Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/13/15
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
915 PM MST MON AUG 10 2015
.SYNOPSIS...
SOUTHERLY FLOW ALOFT WILL GRADUALLY INCREASE MOISTURE LEVELS THROUGH
TUESDAY...WITH TUESDAY AFTERNOON AND EVENING HAVING THE BEST CHANCE
FOR SHOWERS AND THUNDERSTORMS ACROSS ARIZONA. VERY STRONG HIGH
PRESSURE WILL BUILD INTO THE REGION FROM THE EAST BRINGING MUCH
ABOVE NORMAL TEMPERATURES AND REDUCED THUNDERSTORM CHANCES FROM
WEDNESDAY INTO SATURDAY. COOLER TEMPERATURES AND BETTER CHANCES FOR
STORMS WILL RETURN EARLY NEXT WEEK.
&&
.DISCUSSION...
LATEST CAMS CONTINUE TO SUGGEST THE POSSIBILITY OF ISOLATED
CONVECTION AS FAR WEST AS THE PHOENIX AREA...THOUGH AREAS TO THE
EAST TOWARDS GILA COUNTY ARE SOMEWHAT MORE FAVORED. LOCAL 00Z AND
03Z KPSR SOUNDING DATA SHOWED SFC-H8 MIXING RATIOS NEAR 10
G/KG...HOWEVER DROPPING OFF STEADILY TOWARDS THE H7 LAYER RESULTING
IN SUBSTANTIAL CINH. 00Z KTWC SOUNDING WAS SOMEWHAT MORE FAVORABLE
DEPICTING A DEEPER MOISTURE PROFILE...HOWEVER THE LACK OF ORGANIZED
CONVECTION AND DEEPER OUTFLOW BOUNDARIES HAS PRECLUDED THE INGEST OF
MOISTURE NEAR THE H7 LEVEL NORTHWARD. THEREFORE WHILE SOME DEEPER
CONVECTION PERCOLATES ALONG THE MARICOPA/GILA COUNTY LINE...RADAR
RETURNS ACROSS THE REGION ARE VERY QUIET...AND POPS WERE REDUCED
SOMEWHAT OVERNIGHT.
MEANWHILE...LATEST WV IMAGERY SHOWS A WELL-DEFINED PVD ACROSS CNTRL
CHIHUAHUA CONTINUING TO MOVE TOWARDS SE AZ. THE LEADING EDGE OF
DIVERGENT FLOW ALOFT AND LARGER SCALE ASCENT WAS JUST BEGINNING TO
MOVE INTO THE SERN PART OF THE STATE...WITH THE BULK OF ENERGY
FORCING A MODEST CONVECTIVE SYSTEM THROUGH SRN SONORA. THIS
EVOLUTION OF FEATURES SUGGESTS SOME POTENTIAL FOR ACCAS SHOWERS
OVERNIGHT THROUGH CNTRL ARIZONA (AS SUPPORTED BY NAM FORECAST BUFR
SOUNDINGS)...HOWEVER HRRR TRENDS HAVE BEEN SHOWING MIXED SIGNALS AND
MORE OFTEN NEGATIVE FOR RAINFALL THAN POSITIVE. THEREFORE...COULD
NOT COMPLETELY REMOVE POPS...AND IT STILL WOULD NOT BE OUT OF THE
REALM OF POSSIBILITY TO SEEING SOME ISOLD/SCT SHOWERS OVERNIGHT.
OTHERWISE...RATHER EXTENSIVE CLOUD COVER WAS HOLDING TEMPERATURES UP
WARMER THAN PREVIOUSLY FORECAST THROUGH THE EASTERN HALF OF THE
FORECAST AREA. THERE ARE SOME UPSTREAM BREAKS IN CLOUDS...AND
FORECAST LOWS WERE ALREADY GUIDED TO SLIGHTLY ABOVE PERSISTENCE...SO
ONLY MINOR MODIFICATIONS WERE NECESSARY.
&&
.PREVIOUS DISCUSSION...
/254 PM MST MON AUG 10 2015/
IT NOW APPEARS THAT TUESDAY WILL LIKELY BE THE MOST ACTIVE DAY...AS
THE FLOW ALOFT BECOMES SOUTHERLY THROUGH THE WHOLE COLUMN WITH LESS
CLOUDINESS LIKELY ON TUESDAY MORNING. DECENT MID-LEVEL SHEAR WILL
PERHAPS ENHANCE THE THUNDERSTORM INTENSIFY/COVERAGE..WITH AT LEAST
SOME STORM ACTIVITY WORKING ITS WAY INTO SW AZ.
WEDNESDAY THROUGH SATURDAY...
IT IS INCREASINGLY LIKELY THAT WE WILL SEE SOME VERY HOT
TEMPERATURES DURING THIS PERIOD AS THE MAIN LONG-WAVE PATTERN RE-
ADJUSTS ITSELF OVER NORTH AMERICA. RATHER DEEP TROFING WILL DROP
INTO THE GREAT LAKES/NE US...AND THE MAIN UPPER RIDGE AXIS FORCED
WESTWARD OVER THE DESERT SW. EVEN THOUGH OUR MID/UPPER-LEVEL FLOW
WILL REMAIN MAINLY FROM A SE-LY DIRECTION DURING THIS PERIOD...WHICH
NORMALLY IS THE BEST DIRECTION FOR MONSOON MOISTURE TO BE IMPORTED
INTO THE REGION...THE UPPER HIGH CENTER BUILDING OVER OUR REGION
WILL BE QUITE STRONG (500MB HEIGHTS RISING INTO THE 596-598DM
RANGE). THIS UPPER HIGH CENTER...WHICH HAS BEEN CENTERED OVER THE
GULF COAST REGION THE LAST FEW DAYS...HAS BROUGHT THAT REGION VERY
HOT AND DRY CONDITIONS...WITH HIGHS APPROACHING OR EXCEEDING 100
DEGREES AT MANY LOCATIONS...INCLUDING HOUSTON AND NEW ORLEANS.
STRONG SUBSIDENCE ALOFT HAS COMPLETELY SHUT DOWN THE CONVECTION THAT
NORMALLY KEEPS HIGHS IN THE LOW-MID 90S AT THESE COASTAL
LOCATIONS...AND IT APPEARS THAT THIS SUBSIDENCE IS HEADED OUR
WAY...AS INDICATED ON THE LATEST FORECAST SOUNDINGS. THUS...IT
APPEARS THAT THUNDERSTORM ACTIVITY WILL BE NOTICEABLY REDUCED DURING
THIS PERIOD...WITH MOST ACTIVITY BEING CONFINED TO THE HIGHER
TERRAIN OF SOUTH-CENTRAL AND SW AZ. THIS LACK OF CONVECTIVE
ACTIVITY/INCREASED SUNSHINE ALONG WITH VERY WARM AIR ALOFT (500MB
TEMPS IN THE -3C TO -4C RANGE) WILL ALLOW TEMPERATURES TO RISE WELL
ABOVE NORMAL...WITH WIDESPREAD READINGS IN THE 110-115F RANGE ACROSS
THE LOWER DESERTS. THESE VERY HOT DAYS ALONG WITH NIGHTTIME LOWS
NEAR 90 AT THE WARMER URBAN LOCATIONS MAKES THE ISSUANCE OF HEAT
RELATED PRODUCTS LATER THIS WEEK VERY LIKELY...ESPECIALLY FOR THE
THU-FRI TIME PERIOD.
SUNDAY AND MONDAY...
ALTHOUGH SOME MODEL DISAGREEMENT DOES CROP UP DURING THIS
PERIOD...IT APPEARS LIKELY THAT THE RIDGING OVER THE DESERT SOUTHWEST
WILL BEGIN TO WEAKEN...WITH COOLER TEMPERATURES AND A BETTER CHANCE
FOR THUNDERSTORMS RETURNING TO THE REGION.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
FAR LESS SHRA ACTIVITY MONDAY EVENING WITH JUST THICKER HIGH CLOUDS
AND SLY SFC WINDS EVENTUALLY TURNING TO EASTERLY OVERNIGHT. THERE
STILL COULD BE ISOLD/SCT -SHRA OVERNIGHT...THOUGH CONFIDENCE AND
PROPOSED COVERAGE DOES NOT WARRANT A TAF MENTION. ORIGINALLY HAD A
VALID VCSH TAF GROUPING...HOWEVER WILL LIKELY REMOVE THIS MENTION IN
06Z ISSUANCE.
POTENTIALLY A HIGH IMPACT AVIATION PERIOD LATE TUESDAY AFTERNOON AND
EARLY EVENING AS ORGANIZED THUNDERSTORMS ARE LIKELY OVER PARTS OF
CNTRL AND SRN ARIZONA. CONFIDENCE IS MODERATE ON TIMING AND
PLACEMENT OF HIGHEST IMPACTS...WITH BETTER POTENTIAL FOR STORMS TO
MOVE TOWARDS THE WESTERN PARTS OF THE PHOENIX METRO VERSUS THE EAST.
BEST MODEL OUTPUT SUGGESTS GOOD POTENTIAL FOR STRONG GUSTY OUTFLOW
WINDS AND BLOWING DUST IMPACTING SOME OR ALL OF THE PHOENIX TERMINAL
SITES.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
GOOD CONFIDENCE OF ONLY HIGH CLOUDS OVER SERN CALIFORNIA SITES
THROUGH TUESDAY EVENING...WITH TSRA REMAINING EAST OVER ARIZONA. SFC
WINDS WILL FAVOR A SOUTHERLY DIRECTION...AND EVEN KIPL HAS NOT SEEN
THE TYPICAL WESTERLY SUNDOWNER WIND THIS EVENING (ALTHOUGH THERE
STILL MAY BE A PERIOD OF VARIABLE WINDS TOWARDS SUNRISE).
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AND MUCH WARMER AIR WILL BE DRAWN INTO THE REGION FROM THE
EAST...RESULTING IN A DECREASE OF STORM CHANCES AND HUMIDITIES AND
AN INCREASE IN HIGH TEMPERATURES. WINDS WILL FOLLOW TYPICAL DIURNAL
AND DRAINAGE DRIVEN TRENDS WITH SOME ELEVATED UPSLOPE GUSTINESS IN
THE AFTERNOONS. MORE PRONOUNCED AND MOIST EASTERLY FLOW WILL RETURN
TO THE AREA BY THE LATE WEEKEND AND SHOULD WORK ON THE VERY WARM
TEMPERATURES WILL BOOSTING DAYTIME HUMIDITIES BY SUNDAY INTO MONDAY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MO/HIRSCH
PREVIOUS DISCUSSION...PERCHA
AVIATION...MO
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
312 PM MDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 312 PM MDT TUE AUG 11 2015
SCATTERED THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS THIS
AFTERNOON...AS MOISTURE (PRECIPITABLE WATER OVER 1 INCH) AND
INSTABILITY (CAPES ABOVE 1000 J/KG MOST AREAS) REMAIN PLENTIFUL.
GENERALLY FOLLOWED THE HRRR FOR CONVECTIVE TRENDS FOR LATE AFTERNOON
INTO THE EVENING...WITH A WAVE OF STRONGER CONVECTION OVER THE
MOUNTAINS MOVING INTO THE NORTHERN I-25 CORRIDOR OVER PUEBLO AND EL
PASO COUNTIES IN THE 21Z-01Z TIME FRAME...BRINGING A THREAT OF HEAVY
RAIN TO AREAS AROUND COLORADO SPRINGS/WALDO CANYON. FARTHER
SOUTH...CONVECTION ALONG THE SOUTHERN I-25 CORRIDOR WILL EXPAND
EASTWARD INTO THE EVENING...WITH SOME POCKETS OF HEAVY RAIN ALONG
AND SOUTH OF THE ARKANSAS RIVER. MOUNTAINS AND INTERIOR VALLEYS WILL
SEE A CONTINUATION OF SCATTERED CONVECTION...WITH MODELS AND LATEST
SATELLITE LOOP SUGGESTING LEAST ACTIVITY OVER THE SOUTHWEST
MOUNTAINS AS STRONGER CONVECTION OVER AZ STAY FAIRLY FAR TO THE
WEST.
OVERNIGHT...HRRR DEVELOPS ANOTHER BAND OF HEAVIER PRECIP OVER THE
ARKANSAS VALLEY 04Z-06Z FROM FREMONT COUNTY EAST THROUGH PUEBLO AND
LA JUNTA...WITH FAIRLY VIGOROUS CONVECTION WELL INTO THE NIGHT. NOT
SURE HOW REALISTIC THIS IS GIVEN INITIAL CONVECTION THIS AFTERNOON
POTENTIALLY STABILIZING THE AIR MASS SOMEWHAT...BUT WILL MAINTAIN
POPS PAST MIDNIGHT MANY AREAS AS MOST MODELS KEEP AT LEAST SOME
PRECIP GOING PAST 06Z.
ON WEDNESDAY...EXPECT A DOWNTURN IN CONVECTION AS UPPER RIDGE
CONTINUES TO SLOWLY BUILD NORTHWARD ACROSS THE STATE...WHILE POCKET
OF DRIER AIR OVER WESTERN NM ROTATES NORTHWARD INTO THE REGION.
STILL ENOUGH RESIDUAL MOISTURE FOR ISOLATED TSRA MOST LOCATIONS IN
THE AFTERNOON...THOUGH STORM INTENSITY AND THE THREAT OF HEAVY RAIN
SHOULD BE LESS THAN THE PAST COUPLE DAYS. HIGHEST POPS WILL BE OVER
THE MOUNTAINS...ESPECIALLY NORTHERN HALF OF THE AREA WHERE SLIGHTLY
DEEPER MOISTURE WILL REMAIN. MAX TEMPS MOST LOCATIONS WILL BEGIN TO
MOVE UPWARD AS AIR MASS DRIES AND HEIGHTS BUILD...THOUGH READINGS
WILL STILL BE AT OR SLIGHTLY BELOW MID AUGUST AVERAGES BY LATE DAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 312 PM MDT TUE AUG 11 2015
WEDNESDAY NIGHT THROUGH FRIDAY...A LARGE RIDGE OF HIGH PRESSURE IS
EXPECTED TO BE CENTERED OVER THE REGION THROUGH FRIDAY...KEEPING
WINDS ALOFT LIGHT. MOISTURE TRAPPED UNDER THE HIGH WILL FEED DIURNAL
AFTN AND EVE MT SHOWERS AND STORMS...AND STORMS THAT DO DEVELOP WILL
BE SLOW-MOVING AND MOVEMENT WILL BE DIFFICULT TO ANTICIPATE. LOOK
FOR MAX TEMPS TO REMAIN SOMEWHAT STEADY THROUGH THE PERIOD WITH AFTN
HIGHS IN THE 80S FOR THE HIGH VALLEYS...AND 80S TO MID 90S FOR THE E
PLAINS.
SATURDAY THROUGH MONDAY...MODELS INDICATE THAT AN UPPER SHORTWAVE
WILL CROSS MONTANA ON SATURDAY...WHICH WILL HELP TO SOMEWHAT FLATTEN
THE UPPER RIDGE AND EDGE IT TO THE SOUTH. A FRONTAL BOUNDARY WILL
DROP DOWN THE E PLAINS ON SUNDAY...BUT AT THIS TIME THERE DOES NOT
SEEM TO BE MUCH BY WAY OF SIGNIFICANT COOLING OR INCREASED
CONVECTIVE ACTIVITY WITH THIS FEATURE. LOOK FOR A CONTINUATION OF
THE DIURNAL AFTN AND EVE MT STORMS...THOUGH THERE IS A SLIGHT HINT
OF PERHAPS SOME LINGERING SHOWERS DURING THE OVERNIGHT PERIOD. AS
FOR TEMPS...MAX TEMPS WILL REMAIN IN THE 80S TO LOWER 90S FOR THE
PLAINS...AND 80S FOR THE HIGH VALLEYS.
TUESDAY...LONG RANGE MODELS SHOW A LOW DROPPING OUT OF CANADA AND
INTO MT AND THE DAKOTAS FOR TUE...SHUNTING THE UPPER RIDGE TO THE
SW. THIS IS STILL A BIT FAR OUT TIME-WISE TO MAKE SIGNIFICANT
CHANGES...BUT IF THIS SOLUTION PERSIST OVER THE NEXT FEW DAYS THEN
THIS MIGHT BRING COOLER TEMPS AND MORE PCPN FOR THE FORECAST AREA.
MOORE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 312 PM MDT TUE AUG 11 2015
FOR LATE THIS AFTERNOON AND EVENING...FOLLOWED THE HRRR FORECAST FOR
CONVECTION...WITH TSRA MOUNTAINS MOVING ACROSS LOWER ELEVATIONS 21Z-
04Z. BEST WINDOW FOR STORMS AT KCOS AND KPUB STILL LOOKS TO BE 22Z-
01Z...WITH PERHAPS SOME WEAKER CONVECTION PERSISTING 01Z-04Z.
POTENTIAL FOR MVFR/BRIEF IFR BOTH SITES AS RAIN WILL BE HEAVY AT
TIMES. AT KALS...STILL A LOW THREAT OF TSRA INTO THE
EVENING...THOUGH STORM CHANCES LOOK LOWER HERE AS SOME DRY AIR
BEGINS TO WORK NORTHWARD OUT OF NM. TSRA DIMINISH AND SHIFT EAST
TOWARD KS OVERNIGHT...WITH A REPEAT OF MVFR STRATUS POSSIBLE AT KCOS
AND OVER THE EASTERN PLAINS AFTER ABOUT 10Z AS SURFACE WINDS BECOME
LIGHT SE. ON WED...VFR CONDITIONS FROM MID MORNING ONWARD WITH FEWER
AFTERNOON STORMS AS AIR MASS BEGINS TO DRY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1134 AM MDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM MDT TUE AUG 11 2015
CHANCES FOR HEAVY RAIN THE MAIN CONCERN FOR TODAY...WITH PLENTY OF
MOISTURE REMAINING OVR THE FORECAST AREA. FORECAST MODELS ARE NOT IN
GOOD AGREEMENT AS TO WHERE THE POTENTIAL HEAVY RAIN BULLSEYES MAY BE
TODAY. THE NAM SHOWS A DISTURBANCE LIFTING NORTHWARD ACRS THE AREA
THIS MORNING AND SHOWS A BAND OF HEAVIER PCPN WORKING NORTHWARD WITH
THE DISTURBANCE. HOWEVER...THE NAM IS CURRENTLY NOT VERIFYING WELL
AS IT SHOW FAIRLY WIDESPREAD PCPN ACRS THE AREA BETWEEN 06Z AND 12Z
AND SO FAR THIS IS NOT HAPPENING. IN THE AFTERNOON HOURS THE NAM
HAS THE BEST CHANCES FOR PCPN OVR THE ERN PLAINS AND NORTHERN
PORTIONS OF THE CWA. WITH EAST TO SOUTHEAST UPSLOPE OVR EL PASO
COUNTY THRU THE DAY AND GOOD CHANCES FOR PCPN...ESPECIALLY THIS
EVENING...LOCALLY HEAVY RAINFALL AND FLASH FLOODING WL BE A
CONCERN...ESPECIALLY BECAUSE MUCH OF EL PASO COUNTY HAS HAD
SIGNIFICANT PCPN AMOUNTS IN THE LAST DAY AND A HALF RESULTING IN
SATURATED SOILS WHICH WL RESULT IN A LOT OF RUNOFF IF THE RAIN IS
HEAVY. THE NSSL 4KM WRF IS SIMILAR TO THE NAM...SHOWING HAVING PCPN
ACRS PORTIONS OF THE SERN PLAINS EARLY THIS MORNING...BUT THEN SHOWS
DECREASING PCPN CHANCES BY LATE MORNING. IT THEN HAS SCT PCPN FOR
THE AFTERNOON AND EVENING HOURS WITH LOCALIZED AREAS OF HEAVY RAIN.
THE HRRR DOES NOT SHOW THE SAME KIND OF HEAVY RAIN BAND MOVING NORTH
ACRS THE FORECAST AREA THIS MORNING LIKE THE NAM SHOWS. EXCEPT OVR
THE FAR ERN AREAS WHERE IT SHOWS WIDESPREAD PCPN UNTIL LATE MORNING.
CURRENT RADAR IMAGES SHOW PCPN WORKING ITS WAY NORTH INTO THE SERN
CORNER OF CO...WITH WIDESPREAD PCPN ALSO MOVING INTO THE SW MTNS.
FOR NOW WL MAINLY BROADBRUSH MUCH OF THE AREA WITH SCT POPS...EXCEPT
FOR SOME HIGHER POPS OVR PORTIONS OF THE HYR TRRN.
BY LATE TONIGHT...PCPN WL BE ON THE DECREASE ALTHOUGH AT LEAST SCT
PCPN SHOULD CONTINUE ALONG MUCH OF THE CONTDVD. SOME ISOLD
SHOWERS/TSTMS SHOULD ALSO CONTINUE MUCH OF THE NIGHT OVR THE FAR
SERN PLAINS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 357 AM MDT TUE AUG 11 2015
WEDNESDAY-FRIDAY...A BROAD UPPER HIGH CENTERED ACROSS NORTHEASTERN
NEW MEXICO AND NORTHWESTERN TEXAS EARLY WEDNESDAY IS PROGGED TO
BUILD SLOWLY NORTH AND WEST ACROSS THE CENTRAL ROCKIES AND INTO THE
FOUR CORNERS REGION THROUGH THE END OF THE WORK WEEK. THIS WILL
ALLOW FOR A GRADUAL LESSENING OF AFTERNOON AND EVENING STORMS ACROSS
THE AREA...AS THE MONSOONAL MOISTURE PLUME IS SHUNTED NORTH AND WEST
OF THE AREA...ALONG WITH WARMING TEMPERATURES ALOFT UNDER THE
BUILDING RIDGE HELPING TO SUPPRESS CONVECTION. BEST COVERAGE OF
STORMS THROUGH THE PERIOD LOOKS TO BE ACROSS THE CENTRAL MOUNTAINS
THROUGH THE PIKES PEAK REGION WITH A FEW STORMS DRIFTING OFF THE
HIGHER TERRAIN ACROSS THE IMMEDIATE ADJACENT PLAINS. THERE STILL
WILL BE ENOUGH MOISTURE...COMBINED WITH SLOW STORM MOVEMENT...TO
KEEP THE POTENTIAL FOR LOCALLY HEAVY RAINFALL ACROSS THE AREA.
SHOULD ALSO SEE TEMPERATURES WARMING BACK TO ABOVE SEASONAL AVERAGES
THROUGH THE PERIOD...WITH THE WARMING ALOFT AND LESS EXPECTED
COVERAGE OF STORMS.
SATURDAY-MONDAY...UPPER HIGH GETS SHUNTED SOUTH AND WEST ACROSS THE
DESERT SOUTHWEST...AS SEVERAL EMBEDDED SHORT WAVES TRANSLATE THROUGH
THE FASTER ZONAL FLOW ALOFT ACROSS THE NORTHERN TIER OF STATES. ONE
WAVE LOOKS TO SEND A COLD FRONT ACROSS THE EASTERN PLAINS SATURDAY
NIGHT WHICH WILL ALLOW FOR BETTER COVERAGE OF STORMS...ESPECIALLY
OVER AND NEAR THE EASTERN MOUNTAINS...AS LOW LEVEL MOISTURE
INCREASES WITHIN EASTERLY UPSLOPE FLOW. WITH MORE MOISTURE AND
SLIGHTLY COOLER AIR ALOFT...SHOULD SEE TEMPERATURES COOLING BACK TO
AROUND SEASONAL AVERAGES THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1128 AM MDT TUE AUG 11 2015
STILL A SMALL PATCH OF STRATUS HANGING ON AROUND KCOS AS OF
1730Z...EXPECT THIS TO FINALLY DISSIPATE 18Z-19Z AS SATELLITE
LOOPS SHOW CLOUDS THINNING/DECREASING. FOR THIS AFTERNOON AND
EVENING...FOLLOWED THE HRRR FORECAST FOR CONVECTION...WITH TSRA
DEVELOPING OVER THE MOUNTAINS 18Z-21Z...THEN MOVING ACROSS LOWER
ELEVATIONS 21Z-04Z. BEST WINDOW FOR STORMS AT KCOS AND KPUB LOOKS
TO BE 22Z-01Z...WITH PERHAPS SOME WEAKER CONVECTION PERSISTING
01Z-04Z. AT KALS...CONVECTIVE WINDOW A LITTLE WIDER WITH VCTS
MENTION FOR MUCH OF THE AFTERNOON INTO THE EVENING. TSRA DIMINISH
AND SHIFT EAST TOWARD KS OVERNIGHT...WITH A REPEAT OF MVFR STRATUS
AT KCOS POSSIBLE AFTER ABOUT 10Z AS SURFACE WINDS BECOME LIGHT
SE.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...MW
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
357 AM MDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM MDT TUE AUG 11 2015
CHANCES FOR HEAVY RAIN THE MAIN CONCERN FOR TODAY...WITH PLENTY OF
MOISTURE REMAINING OVR THE FORECAST AREA. FORECAST MODELS ARE NOT IN
GOOD AGREEMENT AS TO WHERE THE POTENTIAL HEAVY RAIN BULLSEYES MAY BE
TODAY. THE NAM SHOWS A DISTURBANCE LIFTING NORTHWARD ACRS THE AREA
THIS MORNING AND SHOWS A BAND OF HEAVIER PCPN WORKING NORTHWARD WITH
THE DISTURBANCE. HOWEVER...THE NAM IS CURRENTLY NOT VERIFYING WELL
AS IT SHOW FAIRLY WIDESPREAD PCPN ACRS THE AREA BETWEEN 06Z AND 12Z
AND SO FAR THIS IS NOT HAPPENING. IN THE AFTERNOON HOURS THE NAM
HAS THE BEST CHANCES FOR PCPN OVR THE ERN PLAINS AND NORTHERN
PORTIONS OF THE CWA. WITH EAST TO SOUTHEAST UPSLOPE OVR EL PASO
COUNTY THRU THE DAY AND GOOD CHANCES FOR PCPN...ESPECIALLY THIS
EVENING...LOCALLY HEAVY RAINFALL AND FLASH FLOODING WL BE A
CONCERN...ESPECIALLY BECAUSE MUCH OF EL PASO COUNTY HAS HAD
SIGNIFICANT PCPN AMOUNTS IN THE LAST DAY AND A HALF RESULTING IN
SATURATED SOILS WHICH WL RESULT IN A LOT OF RUNOFF IF THE RAIN IS
HEAVY. THE NSSL 4KM WRF IS SIMILAR TO THE NAM...SHOWING HAVING PCPN
ACRS PORTIONS OF THE SERN PLAINS EARLY THIS MORNING...BUT THEN SHOWS
DECREASING PCPN CHANCES BY LATE MORNING. IT THEN HAS SCT PCPN FOR
THE AFTERNOON AND EVENING HOURS WITH LOCALIZED AREAS OF HEAVY RAIN.
THE HRRR DOES NOT SHOW THE SAME KIND OF HEAVY RAIN BAND MOVING NORTH
ACRS THE FORECAST AREA THIS MORNING LIKE THE NAM SHOWS. EXCEPT OVR
THE FAR ERN AREAS WHERE IT SHOWS WIDESPREAD PCPN UNTIL LATE MORNING.
CURRENT RADAR IMAGES SHOW PCPN WORKING ITS WAY NORTH INTO THE SERN
CORNER OF CO...WITH WIDESPREAD PCPN ALSO MOVING INTO THE SW MTNS.
FOR NOW WL MAINLY BROADBRUSH MUCH OF THE AREA WITH SCT POPS...EXCEPT
FOR SOME HIGHER POPS OVR PORTIONS OF THE HYR TRRN.
BY LATE TONIGHT...PCPN WL BE ON THE DECREASE ALTHOUGH AT LEAST SCT
PCPN SHOULD CONTINUE ALONG MUCH OF THE CONTDVD. SOME ISOLD
SHOWERS/TSTMS SHOULD ALSO CONTINUE MUCH OF THE NIGHT OVR THE FAR
SERN PLAINS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 357 AM MDT TUE AUG 11 2015
WEDNESDAY-FRIDAY...A BROAD UPPER HIGH CENTERED ACROSS NORTHEASTERN
NEW MEXICO AND NORTHWESTERN TEXAS EARLY WEDNESDAY IS PROGGED TO
BUILD SLOWLY NORTH AND WEST ACROSS THE CENTRAL ROCKIES AND INTO THE
FOUR CORNERS REGION THROUGH THE END OF THE WORK WEEK. THIS WILL
ALLOW FOR A GRADUAL LESSENING OF AFTERNOON AND EVENING STORMS ACROSS
THE AREA...AS THE MONSOONAL MOISTURE PLUME IS SHUNTED NORTH AND WEST
OF THE AREA...ALONG WITH WARMING TEMPERATURES ALOFT UNDER THE
BUILDING RIDGE HELPING TO SUPPRESS CONVECTION. BEST COVERAGE OF
STORMS THROUGH THE PERIOD LOOKS TO BE ACROSS THE CENTRAL MOUNTAINS
THROUGH THE PIKES PEAK REGION WITH A FEW STORMS DRIFTING OFF THE
HIGHER TERRAIN ACROSS THE IMMEDIATE ADJACENT PLAINS. THERE STILL
WILL BE ENOUGH MOISTURE...COMBINED WITH SLOW STORM MOVEMENT...TO
KEEP THE POTENTIAL FOR LOCALLY HEAVY RAINFALL ACROSS THE AREA.
SHOULD ALSO SEE TEMPERATURES WARMING BACK TO ABOVE SEASONAL AVERAGES
THROUGH THE PERIOD...WITH THE WARMING ALOFT AND LESS EXPECTED
COVERAGE OF STORMS.
