SHOWERS AND TSTORMS IN THE FORECAST WITH POP
BETWEEN 20 TO 30 PERCENT ACROSS MOST LOCATIONS. TEMPERATURES WILL
INCREASE TO AROUND NORMAL WITH HIGHS IN THE 80S OUTSIDE OF THE
MOUNTAINS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 440 AM MDT MON JUN 23 2014
WARM AND UNSETTLED CONDITIONS WILL CONTINUE THURSDAY AND FRIDAY
AS AN UPPER TROF ALONG THE WEST COAST MOVES EAST DURING THAT TIME.
CHANCES FOR MAINLY LATE DAY CONVECTION WILL REMAIN THROUGH FRIDAY
AS WEAK IMPULSES PASS BY AHEAD OF THIS SYSTEM. THE MAIN UPPER TROF
AXIS WILL THEN PASS ACROSS THE REGION LATE FRIDAY AND LEAVE A
RATHER DRY ZONAL FLOW IN ITS WAKE FOR SATURDAY AND SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 440 AM MDT MON JUN 23 2014
MAINLY VFR TODAY OTHER THAN SOME PATCHY LOW VSBYS IN THE LARAMIE
VALLEY THIS MORNING DUE TO FOG. SCTD SHOWERS AND TSTRMS DEVELOPING
THIS AFTERNOON AND CONTINUING INTO THIS EVENING WITH ASSOCIATED
LOWER VSBYS. SOME MVFR CIGS/VSBYS MAY DEVELOP OVER PARTS OF THE
PLAINS LATER TONIGHT AS WEAK UPSLOPE FLOW DEVELOPS.
&&
.FIRE WEATHER...
ISSUED AT 219 AM MDT MON JUN 23 2014
NO FIRE WEATHER CONCERNS ANTICIPATED THIS WEEK WITH MINIMUM
DAYTIME HUMIDITIES ABOVE 20 PERCENT ACROSS MOST AREAS...AND EVEN
ABOVE 40 PERCENT ACROSS THE HIGH PLAINS THROUGH THE MIDDLE OF THE
WEEK. IN ADDITION...SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH
WEDNESDAY BRINGING A GOOD CHANCE OF WETTING RAINS TO MOST AREAS
EAST OF THE LARAMIE VALLEY. SOME DRIER AIR WILL PUSH INTO
SOUTHEAST WYOMING BY LATE THIS WEEK...BUT DO NOT EXPECT CRITICAL
FIRE WEATHER CONDITIONS AT THIS TIME.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...FINCH
SHORT TERM...TJT
LONG TERM...RE
AVIATION...RE
FIRE WEATHER...TJT