SATURDAY-MONDAY...UPPER HIGH GETS SHUNTED SOUTH AND WEST ACROSS THE
DESERT SOUTHWEST...AS SEVERAL EMBEDDED SHORT WAVES TRANSLATE THROUGH
THE FASTER ZONAL FLOW ALOFT ACROSS THE NORTHERN TIER OF STATES. ONE
WAVE LOOKS TO SEND A COLD FRONT ACROSS THE EASTERN PLAINS SATURDAY
NIGHT WHICH WILL ALLOW FOR BETTER COVERAGE OF STORMS...ESPECIALLY
OVER AND NEAR THE EASTERN MOUNTAINS...AS LOW LEVEL MOISTURE
INCREASES WITHIN EASTERLY UPSLOPE FLOW. WITH MORE MOISTURE AND
SLIGHTLY COOLER AIR ALOFT...SHOULD SEE TEMPERATURES COOLING BACK TO
AROUND SEASONAL AVERAGES THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 357 AM MDT TUE AUG 11 2015
VFR CONDITIONS ARE GENERALLY EXPECTED AT THE TAF SITES TODAY AND
THROUGH THE EVENING...HOWEVER SHOWERS AND TSTMS WL BE POSSIBLE IN
THE VCNTY OF TAF SITES TODAY AND THIS EVENING WHICH COULD AT TIMES
RESULT IN BRIEF MVFR CONDITIONS IN HEAVY RAIN. LATE TONIGHT THERE WL
BE THE POTENTIAL FOR LOW STRATUS AND FOG AT KCOS AND KPUB AS
INDICATED BY MOS GUIDANCE AND BUFKIT SOUNDINGS...WITH MVFR OR IFR
CONDITIONS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...MW
AVIATION...28
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1101 PM MDT MON AUG 10 2015
.UPDATE...
ISSUED AT 840 PM MDT MON AUG 10 2015
MCS LOCATED IN PUEBLO AND CROWLEY COUNTIES WILL CONTINUE TO
SLOWLY MOVE OFF TO THE ESE OVER THE NEXT FEW HOURS AS DEEP LOW
LEVEL MOISTURE AND LOW LEVEL MOISTURE CONVERGENCE HELP FUEL THE
STORM SYSTEM. RAISED POPS ACROSS CENTRAL AND SAN JUANS MTNS AS 00Z
NAM TRENDED TOWARDS ENHANCED ACTIVITY OVERNIGHT ACROSS THE HIGHER
TERRAIN. OTHERWISE CURRENT FORECAST REMAINS ON TRACK. LUKINBEAL
UPDATE ISSUED AT 537 PM MDT MON AUG 10 2015
THE THREAT OF FLASH FLOODING WILL CONTINUE ACROSS THE I-25
CORRIDOR THROUGH THE LATE EVENING HOURS AS A LINE OF TSRA
CURRENTLY EXTENDS FROM NE EL PASO COUNTY THROUGH WESTERN FREMONT
COUNTY WILL SLOWLY MOVE ESE OVER THE NEXT SEVERAL HOURS. LOW LEVEL
CONVERGENCE ALONG TWO OUTFLOW BOUNDARIES IN FAR SE EL PASO COUNTY
MAY INTENSIFY ACTIVITY FURTHER ALONG THE TSRA LINE. LATEST RUNS OF
THE HRRR CONTINUE TO BRING MODERATE TO HEAVY RAINFALL INTO EL
PASO...PUEBLO...CROWLEY...AND OTERO COUNTIES BETWEEN 01-06Z
TONIGHT. DEEP MOISTURE IS IN PLACE ACROSS THE PLAINS WITH PWATS
RANGING FROM 1.2-1.6 INCHES WITH DEW POINTS IN THE LOW 60S. WARM
RAIN PROCESSES IN THE LOWEST 100 MB WILL CONTINUE TO PROMOTE THE
DEVELOPMENT OF HEAVY RAINFALL THROUGH 06Z THIS EVENING ACROSS THE
PLAINS. ANOTHER POTENTIAL AREA OF CONCERN OVERNIGHT WILL BE THE
SAN LUIS VALLEY...SAN JUANS...AND CENTRAL MTNS WHERE AN UPPER
LEVEL DISTURBANCE IN COMBINATION WITH HIGH LOW-MID LEVEL MOISTURE
WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS WITH THE POTENTIAL TO
PRODUCE HEAVY RAINFALL. RAINFALL RATES WILL DECREASE AFTER 06Z AS
CLOUD TOPS LOWER ACROSS THE CWA DUE TO UPPER LEVEL SUBSIDENCE
MOVING OVERHEAD...DIMINISHING THE POTENTIAL FOR FLASH FLOODING.
LUKINBEAL
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 235 PM MDT MON AUG 10 2015
TSRA MOST NUMEROUS THIS AFTERNOON OVER THE PLAINS SOUTH OF THE
ARKANSAS RIVER...THOUGH AN ISOLATED CELL OVER TELLER AND EL PASO
COUNTIES EARLIER IN THE DAY MANAGED TO PRODUCE FLASH FLOODING OVER
WESTERN PORTIONS OF COLORADO SPRINGS AND THE EASTERN EDGE OF THE
WALDO CANYON BURN SCAR. MAIN QUESTION FOR TONIGHT WILL REVOLVE
AROUND LOCATION OF HEAVIER RAINFALL AND HOW LATE WILL STORMS
PERSIST INTO TUE MORNING. 19Z/20Z RUNS OF THE HRRR BRING ANOTHER
WAVE OF TSRA AND HEAVY RAIN THROUGH EL PASO COUNTY 00Z-02Z...THEN
ACROSS PUEBLO COUNTY AND NORTHERN PORTIONS OF THE ARKANSAS VALLEY
02Z-05Z. 12Z VERSIONS OF THE NAM/NAM 4KM/NSSL WRF ON THE OTHER
HAND...KEEP HEAVIEST RAINFALL MAINLY OVER THE MOUNTAINS
OVERNIGHT...WITH FOCUS FOR MOST TSRA SHIFTING TOWARD THE SAN JUAN
MOUNTAINS AFTER 06Z AS AREA OF DEEP TROPICAL MOISTURE OVER THE 4
CORNERS ROTATES NORTHEASTWARD. FORECAST LEANS A LITTLE TOWARD THE
HRRR...AS LAPS CAPES ARE STILL ABOVE 1000 J/KG OVER THE EASTERN
MOUNTAINS AND I-25 CORRIDOR...SUGGESTING ANOTHER BOUT OF TSRA IS
POSSIBLE. CONSIDERED A FLASH FLOOD WATCH FOR EL PASO COUNTY FOR
THIS EVENING AS HEAVY RAIN HAS FALLEN ACROSS THE REGION...THOUGH
WITH HRRR SHIFTING AXIS OF STRONGER STORMS SOUTH FAIRLY
QUICKLY...WILL REFRAIN FROM ISSUANCE AT THIS POINT. POCKETS OF
HEAVY RAIN LOOK POSSIBLE FARTHER SOUTH OVER THE PLAINS...BUT MOST
AREAS HAVE BEEN DRY ENOUGH LATELY TO TAKE AT LEAST A COUPLE HOURS
OF HEAVER PRECIP. PRECIP SLOWLY WANES OVERNIGHT...BUT NEVER
COMPLETELY COMES TO AN END...SO WILL KEEP SOME POPS GOING MANY
AREAS INTO EARLY TUE MORNING.
ON TUE...MOISTURE REMAINS IN PLACE...THOUGH HEIGHTS BEGIN TO BUILD
SLIGHTLY AS UPPER HIGH STARTS ITS NORTHWARD EXPANSION. STILL
APPEARS MOST LOCATIONS WILL SEE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ONCE AGAIN...THOUGH EXTENT OF OVERNIGHT CONVECTION
AND POTENTIAL MCS OVER THE EASTERN PLAINS/NORTHEASTERN NM WILL
LIKELY PLAY A ROLE IN AMOUNT OF CONVECTIVE COVERAGE...ESPECIALLY
OVER THE PLAINS WHERE EARLY MORNING SHOWERS COULD LIMIT
INSTABILITY. BROAD- BRUSH OF SCATTERED POPS LOOKS FINE...AND WITH
MOISTURE LEVELS REMAINING RELATIVELY HIGH...LOCALLY HEAVY RAINFALL
WILL AGAIN BE POSSIBLE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 235 PM MDT MON AUG 10 2015
UPPER RIDGE EXPANDS NORTHWARD WED-FRI...WITH THE UPPER LEVEL HIGH
PRESSURE CENTER REMAINING ALONG THE CO/NM BORDER THROUGH THE
PERIOD. TRAPPED MOISTURE UNDER THE HIGH WILL CONTINUE TO BE
RECYCLED...WITH DAILY AFTERNOON/EVENING TSRA OVER THE
MOUNTAINS...THOUGH COVERAGE MAY BECOME RATHER SPARSE WED/THU AS
TEMPERATURES ALOFT WARM. PLAINS/VALLEY TSRA CHANCES LOOK FAIRLY
LOW...THOUGH TOUGH TO RULE OUT A COUPLE STORMS DRIFTING AWAY FROM
THE MOUNTAINS EACH DAY...ESPECIALLY ALONG AND WEST OF I-25.
FORECAST HAS LOW POPS FOR ALL AREAS EACH DAY WED-FRI...WHICH MAY
BE A LITTLE OVERDONE...BUT WILL RUN WITH FOR NOW. RIDGE FLATTENS
SLIGHTLY FRI INTO THE WEEKEND...WHILE WEAK FRONT OOZES INTO THE
EASTERN PLAINS LATE SUN. EXPECT A GRADUAL INCREASE IN TSRA CHANCE
MOST LOCATIONS AS SLIGHTLY DEEPER MOISTURE MOVES IN FROM THE
WEST...WHILE LOW LEVELS ON THE PLAINS MOISTEN AND WESTERLY STEERING
CURRENTS BECOME MORE FAVORABLE FOR STORMS TO MOVE ONTO THE PLAINS.
TEMPS FROM WED INTO THE WEEKEND WILL REMAIN AT OR SLIGHTLY ABOVE
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1045 PM MDT MON AUG 10 2015
MONSOON DISTURBANCE WILL CONTINUE TO TRACK ACROSS FLIGHT
AREA TONIGHT...WITH SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS CONTINUING ACROSS THE FLIGHT AREA. ANOTHER
MONSOON DISTURBANCE WILL MOVE ACROSS THE FLIGHT AREA
TUESDAY AFTERNOON AND EVENING. CONDITIONS WILL GENERALLY
BE VFR OUTSIDE OF PRECIPITATION AND MVFR INSIDE OF
PRECIPITATION. HOWEVER...LOCAL IFR/LIFR CONDITIONS WILL
BE POSSIBLE IN AREAS OF MORE INTENSE PRECIPITATION. THIS
INCLUDES THE KCOS...KPUB AND KALS TAF SITES THROUGH 06Z
TUESDAY NIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AL/LW
SHORT TERM...PETERSEN
LONG TERM...PETERSEN
AVIATION...LW
AREA FORECAST DISCUSSION
NWS TAUNTON MA
429 PM EDT TUE AUG 11 2015
.SYNOPSIS...
A COLD FRONT THAT WILL APPROACH SOUTHERN NEW ENGLAND TONIGHT. SCATTERED
SHOWERS/THUNDERSTORMS THROUGH EARLY EVENING...WITH CONTINUED RISK
OF LOCALLY HEAVY DOWNPOURS. SOME LINGERING INSTABILITY WEDNESDAY
WILL GENERATE SOME CLOUDS AND A SCATTERED SHOWER OR ISOLATED
THUNDERSTORM. HIGH PRESSURE WILL BRING DRY AND MILD CONDITIONS
DURING THURSDAY INTO FRIDAY. A FRONT WILL APPROACH FRIDAY
NIGHT...SLOWLY CROSSING THE REGION THIS WEEKEND. THE BEST CHANCE
FOR SHOWERS AND THUNDERSTORMS LOOK TO OCCUR SATURDAY INTO EVENING.
DRY AND SEASONABLE CONDITIONS RETURN LATE THIS WEEKEND INTO EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THROUGH 7 PM...
CONTINUE TO HAVE HEAVY SHOWERS TRACKING THROUGH SE MA WITH GRADUAL TRANSITION
OF WHOLE AREA TO EAST. THERE IS SOME TRAINING BUT NOT CONTINUOUS ENOUGH
DISTRIBUTION OF CELLS TO CAUSE MORE THAN LOCALIZED STREET FLOODING AT
THIS TIME.
BEEN A CHALLENGING FORECAST FOR WIND GUSTS TODAY. THE INVERSION
HELD ENOUGH TO PREVENT THE STRENTHENING LOW LEVEL JET FROM MIXING
COMPLETELY DOWN TO THE SURFACE. DID SEE A FEW GUSTS OVER 30 KT IN
MASS BAY AS CORE OF LOW LEVEL JET MOVED THROUGH. RISK OF THOSE
STRONGER WIND GUSTS ASSOCIATED WITH THE LOW LEVEL JET HAS PASSED.
RISK OF ISOLATED STRONG TSTMS CT RIVER VALLEY AND WEST THROUGH 7
PM AS THAT REGION GRADUALLY DESTABILIZES WITH FINALLY GETTING
SOME BREAKS IN THE CLOUD COVER. SBCAPES WERE EDGING ABOVE 1000
J/KG BUT PROBABLY TOO LITTLE TOO LATE FOR MORE THAN A RISK OF JUST
AN ISOLATED STRONG TSTM OR TWO. WITH PWATS 1.7+ AND SLOW MOVEMENT
OF CELLS IN EASTERN NEW YORK...WE WILL NEED TO MONITOR CLOSELY 1
TO 3 HOUR RAFL FOR ANY CELL CLUSTERS THAT CONTAIN SOME LONGEVITY
IN OUR AREA. NOTE THAT HIGH RESOLUTION HRRR MODEL SUGGESTS THAT
CONVECTIVE ELEMENTS WILL WEAKEN AS THEY MOVE EAST OF THE CT RIVER
VALLEY.
AFTER 7 PM...ANY CONVECTION SHOULD SUBSIDE. COLD FRONT MOVES
THROUGH BUT DEACCELERATES AND THUS DEWPOINTS ONLY SLOWLY DROP
DURING EARLY MORNING HOURS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WED...THINK MOST OF WED SHOULD BE DRY...ALTHOUGH SOME MIXED
SIGNALS FOR WIDELY SCATTERED CONVECTION ACROSS EASTERN MA.
SURFACE COLD FRONT SEEMS TO SAG BACK A LITTLE ACROSS EASTERN AND
SOUTHEASTERN MA THROUGH WED AFTERNOON AND SO PROVIDES AN
OPPORTUNITY FOR SOME MOISTURE CONVERGENCE. COLD TEMPERATURES ALOFT
REFLECTED IN TOTAL TOTALS NEAR/A LITTLE ABOVE 50 ACROSS EASTERN MA
PROVIDE SOME INSTABILITY. HOWEVER...AIR MASS DRIES SOME AS
REFLECTED IN K INDICES ONLY IN MID TO UPPER 20S. LIGHT WIND FIELD
DURING DAY WILL LIKELY PROMPT SEA BREEZES ALONG THE
COAST...POSSIBLY PROVIDING A FOCUS FOR SOME WIDELY SCATTERED
CONVECTION IN EASTERN MA. ENOUGH SUN EXPECTED TO BRING INTERIOR
TEMPERATURES INTO THE LOWER 80S WED AFTERNOON.
WED NIGHT...SURFACE COLD FRONT MOVES EAST OF AREA AND UPPER TROF
AXIS SLOWLY MOVES THROUGH. DRIER AIR/LOWERING DEWPOINTS EXPECTED.
MAY JUST HAVE A LITTLE PATCHY EARLY MORNING FOG SOME VALLEYS.
TEMPERATURES SHOULD DROP TO MID 50S NW MA TO LOW TO MID 60S SE
COASTAL PLAIN.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...
* DRY AND SEASONABLE CONDITIONS EXPECTED ON THURSDAY
* A COLD FRONT WILL SLOWLY MOVE ACROSS THE REGION LATE FRIDAY
NIGHT INTO SATURDAY NIGHT
* MAINLY DRY CONDITIONS SHOULD FOLLOW FOR SUNDAY-MONDAY
OVERVIEW...
MEDIUM RANGE MODELS AND ENSEMBLES CONTINUE TO FEATURE AMPLIFIED
UPPER LEVEL PATTERN ACROSS NORTH AMERICA FOR THU/FRI TIMEFRAME.
STARTING OFF THU/FRI WITH RIDGING OVER THE PLAINS STATES THRU THE
UPPER MIDWEST...WITH A WEAKENING UPPER TROUGH OVER THE EASTERN
STATES. THEN THE UPPER RIDGE SLIDES EAST SOMEWHAT DURING THIS
WEEKEND AS THE WEAK TROUGH LIFTS OUT. UPPER RIDGING MAY HOLD OVER
OUR AREA INTO THE BEGINNING OF NEXT WEEK.
USING ENSEMBLE GUIDANCE FOR THIS FORECAST PACKAGE. TEMPERATURES
EXPECTED TO RANGE FROM SEASONABLE TO A FEW DEGREES ABOVE NORMAL
THROUGH THE PERIOD.
DETAILS...
THURSDAY-FRIDAY...SURFACE HIGH PRESSURE BRINGS DRY CONDITIONS TO THE
AREA DURING THIS PERIOD. WILL SEE GENERALLY MOSTLY SUNNY SKIES AND
SEASONABLY MILD/WARM TEMPS.
FRIDAY NIGHT THROUGH SUNDAY...WEAK COLD FRONT/SURFACE TROUGH SLOWLY
APPROACHES IN THE NW FLOW ALOFT. CONTINUE TO THINK THAT BEST CHANCE
FOR SHOWERS/SCT THUNDERSTORMS WILL BE SAT INTO POSSIBLY SAT NIGHT.
MAY SEE A COUPLE OF DOWNPOURS AND LOCALLY GUSTY WINDS IN A FEW OF
THE T-STORMS SAT AFTERNOON/EVENING. 12Z OPERATIONAL RUNS AND MOST
GFS ENSEMBLE MEMBERS INDICATE THE FRONT SHOULD EITHER PUSH SOUTH OF
OUR AREA ON SUNDAY...OR WASH OUT. SO EXPECTING MAINLY DRY CONDITIONS
ACROSS OUR AREA ON SUNDAY. MODERATE CONFIDENCE WITH THIS PORTION OF
THE FORECAST.
MONDAY...SHOULD SEE HIGH PRESSURE BRINGING DRY CONDITIONS AND
TEMPS A FEW DEGREES ABOVE NORMAL.
TUESDAY...DRY CONDITIONS ANTICIPATED TO START...BUT A COLD FRONT MAY
APPROACH FROM THE WEST DURING THE DAY WHICH COULD BRING A CHANCE FOR
SHOWERS/T-STORMS. TEMPS A FEW DEGREES ABOVE NORMAL.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TONIGHT...MODERATE CONFIDENCE. MVFR CIGS/VSBYS IN SHOWERS SE MA
LATE THIS AFTERNOON AND EARLY EVENING. RESIDUAL MOISTURE AND
RELATIVELY HIGH DEWPOINTS WILL LIKELY PROMOTE WIDESPREAD MVFR
CIGS/VSBYS IN FOG OVERNIGHT WITH AREAS OF IFR CIGS/VSBYS.
ELSEWHERE...PATCHY MVFR CIGS/VSBYS IN SCATTERED SHOWERS/TSTMS
THROUGH EARLY EVENING AND IN AREAS OF FOG OVERNIGHT...AIDED BY
RESIDUAL MOISTURE FROM TODAY/S RAIN.
WEDNESDAY...MODERATE TO HIGH CONFIDENCE. CIGS/VSBYS IMPROVE TO
VFR WITH PARTIAL CLEARING. SOME AFTERNOON CUMULUS CLOUDS WITH
SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS FAR NORTHERN AND
ACROSS EASTERN MA.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. ANTICIPATE GRADUAL
IMPROVEMENT IN CONDITIONS THROUGH EARLY EVENING BUT RISK OF MVFR
CIGS AND VSBYS REFORMING OVERNIGHT.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. GRADUAL IMPROVEMENT
IN CIGS FOR A TIME VERY LATE AFTERNOON AND EARLY EVENING BUT MVFR
CIGS LIKELY REFORMING OVERNIGHT. VSBYS MAY DROP OVERNIGHT FOR A
TIME 2 TO 4 MILES IN FOG. RISK OF A TSTM 21Z TO 00Z.
OUTLOOK /THURSDAY THROUGH SUNDAY/...
THURSDAY AND FRIDAY...HIGH CONFIDENCE. MAINLY VFR. MAY SEE LATE
NIGHT/EARLY MORNING PATCHY MVFR-IFR VSBYS EACH DAY ACROSS NORMALLY
PRONE INLAND VALLEYS.
SATURDAY...MODERATE CONFIDENCE. MAINLY VFR. LOW CHANCE FOR LOCAL
MVFR CIGS/VSBYS IN ISOLATED TO SCATTERED SHOWERS OR T-STORMS.
SUNDAY...MODERATE CONFIDENCE. MAINLY VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TONIGHT AND WEDNESDAY...MODERATE TO HIGH CONFIDENCE. WINDS
DIMINISHING TONIGHT BELOW SMALL CRAFT CRITERIA BUT WILL TAKE
LONGER FOR SEAS IN OUTER WATERS TO SUBSIDE BELOW 5 FEET.
HENCE...SMALL CRAFT ADVISORY CONTINUES FOR SE AND S OUTER COASTAL
WATERS UNTIL WED EARLY/MID AFTERNOON.
OUTLOOK /THURSDAY THROUGH SUNDAY/...
THURSDAY...HIGH CONFIDENCE. EXPECT HIGH PRESSURE OVER THE
WATERS...WINDS AND SEAS BELOW SMALL CRAFT CRITERIA.
FRIDAY...MODERATE CONFIDENCE. SW WINDS INCREASE FRI AFTERNOON...
GUSTING UP TO AROUND 20 KT. THERE IS A CHANCE THAT SEAS BUILD TO UP
TO 5 FT ON THE OUTER COASTAL WATERS. ELSEWHERE...WINDS AND SEAS
SHOULD REMAIN BELOW SMALL CRAFT LEVELS.
SATURDAY...MODERATE CONFIDENCE. WINDS AND SEAS SHOULD REMAIN
BELOW SMALL CRAFT CONDITIONS. SCT SHOWERS/THUNDERSTORMS MAY
BRIEFLY REDUCE VSBYS SAT AFTERNOON/NIGHT. LOW CHANCE FOR BRIEF
GUSTY WINDS.
SUNDAY...MODERATE CONFIDENCE. WINDS AND SEAS BELOW SCA THRESHOLDS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT WEDNESDAY FOR ANZ231>235-
237-250-251.
SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ230-
236.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...NMB/THOMPSON
NEAR TERM...THOMPSON
SHORT TERM...THOMPSON
LONG TERM...NMB
AVIATION...NMB/THOMPSON
MARINE...NMB/THOMPSON
AREA FORECAST DISCUSSION
NWS ALBANY NY
151 PM EDT TUE AUG 11 2015
.SYNOPSIS...
AHEAD OF AN APPROACHING COLD FRONT...SCATTERED SHOWERS
AND POSSIBLY A THUNDERSTORM WILL OCCUR ACROSS THE REGION THROUGH THE
EARLY EVENING HOURS. SLIGHTLY COOLER AND LESS HUMID CONDITIONS WILL
BUILD IN FOR WEDNESDAY...ALTHOUGH WITH A CONTINUED CHANCE FOR
SHOWERS AND THUNDERSTORMS AS AN UPPER LEVEL TROUGH REMAINS IN PLACE.
DRY WEATHER WILL RETURN TO THE REGION FOR THURSDAY WITH TEMPERATURES
JUST SLIGHTLY BELOW NORMAL LEVELS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 151 PM...STEADY RAINFALL HAS ENDED AND SHIFTED WELL INTO
EASTERN AND NORTHERN NEW ENGLAND. COLD FRONT REMAINS UPSTREAM OF
THE REGION...WITH THE BOUNDARY NOW LOCATED OVER CENTRAL NY. RADAR
IMAGERY SHOWS SOME SCATTERED SHOWERS HAVE DEVELOPED AHEAD OF THE
BOUNDARY. VISIBLE SATELLTE IMAGERY SHOWS SOME BREAKS IN THE CLOUD
COVER...BUT OVERALL...MOST AREAS ARE REMAINING MOSTLY CLOUDY.
BASED ON CURRENT RADAR ACTIVITY AND 3KM HRRR GUIDANCE...WILL GO
WITH CHC TO LIKELY POPS FOR THIS AFTN INTO THE EARLY EVENING
HOURS. WILL KEEP A SLIGHT CHC FOR THUNDER IN THE FORECAST AS
WELL...AS SOME THUNDER HAS OCCURRED OVER THE SOUTHEASTERN
CATSKILLS ALREADY...AND SOME SFC BASED CAPE IS POSSIBLE WITH THE
OCCASIONAL BREAKS IN THE CLOUD COVER. ANY T-STORM WILL REMAIN
BELOW SEVERE LEVELS DUE TO LIMITED INSTABILITY.
EXPECT HIGHS TODAY TO GENERALLY RANGE FROM THE UPPER 60S TO UPPER
70S. WITH TEMPS ALREADY WARMING INTO THE UPPER 70S IN THE CAPITAL
REGION...WILL HAVE A SHOT AT CONTINUING ONGOING STREAK OF REACHING
80+ AT ALBANY TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
TONIGHT EXPECT SHOWER AND THUNDERSTORM ACTIVITY TO DIMINISH
DURING THE EVENING AS THE LOW PRESSURE SYSTEMS AND ASSOCIATED
FRONTAL BOUNDARIES SLIDE OFF THE NEW ENGLAND COAST. LOWS TONIGHT
ARE EXPECTED TO RANGE FROM THE MID 50S TO MID 60S.
ON WEDNESDAY WILL KEEP A SLIGHT CHANCE TO CHANCE OF SHOWERS ALONG
WITH A SLIGHT CHANCE TO CHANCE OF THUNDERSTORMS AS AN UPPER
TROUGH AXIS WITH A FAIRLY STRONG ASSOCIATED VORT MAX SWING THROUGH
THE FA DURING THE AFTERNOON HOURS. ML MUCAPES APPROACH 1000 J/KG
ACRS PARTS OF THE AREA ON WEDNESDAY AFTERNOON. HIGHS ON WEDNESDAY
WILL BE IN THE UPPER 60S TO LOWER 80S.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT LOOKS DRY AT THIS POINT IN
TIME AS A RIDGE OF HIGH PRESSURE BUILDS EAST FROM THE OHIO VALLEY
WEDNESDAY NIGHT AND SETTLES ACROSS THE MIDDLE ATLANTIC REGION
THURSDAY NIGHT. EXPECT LOWS WEDNESDAY NIGHT TO BE IN THE UPPER
40S TO UPPER 50S. HIGHS ON THURSDAY ARE EXPECTED TO BE IN THE
UPPER 60S TO LOWER 80S WITH LOWS THURSDAY NIGHT IN THE 50S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE EXTENDED FEATURES THE MEAN UPPER LEVEL TROUGH STILL OVER SE
CANADA AND THE NORTHEAST AS WE HEAD INTO THE FIRST HALF OF THE
WEEKEND...BUT THE MEDIUM RANGE GUIDANCE CONTINUES TO SHOW A TREND
TOWARDS INCREASING LOW AND MID LEVEL HEIGHTS WITH RIDGING BUILDING
IN OVER THE EAST COAST...AND A WARMING TREND TO ABOVE NORMAL TEMPS
INTO EARLY NEXT WEEK.
FRI-FRI NIGHT...A SHORT-WAVE TROUGH IN THE W/NW FLOW ALOFT
APPROACHES UPSTATE NY AND WRN NEW ENGLAND IN THE AFTERNOON. THE GFS
IS MORE AGGRESSIVE WITH THE SHORT-WAVE THAN THE ECMWF/CAN GGEM IN
TERMS OF THE TIMING AND THE AREAL EXTENT OF SHOWERS/ISOLD
THUNDERSTORMS. WE PLACED SLIGHT TO LOW CHC POPS IN FROM THE NRN
CATSKILLS/CAPITAL REGION/BERKSHIRES NORTH AND WEST FOR THE AFTERNOON
AND INTO THE EARLY EVENING. THE COLD FRONT TO THE LOW PRESSURE
SYSTEM MOVING ACROSS W-CNTRL QUEBEC LOOKS TO ARRIVE FOR SATURDAY.
H850 TEMPS INCREASE TO ABOUT +15C TO +17C WITH A WEAK THERMAL
TROUGH/WARM FRONT PASSAGE...AS HIGH TEMPS WILL BE IN THE 80-85F
RANGE IN THE MAJOR RIVER VALLEYS...AND 70S TO NEAR 80F OVER THE
HILLS AND MTNS. LOWS WILL GENERALLY BE IN THE M50S TO L60S.
SAT-SAT NIGHT...PRETTY GOOD AGREEMENT WITH THE WPC
GRAPHICS/GEFS/ECMWF/GFS/CANADIAN GUIDANCE THAT A COLD FRONT WILL
SLOWLY PROGRESS FROM THE ST LAWRENCE RIVER VALLEY S/SE ACROSS THE
FCST AREA. THE AMOUNT OF SFC DESTABILIZATION WILL DEPEND ON THE
COVERAGE AND INTENSITY OF THUNDERSTORMS. THE GFS HAS THE GREATEST
INSTABILITY FROM THE CAPITAL DISTRICT SOUTHEAST INTO WRN NEW
ENGLAND...BUT GENERALLY LESS THAN 800 J/KG. CHC POPS WERE INCLUDED
UNTIL 00Z/SUN...AND THEN ONLY SLIGHT CHC VALUES WERE USED FOR THE
EXTREME SE PORTION OF THE FCST AREA /SE OF THE CAPITAL DISTRICT/ FOR
SAT NIGHT PRIOR TO MIDNIGHT. HIGHS LOOK SIMILAR TO FRI WITH 80S IN
THE LOWER ELEVATIONS AND NW CT...AND MID AND U70S OVER THE MTNS.
LOWS WILL RANGE FROM THE M50S OVER THE SRN DACKS TO LOWER 60S OVER
THE CAPITAL DISTRICT/MID HUDSON VALLEY/TACONICS/NW CT.
SUNDAY INTO MONDAY...SFC HIGH PRESSURE RIDGES IN FROM THE MID
ATLANTIC STATES OVER THE NORTHEAST...AS THE FRONT DRIFTS OFF THE
COAST. H850 TEMPS RISE BACK TO +15 TO +17C. MID LEVEL HEIGHTS
BEGIN TO RISE OVER THE FCST AREA. SFC DEWPTS WILL RANGE FROM THE
M50S TO L60S /SOME SPOTTY M60S OVER THE MID HUDSON VALLEY/. EXPECT
HIGHS TO BE IN THE MID 80S IN MANY OF THE VALLEY AREAS...AND U70S TO
L80S OVER THE HIGHER TERRAIN. SOME RADIATIONAL COOLING WILL ALLOW
TEMPS TO FALL BACK INTO THE 50S TO AROUND 60F IN A FEW SPOTS. A
HOTTER MID AUGUST AIR MASS CONTINUES TO RIDGE IN FROM THE MID
ATLANTIC COASTAL REGION WITH HIGHS APPROACHING THE MID AND U80S IN
THE VALLEY AREAS...AND UPPER 70S TO L80S OVER THE MTNS. IT WILL
ALSO BECOME MORE HUMID TO OPEN THE WEEK...WITH PERHAPS A FEW ISOLD
SHOWERS OVER THE SRN DACKS/SRN GREENS LATE IN THE PM.
OVERALL...TEMPS WILL GENERALLY BE SLIGHTLY ABOVE NORMAL WITH PCPN
BELOW NORMAL IN THE LONG TERM.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE WILL CONTINUE TO MOVE DOWN THE SAINT LAWRENCE VALLEY
THIS AFTERNOON AND EVENING. THE ASSOCIATED OCCLUDED FRONT WILL
MOVE ACROSS THE TAF SITES BETWEEN 21Z AND 22Z THIS AFTERNOON.
AHEAD OF AND ALONG THE FRONT THERE WILL BE SCATTERED SHOWERS AND
POSSIBLY A TSTM. HAVE INCLUDED VCSH WITH VFR VSBYS AND MVFR/VFR
CIGS INTO THIS EVENING...AND TEMPO GROUPS FOR MVFR VSBYS AND
MVFR/IFR CIGS UNTIL THE FRONT PASSES.
AFTER THE FRONT PASSES THERE SHOULD BE A BRIEF PERIOD OF VFR
CONDITIONS AT THE KGFL/KALB/KPOU/KPSF TAF SITES. HOWEVER...AFTER
ALL THE RAIN THERE WILL BE PLENTY OF RESIDUAL LOW LEVEL MOISTURE
AROUND AND WINDS WILL GENERALLY BE LIGHT...SO EXPECT MVFR/IFR
CONDITIONS DUE TO FOG TO BE A PROBLEM LATER TONIGHT AND EARLY
WEDNESDAY MORNING. AFTER AROUND 12Z WEDNESDAY...VFR CONDITIONS
SHOULD RETURN.
SURFACE WINDS WILL BE SOUTHERLY AT 5 TO 10 KTS UNTIL THE FRONT
MOVES THROUGH...THEN SHIFT TO WESTERLY AROUND 21Z AT KALB/KGFL...
AND 22Z AT KPSF/KPOU BEHIND THE FRONT. TONIGHT WINDS WILL BECOME
LIGHT AND VARIABLE...THEN NORTHWEST AT 5 TO 10 KTS ON WEDNESDAY.
OUTLOOK...
WEDNESDAY AFTN: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
A DEVELOPING LOW PRESSURE SYSTEM LOCATED OVER THE CENTRAL GREAT
LAKES WILL TRACK NORTHEASTWARD INTO THE SAINT LAWRENCE VALLEY
TODAY. THIS LOW WILL DRAG A COLD FRONT THROUGH OUR REGION LATE
TODAY. THE SYSTEM WILL BRING A WIDESPREAD SOAKING RAINFALL TO THE
REGION WITH SOME EMBEDDED THUNDERSTORMS AND LOCALLY HEAVY RAINFALL
TODAY. SLIGHTLY COOLER AND LESS HUMID CONDITIONS WILL BUILD IN FOR
WEDNESDAY...ALTHOUGH WITH A CONTINUED CHANCE FOR SHOWERS AND
THUNDERSTORMS AS AN UPPER LEVEL TROUGH REMAINS IN PLACE.
RELATIVE HUMIDITY VALUES WILL ONLY DROP TO 65 TO 85 PERCENT
TODAY...RECOVER TO 90 TO 100 PERCENT TONIGHT AND DROP TO 45 TO 65
PERCENT ON WEDNESDAY.
WINDS TODAY WILL BE SOUTHERLY AROUND 5 TO 15 MPH WITH OCCASIONAL
GUSTS OF 20 TO 30 MPH...ESPECIALLY ACROSS THE HIGHER TERRAIN.
WINDS WILL SHIFT TO THE WEST AT 5 TO 10 MPH TONIGHT AND WINDS WILL
BE NORTHWEST AT 5 TO 15 MPH WITH GUSTS 25 TO 35 MPH ACROSS THE
HIGHER TERRAIN.
&&
.HYDROLOGY...
MODERATE TO LOCALLY HEAVY RAINFALL AMOUNTS ARE EXPECTED THROUGH
EARLY THIS EVENING ALTHOUGH SINCE IT HAS BEEN DRY OF LATE ACROSS
MUCH OF THE AREA...ONLY WITHIN BANK RIVER RISES ARE EXPECTED.
THERE COULD BE SOME LOCALIZED MINOR FLOODING IN URBAN...LOW
LYING...AND POOR DRAINAGE AREAS. AVERAGE BASIN RAINFALL OF 1 TO 2
INCHES IS FORECAST...WITH LOCALIZED AMOUNTS UP TO 3 INCHES
POSSIBLE ACROSS THE SOUTHEAST FACING SLOPES OF THE HIGHER TERRAIN.
THE THREAT FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL
CONTINUE THROUGH WEDNESDAY AS AN UPPER LEVEL TROUGH REMAINS IN
PLACE ACROSS THE REGION.
MORE RAINFALL IS EXPECTED AS WE ENTER THE WEEKEND WITH SCATTERED
SHOWERS AND THUNDERSTORMS ESPECIALLY ON SATURDAY AFTERNOON AND
SATURDAY EVENING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/GJM/11/JPV
NEAR TERM...FRUGIS/GJM/11
SHORT TERM...11
LONG TERM...WASULA
AVIATION...GJM
FIRE WEATHER...11
HYDROLOGY...11/JPV
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
940 PM EDT WED AUG 12 2015
.DISCUSSION...
...HIGH RAIN CHANCES AND LOCALLY HEAVY RAINFALL THU AND FRI..
TONIGHT...A FEW LINGERING POCKETS OF INSTABILITY WILL ALLOW FOR
ISOLATED SHOWERS/STORMS THROUGH LATE EVENING. THEN OVERNIGHT AS A
FRONTAL TROUGH SAGS DOWN INTO NORTH FLORIDA...A BAND OF HIGHER
MOISTURE WILL START TO AFFECT OUR NORTHERN SECTIONS. THE HRRR AND
LOCAL WRF MODELS SHOW SOME PRECIP IN OUR NORTH BEFORE SUNRISE. THE
CURRENT FORECAST ALREADY TOOK THIS INTO ACCOUNT...SO WILL NOT MAKE
ANY SIGNIFICANT CHANGES.
PREVIOUS DISCUSSION
THU-FRI...DEEP MOISTURE WILL SETTLE OVER CENTRAL FLORIDA TO END THE
WORK WEEK WITH A FRONTAL BOUNDARY TRYING TO REACH JUST NORTH OF
VOLUSIA AND LAKE COUNTIES ON FRIDAY. EXPECT NUMEROUS SHOWERS AND
LIGHTNING STORMS TO DEVELOP SOUTH OF THE FRONTAL BOUNDARY WITH
WSW/SW LOW LVL FLOW...PWATS INCREASING TO TWO INCHES AND COOLING MID
LVL TEMPS TO -7 TO -8 DEGS C MAINLY DURING DAYTIME HEATING EACH DAY.
SOME AREAS OF LOCALLY HEAVY RAIN MAY DEVELOP EACH AFTERNOON WITH
LOCALLY UP TO 2-3 INCHES ON BOTH THU AND FRIDAY AFTERNOONS. HIGHER
THAN NORMAL NOCTURNAL RAIN CHANCES ARE EXPECTED THU NIGHT AND FRIDAY
NIGHT WITH DEEP MOISTURE CONTINUING AND SW FLOW BECOMING SOUTHERLY.
HIGHS WILL BE IN THE UPPER 80S TO NEAR 90 WITH LOWS IN THE LOWER TO
MID 70S. CONSIDERABLE CLOUD COVER IS EXPECTED AHEAD OF THE FRONT
WITH MOSTLY CLOUDY CONDITIONS WITH CONVECTION EACH DAY.
SAT-SUN...MID LVL TROUGH WILL RETROGRADE THIS WEEKEND WITH LOW LVL
FLOW BECOMING SE/ESE. MOISTURE LEVELS WILL STILL REMAIN HIGH WITH
SHOWER AND THUNDERSTORM CHANCES IN THE 50-60 PCT RANGE WITH HIGHER
RAIN CHANCES OVER THE INTERIOR IN THE AFTERNOON AND EVENING EACH
DAY. HIGHS NEAR 90 WITH RAIN CHANCES ABOVE NORMAL FOR MID AUGUST.
MON-WED...LOW LVL SE FLOW WILL BECOMING E/ESE INTO MID WEEK WITH
PWATS REMAINING FAIRLY HIGH FROM 1.7-1.9 INCHES. EXPECT RAIN CHANCES
TO DECREASE TO THE SCATTERED RANGE INTO MID WEEK FROM 40-50 PCT.
SHOULD SEE MORNING MORNING SUNSHINE EACH DAY ALLOWING HIGHS TO WARM
A BIT HIGHER...ESPEC OVER THE INTERIOR. HIGHS WILL BE IN THE UPPER
80S COASTAL TO AROUND 90/LWR 90S FOR THE INTERIOR.
&&
.AVIATION...THERE IS A SMALL CHANCE FOR SHOWERS/STORMS IN THE
NORTHERN TERMINALS OVERNIGHT AS FRONTAL BAND MOISTURE ARRIVES.
EXPECT THAT THU WILL NOT FOLLOW THE TYPICAL SCRIPT FOR CONVECTION
ESPECIALLY IN THE NORTH WHERE HIGHER MOISTURE AND MORE CLOUDS
COMPLICATE TIMING/INTENSITY OF STORMS. CURRENT SET OF TAFS TOOK A
STAB AT TIMING...BUT THIS WILL SURELY BE REFINED AND TEMPO GROUPS
ADDED AT MOST TERMINALS. IN GENERAL...WOULD EXPECT THE GREATEST
COVERAGE OF STORMS TO OCCUR DURING DAYTIME HEATING.
&&
.MARINE...
TONIGHT-WEEKEND...A CHANCE FOR STORMS WILL EXIST OVERNIGHT WITH THE
MOST VIGOROUS ACTIVITY LIKELY BEING OVER THE GULF STREAM.
OTHERWISE...SOUTHWEST FLOW 10 KNOTS OR LESS WILL BE MAINTAINED
THROUGH FRI...THEN THE GRADIENT WIND WILL BECOME SOUTHEAST OVER THE
WEEKEND. THE MAIN MARINER CONCERN WILL BE STORMS MOVING FROM THE
MAINLAND ACROSS THE COAST THU-FRI...MAINLY IN THE AFTERNOON AND
EVENING. SOME WILL BE STRONG AND REQUIRE SPECIAL MARINE WARNINGS.
ON SAT/SUN THE MODELS SHOW STEERING FLOW BECOMING MUCH WEAKER AND
LOW LEVEL WINDS SOUTHEASTERLY...SO LOOK FOR SEA BREEZE GENERATED
STORMS TO MAINLY AFFECT LAND AREAS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...URLICH
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
527 AM EDT TUE AUG 11 2015
.SYNOPSIS...
09Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THAT A SIGNIFICANT UPPER
LEVEL PATTERN AMPLIFICATION EXPECTED FOR THE MIDDLE PORTION OF THE
WEEK HAS ALREADY BEGUN. IMPRESSIVE LONGWAVE RIDGING NOW EXTENDS
FROM THE SOUTHERN PLAINS NORTHWARD THROUGH THE INTER-MOUNTAIN WEST
INTO SOUTH-CENTRAL CANADA. DOWNSTREAM LONGWAVE TROUGHING HAS NOW
DUG INTO THE GREAT LAKES/OHIO VALLEY...AND IS FORECAST BY GUIDANCE
ENSEMBLES TO CONTINUE AMPLIFYING DOWN INTO THE SOUTHEASTERN CONUS
DURING THE NEXT 24-36 HOURS. CURRENTLY OUR FORECAST AREA IS UNDER
WEAK RIDGING IN THE MID-LEVELS THAT WILL BE DECAYING THROUGH THE
NEXT 24 HOURS. IN FACT...LOOKING UP THROUGH THE COLUMN...THERE IS
VERY LITTLE FLOW UNTIL YOU GET ABOVE 400MB WHERE A DEFINED
NORTHEASTERLY WIND IS FINALLY ENCOUNTERED. THIS LIGHT FLOW THROUGH
MUCH OF THE COLUMN WILL RESULT IN A SLOW STORM MOTION FOR THE
THUNDERSTORMS THAT DO DEVELOP LATER TODAY.
AT THE SURFACE...
THE GRADIENT IS QUITE WEAK ACROSS THE FL PENINSULA AND EASTERN
GULF OF MEXICO...WITH THE NOSE OF THE SUBTROPICAL RIDGE JUST
SLIGHTLY WORKING INTO SOUTH FLORIDA. THE RESULTING WIND PATTERN IS
LIGHT FROM THE SOUTH OR SOUTHEAST...BUT WILL BECOME MORE WESTERLY
WITH TIME TODAY...ESPECIALLY WITH THE DEVELOPMENT OF WEAK SEA-
BREEZE CIRCULATIONS.
SKIES ARE PARTLY TO MOSTLY CLEAR EARLY THIS MORNING...AND SHOULD
SEE PLENTY OF SUNSHINE TO START OUT THE DAY BEFORE A SCT-BKN
CUMULUS FIELD BECOMES ESTABLISHED LATER THIS MORNING/EARLY
AFTERNOON. LOCALIZED LAND BREEZE CONVERGENCE IS HELPING FOCUS A
FEW WIDELY SCT SHOWERS OFF THE COAST OF LEE/CHARLOTTE COUNTIES.
MAY SEE ONE OR TWO OF THESE CELLS IMPACT THE IMMEDIATE COAST
DURING THE FIRST COUPLE OF DAYLIGHT HOURS...BUT OTHERWISE...THE
REMAINDER OF THE AREA WILL BE DRY THROUGH MUCH IF NOT ALL OF THE
MORNING HOURS.
&&
.SHORT TERM...
TODAY...
THE SYNOPTIC PATTERN TODAY SUGGEST A FORECAST TYPICAL OF A LIGHT
WEST/SW FLOW REGIME IN THE SUMMER. A FEW WIDELY SCT SHOWERS/STORMS
DEVELOPING NEAR THE COAST DURING MIDDAY WITH THE ONSET OF THE
SEA-BREEZE FOLLOWED BY A SLOW MIGRATION AND EXPANSION OF THE
STORMS INLAND AS THE AFTERNOON PROGRESSES. AFTER 19-20Z...MOST OF
THE HIRES CONVECTION ALLOWING GUIDANCE HAVE THE MAJORITY OF STORMS
INLAND FROM I-75...WITH VERY LITTLE ACTIVITY AT THE BEACHES. THIS
MAKES SINCE WITH THE SEA-BREEZE FOCUS MOVING INLAND AND THE
STABILIZING POST ENVIRONMENT MOVING ONSHORE. SOME DRIER AIR IN THE
MID-LEVELS MAY HOLD BACK CONVECTION A BIT ALONG AND NORTH OF THE
I-4 CORRIDOR...SO HAVE HIGHEST POPS (55-65% COVERAGE) ACROSS
SOUTHERN POLK/HIGHLANDS/HARDEE/DESOTO EARLY THIS EVENING.
TONIGHT...EVENING STORMS (MAINLY OVER SOUTH-CENTRAL INTERIOR
ZONES) DISSIPATE WITHIN A FEW HOURS OF SUNSET AND SET UP A MOSTLY
DRY AND SEASONABLE OVERNIGHT...AT LEAST FOR A WHILE. ALOFT...THE
UPPER RIDGE WILL HAVE COMPLETELY BROKEN DOWN WITH THE EASTERN
CONUS TROUGH DIGGING SOUTHWARD OVER THE NORTHERN/CENTRAL
PENINSULA. AT THE SURFACE..AN ASSOCIATED FRONTAL BOUNDARY WILL BE
APPROACHING THE I-10 CORRIDOR. THE DEVELOPING GRADIENT AHEAD OF
THE FRONT WILL RESULT IN A MORE WELL-DEFINED WESTERLY FLOW INTO
THE WEST-CENTRAL FL COAST UP THROUGH THE NATURE COAST LATE AT
NIGHT. THIS FLOW IS ALREADY FAVORED FOR LATE NIGHT/EARLY MORNING
SHOWER DEVELOPMENT...BUT ADD IN THE WEAK SYNOPTIC SUPPORT FOR
ASCENT ALOFT...AND WOULD CERTAINLY EXPECT TO SEE SCT
SHOWERS/STORMS DEVELOPING OVER THE COASTAL WATERS AND MIGRATING
TOWARD SHORE BEFORE DAWN. WILL HAVE A 30% CHANCE POP NORTH OF
TAMPA BAY AFTER 09Z FOR THIS CONVECTION...HOWEVER...COULD SEE THIS
COVERAGE ACTUALLY VERIFY A BIT LOW GIVEN THE SYNOPTIC SUPPORT.
WEDNESDAY...
SURFACE BOUNDARY STALLS NEAR THE I-10 CORRIDOR...WITH WEAK...BUT
DEEP LAYER CYCLONIC FLOW ALOFT OVER THE NORTHERN HALF OF THE
AREA. LIKELY TO BE DEALING WITH ON AND OFF SHOWERS/STORMS NORTH
OF TAMPA DURING THE MORNING/EARLY AFTERNOON...WITH PERHAPS A BIT
OF A SLOWDOWN IN SHOWER DEVELOPMENT LATER IN THE DAY...OR AT LEAST
A MIGRATION OF THE BEST SHOWER COVERAGE INLAND TO COINCIDE WITH
THE DIURNAL HEATING. SOUTH OF THE I-4 CORRIDOR...THE PATTERN WILL
STILL MORE RESEMBLE A TYPICAL SUMMER DAY UNDER WESTERLY FLOW. FEW
SHOWER/STORMS AT THE COAST DURING THE MORNING...WITH A MORE
DEFINED SEA-BREEZE TRACKING INLAND AND TAKING THE BEST STORM
COVERAGE WITH IT BY THE MIDDLE/LATER PART OF THE AFTERNOON.
BETTER CHANCES FOR MORE ORGANIZED RAINFALL DEVELOP ALONG THE WEAK
FRONTAL BOUNDARY WEDNESDAY NIGHT INTO THURSDAY. MORE ON THIS
POTENTIAL IN THE LONG TERM DISCUSSION BELOW.
&&
.LONG TERM...
.LONG TERM /THURSDAY-MONDAY/...
A TROUGH CONTINUES TO HOLD OVER THE EASTERN SEABOARD OF THE UNITED
STATES THURSDAY INTO THE WEEKEND. THE SURFACE FRONTAL BOUNDARY MOVES
ONTO THE PENINSULA OF FLORIDA LATE WEDNESDAY INTO
THURSDAY...SETTLING AROUND THE INTERSTATE 4 CORRIDOR ACCORDING TO
SOLUTIONS PROVIDED BY BOTH THE 00Z GFS AND 00Z ECMWF. THE SURFACE
BOUNDARY WILL MEANDER ACROSS THE REGION OVER THE WEEKEND BEFORE
SLOWLY RETREATING NORTHWARD EARLY NEXT WEEK.
THIS PATTERN WILL CREATE THE POTENTIAL FOR ADDITIONAL HEAVY RAINFALL
AS PLENTY OF MOISTURE AND UPPER LEVEL SUPPORT WILL BE AVAILABLE. THE
DIFFERENCES BETWEEN THE GFS AND ECMWF ARE SURPRISINGLY MINIMAL EVEN
INTO EARLY NEXT WEEK. THEY DO START DIVERGING BEYOND THE FORECAST
PERIOD...BUT IT HAS MINIMAL AFFECT ON THE FORECAST. THE GENERAL
CONSENSUS BETWEEN GUIDANCE SOLUTIONS RAISES FORECAST
CONFIDENCE...BUT TRYING TO FORECAST THE TIMING AND LOCATION OF A
FRONTAL BOUNDARY IS STILL A CHALLENGE IN THE EXTENDED. THOSE WHO
HOLD INTERESTS ALONG AREA RIVERS OR LOW-LYING FLOOD-PRONE AREAS
...PARTICULARLY THOSE SATURATED AREAS THAT HAVE SUFFERED RECENT
FLOODING...SHOULD MONITOR THE EVOLUTION OF THE FORECAST OVER THE
COMING DAYS.
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA
EARLY THIS MORNING. WE ARE EXPECTING SCT STORM DEVELOPMENT FROM
MIDDAY INTO THE EARLY AFTERNOON ALONG THE I-75 CORRIDOR AROUND THE
TERMINALS...BUT ALSO EXPECT MUCH OF THE CONVECTION TO MOVE INLAND
FROM THE FORECAST SITES BY 20-21Z.
&&
.MARINE...
A LIGHT GRADIENT WILL PERSIST ACROSS THE EASTERN GULF OF MEXICO
THROUGH TODAY...FOLLOWED BY THE APPROACH OF A FRONTAL SYSTEM FROM
THE NORTH LATER TODAY INTO THURSDAY. THE FRONT WILL STALL OVER THE
NORTHEAST GULF INTO EARLY FRIDAY AND THEN DISSIPATE. A WEAK
GRADIENT WILL AGAIN DEVELOP OVER THE FORECAST WATERS FOR THE
UPCOMING WEEKEND. SHOWERS AND THUNDERSTORMS WILL BE ENHANCED OVER
THE FORECAST WATERS AHEAD OF THE FRONT LATER WEDNESDAY INTO
THURSDAY...ESPECIALLY FROM TAMPA BAY NORTHWARD.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS ARE EXPECTED THROUGH THE NEXT SEVERAL
DAYS HAS ABUNDANT LOW LEVEL MOISTURE KEEPS RELATIVE HUMIDITY
LEVELS WELL ABOVE CRITICAL VALUES. SHOWERS AND STORMS WILL
BECOME NUMEROUS IN NATURE OVER THE NORTHERN AND INTERIOR PORTIONS
OF THE AREA WEDNESDAY INTO THURSDAY AS A FRONTAL BOUNDARY
APPROACHES AND STALLS OVER THE NORTHERN PART OF THE STATE.
FOG POTENTIAL...NO SIGNIFICANT FOG IS EXPECTED FOR THE NEXT
SEVERAL DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 91 79 91 78 / 20 10 40 50
FMY 91 76 92 77 / 50 10 40 40
GIF 93 75 93 76 / 50 40 50 50
SRQ 89 78 89 78 / 30 20 30 50
BKV 93 73 91 74 / 20 20 50 50
SPG 91 79 90 79 / 20 20 40 60
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...14/MROCZKA
LONG TERM...02/GARCIA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
358 AM EDT TUE AUG 11 2015
.DISCUSSION...
...LOCALLY HEAVY RAINS POSSIBLE LATER THIS WEEK...
TODAY-TONIGHT...
REMNANT TROF ASSOCIATED WITH THE RECENT FRONTAL BNDRY HAS DRIFTED
BACK INTO CENTRAL FL JUST S OF THE I-4 CORRIDOR. THE ATLC RIDGE
AXIS HAS RETURNING AS THE DOMINANT WX FEATURE FOR THE REGION...THOUGH
THE POSITION OF THE TROF IS KEEPING IS SOMEWHAT DISORGANIZED. EVNG
RAOBS SHOW PWAT VALUES BTWN 1.5"-1.7" OVER CNTRL/N FL...INCREASING
TO 2.2" OVER S FL. RAP ANALYSIS BACKING THIS UP WITH H100-H70 MEAN
RH VALUES BTWN 70-80PCT S OF THE TROF AXIS...BUT STILL LINGERING
BTWN 60-70PCT N OF THE AXIS. SUBSTANTIAL MID LVL DRY AIR REMAINS
IN PLACE OVER MOST OF THE CWA WITH H85-H50 MEAN RH BTWN 40-50PCT.
WARM MID LVLS REMAIN IN PLACE WITH H70 TEMPS BTWN 9-10C...H50 TEMPS
BTWN -5/-6C...YIELDING LAPSE RATES ARND 5.5C/KM THRU THE LYR.
DYNAMICALLY SPEAKING...THE POSITION OF THE TROF HAS ALLOWED A LCL
MID LVL VORT MAX TO DVLP N OF THE BAHAMAS...BUT THE WIND FIELD IS
NOT STRONG ENOUGH TO ADVECT THIS ENERGY ONSHORE IN ANY LARGE SCALE
MANNER. UPR LVLS ARE NEUTRAL AT BEST DUE TO A DEPARTING 40-50KT
NERLY JET STREAK OVER THE GOMEX.
DIURNAL CONVECTION WILL INCREASE AS THE DRY AIR ALOFT SLOWLY
MODIFIES. PGRAD THRU THE H100-H50 LYR WILL BE QUITE WEAK WITH MEAN
W/SWRLY FLOW BLO 10KTS. AN EAST COAST SEA BREEZE WILL DVLP BY
MIDDAY...LCL MOS GUIDANCE INDICATING FORMATION BTWN 16Z- 17Z AND
PUSHING INLAND TO BTWN THE KISSIMMEE/ST. JOHNS RIVER BASINS ARND
21Z. WEAK DYNAMIC/THERMODYNAMIC INSTABILITY WILL LIMIT CONVECTIVE
STRENGTH... THOUGH THE WEAK STEERING FLOW WILL INCREASE POTENTIAL
FOR LCL HEAVY PRECIP.
SCT POPS AREAWIDE...INCREASING FROM 30PCT ALNG AND N OF THE I-4
CORRIDOR TO 50PCT ARND LAKE OKEECHOBEE TO ACCOUNT FOR HIGHER
MOISTURE. LACK OF DYNAMIC SUPPORT INDICATES CONVECTION SHOULD BURN
OUT WITHIN AN HR OF SUNSET WITH THE LOSS OF DAYTIME HEATING. MAX
TEMPS IN THE L/M90S... THOUGH A FEW SPOTS ALONG THE IMMEDIATE COAST
MAY HOLD IN THE U80S DEPENDING ON THE TIMING OF THE SEA BREEZE
PASSAGE. SFC DEWPOINTS IN THE L/M70S SUGGEST SIMILAR MIN TEMPS.
WED-THU...A FRONTAL BOUNDARY ALONG THE MID ATLC SEABOARD TO THE
NRN GULF COAST WL NUDGE SWD INTO N FL IN THE FORM OF A TROUGH.
INCRSG RAIN CHCS WL OCCUR AS PATTERN AMPLIFICATION OVER THE CONUS
AND AN ASCD DIGGING UPR WAVE PATTERN OVER THE EASTERN CONUS LOOKS
TO LINGER THROUGH THE REMAINDER OF THE WEEK. SFC TROUGH N OF AREA
WL COMBINE WITH INCRSG MOISTURE AND FAVORABLE STEERING PATTERN TO
RAISE THE LIKELIHOOD OF AFTN SHOWERS AND STORMS ACROSS THE
FORECAST AREA. EXPECT HIGHER RAIN CHCS ESP OVER NORTHERN AND
CENTRAL COUNTIES INTO THE OVERNIGHT PERIOD AS WELL.
LATE WEEK...THE WEAKENING BOUNDARY WI LINGER OVER N FL INTO THE
WEEKEND WITH DEEP LAYERED MOISTURE ACROSS THE REGION TO PRODUCE
NMRS DIURNAL SHOWERS AND SLOW MOVING STORMS. LOCALLY HEAVY RAIN
WILL BE POSSIBLE IN SPOTS BEGINNING THURSDAY AND INTO SATURDAY.
GFS TRIES TO SHOW ADDITIONAL FALLING HGHTS ALOFT WITH WEAK CUTOFF
LOW POSSIBLE OVER THE SE...WHEREAS THE LTST ECMWF KEEPS AN OPEN
WAVE CONFIGURATION. AT ANY RATE...A SLIGHTLY WETTER THAN NORMAL
FORECAST CAN BE ANTICIPATED INTO EARLY NEXT WEEK WITH ONSET OF THE
EXPECTED HIGH AMPLITUDE SYNOPTIC PATTERN.
&&
.AVIATION...THRU 12/12Z
SFC WINDS: THRU 11/14Z...VRBL AOB 3KTS. BTWN 11/14Z-11/16Z...W/SW
6-9KTS. BTWN 11/16Z-11/18Z...BCMG E/SE 8-11KTS BTWN KOMN-KSUA
ASSOCD WITH THE EAST COAST SEA BREEZE. BTWN 11/19Z-11/21Z...BCMG
E/SE 6-9KTS ALNG THE I-4 CORRIDOR. BTWN 12/00Z-12/03Z...BCMG S/SW
3-5KTS.
VSBY/WX/CIGS: BTWN 10/16Z-10/24Z...SCT MVFR SHRAS/ISOLD IFR TSRAS
ALL SITES...S OF KTIX-KISM SLGT CHC LIFR +TSRAS WITH SFC WND G35KTS.
&&
.MARINE...
TODAY-TONIGHT...WEAK SFC TROF OVER CNTRL FL WILL COMBINE WITH A
BROAD RIDGE AXIS OVER S FL/NRN BAHAMAS TO GENERATE A LIGHT TO GENTLE
S/SW BREEZE OVER THE LCL ATLC TODAY...WINDS BCMG E/SE NEAR THE COAST
ARND MIDDAY AS THE EAST COAST SEA BREEZE DVLPS. GENTLE TO MODERATE
SW BREEZE OVERNIGHT AS A NEW FRONTAL BOUNDARY PUSHES INTO THE THE
DEEP SOUTH AND STALLS OVER THE FL PANHANDLE. SEAS AOB 2FT NEARSHORE
AND 2-3FT OFFSHORE.
FAVORABLE BOATING CONDITIONS WL OCCUR DURING THE EXTENDED PERIOD WITH
SEAS AROUND 2 FT OR LESS NEAR SHORE AND 2 TO 3 FT OVER THE OUTER
WATERS. THESE SIMILAR CONDITIONS CAN BE EXPECTED INTO THE WEEKEND
AS WELL WITH AN INCREASE IN STORMS PRODUCING SOME HIGHER WINDS AND
SEAS NEAR THE IMMEDIATE COAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 90 76 93 74 / 30 20 60 50
MCO 94 76 94 76 / 30 20 60 40
MLB 91 77 92 76 / 30 20 60 40
VRB 91 73 92 73 / 40 20 50 40
LEE 93 77 92 76 / 30 20 60 40
SFB 94 77 94 76 / 30 20 60 50
ORL 94 77 95 77 / 30 20 60 40
FPR 91 73 92 74 / 40 20 50 40
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....PENDERGRAST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
356 PM EDT TUE AUG 11 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE INTO THE AREA WEDNESDAY...THEN PUSH
SOUTH INTO NORTHERN FLORIDA THURSDAY BEFORE DISSIPATING OVER THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH THIS EVENING...DNVA IN THE WAKE OF SHORTWAVE ENERGY MOVING
INTO EASTERN NORTH CAROLINA HAS HELPED TO LIMIT DEEP CONVECTION
FOR MUCH OF THE DAY. HOWEVER...A RECENT INCREASE IN INSOLATION
DUE TO A THINNING OF THE MID/HIGH-LEVEL CLOUD CANOPY IS AIDING
DESTABILIZATION ACROSS MUCH OF THE REGION WITH SBCAPES APRCHG
2000-3000 J/KG AND LIFTED INDICES -5 TO -7C OVER THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS OF 11/19Z.
A STEADY INCREASE IN CONVECTION IS EXPECTED OVER THE NEXT FEW
HOURS...MAINLY CONCENTRATING ACROSS SOUTHEAST SOUTH CAROLINA AND
FAR SOUTHERN GEORGIA. THERE REMAINS SOME UNCERTAINTY HOW FAR
NORTH CONVECTION WILL PROPAGATE AND/OR DEVELOP WITH MUCH OF
INTERIOR SOUTHEAST SOUTH CAROLINA...INCLUDING THE CHARLESTON METRO
AREA...EMBEDDED WITHIN AN INSTABILITY MINIMUM. HIGH RESOLUTION
MODELS SUCH AS THE RAP AND H3R ARE CERTAINLY LESS BULLISH ACROSS
THE CHARLESTON TRI-COUNTY AREA COMPARED TO PREVIOUS RUNS...SO
FORECASTER CONFIDENCE IS CERTAINLY LOWER THAN AVERAGE FOR THIS
LATE IN THE DAY. WILL GO WITH A 50-70 PERCENT POP REGIME THROUGH
EARLY EVENING WITH THE HIGHEST GRIDDED POPS CLUSTERED ROUGHLY
ALONG/SOUTH OF A METTER-BEAUFORT LINE...INCLUDING THE SAVANNAH
METRO AREA. A RISK FOR HEAVY RAIN AND ISOLATED SEVERE TSTMS
REMAINS IN PLACE WITH DAMAGING WINDS...CLOUD TO GROUND LIGHTNING
AND MINOR FLOODING OF LOW LYING AND POOR DRAINAGE AREAS BEING THE
PRIMARY HAZARDS.
TONIGHT...A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST AND
BE BE POSITIONED ACROSS THE FAR SOUTHERN MIDLANDS AND CSRA JUST
BEFORE SUNRISE WEDNESDAY. INDICATIONS ARE THAT THE RIBBON OF
HIGHEST MOISTURE WILL SHIFT OFF THE COAST LATER THIS EVENING AND
WITH IT THE BETTER CHANCES FOR SHOWERS/TSTMS. POPS WILL BE TRICKY
AS MUCH WILL DEPEND ON HOW QUICKLY THE PLUME OF MOISTURE PUSHES
OFFSHORE AND HOW THE MESOSCALE PATTERN CHANGES/MODULATES IN
RESPONSE TO STRONGER CONVECTION LATE THIS AFTERNOON/EVENING. WILL
CARRY 30-50 PERCENT POPS WITH LIKELY POPS OVER THE COASTAL WATERS.
LOWS TONIGHT WILL RANGE
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
WEDNESDAY...THE COLD FRONT WILL MEANDER ALONG THE COAST THOUGH THE
AFTERNOON SEA BREEZE MAY PUSH IT BACK INLAND. MODEL PWATS SHOW ONLY
A SLIGHT AMOUNT OF DRIER AIR TRYING TO PUSH IN FROM THE NORTHWEST
LATE IN THE DAY. THUS THE RAIN CHANCES INLAND WILL BE LIMITED AT
BEST. CLOSER TO THE COAST WHERE THE FRONT...SEA BREEZE AND DEEPER
MOISTURE EXIST...WE EXPECT SCATTERED AFTERNOON/EVENING SHOWERS AND
TSTMS. THE BEST COVERAGE LOOKS TO BE ACROSS SOUTHEAST GEORGIA DUE TO
DEEPER MOISTURE. HIGHS WILL RANGE FROM UPPER 80S ALONG THE COAST TO
LOWER 90S FAR INLAND.
THURSDAY...SOME DRIER AIR SPREADS INTO THE AREA AS HIGH PRESSURE
BUILDS FROM THE NORTH. PWATS EXPECTED TO DROP BELOW 1.5" DURING THE
DAY WITH SFC DEWPOINTS IN THE UPPER 60S EXCEPT ALONG THE COAST.
HOWEVER WITH TEMPS IN THE LOWER 90S AND SOME SHORTWAVE ENERGY
APPROACHING DURING THE AFTERNOON...ISOLATED SHOWERS AND TSTMS
EXPECTED.
FRIDAY...NORTHEAST LOW-LEVEL FLOW WILL GRADUALLY INCREASE MOISTURE
OFF THE ATLANTIC THOUGH INLAND AREAS WILL STILL BE FAIRLY DRY
THROUGHOUT THE COLUMN. A DEEPENING UPPER TROUGH OVER THE SOUTHEAST
COAST WILL SPREAD VORTICITY ENERGY INTO THE AREA FROM THE SOUTH.
THIS COMBINED WITH CONVERGENCE ALONG THE AFTERNOON SEA BREEZE SHOULD
PRODUCE SCATTERED CONVECTION...HIGHEST COVERAGE ACROSS FAR SOUTHEAST
PORTIONS. HIGH TEMPS WILL BE IN THE UPPER 80S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A STALLED FRONT TO THE SOUTH AND EAST ALONG WITH SOME WEAK AREAS OF
LOW PRESSURE WILL PERSIST THROUGH THE WEEKEND BEFORE EVENTUALLY
DISSIPATING EARLY NEXT WEEK AS HIGH PRESSURE TRIES TO BUILD FROM THE
SOUTHEAST. THIS PATTERN MEANS THERE WILL BE SOME SHOWER AND
THUNDERSTORM CHANCES THROUGH THE PERIOD...ESPECIALLY FOR SOUTHEAST
GEORGIA AND COASTAL SC WHICH WILL BE NEARER THE DEEPER MOISTURE.
TEMPS SHOULD BE ABOUT NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
INITIAL CONCERN IS PINNING DOWN THE TIMING AND POTENTIAL IMPACTS
FROM TSTMS. RADAR SHOWS CONVECTION EXPANDING OVER EAST-CENTRAL
GEORGIA...WHICH HIGH RESOLUTION MODELS CAPTURED FAIRLY WELL. THIS
ACTIVITY IS EXPECTED TO GRADUALLY EXPAND EAST AND POSSIBLY UP THE
SEA BREEZE. THE BETTER CHANCES FOR IMPACTS WILL BE AT
KSAV...ROUGHLY 20-23Z WHERE TEMPO LOW-END MVFR VSBYS WILL BE SHOWN
IN TSRA. AT KCHS...ITS A BIT MORE UNCERTAIN. MAINTAINED TEMPO 4SM
-TSRA 20-23Z FOR NOW...BUT ADJUSTMENTS MAY BE NEEDED. SHOWER/TSTM
ACTIVITY BY LINGER INTO THE EVENING HOURS BEFORE SHIFTING
OFFSHORE...BUT GUIDANCE SUGGESTS MOST OF THIS WILL MISS THE
TERMINALS. VFR EXPECTED OUTSIDE OF TSTMS. THERE IS A LOW RISK FOR
LOW CLOUDS/STRATUS AT THE TERMINALS JUST BEFORE SUNRISE WEDNESDAY.
EXTENDED AVIATION OUTLOOK...BRIEF FLIGHT RESTRICTIONS POSSIBLE EACH
DAY IN AFTERNOON/EVENING SHOWERS AND TSTMS.
&&
.MARINE...
TONIGHT...LOW-LEVEL JETTING WILL OCCUR OVERNIGHT AHEAD OF AN
APPROACHING COLD FRONT. 15-20 KT LOOKS REASONABLE FOR MOST LEGS.
A FEW STRONG TSTMS COULD ALSO OCCUR OVERNIGHT WITH GUSTS TO 35
KT...LOCALLY HEAVY RAINFALL REDUCING VSBYS TO LESS THAN 1 NM AND
CLOUD TO WATER LIGHTNING.
WEDNESDAY THROUGH SUNDAY NIGHT...A WEAK COLD FRONT WILL DROP
INTO THE WATERS LATE WEDNESDAY THEN STALL JUST OFF THE COAST
WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTHWEST. A WEAK
PRESSURE PATTERN WILL EXIST THROUGH WEDNESDAY NIGHT WITH THE MAIN
DRIVE BEING A MODEST AFTERNOON SEA BREEZE ALONG THE COAST
WEDNESDAY. BY THURSDAY AS HIGH PRESSURE STRENGTHENS FROM THE NORTH
AND A COASTAL TROUGH DEVELOPS...A NORTHEAST FLOW SETS UP OVER THE
WATERS WITH INCREASING WINDS AND SEAS. HOWEVER...CONDITIONS
CURRENTLY EXPECTED TO REMAIN BELOW ADVISORY THRESHOLDS THROUGH THE
WEEKEND.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/JRL
...PRELIMINARY AREA FORECAST DISCUSSION...
.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN TODAY. A WEAK COLD FRONT WILL MOVE INTO
THE AREA WEDNESDAY...THEN PUSH SOUTH INTO NORTHERN FLORIDA
THURSDAY BEFORE EVENTUALLY DISSIPATING OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
MESOSCALE UPDATE...DNVA IN THE WAKE OF SHORTWAVE ENERGY MOVING
INTO EASTERN NORTH CAROLINA HAS HELPED TO LIMIT DEEP CONVECTION
FOR MUCH OF THE DAY. HOWEVER...A RECENT INCREASE IN INSOLATION
DUE TO A THINNING OF THE MID/HIGH-LEVEL CLOUD CANOPY IS AIDING
DESTABILIZATION ACROSS MUCH OF THE REGION WITH SBCAPE APPROACHING
2500-3000 J/KG OVER THE SOUTHERN TWO-THIRDS OF THE FORECAST AREA
AS OF 11/17Z.
A STEADY INCREASE IN CONVECTION IS EXPECTED OVER THE NEXT FEW
HOURS...MAINLY CONCENTRATING ACROSS SOUTHEAST GEORGIA AND FAR
SOUTHERN SOUTH CAROLINA. THERE REMAINS SOME UNCERTAINTY HOW FAR
NORTH CONVECTION WILL PROPAGATE AND/OR DEVELOP INTO/OVER MUCH OF
INTERIOR SOUTHEAST SOUTH CAROLINA...INCLUDING THE CHARLESTON METRO
AREA...EMBEDDED WITHIN AN INSTABILITY MINIMUM. HIGH RESOLUTION
MODELS SUCH AS THE RAP AND H3R ARE CERTAINLY LESS BULLISH ACROSS THE
CHARLESTON TRI-COUNTY AREA COMPARED TO PREVIOUS RUNS...SO FORECASTER
CONFIDENCE IS CERTAINLY LOWER THAN AVERAGE FOR THIS TIME OF DAY.
A RISK FOR HEAVY RAIN AND ISOLATED SEVERE TSTMS REMAINS IN PLACE
WITH DAMAGING WINDS...CLOUD TO GROUND LIGHTNING AND MINOR
FLOODING OF LOW LYING AND POOR DRAINAGE AREAS BEING THE PRIMARY
HAZARDS. TRENDS CONTINUE TO BE MONITORED.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
TO BE ISSUED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
TO BE ISSUED.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
INITIAL CONCERN IS PINNING DOWN THE TIMING AND POTENTIAL IMPACTS
FROM TSTMS. RADAR SHOWS CONVECTION EXPANDING OVER EAST-CENTRAL
GEORGIA...WHICH HIGH RESOLUTION MODELS CAPTURED FAIRLY WELL. THIS
ACTIVITY IS EXPECTED TO GRADUALLY EXPAND EAST AND POSSIBLY UP THE
SEA BREEZE. THE BETTER CHANCES FOR IMPACTS WILL BE AT
KSAV...ROUGHLY 20-23Z WHERE TEMPO LOW-END MVFR VSBYS WILL BE SHOWN
IN TSRA. AT KCHS...ITS A BIT MORE UNCERTAIN. MAINTAINED TEMPO 4SM
-TSRA 20-23Z FOR NOW...BUT ADJUSTMENTS MAY BE NEEDED. SHOWER/TSTM
ACTIVITY BY LINGER INTO THE EVENING HOURS BEFORE SHIFTING
OFFSHORE...BUT GUIDANCE SUGGESTS MOST OF THIS WILL MISS THE
TERMINALS. VFR EXPECTED OUTSIDE OF TSTMS. THERE IS A LOW RISK FOR
LOW CLOUDS/STRATUS AT THE TERMINALS JUST BEFORE SUNRISE WEDNESDAY.
EXTENDED AVIATION OUTLOOK...WEDNESDAY THROUGH SUNDAY...MODERATE
CONFIDENCE IN IMPACTS WED DUE TO SHOWERS/TSTMS. RISK OF IMPACTS
FROM SHOWERS/TSTMS/LOW CIGS LOWER THU- SUN BEHIND A COLD
FRONT...ESPECIALLY AT KCHS.
&&
.MARINE...
TO BE ISSUED.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
141 AM EDT TUE AUG 11 2015
.SYNOPSIS...
ISSUED AT 715 PM EDT MON AUG 10 2015
THE CHANCES FOR SHOWERS AND A FEW STORMS WILL DIMINISH THROUGH THE
EVENING AS DRIER AIR FILTERS IN FROM THE NORTH. DRY AND LESS HUMID
WEATHER IS THEN EXPECTED THROUGH MID WEEK. LOW TEMPERATURES
TONIGHT WILL DROP INTO THE LOWER TO MID 60S. HIGH TEMPERATURES ON
TUESDAY WILL REACH INTO THE MID TO UPPER 70S.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM EDT MON AUG 10 2015
LEAD SHORT WAVE WHICH TRACKED ACROSS THE AREA EARLIER TODAY ALLOWED
FOR INITIAL WEAK LAKE ENHANCED SURFACE TROUGH TO SERVE AS FOCUSING
MECHANISM FOR SCATTERED SHOWERS/ISOLATED STORMS. OVER PAST
HOUR...STARTING TO SEE UPSWING IN CONVECTIVE COVERAGE ALONG THIS
BOUNDARY AS A STRONGER UPSTREAM VORT MAX ACROSS NORTHERN ILLINOIS
CONTINUES TO APPROACH THE AREA. A SECONDARY AREA OF
SCATTERED/NUMEROUS SHOWERS/STORMS HAS DEVELOPED ACROSS FAR
SOUTHERN/AND MAINLY SOUTH OF FORECAST AREA ACROSS CENTRAL INDIANA.
THIS AREA APPEARS BE TIED MORE CLOSELY TO ENHANCED LOW LEVEL THETAE
ADVECTION...WHICH ALSO IS COLOCATED WITH MORE PRONOUNCED INSTABILITY
AXIS WITH LATEST RUC ANALYSIS DEPICTING 100 HPA MLCAPES ON THE ORDER
OF 1000-1500 J/KG. MODEST DEEP LAYER SHEAR AND AND WEAK TO MODERATE
INSTABILITY WILL CONTINUE TO POSE SOME THREAT OF ISOLD STRONG STORMS
WITH GUSTY WINDS AS THE MAIN THREAT. WHILE BRIEF VERY HEAVY RAINFALL
IS POSSIBLE...PROPAGATION VECTORS ARE SLIGHTLY MORE PROGRESSIVE THIS
AFTERNOON IN COMPARISON TO LAST EVENING AND CURRENT THINKING IS THAT
WHILE LOCALIZED PONDING OF WATER/MINOR FLOODING IS POSSIBLE WITH THE
STRONGER STORMS...FLASH FLOODING CONCERNS SHOULD BE MINIMAL.
PRIMARY INSTABILITY AXIS SHOULD BEGIN TO ADVECT ACROSS FAR EASTERN
PORTIONS OF THE FORECAST AREA LATE THIS AFTERNOON...BUT WEAK
INSTABILITY WILL REMAIN ACROSS ENTIRE FORECAST AREA AS
AFOREMENTIONED NORTHERN ILLINOIS VORT MAX ALLOWS FOR EROSION OF
RELATIVELY 800-700 HPA LAYER NOTED PER EARLIER AMDAR REGIONAL
SOUNDINGS. THIS SHOULD ALLOW FOR ENOUGH LINGERING INSTABILITY WITH
STRONGER ILLINOIS VORT MAX TO KEEP SOME CHANCE OF ISOLD-SCT
CONVECTION ACROSS THE AREA EARLY THIS EVENING. QUIET CONDITIONS
EXPECTED LATER THIS EVENING INTO THE OVERNIGHT AS SECONDARY SFC
TROUGH USHERS IN COOLER AND DRIER LOW LEVEL AIR. QUIET WEATHER
EXPECTED FOR TUESDAY WITH PERSISTENT MID LEVEL SUBSIDENCE...ALTHOUGH
THE NEXT IN SERIES OF UPPER LEVEL SHORT WAVES IS EXPECTED TO DIG
ACROSS THE GREAT LAKES EARLY TUESDAY...WHICH COULD PROMOTE AN
ISOLATED SHOWER ACROSS SOUTHEAST LOWER MICHIGAN. GIVEN VERY MARGINAL
MOISTURE PROFILES...WILL OMIT FROM FORECAST WITH JUST SLIGHTLY MORE
CONCENTRATED DIURNAL CU ACROSS THE FAR NORTHEAST. DESPITE LOW LEVEL
CAA...GOOD DEAL OF INSOLATION MOST AREAS SHOULD ALLOW FOR HIGHS IN
THE MID TO UPPER 70S.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 PM EDT MON AUG 10 2015
HIGH PRESSURE MOVING OUT OF CANADA WILL BRING COOL...DRY
WEATHER FOR THE FIRST PORTION OF THE LONG TERM PERIOD. AS THE
LONGWAVE PATTERN BECOMES MORE ZONAL INTO THE WEEKEND...
TEMPERATURES WILL WARM AND A FEW FRONTAL BOUNDARIES WILL DROP
SOUTHWARD INTO THE GREAT LAKES REGION WITH SHOWERS AND
THUNDERSTORMS POSSIBLE. THE FIRST OF THESE FRONTS WILL DROP
THROUGH ON FRIDAY. A FEW STORMS ARE POSSIBLE ALONG THIS
FRONT...BUT LIMITED INSTABILITY SHOULD LIMIT WIDESPREAD
DEVELOPMENT. THIS FIRST FRONT WILL SETTLE SOUTH OF THE AREA OVER
THE WEEKEND WHICH SHOULD KEEP OUR AREA DRY.
BETTER SHOWERS AND STORM CHANCES RETURN BY THE EARLY PART OF NEXT
WEEK AS MODEL CONSENSUS STALLS A FRONTAL BOUNDARY ACROSS THE
SOUTHERN GREAT LAKES. DEWPOINTS IN THE UPPER 60S TO LOW 70S COUPLED
WITH DAYTIME HEATING SHOULD PROVIDE WEAK TO MODERATE INSTABILITY
EACH DAY...DEPENDING ON THE DEGREE OF HEATING. AT THIS TIME...MID
LEVEL LAPSE RATES AND DEEP LAYER SHEAR LOOK LACKLUSTER WHICH SHOULD
PRECLUDE ANY ORGANIZED SEVERE WEATHER THREAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 140 AM EDT TUE AUG 11 2015
SOME POSTFRONTAL BR POSSIBLE THROUGH THE EARLY MORNING BUT
INCREASING SURFACE WIND SPEEDS AND DRY AIR ADVECTION SHOULD KEEP
CONDITIONS IN HIGH END MVFR OR BETTER. OTHERWISE VFR CONDITIONS
EXPECTED FOR THE REST OF THE PERIOD AS RIDGE OF HIGH PRESSURE
BUILDS OVER THE GREAT LAKES. NORTHWEST WINDS WILL GUST TO AROUND
20 KNOTS THIS AFTERNOON...ESPECIALLY AT KSBN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT FROM 9 AM CDT THIS MORNING THROUGH LATE
TONIGHT FOR INZ003.
MI...BEACH HAZARDS STATEMENT FROM 10 AM EDT THIS MORNING THROUGH LATE
TONIGHT FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 2 AM EDT
WEDNESDAY FOR LMZ043-046.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...MARSILI
LONG TERM...BENTLEY
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
950 PM CDT WED AUG 12 2015
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 948 PM CDT WED AUG 12 2015
WV Imagery and 00Z upper air analysis indicate an upper level area
of high pressure centered across the South Plains of west Texas
and eastern New Mexico. Near the surface, a lee side trough of low
pressure remains anchored across extreme eastern Colorado.
&&
.SHORT TERM...(THIS EVENING THROUGH Thursday)
ISSUED AT 250 PM CDT WED AUG 12 2015
Temperatures for later this afternoon were necessarily trimmed again
by the HRRR due to widespread cloudiness, rain and cooled air near
the moist upslope convergence zone region between roughly highway 183
and 83. Although the areal coverage has been dramatically reduced
this afternoon, isolated showers could occur easily still occur
through tonight. The convective allowing models as a whole are far
less supportive of additional shower and thunderstorms development
heading into Thursday, perhaps partially owing to less of a
convergence zone with as surface winds turn southerly. With a lack
of widespread precipitation and/or cloudiness, the opportunity for
much warmer raw model forecast temperatures reaching into the 90s
is likely, which will be the case over the next several days.
.LONG TERM...(Thursday NIGHT THROUGH Wednesday)
ISSUED AT 250 PM CDT WED AUG 12 2015
The best chances for precipitation will be a very slight chance for
most of the area, with a best chance in west central Kansas around
Sunday night, when models forecast shortwave energy across the
northern high plains. It is possible the entire area remains dry
during this time. A better opportunity arrives by mid week ,and
could last several days as a baroclinic zone impacts the region
with a breakdown of the upper ridge.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z Thursday EVENING)
ISSUED AT 534 PM CDT WED AUG 12 2015
Light upslope winds will continue tonight, then become more
southerly by mid morning with VFR conditions expected into
Thursday. Some models hint at some convection after 05Z however
confidence is too low to put into forecast attm.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 89 67 91 / 10 10 10 10
GCK 64 90 66 91 / 10 0 10 10
EHA 65 92 66 91 / 0 0 10 10
LBL 66 92 67 92 / 10 0 10 10
HYS 65 90 67 92 / 10 10 20 10
P28 66 90 69 91 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Kruse
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
402 PM CDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH Wednesday)
ISSUED AT 401 PM CDT TUE AUG 11 2015
The near term will bring chances for heavy rain producing
thunderstorms. The first opportunity will be later tonight as the 4
km NAM, HRRR and NMM models all redevelop convection later in the
day over eastern colorado that moves in to about the western two or
perhaps 3 tiers of KS counties. the key here to support convection
is the very high precipitable water values, and hence conditional
instability present. still no severe weather threat, with mainly
efficient warm rain processes and frequent lightning. easterly
surface wind, and an increasing surface pressure gradient is
expected wednesday with a transient 500 mb shortwave, in the western
counties, in proximity to the high precipitable water axis on the
west edge of the surface high. models again generate precipitation
into wednesday in this zone. extensive cloud cover may again muddle
the high temperature forecast, as occurred today and temperatures
should be at or below normal.
.LONG TERM...(Wednesday NIGHT THROUGH Tuesday)
ISSUED AT 401 PM CDT TUE AUG 11 2015
The upper ridge over the central and southern rockies will continue
to amplify, resulting in vorticity disturbances shifted farther
north across the northern plains. however, the GFS and ECMWF show a
vigourous wave during the weekend moving through the northern
states, effectively flattening the upper ridge and returning zonal
flow aloft to the central high plains. this setup will result in low
pressure across western kansas just ahead of an approaching
baroclinic zone/frontal boundary by early to mid week, and a return
to convective chances. the more zonal pattern may stay in place for
at least several days.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Wednesday AFTERNOON)
ISSUED AT 135 PM CDT TUE AUG 11 2015
THE FOCUS FOR TODAY WILL BE INCREASING CEILINGS AT GCK AND
POTENTIAL REDEVELOPMENT OF NON SEVERE CONVECTION LATE IN THE TAF
PERIOD. THE CURRENT TRENDS SHOW INCREASING Ceilings AT GCK,
HOWEVER THE CLOUD FIELD WILL REMAIN OVER THE AREA FOR MUCH OF THE
AFTERNOON WITH A MOIST USPSLOPE ENVIRONMENT . THE REGIONAL RADAR
PERSPECTIVE AT THIS TIME IS FAIRLY NON ACTIVE, ESPECIALLY IN THE
WESTERN PLAINS. THE CONVECTIVE ALLOWING MODELS ESPECIALLY THE HRRR
WERE GENERALLY MORE ACTIVE FOR LATER THIS AFTERNOON THAN IS
CURRENTLY OCCURRING. BETTER CHANCES FOR ADDITIONAL ROUNDS OF
SHOWERS AND ISOLATED THUNDERSTORMS MAY OCCUR IN OUR WESTERN
COUNTIES, INCLUDING GCK, BY MID EVEING OR LATER, INTO THE
OVERNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 87 65 90 / 40 30 10 0
GCK 66 88 65 91 / 50 20 10 0
EHA 66 90 66 92 / 50 10 10 10
LBL 68 89 68 92 / 40 20 10 0
HYS 65 88 65 91 / 10 20 10 10
P28 68 87 67 89 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
214 AM CDT TUE AUG 11 2015
...Updated short term and long term discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 213 AM CDT TUE AUG 11 2015
For today a weak upper level disturbance is forecast to move
through the upper ridge axis and out into western Kansas. Ahead of
this disturbance I305 and I310 isentropic surfaces do indicated an
increase in moisture and lift, mainly across western Kansas. Given
this lift and timing on the upper level system will favor the
better opportunity for precipitation during the afternoon and
early evening. Still am unable t rule out some scattered
precipitation earlier in the day, especially across far southwest
Kansas as the isentropic lift and moisture improves between 12z
and 18z Tuesday. Based on expected cloud cover and afternoon 850mb
temperatures from the NAM and GFS will continue to favor highs
today mainly in the mid 80s. The warmer temperatures will be
across central Kansas where less cloud cover is expected while the
cooler temperatures will be in southwest Kansas.
There will be a chance for thunderstorms lingering into the
overnight hours as moisture and lift in the 800mb to 600mb level
continues to slowly move east across western Kansas. Based on the
NAM it appears that the better moisture an lift early tonight will
be mainly across west central Kansas so placed higher chances for
convection through midnight. Toward daybreak on Wednesday 850mb
warm air advection will begin to improve across western Kansas as
both the NAM and GFS begin to warm the 700mb temperatures.
Moisture, 850mb warm air advection, and isentropic lift will all
be in place by 12z just east of the 10c to 14c 700mb temperature
gradient so will increase the chance for convection again across
western Kansas late tonight and continue it into early Wednesday
morning.
.LONG TERM...(Wednesday THROUGH Monday)
ISSUED AT 213 AM CDT TUE AUG 11 2015
Temperatures on Wednesday will be a little tricky given how much
sun will develop during the afternoon. Even taking into account
the warmer GFS who favors more sun and warmer 850mb temperature
late day it currently appears the MAV/MOSGUIDE is too warm so will
stay close to the previous forecast which is only a couple of
degrees warmer than the cooler MET for highs.
Mid level temperatures are forecast to continue to warm mid week
as an upper level high moves from the Texas panhandle into
southern Colorado/northern New Mexico. Flow aloft will be weak
aloft but given that a surface boundary forecast to be located
near the Colorado border am unable to completely rule on a slight
chance for late day/evening storms across far western Kansas mid
week. At this time chances for convection will be isolated to
widely scattered at best.
The better opportunity for convection may be late week if the GFS
and ECMWF are correct with an upper level disturbance rotating
around the upper high and dropping south into the central plains.
Based on where the mid level baroclinic zone should be located
late week the opportunity will be more favorable across north
central Kansas.
The upper level ridge axis will shift east into the plains over
the weekend period as an upper low, located off the northern
California coast late week, weakens and lifts northeast toward the
northern Rockies. Temperatures late week into the weekend period
will be on the rise, however at this time the latest
CRExtendedFcst_Init may be a little slow on how quickly and how
warm temperatures will be over the weekend period based on the
850mb to 700mb temperatures. At this time however did not deviate
far from what the CRExtendedFcst_Init suggested.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Tuesday NIGHT)
ISSUED AT 1202 AM CDT TUE AUG 11 2015
BUFR soundings indicating a shallow layer of saturated air will
develop early this morning across portions of western Kansas as a
light easterly upslope flow develops. RAP and HRRR suggesting
mainly status will be possible towards daybreak west of highway
283, however at this time can not completely rule out some light
fog developing, especially at DDC and GCK. Will therefore trend
towards MVFR visibilities for a couple of hours around 12z Tuesday
with scattered IFR clouds at GCK. Otherwise VFR conditions can be
expected today with only an increase in mid level moisture
anticipated ahead of a weak upper level disturbance. Light east
winds will gradually shift to the southeast early this morning as
a surface ridge axis crosses western Kansas.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 86 66 89 66 / 30 30 20 10
GCK 85 66 89 65 / 30 40 20 10
EHA 82 66 90 66 / 40 30 10 10
LBL 85 68 89 67 / 30 20 20 10
HYS 86 65 88 66 / 20 20 10 10
P28 87 68 88 68 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Burgert
LONG TERM...Burgert
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1203 AM CDT TUE AUG 11 2015
...Updated synopsis and aviation discussion...
.SYNOPSIS...
ISSUED AT 1202 AM CDT TUE AUG 11 2015
At 00z Tuesday a 500mb ridge axis extended from the panhandle of
Texas to eastern Montana. Water Vapor loop indicated an upper
level disturbance located over central New Mexico. A 700mb ridge
axis was located across western Kansas and western Oklahoma. A
large area of convection earlier this evening was located west of
this 700mb ridge axis and ahead of the upper level disturbance. A
surface ridge axis extended from central south Dakota to central
Kansas, and a weak surface boundary was located from southwest
Kansas into northern Oklahoma. 850mb temperatures at 00z Tuesday
across the boundary ranged from 23c at Dodge City to +15 at Omaha.
&&
.SHORT TERM...(THIS EVENING THROUGH Tuesday)
ISSUED AT 321 PM CDT MON AUG 10 2015
The latest arw and HRRR models were the most aggressive models
with respect to developing convection this afternoon. The 4 km nam
and the nmm were not as aggressive. However the nmm and 4 km HRRR
were also more aggressive with thunderstorms. The severe threat
will be minimal today and tonight with any storms that develop as
continued amplification the the upper ridge weakened the shear
profiles. However very heavy rainfall from efficient warm rain
processes will still be likely for the next day or so, but
steering flow will be weak or non existent. based on the HRRR,
thunderstorm coverage could become scattered by late in the
afternoon. additionally. thunderstorms development across
southeast colorado could spread into far southwest kansas later
this evening aided by weak vorticity advection embedded in the
northwest flow in the models.
.LONG TERM...(Tuesday NIGHT THROUGH Monday)
ISSUED AT 321 PM CDT MON AUG 10 2015
Beyond the short term, increasingly less humid conditions will
develop across central and much of western kansas as surface high
pressure from the northern plains begins to have greater
influence. The general low level moisture transport signal will
remain firmly anchored across the the western counties where the
main if any thunderstorms chances will be located, and the low
level jet may be the best mechanism for get a few thunderstorms
going. Generally high temperatures are forecast around 5 degrees
below climatology through the extended. Lowered dew points should
translate into overnight lows of a few degrees lower as well on
average.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Tuesday NIGHT)
ISSUED AT 1202 AM CDT TUE AUG 11 2015
BUFR soundings indicating a shallow layer of saturated air will
develop early this morning across portions of western Kansas as a
light easterly upslope flow develops. RAP and HRRR suggesting
mainly status will be possible towards daybreak west of highway
283, however at this time can not completely rule out some light
fog developing, especially at DDC and GCK. Will therefore trend
towards MVFR visibilities for a couple of hours around 12z Tuesday
with scattered IFR clouds at GCK. Otherwise VFR conditions can be
expected today with only an increase in mid level moisture
anticipated ahead of a weak upper level disturbance. Light east
winds will gradually shift to the southeast early this morning as
a surface ridge axis crosses western Kansas.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 89 66 89 / 20 30 20 10
GCK 65 89 65 91 / 20 20 20 10
EHA 66 90 66 92 / 20 20 20 10
LBL 67 89 67 91 / 20 20 20 10
HYS 66 88 66 91 / 20 20 10 10
P28 68 88 68 88 / 10 20 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Burgert
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1210 PM CDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 1210 PM CDT TUE AUG 11 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 18Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 240 AM CDT TUE AUG 11 2015
A FINAL BATCH OF SHOWERS WILL MOVE SOUTH THROUGH CARTER AND RIPLEY
COUNTIES IN MISSOURI EARLY THIS MORNING...THEN THE REMAINDER OF
THE SHORT TERM FORECAST IS DRY. THIS AFTERNOON...THE 00Z NAM IS
ATTEMPTING TO DEVELOP SOME SHALLOW CONVECTION. LOOKING AT ITS
SOUNDINGS FROM ACROSS THE REGION...IT APPEARS THERE WILL BE
SUBSTANTIAL COOLING IN THE 850MB TO 700MB LAYER...AND POSSIBLY
JUST ENOUGH LOW-LEVEL MOISTURE LEFT TO CREATE A SHALLOW LAYER OF
INSTABILITY BENEATH THE MID-LEVEL INVERSION. THE HRRR DEVELOPS A
FEW LIGHT SHOWERS...WHICH WOULD PROBABLY NOT EVEN MEASURE...SO
WILL KEEP THE FORECAST DRY FOR NOW.
SURFACE HIGH PRESSURE WILL BUILD ACROSS THE REGION TODAY INTO
WEDNESDAY...AND THE FLOW ALOFT WILL BE NORTHWESTERLY AND FAIRLY
HEALTHY FOR THE MIDDLE OF AUGUST. NORTH WINDS UP TO 10KTS WILL MIX
DOWN EACH DAY...AND THAT WILL BRING COOLER AND MUCH DRIER AIR INTO
THE REGION. DEWPOINTS BY THE END OF THE DAY WEDNESDAY WILL BE IN
THE LOWER HALF OF THE 60S...AND UPPER 50S ARE EXPECTED BY DAYBREAK
THURSDAY IN THE EAST...AS THE SURFACE HIGH SETTLES OVERHEAD.
SHOULD SEE A DEFINITE TREND LOWER IN LOW TEMPERATURES FROM THIS
MORNING THROUGH WEDNESDAY NIGHT/THURSDAY MORNING...WITH WEAKENING
WINDS AND EVER DRIER AIR OVER THE REGION. HIGHS WILL TREND LOWER
TODAY AND WEDNESDAY AND THEN LEVEL OUT ON THURSDAY. DID NOT STRAY
FAR FROM THE CONSENSUS OF 00Z GUIDANCE FOR HIGHS OR LOWS THROUGH
THE PERIOD.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 240 AM CDT TUE AUG 11 2015
THE UPPER LEVEL RIDGE THAT HAS BEEN PERSISTENT ACROSS THE HIGH
PLAINS AND ROCKIES MOST OF THE SUMMER WILL REMAIN IN PLACE. THIS
RIDGE WILL BUILD NORTHEAST ACROSS THE GREAT LAKES REGION. AN UPPER
LEVEL TROUGH WILL MAINTAIN ITS PRESENCE OVER THE EASTERN STATES...
BUT UNDERGO A WEAKENING TREND AS IT SITS OVER THE APPALACHIANS. THE
NET RESULT FOR OUR REGION WILL BE A CONTINUATION OF DRY WEATHER.
SURFACE HIGH PRESSURE WILL REMAIN STATIONARY FROM THE CENTRAL PLAINS
TO THE OHIO VALLEY THROUGH THE WEEKEND. WITH LITTLE IN THE WAY OF
TEMPERATURE ADVECTION...HIGHS WILL REMAIN GENERALLY STEADY IN THE
UPPER 80S TO NEAR 90. BY EARLY NEXT WEEK...THE HIGH WILL RETREAT
SLOWLY TOWARD THE EAST...WHICH WILL PRODUCE A SOUTHWEST FLOW OF
SLIGHTLY HIGHER TEMPS AND DEW POINTS.
&&
.AVIATION...
ISSUED AT 1210 PM CDT TUE AUG 11 2015
ASIDE FROM THE POSSIBILITY OF MVFR FOG AT KCGI/KPAH BETWEEN
08-12Z...SURFACE HIGH PRESSURE AND RISING HEIGHTS ALOFT
OVERSPREADING THE REGION SHOULD YIELD VFR CONDITIONS...ALTHOUGH A
COUPLE OF SITES COULD SEE CIGS THIS AFTERNOON IN THE 035-040
RANGE. NORTHERLY WINDS AROUND 10-12 KNOTS GUSTING UP TO 15 KNOTS
THIS AFTERNOON WILL GO CAM OR LIGHT OUT OF THE NORTH AFTER 00-01Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...MY
AVIATION...JP
AREA FORECAST DISCUSSION
NWS PADUCAH KY
646 AM CDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 646 AM CDT TUE AUG 11 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 240 AM CDT TUE AUG 11 2015
A FINAL BATCH OF SHOWERS WILL MOVE SOUTH THROUGH CARTER AND RIPLEY
COUNTIES IN MISSOURI EARLY THIS MORNING...THEN THE REMAINDER OF
THE SHORT TERM FORECAST IS DRY. THIS AFTERNOON...THE 00Z NAM IS
ATTEMPTING TO DEVELOP SOME SHALLOW CONVECTION. LOOKING AT ITS
SOUNDINGS FROM ACROSS THE REGION...IT APPEARS THERE WILL BE
SUBSTANTIAL COOLING IN THE 850MB TO 700MB LAYER...AND POSSIBLY
JUST ENOUGH LOW-LEVEL MOISTURE LEFT TO CREATE A SHALLOW LAYER OF
INSTABILITY BENEATH THE MID-LEVEL INVERSION. THE HRRR DEVELOPS A
FEW LIGHT SHOWERS...WHICH WOULD PROBABLY NOT EVEN MEASURE...SO
WILL KEEP THE FORECAST DRY FOR NOW.
SURFACE HIGH PRESSURE WILL BUILD ACROSS THE REGION TODAY INTO
WEDNESDAY...AND THE FLOW ALOFT WILL BE NORTHWESTERLY AND FAIRLY
HEALTHY FOR THE MIDDLE OF AUGUST. NORTH WINDS UP TO 10KTS WILL MIX
DOWN EACH DAY...AND THAT WILL BRING COOLER AND MUCH DRIER AIR INTO
THE REGION. DEWPOINTS BY THE END OF THE DAY WEDNESDAY WILL BE IN
THE LOWER HALF OF THE 60S...AND UPPER 50S ARE EXPECTED BY DAYBREAK
THURSDAY IN THE EAST...AS THE SURFACE HIGH SETTLES OVERHEAD.
SHOULD SEE A DEFINITE TREND LOWER IN LOW TEMPERATURES FROM THIS
MORNING THROUGH WEDNESDAY NIGHT/THURSDAY MORNING...WITH WEAKENING
WINDS AND EVER DRIER AIR OVER THE REGION. HIGHS WILL TREND LOWER
TODAY AND WEDNESDAY AND THEN LEVEL OUT ON THURSDAY. DID NOT STRAY
FAR FROM THE CONSENSUS OF 00Z GUIDANCE FOR HIGHS OR LOWS THROUGH
THE PERIOD.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 240 AM CDT TUE AUG 11 2015
THE UPPER LEVEL RIDGE THAT HAS BEEN PERSISTENT ACROSS THE HIGH
PLAINS AND ROCKIES MOST OF THE SUMMER WILL REMAIN IN PLACE. THIS
RIDGE WILL BUILD NORTHEAST ACROSS THE GREAT LAKES REGION. AN UPPER
LEVEL TROUGH WILL MAINTAIN ITS PRESENCE OVER THE EASTERN STATES...
BUT UNDERGO A WEAKENING TREND AS IT SITS OVER THE APPALACHIANS. THE
NET RESULT FOR OUR REGION WILL BE A CONTINUATION OF DRY WEATHER.
SURFACE HIGH PRESSURE WILL REMAIN STATIONARY FROM THE CENTRAL PLAINS
TO THE OHIO VALLEY THROUGH THE WEEKEND. WITH LITTLE IN THE WAY OF
TEMPERATURE ADVECTION...HIGHS WILL REMAIN GENERALLY STEADY IN THE
UPPER 80S TO NEAR 90. BY EARLY NEXT WEEK...THE HIGH WILL RETREAT
SLOWLY TOWARD THE EAST...WHICH WILL PRODUCE A SOUTHWEST FLOW OF
SLIGHTLY HIGHER TEMPS AND DEW POINTS.
&&
.AVIATION...
ISSUED AT 646 AM CDT TUE AUG 11 2015
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION...RESULTING IN
NORTH WINDS THROUGHOUT THE PERIOD. A FEW GUSTS INTO THE TEENS WILL
BE POSSIBLE WITH AFTERNOON MIXING. A LITTLE MVFR FOG WILL BURN OFF
QUICKLY THIS MORNING. CONFIDENCE IS LOW IN THE FOG FORECAST FOR
TONIGHT. WINDS WILL WEAKEN OVERNIGHT...BUT STRONG MIXING TODAY
COUPLED WITH DRY ADVECTION SHOULD PREVENT FOG FORMATION IN MOST
LOCATIONS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...MY
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
240 AM CDT TUE AUG 11 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 240 AM CDT TUE AUG 11 2015
A FINAL BATCH OF SHOWERS WILL MOVE SOUTH THROUGH CARTER AND RIPLEY
COUNTIES IN MISSOURI EARLY THIS MORNING...THEN THE REMAINDER OF
THE SHORT TERM FORECAST IS DRY. THIS AFTERNOON...THE 00Z NAM IS
ATTEMPTING TO DEVELOP SOME SHALLOW CONVECTION. LOOKING AT ITS
SOUNDINGS FROM ACROSS THE REGION...IT APPEARS THERE WILL BE
SUBSTANTIAL COOLING IN THE 850MB TO 700MB LAYER...AND POSSIBLY
JUST ENOUGH LOW-LEVEL MOISTURE LEFT TO CREATE A SHALLOW LAYER OF
INSTABILITY BENEATH THE MID-LEVEL INVERSION. THE HRRR DEVELOPS A
FEW LIGHT SHOWERS...WHICH WOULD PROBABLY NOT EVEN MEASURE...SO
WILL KEEP THE FORECAST DRY FOR NOW.
SURFACE HIGH PRESSURE WILL BUILD ACROSS THE REGION TODAY INTO
WEDNESDAY...AND THE FLOW ALOFT WILL BE NORTHWESTERLY AND FAIRLY
HEALTHY FOR THE MIDDLE OF AUGUST. NORTH WINDS UP TO 10KTS WILL MIX
DOWN EACH DAY...AND THAT WILL BRING COOLER AND MUCH DRIER AIR INTO
THE REGION. DEWPOINTS BY THE END OF THE DAY WEDNESDAY WILL BE IN
THE LOWER HALF OF THE 60S...AND UPPER 50S ARE EXPECTED BY DAYBREAK
THURSDAY IN THE EAST...AS THE SURFACE HIGH SETTLES OVERHEAD.
SHOULD SEE A DEFINITE TREND LOWER IN LOW TEMPERATURES FROM THIS
MORNING THROUGH WEDNESDAY NIGHT/THURSDAY MORNING...WITH WEAKENING
WINDS AND EVER DRIER AIR OVER THE REGION. HIGHS WILL TREND LOWER
TODAY AND WEDNESDAY AND THEN LEVEL OUT ON THURSDAY. DID NOT STRAY
FAR FROM THE CONSENSUS OF 00Z GUIDANCE FOR HIGHS OR LOWS THROUGH
THE PERIOD.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 240 AM CDT TUE AUG 11 2015
THE UPPER LEVEL RIDGE THAT HAS BEEN PERSISTENT ACROSS THE HIGH
PLAINS AND ROCKIES MOST OF THE SUMMER WILL REMAIN IN PLACE. THIS
RIDGE WILL BUILD NORTHEAST ACROSS THE GREAT LAKES REGION. AN UPPER
LEVEL TROUGH WILL MAINTAIN ITS PRESENCE OVER THE EASTERN STATES...
BUT UNDERGO A WEAKENING TREND AS IT SITS OVER THE APPALACHIANS. THE
NET RESULT FOR OUR REGION WILL BE A CONTINUATION OF DRY WEATHER.
SURFACE HIGH PRESSURE WILL REMAIN STATIONARY FROM THE CENTRAL PLAINS
TO THE OHIO VALLEY THROUGH THE WEEKEND. WITH LITTLE IN THE WAY OF
TEMPERATURE ADVECTION...HIGHS WILL REMAIN GENERALLY STEADY IN THE
UPPER 80S TO NEAR 90. BY EARLY NEXT WEEK...THE HIGH WILL RETREAT
SLOWLY TOWARD THE EAST...WHICH WILL PRODUCE A SOUTHWEST FLOW OF
SLIGHTLY HIGHER TEMPS AND DEW POINTS.
&&
.AVIATION...
ISSUED AT 1151 PM CDT MON AUG 10 2015
CONVECTION IS NOW SOUTH OF THE TAF SITES SO NO NEED TO WORRY ABOUT
THAT NOW. HOWEVER...MVFR/IFR CIGS/VSBYS POSSIBLE OVERNIGHT DUE TO
ABUNDANT LOW LEVEL MOISTURE TRAPPED UNDER THE NOCTURNAL INVERSION.
BY 15Z TUESDAY CONDITIONS SHOULD BE VFR WITH PLENTY OF SUNSHINE
AND LITTLE TO NO CLOUDINESS BUT A FEW CU ARE POSSIBLE. LIGHT AND
VARIABLE WINDS TONIGHT WILL BECOME NORTHERLY ON TUESDAY AOB 10
KTS. CLEAR SKIES AND LIGHT WINDS EXPECTED TUESDAY EVENING.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...MY
AREA FORECAST DISCUSSION
NWS JACKSON KY
135 AM EDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 1250 AM EDT TUE AUG 11 2015
SOME CONVECTION FORMED OUT AHEAD OF THE BOUNDARY THIS EVENING AND
CONTINUES TO SLOW MOVE SOUTH ACROSS EASTERN KY. THESE SHOWERS AND
STORMS HAVE BEEN WEAKENING AS THEY MOVE SOUTH INTO MORE STABLE
AIR. GENERALLY TIMING NOT TOO BAD IN GRIDS SO JUST SOME MINOR
ADJUSTMENTS...AND ALSO ADJUSTED GRIDS WITH LATEST OBS AND TRENDS.
UPDATE ISSUED AT 952 PM EDT MON AUG 10 2015
A BROKEN LINE OF SHOWERS/THUNDERSTORMS WAS DROPPING SOUTH THROUGH
THE REGION. THEY WERE SHOWING AN OVERALL SLOW WEAKENING TREND.
HOWEVER...ADDITIONAL SHOWERS WERE STARTING TO DEVELOP AHEAD OF
THE LINE. FORECAST GRIDS HAVE BEEN UPDATED TO TIME THE LINE SOUTH
INTO THE FORECAST AREA.
UPDATE ISSUED AT 653 PM EDT MON AUG 10 2015
SHOWERS/THUNDERSTORMS ASSOCIATED WITH A MID/UPPER LEVEL WAVE HAVE
EXITED TO THE EAST EARLY THIS EVENING. ADDITIONAL
SHOWERS/THUNDERSTORMS WERE OCCURRING ALONG A COLD FRONT NORTH OF
THE OHIO RIVER. THIS FRONT AND THE POTENTIAL FOR PRECIP WILL MOVE
SOUTHEAST THROUGH THE AREA DURING THE NIGHT. HAVE MODIFIED THE
PRECIP GRIDS TO REFLECT A LOW POP EARLY THIS EVENING...WITH A
LITTLE BIT BETTER CHANCE TO FOLLOW DURING THE NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 350 PM EDT MON AUG 10 2015
18Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE MOVING THROUGH THE
OHIO VALLEY WITH A COLD FRONT NOW ENTERING WESTERN KENTUCKY. AHEAD
OF THIS BOUNDARY...PLENTY OF MOISTURE AND SOME BREAKS IN THE
CLOUDS HAVE ALLOWED A FEW CLUSTERS OF SHOWERS AND STORMS TO
DEVELOP THROUGH EAST KENTUCKY. TEMPERATURES ACROSS THE AREA VARY
GREATLY BASED ON THE PCPN WITH WESTERN PARTS OF THE CUMBERLAND
VALLEY DOWN NEAR 70 WHILE LOW TO MID 80S ARE NOTED ACROSS THE
NORTH AND EAST. WINDS ARE GENERALLY FROM THE SOUTHWEST TO WEST AT
5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS.
THE MODELS ARE IN GOOD AGREEMENT AT MID LEVELS THROUGH THE SHORT
TERM PORTION OF THE FORECAST WITH AN AMPLIFYING TROUGH DIGGING
THROUGH THE GREAT LAKES AND OHIO VALLEY. THIS WILL PUSH THE
SOUTHERN PLAINS RIDGE BACK TO THE SOUTHWEST WHILE A SLEW OF MINOR
WAVES ROTATE THROUGH THE BASE OF THE TROUGH AND BRUSH BY/MOVE
THROUGH EAST KENTUCKY INTO WEDNESDAY MORNING. THE NAM REMAINS A
BIT STRONGER WITH THE TROUGH THAN THE CONSENSUS OF THE OTHER
MODELS. OTHERWISE...TIMING AND PLACEMENT ARE QUITE SIMILAR AMONGST
THE MODELS. ACCORDINGLY...HAVE FOLLOWED THE HRRR M0ST CLOSELY
THROUGH THE FIRST PART OF THE SHORT TERM WITH A GENERAL BLEND
FAVORED AFTER THAT.
SENSIBLE WEATHER WILL FEATURE AN ACTIVE LATE AFTERNOON AND EARLY
EVENING PERIOD AS CONVECTION MOVES THROUGH EASTERN KENTUCKY DRIVEN
BY INSTABILITY AND DIFFERENTIAL HEATING AS WELL AS OUTFLOW FROM
EARLIER STORMS. THE HIGH MOISTURE CONTENT IN THE AIR WILL MAKE
HEAVY RAINS A THREAT. IN ADDITION...A FEW OF THE STRONGER STORMS
COULD CONTAIN GUSTY WINDS WITH A SMALL POTENTIAL TO DO DAMAGE.
WILL CONTINUE TO MENTION THIS CONCERN IN THE FORTHCOMING UPDATE TO
THE HWO. THE INSTABILITY WILL WANE AFTER SUNSET...BUT THE
APPROACHING SFC FRONT WILL KEEP SHOWERS AND ISOLATED THUNDERSTORMS
POSSIBLE THROUGH THE EVENING AND INTO THE EARLY OVERNIGHT PERIOD.
DO EXPECT THE THUNDER TO BE MOSTLY GONE BY MIDNIGHT...THOUGH...SO
HAVE DROPPED ITS MENTION IN THE WX GRIDS AFTER THAT TIME. PATCHY
FOG WILL BE POSSIBLE AS WELL...POST FRONTAL...LATER TONIGHT...BUT
PLENTY OF CLOUDS AROUND SHOULD KEEP THE VISIBILITIES FROM GETTING
TOO LOW. A FEW SHOWERS MAY LINGER THROUGH FAR EASTERN KENTUCKY
INTO THE DAY TUESDAY AS HIGH PRESSURE ONLY SLOWLY PUSHES INTO THE
AREA. THIS HIGH WILL BRING IN DRIER AIR AND...EVENTUALLY...
CLEARING SKIES FROM WEST TO EAST LATER TUESDAY. A BETTER CHANCE
FOR FOG IN THE VALLEYS...PERHAPS LOCALLY DENSE...CAN THEN BE
ANTICIPATED FOR LATER TUESDAY NIGHT INTO WEDNESDAY MORNING.
STARTED WITH THE SHORTBLEND GUIDANCE THROUGH THE FIRST PART OF
THE FORECAST FOR THE T/TD/WIND GRIDS FOLLOWED BY THE SUPERBLEND
FOR THE REMAINDER OF THE TIME. DID MAKE SOME VERY MINOR CHANGES
TO LOWS TONIGHT AND TUESDAY NIGHT BASED ON THE TERRAIN. AS FOR
POPS...ENDED UP MOST SIMILAR TO A BLEND OF THE WETTER MAV AND
DRIER MET NUMBERS TONIGHT AND TUESDAY WITH SINGLE DIGIT POPS FOR
TUESDAY NIGHT IN LINE WITH GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 251 PM EDT MON AUG 10 2015
DRY AND PLEASANT WEATHER IS ON TAP FOR THE EXTENDED PORTION OF THE
FORECAST. A LARGE RIDGE OF HIGH PRESSURE IS FORECAST TO BECOME
ESTABLISHED OVER THE EASTERN THIRD OF THE CONUS FROM EARLY WEDNESDAY
ONWARD. THE RIDGE WILL USHER IN A MUCH COOLER AND DRIER AIR MASS
THAN ANY WE HAVE SEEN IN THIS PART OF THE COUNTY IN RECENT WEEKS.
BOTH DAY AND NIGHT TIME TEMPERATURES WILL BE RUNNING WELL BELOW
AVERAGE THE FIRST COUPLE OF DAYS AND NIGHTS OF THE PERIOD. HIGHS ON
TUESDAY AND WEDNESDAY ARE EXPECTED TO TOP OUT IN THE UPPER 70S FOR
MOST LOCATIONS...WITH OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT
DIPPING INTO THE UPPER 50S FOR EVERYWHERE...EXCEPT RIGHT ALONG THE
TENNESSEE BORDER...WHERE A FEW READINGS AT OR JUST ABOVE 60 MIGHT BE
REALIZED. NO PRECIPITATION IS IN THE FORECAST AT THIS POINT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 135 AM EDT TUE AUG 11 2015
SEVERAL SITES ARE STARTING OFF VFR THIS EVENING...THERE HAVE BEEN
A FEW EXCEPTIONS WHERE SOME HAVE SEEN RECENT RAIN SHOWERS OR SEEN
SOME MOSTLY CLEAR SKIES AT TIMES. OVERALL THE SHOWER ACTIVITY
CONTINUES TO WAIN AS IT MOVES SOUTH INTO MORE STABLE AIR IN PLACE
ACROSS THE REGION. DID OPT TO KEEP VCSH AT MOST SITES AND VCTS AT
SYM AND SJS AS SOME UPSTREAM STORM DEVELOPMENT COULD SKIRT THOSE
SITES. THE ISSUE OVERALL TONIGHT WILL BE FOG AND STRATUS
DEVELOPMENT...THIS WILL BE ESPECIALLY TRUE IN AREAS THAT HAVE SEEN
RAIN. THAT SAID MOST SITES WILL SEE IFR OR LOWER VIS AND/OR CIGS
OVERNIGHT INTO MORNING HOURS. THIS IS EXPECTED TO LIFT AS WE MOVE
INTO THE EARLY AFTERNOON HOURS. ONCE THE MAIN FRONT MOVES THROUGH
WE COULD SEE SOME ADDITIONAL SHOWER AND STORM DEVELOPMENT MAINLY
IN THE AFTERNOON...BUT MOST OF THIS WILL BE CONFINED TO THE SE.
AFTER THIS DRIER CONDITIONS WILL PREVAIL. WINDS WILL GENERALLY
REMAIN LIGHT THROUGH THE PERIOD BETWEEN 5 TO 10 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
1250 AM EDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 1250 AM EDT TUE AUG 11 2015
SOME CONVECTION FORMED OUT AHEAD OF THE BOUNDARY THIS EVENING AND
CONTINUES TO SLOW MOVE SOUTH ACROSS EASTERN KY. THESE SHOWERS AND
STORMS HAVE BEEN WEAKENING AS THEY MOVE SOUTH INTO MORE STABLE
AIR. GENERALLY TIMING NOT TOO BAD IN GRIDS SO JUST SOME MINOR
ADJUSTMENTS...AND ALSO ADJUSTED GRIDS WITH LATEST OBS AND TRENDS.
UPDATE ISSUED AT 952 PM EDT MON AUG 10 2015
A BROKEN LINE OF SHOWERS/THUNDERSTORMS WAS DROPPING SOUTH THROUGH
THE REGION. THEY WERE SHOWING AN OVERALL SLOW WEAKENING TREND.
HOWEVER...ADDITIONAL SHOWERS WERE STARTING TO DEVELOP AHEAD OF
THE LINE. FORECAST GRIDS HAVE BEEN UPDATED TO TIME THE LINE SOUTH
INTO THE FORECAST AREA.
UPDATE ISSUED AT 653 PM EDT MON AUG 10 2015
SHOWERS/THUNDERSTORMS ASSOCIATED WITH A MID/UPPER LEVEL WAVE HAVE
EXITED TO THE EAST EARLY THIS EVENING. ADDITIONAL
SHOWERS/THUNDERSTORMS WERE OCCURRING ALONG A COLD FRONT NORTH OF
THE OHIO RIVER. THIS FRONT AND THE POTENTIAL FOR PRECIP WILL MOVE
SOUTHEAST THROUGH THE AREA DURING THE NIGHT. HAVE MODIFIED THE
PRECIP GRIDS TO REFLECT A LOW POP EARLY THIS EVENING...WITH A
LITTLE BIT BETTER CHANCE TO FOLLOW DURING THE NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 350 PM EDT MON AUG 10 2015
18Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE MOVING THROUGH THE
OHIO VALLEY WITH A COLD FRONT NOW ENTERING WESTERN KENTUCKY. AHEAD
OF THIS BOUNDARY...PLENTY OF MOISTURE AND SOME BREAKS IN THE
CLOUDS HAVE ALLOWED A FEW CLUSTERS OF SHOWERS AND STORMS TO
DEVELOP THROUGH EAST KENTUCKY. TEMPERATURES ACROSS THE AREA VARY
GREATLY BASED ON THE PCPN WITH WESTERN PARTS OF THE CUMBERLAND
VALLEY DOWN NEAR 70 WHILE LOW TO MID 80S ARE NOTED ACROSS THE
NORTH AND EAST. WINDS ARE GENERALLY FROM THE SOUTHWEST TO WEST AT
5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS.
THE MODELS ARE IN GOOD AGREEMENT AT MID LEVELS THROUGH THE SHORT
TERM PORTION OF THE FORECAST WITH AN AMPLIFYING TROUGH DIGGING
THROUGH THE GREAT LAKES AND OHIO VALLEY. THIS WILL PUSH THE
SOUTHERN PLAINS RIDGE BACK TO THE SOUTHWEST WHILE A SLEW OF MINOR
WAVES ROTATE THROUGH THE BASE OF THE TROUGH AND BRUSH BY/MOVE
THROUGH EAST KENTUCKY INTO WEDNESDAY MORNING. THE NAM REMAINS A
BIT STRONGER WITH THE TROUGH THAN THE CONSENSUS OF THE OTHER
MODELS. OTHERWISE...TIMING AND PLACEMENT ARE QUITE SIMILAR AMONGST
THE MODELS. ACCORDINGLY...HAVE FOLLOWED THE HRRR M0ST CLOSELY
THROUGH THE FIRST PART OF THE SHORT TERM WITH A GENERAL BLEND
FAVORED AFTER THAT.
SENSIBLE WEATHER WILL FEATURE AN ACTIVE LATE AFTERNOON AND EARLY
EVENING PERIOD AS CONVECTION MOVES THROUGH EASTERN KENTUCKY DRIVEN
BY INSTABILITY AND DIFFERENTIAL HEATING AS WELL AS OUTFLOW FROM
EARLIER STORMS. THE HIGH MOISTURE CONTENT IN THE AIR WILL MAKE
HEAVY RAINS A THREAT. IN ADDITION...A FEW OF THE STRONGER STORMS
COULD CONTAIN GUSTY WINDS WITH A SMALL POTENTIAL TO DO DAMAGE.
WILL CONTINUE TO MENTION THIS CONCERN IN THE FORTHCOMING UPDATE TO
THE HWO. THE INSTABILITY WILL WANE AFTER SUNSET...BUT THE
APPROACHING SFC FRONT WILL KEEP SHOWERS AND ISOLATED THUNDERSTORMS
POSSIBLE THROUGH THE EVENING AND INTO THE EARLY OVERNIGHT PERIOD.
DO EXPECT THE THUNDER TO BE MOSTLY GONE BY MIDNIGHT...THOUGH...SO
HAVE DROPPED ITS MENTION IN THE WX GRIDS AFTER THAT TIME. PATCHY
FOG WILL BE POSSIBLE AS WELL...POST FRONTAL...LATER TONIGHT...BUT
PLENTY OF CLOUDS AROUND SHOULD KEEP THE VISIBILITIES FROM GETTING
TOO LOW. A FEW SHOWERS MAY LINGER THROUGH FAR EASTERN KENTUCKY
INTO THE DAY TUESDAY AS HIGH PRESSURE ONLY SLOWLY PUSHES INTO THE
AREA. THIS HIGH WILL BRING IN DRIER AIR AND...EVENTUALLY...
CLEARING SKIES FROM WEST TO EAST LATER TUESDAY. A BETTER CHANCE
FOR FOG IN THE VALLEYS...PERHAPS LOCALLY DENSE...CAN THEN BE
ANTICIPATED FOR LATER TUESDAY NIGHT INTO WEDNESDAY MORNING.
STARTED WITH THE SHORTBLEND GUIDANCE THROUGH THE FIRST PART OF
THE FORECAST FOR THE T/TD/WIND GRIDS FOLLOWED BY THE SUPERBLEND
FOR THE REMAINDER OF THE TIME. DID MAKE SOME VERY MINOR CHANGES
TO LOWS TONIGHT AND TUESDAY NIGHT BASED ON THE TERRAIN. AS FOR
POPS...ENDED UP MOST SIMILAR TO A BLEND OF THE WETTER MAV AND
DRIER MET NUMBERS TONIGHT AND TUESDAY WITH SINGLE DIGIT POPS FOR
TUESDAY NIGHT IN LINE WITH GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 251 PM EDT MON AUG 10 2015
DRY AND PLEASANT WEATHER IS ON TAP FOR THE EXTENDED PORTION OF THE
FORECAST. A LARGE RIDGE OF HIGH PRESSURE IS FORECAST TO BECOME
ESTABLISHED OVER THE EASTERN THIRD OF THE CONUS FROM EARLY WEDNESDAY
ONWARD. THE RIDGE WILL USHER IN A MUCH COOLER AND DRIER AIR MASS
THAN ANY WE HAVE SEEN IN THIS PART OF THE COUNTY IN RECENT WEEKS.
BOTH DAY AND NIGHT TIME TEMPERATURES WILL BE RUNNING WELL BELOW
AVERAGE THE FIRST COUPLE OF DAYS AND NIGHTS OF THE PERIOD. HIGHS ON
TUESDAY AND WEDNESDAY ARE EXPECTED TO TOP OUT IN THE UPPER 70S FOR
MOST LOCATIONS...WITH OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT
DIPPING INTO THE UPPER 50S FOR EVERYWHERE...EXCEPT RIGHT ALONG THE
TENNESSEE BORDER...WHERE A FEW READINGS AT OR JUST ABOVE 60 MIGHT BE
REALIZED. NO PRECIPITATION IS IN THE FORECAST AT THIS POINT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 915 PM EDT MON AUG 10 2015
CONDITIONS ACROSS THE REGION WERE VFR AT THE START OF THE
PERIOD. HOWEVER...A BROKEN LINE OF THUNDERSTORMS WAS JUST NORTH
OF THE JKL FORECAST AREA. IT WAS ASSOCIATED WITH A COLD FRONT
WHICH WILL DROP SOUTH THROUGH THE REGION TONIGHT...BRINGING
SCATTERED SHOWERS AND THUNDERSTORMS AND LOCALIZED IFR. MOST OF
THE PRECIPITATION WILL DIMINISH OR MOVE OUT TO THE SOUTHEAST
BEFORE DAWN. IN ITS WAKE WE WILL HAVE LOW CLOUDS AND FOG DEVELOP
AND BRING WIDESPREAD IFR OR BELOW...WHICH WILL LINGER INTO TUESDAY
MORNING. THE LOW CLOUDS AND FOG WILL LIFT/BREAK UP BY AROUND MID
DAY. SOME LIMITED REDEVELOPMENT OF SHOWERS/THUNDERSTORMS COULD
OCCUR DURING THE DAY TUESDAY...MAINLY IN SOUTHEAST KY. AS LESS
HUMID AIR FINALLY BEGINS TO ARRIVE BY THE END OF THE PERIOD...DRY
WEATHER WILL ARRIVE AND BE WITH US FOR A NUMBER OF DAYS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1245 PM CDT TUE AUG 11 2015
.AVIATION...
MOST TERMINAL SITES ARE VFR AT MIDDAY WITH THE EXCEPTION OF
KBTR...WHERE MVFR CEILINGS ARE OCCURRING WITH THUNDERSTORMS WEST
AND NORTHWEST OF THE TERMINAL. EVEN THOUGH THERE IS A FAIRLY
HEALTHY CIRRUS SHIELD...REDEVELOPMENT OF TSRA IS NOT OUT OF THE
QUESTION. WILL BE CARRYING VCTS AT MOST TERMINALS AT SOME POINT
THIS AFTERNOON WITH THE EXCEPTION OF KMCB...WHERE THE THREAT
APPEARS TO BE LOWER WITH THE PASSAGE OF THE MID-MORNING CLUSTER OF
THUNDERSTORMS.
OVERNIGHT...ANTICIPATE VFR CONDITIONS AT ALL TERMINALS...BUT THERE
IS AT LEAST A SMALL POTENTIAL FOR MVFR VISIBILITIES AT KMCB.
THREAT NOT LOW ENOUGH TO CARRY AT THIS TIME. 35
&&
.PREV DISCUSSION... /ISSUED 348 AM CDT TUE AUG 11 2015/
SHORT TERM...
CONSIDERABLY DRIER COLUMN WITH LOWER DEWPOINTS OVER THE LARGER
SOUTHEAST REGION THIS MORNING...WHICH SHOULD HELP IN LOWERING
APPARENT TEMPERATURES BY A FEW DEGREES THIS AFTERNOON TO PRECLUDE
A HEAT WARNING. THE UPDATED TEMPERATURES AND HUMIDITY GRIDS YIELD
PROJECTED HEAT INDEX READINGS THAT ALIGN WELL WITH ONGOING HEAT
ADVISORY...WHERE 108 TO 112F IS POSSIBLE PRIOR RAINFALL ONSET.
THERE IS SOME UNCERTAINTY ON WHETHER TEMPERATURES WILL ACHIEVE
CRITERIA SHOULD RAINFALL ONSET SOONER...AS INDICATED BY HRRR AND
CONSIDERATIONS FOR DEVELOPING LINEAR MCS DEVELOPING AT THE ARK-
LA-MISS APEX. SOME DOWNRANGE DEVELOPMENT MAY TAKE PLACE BEFORE
SUNRISE THAT MOVES INTO SOUTHWEST MISSISSIPPI AND DISRUPT THE
DIURNAL TEMPERATURE TREND. MODELS ARE IN AGREEMENT WITH INCREASING
PRECIPITATION OVER A LARGE EXPANSE OF THE GULF COAST BY THIS
AFTERNOON AND WENT WITH MODEL BLENDS ON POPS AND TEMPERATURES IN
THE SHORT-TERM. MARGINAL RISK OF SEVERE STORMS TODAY WITH MAIN
THREATS DAMAGING WIND GUSTS THOUGH ISOLATED HAIL CAN NOT BE RULED
OUT AS WET-BULB ZERO LEVELS LOWER WITH STEEP HEIGHT FALLS
THROUGHOUT THE DAY. WEDNESDAY SHOULD SEE DRIER CONDITIONS THOUGH
DAYTIME TEMPERATURES MAY STILL REACH MID 90S WITH LOWER HUMIDITY
LEVELS. 24/RR
LONG TERM...
UPPER RIDGE MOVES OVER DESERT SOUTHWEST AND STRENGTHENS WHILE DEEP
TROUGHING TAKES PLACE OVER THE EASTERN UNITED STATES WEDNESDAY AND
STAYS PLANTED ALONG THE EASTERN SEABOARD THROUGH FRIDAY BEFORE
LIFTING OUT OVER THE WEEKEND. SOME ENERGY IN THE BASE OF THE
TROUGH BREAKS OFF IN TIME TO BRING CUT-OFF LOW DYNAMICS DRIFTING
ALONG THE NORTH GULF COAST INTO NEXT WEEK. THIS TYPICALLY YIELDS
LOWER CONVECTIVE TEMPERATURE CONDITIONS WITH SOME COLD POOL
ENHANCEMENTS FOR EFFICIENT SEA BREEZE CONVECTION THAT SPREADS
LARGE ANVIL CANOPY OVER MUCH OF THE FORECAST AREA IN THE MID TO
LATE AFTERNOON HOURS THAT ERODE BY LATE EVENING. TEMPERATURES AND
RAIN CHANCES SHOULD BE CLOSE TO NORMAL LEVELS DURING THE EXTENDED
PORTIONS OF THE FORECAST PACKAGE. 24/RR
AVIATION...
2Z PACK WILL TRY TO TIME TSTORM COVERAGE PER TERMINAL. MOST SHOULD
SEE SOME ACTIVITY LATER TODAY. SHOULD START OUT DURING THE MORNING
FOR THE NORTHERN MOST SITES THEN PROGRESS SOUTHWARD DURING THE DAY.
WILL SHOW IFR CONDITIONS AS TEMPO GROUPS WILL BRING VIS RESTRICTIONS
AND WIND SPEEDS AND SHIFTS WILL BE A PROBLEM.
MARINE...
WINDS WILL BE MAINLY LESS THAN 10 KNOTS ALONG COASTAL
WATERS AND LAKE WITH SHORT DURATIONS OF 10 TO 15 IN THE AFTERNOON
AND EARLY EVENING HOURS POSSIBLE. THE MAIN CONCERN FOR THE NEXT
SEVERAL DAYS WILL BE THE POTENTIAL FOR THUNDERSTORMS...AS ANY STORMS
THAT DEVELOP COULD CERTAINLY PRODUCE WINDS IN EXCESS OF 40 KNOTS.
OUTSIDE OF THE THUNDERSTORM POTENTIAL EXPECT MOSTLY TRANQUIL
CONDITIONS. A WEAK FRONT WILL MOVE INTO THE COASTAL WATERS WEDNESDAY
WHICH WILL BRING SOME RELIEF FROM OPPRESSIVE HEAT AND HUMIDITY.
DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...HEAT ADVISORY ALL LAND AREAS EXCEPT EXTREME COASTAL SOUTHEAST LA
AND COASTAL MISSISSIPPI THROUGH 7 PM.
RIVER FLOOD WARNING ON MISSISSIPPI RIVER AT RED RIVER
LANDING.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 94 74 94 72 / 50 40 10 0
BTR 95 77 96 75 / 50 40 10 0
ASD 95 74 94 73 / 50 40 40 10
MSY 95 78 93 79 / 40 40 40 20
GPT 92 76 92 75 / 40 50 50 10
PQL 93 75 94 73 / 30 60 40 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LAZ034>037-039-040-
046>050-056>065-071-072.
GM...NONE.
MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MSZ068>071-077.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
348 AM CDT TUE AUG 11 2015
.SHORT TERM...
CONSIDERABLY DRIER COLUMN WITH LOWER DEWPOINTS OVER THE LARGER
SOUTHEAST REGION THIS MORNING...WHICH SHOULD HELP IN LOWERING
APPARENT TEMPERATURES BY A FEW DEGREES THIS AFTERNOON TO PRECLUDE
A HEAT WARNING. THE UPDATED TEMPERATURES AND HUMIDITY GRIDS YIELD
PROJECTED HEAT INDEX READINGS THAT ALIGN WELL WITH ONGOING HEAT
ADVISORY...WHERE 108 TO 112F IS POSSIBLE PRIOR RAINFALL ONSET.
THERE IS SOME UNCERTAINTY ON WHETHER TEMPERATURES WILL ACHIEVE
CRITERIA SHOULD RAINFALL ONSET SOONER...AS INDICATED BY HRRR AND
CONSIDERATIONS FOR DEVELOPING LINEAR MCS DEVELOPING AT THE ARK-
LA-MISS APEX. SOME DOWNRANGE DEVELOPMENT MAY TAKE PLACE BEFORE
SUNRISE THAT MOVES INTO SOUTHWEST MISSISSIPPI AND DISRUPT THE
DIURNAL TEMPERATURE TREND. MODELS ARE IN AGREEMENT WITH INCREASING
PRECIPITATION OVER A LARGE EXPANSE OF THE GULF COAST BY THIS
AFTERNOON AND WENT WITH MODEL BLENDS ON POPS AND TEMPERATURES IN
THE SHORT-TERM. MARGINAL RISK OF SEVERE STORMS TODAY WITH MAIN
THREATS DAMAGING WIND GUSTS THOUGH ISOLATED HAIL CAN NOT BE RULED
OUT AS WET-BULB ZERO LEVELS LOWER WITH STEEP HEIGHT FALLS
THROUGHOUT THE DAY. WEDNESDAY SHOULD SEE DRIER CONDITIONS THOUGH
DAYTIME TEMPERATURES MAY STILL REACH MID 90S WITH LOWER HUMIDITY
LEVELS. 24/RR
.LONG TERM...
UPPER RIDGE MOVES OVER DESERT SOUTHWEST AND STRENGTHENS WHILE DEEP
TROUGHING TAKES PLACE OVER THE EASTERN UNITED STATES WEDNESDAY AND
STAYS PLANTED ALONG THE EASTERN SEABOARD THROUGH FRIDAY BEFORE
LIFTING OUT OVER THE WEEKEND. SOME ENERGY IN THE BASE OF THE
TROUGH BREAKS OFF IN TIME TO BRING CUT-OFF LOW DYNAMICS DRIFTING
ALONG THE NORTH GULF COAST INTO NEXT WEEK. THIS TYPICALLY YIELDS
LOWER CONVECTIVE TEMPERATURE CONDITIONS WITH SOME COLD POOL
ENHANCEMENTS FOR EFFICIENT SEA BREEZE CONVECTION THAT SPREADS
LARGE ANVIL CANOPY OVER MUCH OF THE FORECAST AREA IN THE MID TO
LATE AFTERNOON HOURS THAT ERODE BY LATE EVENING. TEMPERATURES AND
RAIN CHANCES SHOULD BE CLOSE TO NORMAL LEVELS DURING THE EXTENDED
PORTIONS OF THE FORECAST PACKAGE. 24/RR
&&
.AVIATION...
2Z PACK WILL TRY TO TIME TSTORM COVERAGE PER TERMINAL. MOST SHOULD
SEE SOME ACTIVITY LATER TODAY. SHOULD START OUT DURING THE MORNING
FOR THE NORTHERN MOST SITES THEN PROGRESS SOUTHWARD DURING THE DAY.
WILL SHOW IFR CONDITIONS AS TEMPO GROUPS WILL BRING VIS RESTRICTIONS
AND WIND SPEEDS AND SHIFTS WILL BE A PROBLEM.
&&
.MARINE...
WINDS WILL BE MAINLY LESS THAN 10 KNOTS ALONG COASTAL
WATERS AND LAKE WITH SHORT DURATIONS OF 10 TO 15 IN THE AFTERNOON
AND EARLY EVENING HOURS POSSIBLE. THE MAIN CONCERN FOR THE NEXT
SEVERAL DAYS WILL BE THE POTENTIAL FOR THUNDERSTORMS...AS ANY STORMS
THAT DEVELOP COULD CERTAINLY PRODUCE WINDS IN EXCESS OF 40 KNOTS.
OUTSIDE OF THE THUNDERSTORM POTENTIAL EXPECT MOSTLY TRANQUIL
CONDITIONS. A WEAK FRONT WILL MOVE INTO THE COASTAL WATERS WEDNESDAY
WHICH WILL BRING SOME RELIEF FROM OPPRESSIVE HEAT AND HUMIDITY.
&&
.DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...HEAT ADVISORY ALL LAND AREAS EXCEPT EXTREME COASTAL SOUTHEAST LA
AND COASTAL MISSISSIPPI THROUGH 7 PM.
RIVER FLOOD WARNING ON MISSISSIPPI RIVER AT RED RIVER
LANDING.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 95 74 94 72 / 50 40 10 0
BTR 96 77 96 75 / 50 40 10 0
ASD 95 74 94 73 / 50 40 40 10
MSY 95 78 93 79 / 40 40 40 20
GPT 92 76 92 75 / 40 50 50 10
PQL 93 75 94 73 / 30 60 40 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LAZ034>037-039-040-
046>050-056>065-071-072.
GM...NONE.
MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MSZ068>071-077.
GM...NONE.
&&
$$
24/RR
17/TE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1103 PM EDT WED AUG 12 2015
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 315 PM EDT WED AUG 12 2015
FAIR WEATHER WILL CONTINUE THIS EVENING. A WARM FRONT WILL BRING
POTENTIAL FOR A FEW SHOWERS AND THUNDERSTORMS OVER CENTRAL LOWER
MICHIGAN NORTH OF INTERSTATE 96 VERY LATE TONIGHT. FAIR WEATHER
WILL BRIEFLY RETURN THURSDAY BUT A FRONTAL BOUNDARY WILL MOVE
INTO OUR REGION AND THEN STALL OUT THURSDAY NIGHT THROUGH FRIDAY
AND BRING A CHANCE OF SHOWERS AND STORMS THROUGH THAT TIME PERIOD.
FAIR AND HOT WEATHER IS ANTICIPATED THIS WEEKEND WITH HIGH
TEMPERATURES REACHING THE UPPER 80S TO LOWER 90S.
&&
.UPDATE...
ISSUED AT 1103 PM EDT WED AUG 12 2015
UPDATED THE FORECAST AROUND 1030PM TO INCREASE THE 30 PCT CHANCE
AREA FOR SHOWERS AND STORMS ACROSS CENTRAL LOWER MI.
SPECIFICALLY...NOW WE HAVE 30 POPS THROUGH THE NORTHERN 3 TIERS OF
COUNTIES. ALSO ADDED A 20 PCT CHANCE FOR SHOWERS ACROSS THE BULK
OF THE REST OF THE CWA. THE HRRR FOR SEVERAL RUNS NOW HAS BEEN
INDICATING SHOWERS AND A FEW THUNDERSTORMS WORKING SOUTH THROUGH
THE NIGHT ACROSS SOUTHWEST LOWER MICHIGAN. THE EXCEPTION MAY BE
ACROSS THE FAR SOUTHWEST TOWARD SOUTH HAVEN WHERE CONDITIONS
LIKELY WILL REMAIN DRY.
THE SHOWERS AND STORMS ARE FORMING ON THE LEADING EDGE OF MOISTURE
RETURN AS RIDGING IS BEING SHUNTED OFF TO THE SOUTH AND EAST. THE
MOISTURE RETURN IS ALOFT...AND IS BEST SEEN AROUND 850MB/S. 850MB
MOISTURE TRANSPORT...THE LLJ AND MOST UNSTABLE CAPE FIELDS ALL
SHOW A PUSH OF MOISTURE AND INSTABILITY WORKING SOUTHWARD ACROSS
OUR AREA TONIGHT. EXPECTING SCATTERED SHOWERS WITH SOME ISOLATED
EMBEDDED THUNDERSTORMS. NOT EXPECTING STRONG CONVECTION...BUT
THERE MAY BE SOME LOCALLY HEAVY RAIN AND LIGHTNING.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 315 PM EDT WED AUG 12 2015
PRIMARY SHORT TERM FCST CONCERNS INVOLVE DETERMINING POTENTIAL FOR
ANY CONVECTION VERY LATE TONIGHT AND THEN FROM LATE THURSDAY
THROUGH FRIDAY NIGHT.
FAIR WX WILL CONTINUE THIS AFTN/EVE AND WE REMOVED POPS FOR THIS
EVENING BASED ON A CONSENSUS OF LATEST SHORT RANGE GUIDANCE AND
RGNL RADAR TRENDS. A FEW SHOWERS AND STORMS ARE EXPECTED TO
DEVELOP OVER THE U.P. AND FAR NORTHERN LWR MI THIS EVENING. THOSE
WILL MOVE SSE AND COULD AFFECT AREAS WELL TO THE NORTH TO NE OF
KGRR BETWEEN 06Z AND 12Z THUR DUE TO ISENTROPIC UPGLIDE FROM A
A WARM FRONT IN THE AREA.
SW WINDS WILL RAMP UP SOMEWHAT THURSDAY IN ADVANCE OF THE
APPROACHING FRONTAL BOUNDARY. MOST OF THURSDAY SHOULD BE DRY
BEFORE SCATTERED SHOWERS AND STORMS DEVELOP FROM NW TO SE ACROSS
OUR FCST AREA LATE THURSDAY THROUGH THURSDAY NIGHT. THIS AS A
RESULT OF INCREASING ELEVATED INSTABILITY AS H8 LI/S FALL TO -2
TO -4 AND IN AN INCREASINGLY HUMID AND UNSTABLE AIRMASS AS DEW
POINT VALUES RISE THROUGH THE 60S. CONVECTIVE DEVELOPMENT WILL
ALSO BE AIDED BY A 35 TO 40 KT LLJ AND RATHER STRONG 1000-850 MB
MOISTURE TRANSPORT PARTICULARLY BETWEEN 00Z AND 06Z FRI.
THERE WILL BE A CONTINUED CHC OF SCATTERED CONVECTION FRIDAY WITH
A SLOW MOVING FRONTAL BOUNDARY IN THE AREA AND WITH A VERY HUMID
AND INCREASINGLY HUMID AIRMASS IN PLACE. POTENTIAL FOR SOME
STRONGER CONVECTION FRIDAY WILL BE LARGELY CONTINGENT ON HOW MUCH
DAYTIME HEATING AND INSTABILITY DEVELOPS. HOWEVER THE SEVERE
WEATHER THREAT LOOKS LOW DUE TO WEAK WIND FIELDS WITH HEIGHT/WEAK
DEEP LAYER SHEAR AND LACK OF STRONGER FORCING. ANY LINGERING SHOWERS
OR STORMS INTO FRIDAY EVENING WILL GRADUALLY TAPER OFF AND END
OVERNIGHT.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM EDT WED AUG 12 2015
NORTHWEST FLOW WILL DOMINATE THE EXTENDED PERIOD AS UPPER TROUGHING
PERSISTS OVER EASTERN CANADA AND UPPER RIDGING ACROSS THE WESTERN
CONUS...WHICH TEMPORARILY FOLDS OVER THE GREAT LAKES REGION THIS
WEEKEND.
THAT UPPER RIDGING SHOULD BRING FAIR AND WARM WEATHER FOR SATURDAY
AND SUNDAY. DECIDED TO DROP POPS FOR SATURDAY MORNING ALTHOUGH THERE
COULD BE ISOLATED SHOWERS LINGERING ACROSS THE EXTREME SOUTHEAST
FORECAST AREA EARLY IN THE DAY.
HEIGHT FALLS OCCUR SUNDAY NIGHT AND MONDAY AS A SHORTWAVE TROUGH
MOVING ACROSS CANADA BRINGS A TRAILING COLD FRONT INTO MICHIGAN BY
TUESDAY. LATEST MODEL TRENDS ARE THAT THE FRONT CLEARS CLEARS THE
FORECAST AREA BY TUESDAY NIGHT WITH A LULL IN THE PRECIP CHANCES
TUESDAY NIGHT AND WEDNESDAY AS SFC RIDGING IS IN CONTROL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 820 PM EDT WED AUG 12 2015
VFR CONDITIONS ARE EXPECTED THE NEXT 24 HOURS. A PUSH OF MID AND
HIGH CLOUDS WILL COME IN TONIGHT ALONG WITH SOME SCATTERED SHOWERS
AND POSSIBLY A THUNDERSTORM. THE BEST CHANCE FOR SEEING ANY
PRECIPITATION WILL BE BETWEEN 03Z AND 10Z TONIGHT. ANY
PRECIPITATION THAT DOES OCCUR HOWEVER WILL BE ISOLATED TO
SCATTERED SO ONLY HAVE VCSH WORDING IN THE TAFS. CLOUD BASES FOR
THE MOST PART SHOULD BE AT OR ABOVE 6000-7000FT TONIGHT.
ON THURSDAY...A FEW CUMULUS CLOUDS ARE POSSIBLE WITH BASES AROUND
5000FT. HIGHER CONFIDENCE IN BROKEN CLOUDS WITH BASES IN THE
10000-14000FT RANGE THURSDAY.
WINDS TONIGHT WILL TURN FROM THE WEST THIS EVENING TO SOUTHWEST
OVERNIGHT. SPEEDS WILL REMAIN LIGHT TONIGHT UNDER 7 KNOTS. A GUSTY
SOUTHWEST WIND OF 10-22 KNOTS CAN BE EXPECTED ON THURSDAY AFTER
15Z.
&&
.MARINE...
ISSUED AT 315 PM EDT WED AUG 12 2015
FAIRLY MINIMAL WIND AND WAVE ACTION IS ANTICIPATED FOR THE REST OF
THIS AFTERNOON THROUGH TONIGHT. SOUTHWEST WINDS WILL RAMP UP ON
THURSDAY CAUSING WAVE HEIGHTS TO BUILD TO 2 TO 4 FEET. HOWEVER
WINDS AND WAVES SHOULD STAY JUST BELOW SMALL CRAFT CRITERIA
THURSDAY IN THE SW FLOW WARM AIR ADVECTION REGIME.
&&
.HYDROLOGY...
ISSUED AT 315 PM EDT WED AUG 12 2015
SCATTERED SHOWERS/STORMS LATE TONIGHT INTO THU COULD PRODUCE SOME
RAINFALL ACROSS THE NORTHERN FORECAST AREA...BUT NO SIGNIFICANT
RAINFALL AMOUNTS/FLOODING ISSUES ARE EXPECTED. BETTER CHANCES FOR
RAIN WILL ARRIVE THU NIGHT INTO FRIDAY AND THEN LATE SUNDAY NIGHT
THROUGH MONDAY NIGHT. PRECIPITABLE WATER VALUES INCREASE OVER 1.50
INCHES THU NIGHT INTO FRIDAY...SUPPORTING A BETTER CHANCE FOR DECENT
RAINFALL TOTALS. 0.25 TO 0.50 INCHES SEEMS POSSIBLE WITH SOME
LOCALLY HIGHER TOTALS IN STORMS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...DUKE
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...DUKE
HYDROLOGY...EBW
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 PM EDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 521 AM EDT TUE AUG 11 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE
ROCKIES/WRN PLAINS AND A TROF OVER ERN NAMERICA...RESULTING IN NNW
FLOW OVER THE UPPER GREAT LAKES EARLY THIS MORNING. UPSTREAM IN NRN
ONTARIO...SATELLITE IMAGERY AND SFC OBS SHOW LOW CLOUDS STEADILY
MOVING S AND NOW SPREADING OUT OVER FAR NRN LAKE SUPERIOR. THESE
CLOUDS WILL BE THE MAIN FCST ISSUE FOR TODAY. TO THE NW...FOCUSED
WAA REGIME IN MANITOBA IS PRODUCING SHRA/TSTMS EARLY THIS MORNING. A
SIMILAR SETUP MAY OCCUR LATE TONIGHT IN NRN ONTARIO/FAR NE MN AND
WRN LAKE SUPERIOR.
SATELLITE TRENDS AND GOOD AGREEMENT AMONG MODELS POINT TO A RAPID
INCREASE IN LOWER CLOUDS OVER NRN UPPER MI DURING THE NEXT SEVERAL
HRS. WITH OBS VERY SPARSE OVER NRN ONTARIO...TOUGH TO GAUGE HOW LOW
THE CLOUDS WILL BE AND WHETHER THERE MAY BE A RISK OF -DZ. THE ONLY
OB REPORTING CLOUDS IS AT GERALDTON...AND THE CIG THERE HAS BEEN
ABOVE 2KFT...NOT REALLY SUPPORTIVE OF -DZ. HOWEVER...THERE WAS ONE
OB THAT DID INDICATE -DZ. INITIALLY...PLANNED TO DROP PATCHY -DZ
MENTION OVER NCNTRL UPPER MI. HOWEVER...GIVEN THE ONE OB OF -DZ AND
THE POTENTIAL FOR THE WARMER WATERS OF SCNTRL LAKE SUPERIOR TO
FURTHER AID LOW CLOUD DEVELOPMENT IN FAVORABLE UPSLOPE FLOW...OPTED
TO RETAIN MENTION. 850MB THERMAL TROUGH OVER THE AREA TODAY SHOULD
ALLOW PLENTY OF STRATUS AND STRATOCU TO PERSIST WELL INTO THE AFTN
OVER MOST OF THE FCST AREA BEFORE STEADY CLEARING FROM THE W AND NW.
NNW WINDS GUSTING TO AROUND 25 MPH WILL BE AN ISSUE FOR MARINE
INTERESTS...ESPECIALLY ON LAKE SUPERIOR TO THE E OF THE HURON
ISLANDS AND ON NRN LAKE MICHIGAN. THE BREEZY NNW WINDS WILL MEAN
COOLEST CONDITIONS ALONG LAKE SUPERIOR OVER THE E WHERE LAKESIDE
TEMPS WILL BE IN THE LOW/MID 60S DURING THE DAY. MAX TEMPS IN THE
LOW/MID 70S ARE EXPECTED WELL INLAND...WARMEST FAR SCNTRL.
SFC HIGH PRES RIDGE MOVES OVER THE AREA TONIGHT...RESULTING IN
LIGHT/CALM WIND. WITH CLEAR SKIES FOR MUCH OF THE NIGHT...FAVORED
THE LOWER END OF AVBL GUIDANCE. INLAND FROM LAKE SUPERIOR...MANY
LOCATIONS SHOULD FALL TO THE 40S FOR MINS...WITH TRADITIONAL COLD
SPOTS TUMBLING TO AS LOW AS THE LWR 40S. LATE TONIGHT...THE SAME
FOCUSED WAA LEADING TO CONVECTION IN MANITOBA EARLY THIS MORNING
WILL BE POSITIONED IN NRN ONTARIO/FAR NE MN/WRN LAKE SUPERIOR. ALL
MODEL GUIDANCE POINT TOWARD REDEVELOPMENT OF CONVECTION IN THAT AREA
MOSTLY AFTER 06Z. WILL MAINTAIN SCHC POPS FOR SHRA/TSRA OVER NW LAKE
SUPERIOR INCLUDING ISLE ROYALE AFTER 08Z. WOULDN`T BE SURPRISED IF
LATER FCSTS NEED TO RAISE POPS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 313 AM EDT TUE AUG 11 2015
OTHER THAN SATURDAY-SATURDAY NIGHT...MUCH OF THIS PERIOD WILL BE
DOMINATED BY A 500MB TROUGH OF LOW PRESSURE FROM CANADA.
WE WILL BE RETURNING TO A SUMMER-LIKE PATTERN WITH ABOVE NORMAL
TEMPERATURES. NORMAL HIGHS ARE IN THE MID TO UPPER 70S. UPPER 70S TO
LOW 80S WILL BE MORE COMMON THROUGH AT LEAST SUNDAY. HOWEVER...EVEN
THROUGH THERE ARE SLIGHT TO SMALL CHANCES OF PRECIP...DRY CONDITIONS
WILL BE MORE LIKELY. EVEN THE LATEST 5-DAY WPC PRECIP GRAPHIC HAS
ONLY 0.10 TO LESS THAN 0.5IN AVERAGE PRECIP THROUGH 00Z SUNDAY.
THE INITIAL 500MB LOW OVER QUEBEC AT 12Z WILL EXTEND A TROUGH ACROSS
MUCH OF THE GREAT LAKES REGION AND EASTERN U.S...WHILE A RIDGE
REMAINS OVER MUCH OF THE CENTRAL PORTIONS OF THE NATION. WHILE THE
RIDGE WILL ATTEMPT TO BUILD OVERHEAD WEDNESDAY...UP IN CENTRAL-N
CANADA THE NEXT WAVE WILL BE NEARING.
WAA WEDNESDAY BEHIND THE EXITING SFC RIDGE WILL ALLOW FOR SHOWERS TO
SHIFT W-E OVER THE CWA DURING THE DAY. EVEN THE NAM HAS COME AROUND
TO AT LEAST A FEW HUNDREDTHS OF PRECIP. STILL NOT EXPECTING MUCH...IN
THE WAY OF PRECIP OR THUNDERSTORMS. 25-35KT WINDS LOOK TO BE JUST
ABOVE THE SFC WEDNESDAY NIGHT...BUT WITH A PRETTY STRONG INVERSION
IN PLACE...DON/T EXPECT MUCH OF THOSE TO GET REALIZED AT THE SFC.
STILL DON/T EXPECT A CALM NIGHT EITHER...WITH WINDS REMAINING 6-
13KTS...STRONGEST OVER W HALF.
THE SFC LOW STILL IN N CANADA WEDNESDAY NIGHT WILL BRING A COLD
FRONT TO THE NW HALF OF MN BY 12Z THURSDAY. THERE IN UNCERTAINTY IN
JUST HOW MUCH AND HOW WIDESPREAD SHOWERS WILL BE THURSDAY WITH THE
PASSAGE OF THE COLD FRONT...WHICH WILL MOVE TO THE SE OF THE CWA
SHORTLY AFTER 06Z FRIDAY. THE MAIN SHORTWAVE ENERGY WILL SWING
ACROSS ONTARIO...JUST TO OUR N. THE SOUNDING OFF THE NAM LOOK PRETTY
DRY...WITH EVEN LIMITED CLOUD COVER.
WITH THE COLD FRONT JUST TO OUR S FRIDAY...S CENTRAL UPPER MI COULD
STILL BE ABLE TO GET A SLIGHT CHANCE OF SHOWERS/TSTORMS.
OTHERWISE...DRY HIGH PRESSURE OVER THE N PLAINS AND S CENTRAL CANADA
THURSDAY NIGHT WILL BUILD ACROSS THE UPPER GREAT LAKES THROUGH
SATURDAY MORNING.
THE NEXT CANADIAN LOW AROUND SASKATCHEWAN SATURDAY MORNING WILL
SHIFT ACROSS ONTARIO/HUDSON BAY BY 12Z SUNDAY...AND DRAG THE NEXT
COLD FRONT ACROSS THE UPPER GREAT LAKES SUNDAY OR SUNDAY NIGHT.
TIMING IS A CONCERN...SO WILL CONTINUE TO GO WITH A GENERAL BLENDED
SOLUTION FOR SUNDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 129 PM EDT TUE AUG 11 2015
MVFR CIGS WILL BE MOVING OUT THIS AFTERNOON AS DRIER AIR AND MIXING
MOVE IN AT ALL SITES. VFR CONDITIONS WILL CONTINUE THEN AT ALL SITES
THROUGH THE FORECAST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EDT TUE AUG 11 2015
WITH SFC HIGH PRES RIDGE APPROACHING FROM THE W...NNW WINDS WILL BE
FAIRLY BRISK OVER ERN LAKE SUPERIOR TODAY...WITH GUSTS FREQUENTLY
AROUND 20KT. OVER WRN LAKE SUPERIOR...WINDS WILL BE LIGHTER...
ESPECIALLY IN THE AFTN AS MESO HIGH PRES DEVELOPS OVER THE WRN LAKE.
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TONIGHT/WED
MORNING. WINDS WILL THEN INCREASE UP TO 20 KTS OUT OF THE SW WED
AFTN OVER WRN LAKE SUPERIOR AS THE HIGH PRES RIDGE DRIFTS E. THESE
SW WINDS OF 10-20KT WILL CONTINUE INTO THU AHEAD OF COLD FRONT
APPROACHING FROM THE NW. DEPENDING HOW MUCH THE PRES GRADIENT
TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF GUSTS TO INCREASE
TO THE 20-30KT RANGE...ESPECIALLY AT THE HIGH OBS PLATFORMS. THE
STRONGEST GUSTS WOULD OCCUR OVER WRN LAKE SUPERIOR. WINDS WILL
DIMINISH AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON
FRI AS HIGH PRES BUILDS INTO THE UPPER LAKES. THESE LIGHTER WINDS
WILL LINGER INTO AT LEAST SAT MORNING BEFORE WINDS BEGIN TO INCREASE
AGAIN AHEAD OF THE NEXT APPROACHING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
735 AM EDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 521 AM EDT TUE AUG 11 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE
ROCKIES/WRN PLAINS AND A TROF OVER ERN NAMERICA...RESULTING IN NNW
FLOW OVER THE UPPER GREAT LAKES EARLY THIS MORNING. UPSTREAM IN NRN
ONTARIO...SATELLITE IMAGERY AND SFC OBS SHOW LOW CLOUDS STEADILY
MOVING S AND NOW SPREADING OUT OVER FAR NRN LAKE SUPERIOR. THESE
CLOUDS WILL BE THE MAIN FCST ISSUE FOR TODAY. TO THE NW...FOCUSED
WAA REGIME IN MANITOBA IS PRODUCING SHRA/TSTMS EARLY THIS MORNING. A
SIMILAR SETUP MAY OCCUR LATE TONIGHT IN NRN ONTARIO/FAR NE MN AND
WRN LAKE SUPERIOR.
SATELLITE TRENDS AND GOOD AGREEMENT AMONG MODELS POINT TO A RAPID
INCREASE IN LOWER CLOUDS OVER NRN UPPER MI DURING THE NEXT SEVERAL
HRS. WITH OBS VERY SPARSE OVER NRN ONTARIO...TOUGH TO GAUGE HOW LOW
THE CLOUDS WILL BE AND WHETHER THERE MAY BE A RISK OF -DZ. THE ONLY
OB REPORTING CLOUDS IS AT GERALDTON...AND THE CIG THERE HAS BEEN
ABOVE 2KFT...NOT REALLY SUPPORTIVE OF -DZ. HOWEVER...THERE WAS ONE
OB THAT DID INDICATE -DZ. INITIALLY...PLANNED TO DROP PATCHY -DZ
MENTION OVER NCNTRL UPPER MI. HOWEVER...GIVEN THE ONE OB OF -DZ AND
THE POTENTIAL FOR THE WARMER WATERS OF SCNTRL LAKE SUPERIOR TO
FURTHER AID LOW CLOUD DEVELOPMENT IN FAVORABLE UPSLOPE FLOW...OPTED
TO RETAIN MENTION. 850MB THERMAL TROUGH OVER THE AREA TODAY SHOULD
ALLOW PLENTY OF STRATUS AND STRATOCU TO PERSIST WELL INTO THE AFTN
OVER MOST OF THE FCST AREA BEFORE STEADY CLEARING FROM THE W AND NW.
NNW WINDS GUSTING TO AROUND 25 MPH WILL BE AN ISSUE FOR MARINE
INTERESTS...ESPECIALLY ON LAKE SUPERIOR TO THE E OF THE HURON
ISLANDS AND ON NRN LAKE MICHIGAN. THE BREEZY NNW WINDS WILL MEAN
COOLEST CONDITIONS ALONG LAKE SUPERIOR OVER THE E WHERE LAKESIDE
TEMPS WILL BE IN THE LOW/MID 60S DURING THE DAY. MAX TEMPS IN THE
LOW/MID 70S ARE EXPECTED WELL INLAND...WARMEST FAR SCNTRL.
SFC HIGH PRES RIDGE MOVES OVER THE AREA TONIGHT...RESULTING IN
LIGHT/CALM WIND. WITH CLEAR SKIES FOR MUCH OF THE NIGHT...FAVORED
THE LOWER END OF AVBL GUIDANCE. INLAND FROM LAKE SUPERIOR...MANY
LOCATIONS SHOULD FALL TO THE 40S FOR MINS...WITH TRADITIONAL COLD
SPOTS TUMBLING TO AS LOW AS THE LWR 40S. LATE TONIGHT...THE SAME
FOCUSED WAA LEADING TO CONVECTION IN MANITOBA EARLY THIS MORNING
WILL BE POSITIONED IN NRN ONTARIO/FAR NE MN/WRN LAKE SUPERIOR. ALL
MODEL GUIDANCE POINT TOWARD REDEVELOPMENT OF CONVECTION IN THAT AREA
MOSTLY AFTER 06Z. WILL MAINTAIN SCHC POPS FOR SHRA/TSRA OVER NW LAKE
SUPERIOR INCLUDING ISLE ROYALE AFTER 08Z. WOULDN`T BE SURPRISED IF
LATER FCSTS NEED TO RAISE POPS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 313 AM EDT TUE AUG 11 2015
OTHER THAN SATURDAY-SATURDAY NIGHT...MUCH OF THIS PERIOD WILL BE
DOMINATED BY A 500MB TROUGH OF LOW PRESSURE FROM CANADA.
WE WILL BE RETURNING TO A SUMMER-LIKE PATTERN WITH ABOVE NORMAL
TEMPERATURES. NORMAL HIGHS ARE IN THE MID TO UPPER 70S. UPPER 70S TO
LOW 80S WILL BE MORE COMMON THROUGH AT LEAST SUNDAY. HOWEVER...EVEN
THROUGH THERE ARE SLIGHT TO SMALL CHANCES OF PRECIP...DRY CONDITIONS
WILL BE MORE LIKELY. EVEN THE LATEST 5-DAY WPC PRECIP GRAPHIC HAS
ONLY 0.10 TO LESS THAN 0.5IN AVERAGE PRECIP THROUGH 00Z SUNDAY.
THE INITIAL 500MB LOW OVER QUEBEC AT 12Z WILL EXTEND A TROUGH ACROSS
MUCH OF THE GREAT LAKES REGION AND EASTERN U.S...WHILE A RIDGE
REMAINS OVER MUCH OF THE CENTRAL PORTIONS OF THE NATION. WHILE THE
RIDGE WILL ATTEMPT TO BUILD OVERHEAD WEDNESDAY...UP IN CENTRAL-N
CANADA THE NEXT WAVE WILL BE NEARING.
WAA WEDNESDAY BEHIND THE EXITING SFC RIDGE WILL ALLOW FOR SHOWERS TO
SHIFT W-E OVER THE CWA DURING THE DAY. EVEN THE NAM HAS COME AROUND
TO AT LEAST A FEW HUNDREDTHS OF PRECIP. STILL NOT EXPECTING MUCH...IN
THE WAY OF PRECIP OR THUNDERSTORMS. 25-35KT WINDS LOOK TO BE JUST
ABOVE THE SFC WEDNESDAY NIGHT...BUT WITH A PRETTY STRONG INVERSION
IN PLACE...DON/T EXPECT MUCH OF THOSE TO GET REALIZED AT THE SFC.
STILL DON/T EXPECT A CALM NIGHT EITHER...WITH WINDS REMAINING 6-
13KTS...STRONGEST OVER W HALF.
THE SFC LOW STILL IN N CANADA WEDNESDAY NIGHT WILL BRING A COLD
FRONT TO THE NW HALF OF MN BY 12Z THURSDAY. THERE IN UNCERTAINTY IN
JUST HOW MUCH AND HOW WIDESPREAD SHOWERS WILL BE THURSDAY WITH THE
PASSAGE OF THE COLD FRONT...WHICH WILL MOVE TO THE SE OF THE CWA
SHORTLY AFTER 06Z FRIDAY. THE MAIN SHORTWAVE ENERGY WILL SWING
ACROSS ONTARIO...JUST TO OUR N. THE SOUNDING OFF THE NAM LOOK PRETTY
DRY...WITH EVEN LIMITED CLOUD COVER.
WITH THE COLD FRONT JUST TO OUR S FRIDAY...S CENTRAL UPPER MI COULD
STILL BE ABLE TO GET A SLIGHT CHANCE OF SHOWERS/TSTORMS.
OTHERWISE...DRY HIGH PRESSURE OVER THE N PLAINS AND S CENTRAL CANADA
THURSDAY NIGHT WILL BUILD ACROSS THE UPPER GREAT LAKES THROUGH
SATURDAY MORNING.
THE NEXT CANADIAN LOW AROUND SASKATCHEWAN SATURDAY MORNING WILL
SHIFT ACROSS ONTARIO/HUDSON BAY BY 12Z SUNDAY...AND DRAG THE NEXT
COLD FRONT ACROSS THE UPPER GREAT LAKES SUNDAY OR SUNDAY NIGHT.
TIMING IS A CONCERN...SO WILL CONTINUE TO GO WITH A GENERAL BLENDED
SOLUTION FOR SUNDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 734 AM EDT TUE AUG 11 2015
MASS OF LOWER CLOUDS IS DROPPING S ACROSS LAKE SUPERIOR AND WILL
AFFECT KSAW MOST SIGNIFICANTLY. AT KSAW...EXPECT LOWER MVFR CIGS TO
DEVELOP IN THE NEXT COUPLE OF HRS. NOT OUT OF THE QUESTION THAT
THERE COULD BE A PERIOD OF IFR LATE THIS MORNING. KCMX WILL BE ON
THE WRN EDGE OF THE MORE SUBSTANTIAL LOW-LEVEL MOISTURE...AND AT
THIS POINT...IT DOES NOT APPEAR THAT CIGS WILL DROP TO MVFR. KIWD
WILL REMAIN VFR. THE CLOUDS WILL SCATTER AND CLEAR OUT FROM NW TO SE
DURING THE AFTN...LEAVING VFR CONDITIONS TO PREVAIL AT ALL TERMINALS
TONIGHT. WINDS WILL BECOME GUSTY TODAY...ESPECIALLY AT KSAW WHERE N
WINDS WILL GUST TO AROUND 20KT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EDT TUE AUG 11 2015
WITH SFC HIGH PRES RIDGE APPROACHING FROM THE W...NNW WINDS WILL BE
FAIRLY BRISK OVER ERN LAKE SUPERIOR TODAY...WITH GUSTS FREQUENTLY
AROUND 20KT. OVER WRN LAKE SUPERIOR...WINDS WILL BE LIGHTER...
ESPECIALLY IN THE AFTN AS MESO HIGH PRES DEVELOPS OVER THE WRN LAKE.
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TONIGHT/WED
MORNING. WINDS WILL THEN INCREASE UP TO 20 KTS OUT OF THE SW WED
AFTN OVER WRN LAKE SUPERIOR AS THE HIGH PRES RIDGE DRIFTS E. THESE
SW WINDS OF 10-20KT WILL CONTINUE INTO THU AHEAD OF COLD FRONT
APPROACHING FROM THE NW. DEPENDING HOW MUCH THE PRES GRADIENT
TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF GUSTS TO INCREASE
TO THE 20-30KT RANGE...ESPECIALLY AT THE HIGH OBS PLATFORMS. THE
STRONGEST GUSTS WOULD OCCUR OVER WRN LAKE SUPERIOR. WINDS WILL
DIMINISH AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON
FRI AS HIGH PRES BUILDS INTO THE UPPER LAKES. THESE LIGHTER WINDS
WILL LINGER INTO AT LEAST SAT MORNING BEFORE WINDS BEGIN TO INCREASE
AGAIN AHEAD OF THE NEXT APPROACHING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
521 AM EDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 521 AM EDT TUE AUG 11 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE
ROCKIES/WRN PLAINS AND A TROF OVER ERN NAMERICA...RESULTING IN NNW
FLOW OVER THE UPPER GREAT LAKES EARLY THIS MORNING. UPSTREAM IN NRN
ONTARIO...SATELLITE IMAGERY AND SFC OBS SHOW LOW CLOUDS STEADILY
MOVING S AND NOW SPREADING OUT OVER FAR NRN LAKE SUPERIOR. THESE
CLOUDS WILL BE THE MAIN FCST ISSUE FOR TODAY. TO THE NW...FOCUSED
WAA REGIME IN MANITOBA IS PRODUCING SHRA/TSTMS EARLY THIS MORNING. A
SIMILAR SETUP MAY OCCUR LATE TONIGHT IN NRN ONTARIO/FAR NE MN AND
WRN LAKE SUPERIOR.
SATELLITE TRENDS AND GOOD AGREEMENT AMONG MODELS POINT TO A RAPID
INCREASE IN LOWER CLOUDS OVER NRN UPPER MI DURING THE NEXT SEVERAL
HRS. WITH OBS VERY SPARSE OVER NRN ONTARIO...TOUGH TO GAUGE HOW LOW
THE CLOUDS WILL BE AND WHETHER THERE MAY BE A RISK OF -DZ. THE ONLY
OB REPORTING CLOUDS IS AT GERALDTON...AND THE CIG THERE HAS BEEN
ABOVE 2KFT...NOT REALLY SUPPORTIVE OF -DZ. HOWEVER...THERE WAS ONE
OB THAT DID INDICATE -DZ. INITIALLY...PLANNED TO DROP PATCHY -DZ
MENTION OVER NCNTRL UPPER MI. HOWEVER...GIVEN THE ONE OB OF -DZ AND
THE POTENTIAL FOR THE WARMER WATERS OF SCNTRL LAKE SUPERIOR TO
FURTHER AID LOW CLOUD DEVELOPMENT IN FAVORABLE UPSLOPE FLOW...OPTED
TO RETAIN MENTION. 850MB THERMAL TROUGH OVER THE AREA TODAY SHOULD
ALLOW PLENTY OF STRATUS AND STRATOCU TO PERSIST WELL INTO THE AFTN
OVER MOST OF THE FCST AREA BEFORE STEADY CLEARING FROM THE W AND NW.
NNW WINDS GUSTING TO AROUND 25 MPH WILL BE AN ISSUE FOR MARINE
INTERESTS...ESPECIALLY ON LAKE SUPERIOR TO THE E OF THE HURON
ISLANDS AND ON NRN LAKE MICHIGAN. THE BREEZY NNW WINDS WILL MEAN
COOLEST CONDITIONS ALONG LAKE SUPERIOR OVER THE E WHERE LAKESIDE
TEMPS WILL BE IN THE LOW/MID 60S DURING THE DAY. MAX TEMPS IN THE
LOW/MID 70S ARE EXPECTED WELL INLAND...WARMEST FAR SCNTRL.
SFC HIGH PRES RIDGE MOVES OVER THE AREA TONIGHT...RESULTING IN
LIGHT/CALM WIND. WITH CLEAR SKIES FOR MUCH OF THE NIGHT...FAVORED
THE LOWER END OF AVBL GUIDANCE. INLAND FROM LAKE SUPERIOR...MANY
LOCATIONS SHOULD FALL TO THE 40S FOR MINS...WITH TRADITIONAL COLD
SPOTS TUMBLING TO AS LOW AS THE LWR 40S. LATE TONIGHT...THE SAME
FOCUSED WAA LEADING TO CONVECTION IN MANITOBA EARLY THIS MORNING
WILL BE POSITIONED IN NRN ONTARIO/FAR NE MN/WRN LAKE SUPERIOR. ALL
MODEL GUIDANCE POINT TOWARD REDEVELOPMENT OF CONVECTION IN THAT AREA
MOSTLY AFTER 06Z. WILL MAINTAIN SCHC POPS FOR SHRA/TSRA OVER NW LAKE
SUPERIOR INCLUDING ISLE ROYALE AFTER 08Z. WOULDN`T BE SURPRISED IF
LATER FCSTS NEED TO RAISE POPS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 313 AM EDT TUE AUG 11 2015
OTHER THAN SATURDAY-SATURDAY NIGHT...MUCH OF THIS PERIOD WILL BE
DOMINATED BY A 500MB TROUGH OF LOW PRESSURE FROM CANADA.
WE WILL BE RETURNING TO A SUMMER-LIKE PATTERN WITH ABOVE NORMAL
TEMPERATURES. NORMAL HIGHS ARE IN THE MID TO UPPER 70S. UPPER 70S TO
LOW 80S WILL BE MORE COMMON THROUGH AT LEAST SUNDAY. HOWEVER...EVEN
THROUGH THERE ARE SLIGHT TO SMALL CHANCES OF PRECIP...DRY CONDITIONS
WILL BE MORE LIKELY. EVEN THE LATEST 5-DAY WPC PRECIP GRAPHIC HAS
ONLY 0.10 TO LESS THAN 0.5IN AVERAGE PRECIP THROUGH 00Z SUNDAY.
THE INITIAL 500MB LOW OVER QUEBEC AT 12Z WILL EXTEND A TROUGH ACROSS
MUCH OF THE GREAT LAKES REGION AND EASTERN U.S...WHILE A RIDGE
REMAINS OVER MUCH OF THE CENTRAL PORTIONS OF THE NATION. WHILE THE
RIDGE WILL ATTEMPT TO BUILD OVERHEAD WEDNESDAY...UP IN CENTRAL-N
CANADA THE NEXT WAVE WILL BE NEARING.
WAA WEDNESDAY BEHIND THE EXITING SFC RIDGE WILL ALLOW FOR SHOWERS TO
SHIFT W-E OVER THE CWA DURING THE DAY. EVEN THE NAM HAS COME AROUND
TO AT LEAST A FEW HUNDREDTHS OF PRECIP. STILL NOT EXPECTING MUCH...IN
THE WAY OF PRECIP OR THUNDERSTORMS. 25-35KT WINDS LOOK TO BE JUST
ABOVE THE SFC WEDNESDAY NIGHT...BUT WITH A PRETTY STRONG INVERSION
IN PLACE...DON/T EXPECT MUCH OF THOSE TO GET REALIZED AT THE SFC.
STILL DON/T EXPECT A CALM NIGHT EITHER...WITH WINDS REMAINING 6-
13KTS...STRONGEST OVER W HALF.
THE SFC LOW STILL IN N CANADA WEDNESDAY NIGHT WILL BRING A COLD
FRONT TO THE NW HALF OF MN BY 12Z THURSDAY. THERE IN UNCERTAINTY IN
JUST HOW MUCH AND HOW WIDESPREAD SHOWERS WILL BE THURSDAY WITH THE
PASSAGE OF THE COLD FRONT...WHICH WILL MOVE TO THE SE OF THE CWA
SHORTLY AFTER 06Z FRIDAY. THE MAIN SHORTWAVE ENERGY WILL SWING
ACROSS ONTARIO...JUST TO OUR N. THE SOUNDING OFF THE NAM LOOK PRETTY
DRY...WITH EVEN LIMITED CLOUD COVER.
WITH THE COLD FRONT JUST TO OUR S FRIDAY...S CENTRAL UPPER MI COULD
STILL BE ABLE TO GET A SLIGHT CHANCE OF SHOWERS/TSTORMS.
OTHERWISE...DRY HIGH PRESSURE OVER THE N PLAINS AND S CENTRAL CANADA
THURSDAY NIGHT WILL BUILD ACROSS THE UPPER GREAT LAKES THROUGH
SATURDAY MORNING.
THE NEXT CANADIAN LOW AROUND SASKATCHEWAN SATURDAY MORNING WILL
SHIFT ACROSS ONTARIO/HUDSON BAY BY 12Z SUNDAY...AND DRAG THE NEXT
COLD FRONT ACROSS THE UPPER GREAT LAKES SUNDAY OR SUNDAY NIGHT.
TIMING IS A CONCERN...SO WILL CONTINUE TO GO WITH A GENERAL BLENDED
SOLUTION FOR SUNDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 137 AM EDT TUE AUG 11 2015
VFR CONDITIONS ARE EXPECTED THROUGH TAF PERIOD AT KIWD AND KCMX. SCT
MID CLOUDS WILL AFFECT BOTH SITES AT TIMES. AT KSAW...VFR CONDITIONS
SHOULD PREVAIL UNTIL LATE IN THE NIGHT WHEN LOW CLOUDS DROP ACROSS
LAKE SUPERIOR AND MOVE INTO NORTHERN UPPER MICHIGAN ON NORTH WINDS.
CIGS SHOULD SETTLE INTO THE LOW MVFR RANGE AROUND SUNRISE...WITH
SOME POTENTIAL OF IFR CIGS. EXPECT ENOUGH DRYING BY AFTERNOON FOR
CIGS TO LIFT TO VFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EDT TUE AUG 11 2015
WITH SFC HIGH PRES RIDGE APPROACHING FROM THE W...NNW WINDS WILL BE
FAIRLY BRISK OVER ERN LAKE SUPERIOR TODAY...WITH GUSTS FREQUENTLY
AROUND 20KT. OVER WRN LAKE SUPERIOR...WINDS WILL BE LIGHTER...
ESPECIALLY IN THE AFTN AS MESO HIGH PRES DEVELOPS OVER THE WRN LAKE.
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TONIGHT/WED
MORNING. WINDS WILL THEN INCREASE UP TO 20 KTS OUT OF THE SW WED
AFTN OVER WRN LAKE SUPERIOR AS THE HIGH PRES RIDGE DRIFTS E. THESE
SW WINDS OF 10-20KT WILL CONTINUE INTO THU AHEAD OF COLD FRONT
APPROACHING FROM THE NW. DEPENDING HOW MUCH THE PRES GRADIENT
TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF GUSTS TO INCREASE
TO THE 20-30KT RANGE...ESPECIALLY AT THE HIGH OBS PLATFORMS. THE
STRONGEST GUSTS WOULD OCCUR OVER WRN LAKE SUPERIOR. WINDS WILL
DIMINISH AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON
FRI AS HIGH PRES BUILDS INTO THE UPPER LAKES. THESE LIGHTER WINDS
WILL LINGER INTO AT LEAST SAT MORNING BEFORE WINDS BEGIN TO INCREASE
AGAIN AHEAD OF THE NEXT APPROACHING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
313 AM EDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 355 PM EDT MON AUG 10 2015
BEEN A SLOW EAST-SOUTHEAST PUSH TO THE COLD FRONT OVER EASTERN CWA
TODAY. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE FIRED ALONG
AND AHEAD OF FRONT MOST OF THE DAY...ONLY CLEARING KESC/KISQ/KERY
WITHIN LAST COUPLE HOURS. MOST LIGHTNING WITH ANY CELLS HAS BEEN
OVER BAY OF GREEN BAY NEAR SHORELINE OF MENOMINEE COUNTY. SCATTERED
CU LEFT IN WAKE OF FRONT ELSEWHERE...THOUGH STRATUS AND FOG IS OVER
EASTERN LK SUPERIOR AND ADJACENT SHORELINE FROM HARVEY TO MUNISING
TO GRAND MARAIS AND WHITEFISH POINT. VISIBLE SATELLITE AND MODEL
GUIDANCE POINT TO FOG SHIRNKING IN COVERAGE THROUGH THE EVENING AND
EVENTUALLY DISIPPATING OVERNIGHT. DENSE FOG ADVISORY FOR EASTERN LK
SUPERIOR GOES UNTIL 11 PM THIS EVENING. EVENING SHIFT CAN ALTER THAT
HEADLINE TIMING BASED ON OBSERVATION TRENDS.
LOOKING UPSTREAM OVER NORTHERN ONTARIO...A SHORTWAVE IS DROPPING
TOWARD THUNDER BAY AND ISLE ROYALE. ENVIRONMENT CANADA/NWS DLH/NWS
MQT COMPOSITE RADAR LOOP SHOWS NUMEROUS SHRA AND SOME TSRA SPILLING
TOWARD ISLE ROYALE...BUT GREATER COVERAGE IS STAYING UPSTREAM. WILL
CARRY SCATTERED SHOWERS AND THUNDERSTORMS OVER ISLE ROYALE INTO THE
EVENING. NAM AND GEM-REGIONAL AND THE HRRR INDICATE REMNANTS OF THE
UPSTREAM SHOWERS MAY REACH WEST AND NORTHWEST CWA THIS EVENING. AT
THE LEAST...WILL SEE SCT-BKN MID CLOUDS. REST OF OVERNIGHT APPEARS
QUIET. GRADIENT NORTH TO NORTHWEST WINDS BETWEEN HIGH PRESSURE FM
NORTHERN MANITOBA TO THE NORTHERN PLAINS AND LOW OVER JAMES BAY
SHOULD RESTRICT IDEAL RADIATIONAL COOLING AND SIGNIFICANT FOG
POTENTIAL. COULD SEE PARTCHY FOG THOUGH WHERE THERE WAS SOME RAIN
TODAY.
MAIN ISSUE ON TUESDAY WILL BE LOW CLOUDS. CONSENSUS OF SHORT RANGE
MODELS TRENDING TOWARD GREATER CLOUD COVER AND BASED ON WIDESPREAD
STRATUS OVER NORTHERN ONTARIO THIS AFTN THAT IS FORECAST TO SETTLE
SOUTHWARD INTO TUESDAY...THE TREND MAKES A LOT OF SENSE. BUMPED UP
SKY COVER AND ALSO KEPT SMALL MENTION OF DRIZZLE MAINLY IN THE
MORNING FOR NCNTRL UPR MICHIGAN WITH NORTHERLY UPSLOPE FLOW. GUSTY
NORTH-NORTHWEST WINDS...POSSIBLY UP TO 25 MPH...WILL ALSO CAUSE SOME
IMPACT...MAINLY TO MARINE INTERESTS ALONG LK SUPERIOR SHORE TO EAST
OF BIG BAY AND MARQUETTE AND ALSO ON BAY OF GREEN BAY AND NORTHERN
LK MICHIGAN. THERMAL TROUGH AT H85 OVER THE AREA SHOULD ALLOW
STRATUS AND STRATOCU CLOUDS TO PERSIST THROUGH MUCH OF THE DAY.
TEMPS COOLEST NEAR LK SUPERIOR EAST OF MARQUETTE WITH LOW 60S.
TEMPS OVER SCNTRL CWA COULD STILL REACH MID 70S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 313 AM EDT TUE AUG 11 2015
OTHER THAN SATURDAY-SATURDAY NIGHT...MUCH OF THIS PERIOD WILL BE
DOMINATED BY A 500MB TROUGH OF LOW PRESSURE FROM CANADA.
WE WILL BE RETURNING TO A SUMMER-LIKE PATTERN WITH ABOVE NORMAL
TEMPERATURES. NORMAL HIGHS ARE IN THE MID TO UPPER 70S. UPPER 70S TO
LOW 80S WILL BE MORE COMMON THROUGH AT LEAST SUNDAY. HOWEVER...EVEN
THROUGH THERE ARE SLIGHT TO SMALL CHANCES OF PRECIP...DRY CONDITIONS
WILL BE MORE LIKELY. EVEN THE LATEST 5-DAY WPC PRECIP GRAPHIC HAS
ONLY 0.10 TO LESS THAN 0.5IN AVERAGE PRECIP THROUGH 00Z SUNDAY.
THE INITIAL 500MB LOW OVER QUEBEC AT 12Z WILL EXTEND A TROUGH ACROSS
MUCH OF THE GREAT LAKES REGION AND EASTERN U.S...WHILE A RIDGE
REMAINS OVER MUCH OF THE CENTRAL PORTIONS OF THE NATION. WHILE THE
RIDGE WILL ATTEMPT TO BUILD OVERHEAD WEDNESDAY...UP IN CENTRAL-N
CANADA THE NEXT WAVE WILL BE NEARING.
WAA WEDNESDAY BEHIND THE EXITING SFC RIDGE WILL ALLOW FOR SHOWERS TO
SHIFT W-E OVER THE CWA DURING THE DAY. EVEN THE NAM HAS COME AROUND
TO AT LEAST A FEW HUNDREDTHS OF PRECIP. STILL NOT EXPECTING MUCH...IN
THE WAY OF PRECIP OR THUNDERSTORMS. 25-35KT WINDS LOOK TO BE JUST
ABOVE THE SFC WEDNESDAY NIGHT...BUT WITH A PRETTY STRONG INVERSION
IN PLACE...DON/T EXPECT MUCH OF THOSE TO GET REALIZED AT THE SFC.
STILL DON/T EXPECT A CALM NIGHT EITHER...WITH WINDS REMAINING 6-
13KTS...STRONGEST OVER W HALF.
THE SFC LOW STILL IN N CANADA WEDNESDAY NIGHT WILL BRING A COLD
FRONT TO THE NW HALF OF MN BY 12Z THURSDAY. THERE IN UNCERTAINTY IN
JUST HOW MUCH AND HOW WIDESPREAD SHOWERS WILL BE THURSDAY WITH THE
PASSAGE OF THE COLD FRONT...WHICH WILL MOVE TO THE SE OF THE CWA
SHORTLY AFTER 06Z FRIDAY. THE MAIN SHORTWAVE ENERGY WILL SWING
ACROSS ONTARIO...JUST TO OUR N. THE SOUNDING OFF THE NAM LOOK PRETTY
DRY...WITH EVEN LIMITED CLOUD COVER.
WITH THE COLD FRONT JUST TO OUR S FRIDAY...S CENTRAL UPPER MI COULD
STILL BE ABLE TO GET A SLIGHT CHANCE OF SHOWERS/TSTORMS.
OTHERWISE...DRY HIGH PRESSURE OVER THE N PLAINS AND S CENTRAL CANADA
THURSDAY NIGHT WILL BUILD ACROSS THE UPPER GREAT LAKES THROUGH
SATURDAY MORNING.
THE NEXT CANADIAN LOW AROUND SASKATCHEWAN SATURDAY MORNING WILL
SHIFT ACROSS ONTARIO/HUDSON BAY BY 12Z SUNDAY...AND DRAG THE NEXT
COLD FRONT ACROSS THE UPPER GREAT LAKES SUNDAY OR SUNDAY NIGHT.
TIMING IS A CONCERN...SO WILL CONTINUE TO GO WITH A GENERAL BLENDED
SOLUTION FOR SUNDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 137 AM EDT TUE AUG 11 2015
VFR CONDITIONS ARE EXPECTED THROUGH TAF PERIOD AT KIWD AND KCMX. SCT
MID CLOUDS WILL AFFECT BOTH SITES AT TIMES. AT KSAW...VFR CONDITIONS
SHOULD PREVAIL UNTIL LATE IN THE NIGHT WHEN LOW CLOUDS DROP ACROSS
LAKE SUPERIOR AND MOVE INTO NORTHERN UPPER MICHIGAN ON NORTH WINDS.
CIGS SHOULD SETTLE INTO THE LOW MVFR RANGE AROUND SUNRISE...WITH
SOME POTENTIAL OF IFR CIGS. EXPECT ENOUGH DRYING BY AFTERNOON FOR
CIGS TO LIFT TO VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT MON AUG 10 2015
NW WINDS UP TO 20 KTS ARE EXPECTED THROUGH TUESDAY. STRONGEST PUSH
OF WINDS WILL OCCUR TONIGHT INTO TUESDAY MORNING OVER EAST HALF.
DENSE FOG WILL GRADUALLY DIMINISH BY OVERNIGHT TONIGHT. ARRIVAL OF
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE NIGHT/WED.
WINDS WILL THEN INCREASE UP TO 20 KTS OUT OF THE SW INTO THU AHEAD
OF THE NEXT APPROACHING COLD FRONT. WINDS WILL DIMINISH TO LESS
THAN 15 KTS ON FRI AS HIGH PRESSURE BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KF
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
137 AM EDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 355 PM EDT MON AUG 10 2015
BEEN A SLOW EAST-SOUTHEAST PUSH TO THE COLD FRONT OVER EASTERN CWA
TODAY. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE FIRED ALONG
AND AHEAD OF FRONT MOST OF THE DAY...ONLY CLEARING KESC/KISQ/KERY
WITHIN LAST COUPLE HOURS. MOST LIGHTNING WITH ANY CELLS HAS BEEN
OVER BAY OF GREEN BAY NEAR SHORELINE OF MENOMINEE COUNTY. SCATTERED
CU LEFT IN WAKE OF FRONT ELSEWHERE...THOUGH STRATUS AND FOG IS OVER
EASTERN LK SUPERIOR AND ADJACENT SHORELINE FROM HARVEY TO MUNISING
TO GRAND MARAIS AND WHITEFISH POINT. VISIBLE SATELLITE AND MODEL
GUIDANCE POINT TO FOG SHIRNKING IN COVERAGE THROUGH THE EVENING AND
EVENTUALLY DISIPPATING OVERNIGHT. DENSE FOG ADVISORY FOR EASTERN LK
SUPERIOR GOES UNTIL 11 PM THIS EVENING. EVENING SHIFT CAN ALTER THAT
HEADLINE TIMING BASED ON OBSERVATION TRENDS.
LOOKING UPSTREAM OVER NORTHERN ONTARIO...A SHORTWAVE IS DROPPING
TOWARD THUNDER BAY AND ISLE ROYALE. ENVIRONMENT CANADA/NWS DLH/NWS
MQT COMPOSITE RADAR LOOP SHOWS NUMEROUS SHRA AND SOME TSRA SPILLING
TOWARD ISLE ROYALE...BUT GREATER COVERAGE IS STAYING UPSTREAM. WILL
CARRY SCATTERED SHOWERS AND THUNDERSTORMS OVER ISLE ROYALE INTO THE
EVENING. NAM AND GEM-REGIONAL AND THE HRRR INDICATE REMNANTS OF THE
UPSTREAM SHOWERS MAY REACH WEST AND NORTHWEST CWA THIS EVENING. AT
THE LEAST...WILL SEE SCT-BKN MID CLOUDS. REST OF OVERNIGHT APPEARS
QUIET. GRADIENT NORTH TO NORTHWEST WINDS BETWEEN HIGH PRESSURE FM
NORTHERN MANITOBA TO THE NORTHERN PLAINS AND LOW OVER JAMES BAY
SHOULD RESTRICT IDEAL RADIATIONAL COOLING AND SIGNIFICANT FOG
POTENTIAL. COULD SEE PARTCHY FOG THOUGH WHERE THERE WAS SOME RAIN
TODAY.
MAIN ISSUE ON TUESDAY WILL BE LOW CLOUDS. CONSENSUS OF SHORT RANGE
MODELS TRENDING TOWARD GREATER CLOUD COVER AND BASED ON WIDESPREAD
STRATUS OVER NORTHERN ONTARIO THIS AFTN THAT IS FORECAST TO SETTLE
SOUTHWARD INTO TUESDAY...THE TREND MAKES A LOT OF SENSE. BUMPED UP
SKY COVER AND ALSO KEPT SMALL MENTION OF DRIZZLE MAINLY IN THE
MORNING FOR NCNTRL UPR MICHIGAN WITH NORTHERLY UPSLOPE FLOW. GUSTY
NORTH-NORTHWEST WINDS...POSSIBLY UP TO 25 MPH...WILL ALSO CAUSE SOME
IMPACT...MAINLY TO MARINE INTERESTS ALONG LK SUPERIOR SHORE TO EAST
OF BIG BAY AND MARQUETTE AND ALSO ON BAY OF GREEN BAY AND NORTHERN
LK MICHIGAN. THERMAL TROUGH AT H85 OVER THE AREA SHOULD ALLOW
STRATUS AND STRATOCU CLOUDS TO PERSIST THROUGH MUCH OF THE DAY.
TEMPS COOLEST NEAR LK SUPERIOR EAST OF MARQUETTE WITH LOW 60S.
TEMPS OVER SCNTRL CWA COULD STILL REACH MID 70S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 316 PM EDT MON AUG 10 2015
AT THE START OF THE LONG TERM PERIOD THE UPPER GREAT LAKES REGION
WILL BE UNDER NORTHWESTERLY FLOW ALOFT...AS AN UPPER TROUGH WILL BE
LOCATED OVER WESTERN QUEBEC AND AN UPPER RIDGE OVER THE U.S.
ROCKIES AND CANADIAN PRAIRIES. THIS NORTHWESTERLY FLOW ALOFT WILL
PERSIST THROUGH MUCH OF THE LONG TERM PERIOD...AS THE QUEBEC TROUGH
IS RE-ENFORCED BY WAVE THE CURRENTLY OVER SOUTHEAST ALASKA. THAT
WILL LEAD TO A COUPLE OPPORTUNITIES FOR SHOWERS/THUNDERSTORMS BUT
HIGH PRESSURE WILL CONTROL MUCH OF THE LONG TERM FORECAST.
A RIDGE WILL BE OVER THE UPPER GREAT LAKES AT THE START OF THE
PERIOD...FROM A HIGH IN THE CENTRAL MISSISSIPPI VALLEY...WHICH WILL
LEAD TO A MOSTLY CLEAR START TO TUESDAY NIGHT. THAT WILL BE SHORT
LIVED...AS A WEAK SHORTWAVE DIVES SOUTHEAST OUT OF FAR WESTERN
ONTARIO AND ACROSS NORTHWESTERN LAKE SUPERIOR. EXPECT SHOWERS AND
MAYBE A FEW THUNDERSTORMS TO BE ASSOCIATED WITH THIS WAVE...AS
THERE IS DECENT 925-700MB WARM AIR ADVECTION WITH IT. THIS SHOULD
ARRIVE LATE IN THE NIGHT TOWARDS THE KEWEENAW AND THEN SHIFT
SOUTHEAST THROUGH THE CENTRAL U.P. DURING THE DAY ON WEDNESDAY.
MODELS ARE SHOWING ENOUGH OF A SIGNAL IN WITH THE WARM AIR
ADVECTION TO TREND POPS UP TO CHANCES FOR PARTS OF THE AREA ON
WEDNESDAY. WHILE MUCAPE VALUES ARE NOT OVERLY IMPRESSIVE LATE
TUESDAY NIGHT INTO WEDNESDAY...THINK THE STEEPENING LAPSE RATES ON
THE WESTERN EDGE OF THE WARM AIR ADVECTION WOULD SUPPORT THERE
BEING SOME THUNDERSTORMS AND HAVE ADDED A SLIGHT CHANCE OF THUNDER
ALONG THE WESTERN EDGE OF THE POPS.
WHILE THAT WAVE WILL QUICKLY SLIDE TO THE SOUTHEAST...THEN NEXT
WAVE AND ASSOCIATED COLD FRONT (FROM A LOW MOVING THROUGH NORTHERN
ONTARIO) WILL MOVE SOUTHEAST THROUGH THE CWA LATE WEDNESDAY NIGHT
AND THURSDAY. THERE ARE STILL SOME TIMING DIFFERENCES IN THE
MODELS...WITH THEM SPEEDING IT UP SOME FROM PREVIOUS RUNS. THIS
WILL LIKELY PUSH THE FRONT AND A BULK OF THE PRECIPITATION THROUGH
THE AREA ON THURSDAY MORNING AND INTO EARLY THURSDAY AFTERNOON.
WILL SHOW CHANCE POPS MOVING THROUGH THE AREA DURING THAT
PERIOD...WITH THE HIGHEST NEAR THE LAKE MICHIGAN SHORELINE WITH THE
ADDED HELP OF DIURNAL HEATING. WILL HAVE THUNDER CHANCES FOLLOW THE
POPS...AS THERE ARE FAIRLY STEEP LAPSE RATES (7 C/KM OR HIGHER)
ALONG AND AHEAD OF THE FRONT. IF THE FRONT MOVES THROUGH A LITTLE
SLOWER...THERE WOULD BE ENOUGH SHEAR TO SUPPORT STRONGER
THUNDERSTORMS OVER THE SOUTHEASTERN U.P. ON THURSDAY AFTERNOON.
BEHIND THE COLD FRONT...THERE ARE SOME HINTS IN THE MODELS OF A
VERY WEAK SHORTWAVE BRUSHING THE AREA ON THURSDAY
NIGHT...OTHERWISE...HIGH PRESSURE FROM THE CANADIAN PRAIRIES WILL
MOVE SOUTHEAST OVER THE UPPER GREAT LAKES REGION ON FRIDAY AND
REMAIN INTO SATURDAY. THAT SHOULD LEAD TO A NICE COUPLE OF DAYS IN
THE U.P. WITH HIGHS IN THE 70S TO AROUND 80 DEGREES WITH AFTERNOON
LAKE BREEZES. THE HIGH WILL START TO SHIFT TO THE SOUTHEAST ON
SATURDAY NIGHT AS THE UPPER RIDGE AXIS CROSSES THE UPPER GREAT LAKES
REGION. BEHIND THAT UPPER RIDGE...ANOTHER TROUGH WILL MOVE THROUGH
THE AREA FOR LATER SUNDAY AND INTO SUNDAY NIGHT AND WILL SPREAD
CHANCE POPS EAST ACROSS THE AREA FOR THAT TIME FRAME. AT THIS
TIME...MODELS ARE CONSISTENT ON IT QUICKLY SHIFTING EAST AND
LEADING TO A MAINLY DRY MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 137 AM EDT TUE AUG 11 2015
VFR CONDITIONS ARE EXPECTED THROUGH TAF PERIOD AT KIWD AND KCMX. SCT
MID CLOUDS WILL AFFECT BOTH SITES AT TIMES. AT KSAW...VFR CONDITIONS
SHOULD PREVAIL UNTIL LATE IN THE NIGHT WHEN LOW CLOUDS DROP ACROSS
LAKE SUPERIOR AND MOVE INTO NORTHERN UPPER MICHIGAN ON NORTH WINDS.
CIGS SHOULD SETTLE INTO THE LOW MVFR RANGE AROUND SUNRISE...WITH
SOME POTENTIAL OF IFR CIGS. EXPECT ENOUGH DRYING BY AFTERNOON FOR
CIGS TO LIFT TO VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT MON AUG 10 2015
NW WINDS UP TO 20 KTS ARE EXPECTED THROUGH TUESDAY. STRONGEST PUSH
OF WINDS WILL OCCUR TONIGHT INTO TUESDAY MORNING OVER EAST HALF.
DENSE FOG WILL GRADUALLY DIMINISH BY OVERNIGHT TONIGHT. ARRIVAL OF
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE NIGHT/WED.
WINDS WILL THEN INCREASE UP TO 20 KTS OUT OF THE SW INTO THU AHEAD
OF THE NEXT APPROACHING COLD FRONT. WINDS WILL DIMINISH TO LESS
THAN 15 KTS ON FRI AS HIGH PRESSURE BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...SRF
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1218 PM CDT TUE AUG 11 2015
.DISCUSSION...
Issued at 314 AM CDT TUE AUG 11 2015
Slightly below normal temperatures and significantly lower humidity
throughout the region today will allow maximum heat indices to fall
nearly 15 degrees from yesterday`s max values, and will feel like a
brief reprieve from summer after days of sticky conditions. North
northeasterly surface winds will remain sustained at ~10-12 mph
through the day as the pressure gradient tightens in response to
surface high pressure building over north central KS, which will
also promote additional mixing out of low-level moisture on top of
the dry air advection already occurring. Felt that the RAP had the
right idea but was a little overdone in mixing to nearly 750 hPa, so
balanced between the RAP`s and HRRR`s warmer/drier solution with
consensus model solutions to bring highs into the mid 80s in most
locations this afternoon, and dewpoints into the lower 60s.
Upper-level high pressure over the desert southwest will expand and
bulge eastward over the next several days, keeping the forecast area
fully entrenched in northwest to northerly flow aloft through the
work week and into the weekend. At the surface, persistent high
pressure will very gradually drift and build to the southeast,
abating winds and mixing for Wednesday, then eventually allowing
weak southerly flow to return late Thursday or early Friday.
Sunshine should be abundant and precipitation chances nil this week
as the blocking upper high prevents even the most ambitious short-
wave energy from riding the length of the ridge and down into the
region. When the upper high finally begins to retreat southwest and
break down, ridging will edge northeastward into the upper Midwest,
bringing the thermal ridge closer to the forecast area and allowing
temperatures to return to the lower 90s for the weekend. Storm
chances don`t return until very late in the period when upper-level
flow finally flattens to zonal and a shortwave trough slides through
the central Plains, but timing of this feature continues to slow,
and its northern track could limit the possibility of precipitation
in the majority of the CWA.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1209 PM CDT TUE AUG 11 2015
VFR CIGS and VIS are expected through the period as the region is
under dry deep-layer northwesterly flow. The surface winds will
remain light and out of the northeast as well.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...Pietrycha
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
622 AM CDT TUE AUG 11 2015
.DISCUSSION...
Issued at 314 AM CDT TUE AUG 11 2015
Slightly below normal temperatures and significantly lower humidity
throughout the region today will allow maximum heat indices to fall
nearly 15 degrees from yesterday`s max values, and will feel like a
brief reprieve from summer after days of sticky conditions. North
northeasterly surface winds will remain sustained at ~10-12 mph
through the day as the pressure gradient tightens in response to
surface high pressure building over north central KS, which will
also promote additional mixing out of low-level moisture on top of
the dry air advection already occurring. Felt that the RAP had the
right idea but was a little overdone in mixing to nearly 750 hPa, so
balanced between the RAP`s and HRRR`s warmer/drier solution with
consensus model solutions to bring highs into the mid 80s in most
locations this afternoon, and dewpoints into the lower 60s.
Upper-level high pressure over the desert southwest will expand and
bulge eastward over the next several days, keeping the forecast area
fully entrenched in northwest to northerly flow aloft through the
work week and into the weekend. At the surface, persistent high
pressure will very gradually drift and build to the southeast,
abating winds and mixing for Wednesday, then eventually allowing
weak southerly flow to return late Thursday or early Friday.
Sunshine should be abundant and precipitation chances nil this week
as the blocking upper high prevents even the most ambitious short-
wave energy from riding the length of the ridge and down into the
region. When the upper high finally begins to retreat southwest and
break down, ridging will edge northeastward into the upper Midwest,
bringing the thermal ridge closer to the forecast area and allowing
temperatures to return to the lower 90s for the weekend. Storm
chances don`t return until very late in the period when upper-level
flow finally flattens to zonal and a shortwave trough slides through
the central Plains, but timing of this feature continues to slow,
and its northern track could limit the possibility of precipitation
in the majority of the CWA.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday Morning)
Issued at 622 AM CDT TUE AUG 11 2015
VFR conditions and northerly winds will continue at all sites
through the TAF period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...Laflin
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
314 AM CDT TUE AUG 11 2015
.DISCUSSION...
Issued at 314 AM CDT TUE AUG 11 2015
Slightly below normal temperatures and significantly lower humidity
throughout the region today will allow maximum heat indices to fall
nearly 15 degrees from yesterday`s max values, and will feel like a
brief reprieve from summer after days of sticky conditions. North
northeasterly surface winds will remain sustained at ~10-12 mph
through the day as the pressure gradient tightens in response to
surface high pressure building over north central KS, which will
also promote additional mixing out of low-level moisture on top of
the dry air advection already occurring. Felt that the RAP had the
right idea but was a little overdone in mixing to nearly 750 hPa, so
balanced between the RAP`s and HRRR`s warmer/drier solution with
consensus model solutions to bring highs into the mid 80s in most
locations this afternoon, and dewpoints into the lower 60s.
Upper-level high pressure over the desert southwest will expand and
bulge eastward over the next several days, keeping the forecast area
fully entrenched in northwest to northerly flow aloft through the
work week and into the weekend. At the surface, persistent high
pressure will very gradually drift and build to the southeast,
abating winds and mixing for Wednesday, then eventually allowing
weak southerly flow to return late Thursday or early Friday.
Sunshine should be abundant and precipitation chances nil this week
as the blocking upper high prevents even the most ambitious short-
wave energy from riding the length of the ridge and down into the
region. When the upper high finally begins to retreat southwest and
break down, ridging will edge northeastward into the upper Midwest,
bringing the thermal ridge closer to the forecast area and allowing
temperatures to return to the lower 90s for the weekend. Storm
chances don`t return until very late in the period when upper-level
flow finally flattens to zonal and a shortwave trough slides through
the central Plains, but timing of this feature continues to slow,
and its northern track could limit the possibility of precipitation
in the majority of the CWA.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1131 PM CDT MON AUG 10 2015
Dry air continues to move over the region as surface high pressure
settles into place. Overnight fog is still a possibility, though with
new model runs, the outlook is improving slightly. Still think the
terminal sites will see development, but will likely remain shallow
and patchy, with the exception of KSTJ. This should taper off after
sunrise with gradually veering winds and clear sky conditions through
the remainder of the period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...Welsh
AREA FORECAST DISCUSSION
NWS GLASGOW MT
919 PM MDT WED AUG 12 2015
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH FRIDAY...
EVENING UPDATE...
CHANGES FOR THIS EVENING FOCUSED AROUND ROLLING BACK POPS FOR THE
EARLY MORNING HOURS AND SLIGHTLY DURING THIS EVENING. HRRR MODEL
IS PLACING A LITTLE REMAINING QPF ALONG THE NORTHEASTERN SECTIONS
OF THE CWA AND THIS IS FINALLY APPEARING ON RADAR BUT SHOULD
EXIT AROUND MIDNIGHT. WINDS AND SKY WERE ALSO RENEGOTIATED FOR THE
EVENING. GAH
PREVIOUS SHORT TERM DISCUSSION...
THE STRONG UPPER LEVEL RIDGE WILL REMAIN IN PLACE DURING THE SHORT
TERM PERIOD. THIS RIDGE WILL BE ANCHORED BY PERSISTENT HOT
DESERT AIR CENTERED OVER THE FOUR CORNERS REGION. THIS HOT AIR HAS
DRIFTED NORTH INTO NORTHEAST MONTANA AND SOUTHERN AREAS OF THE
PRAIRIE PROVINCES. THIS MEANS THAT WELL ABOVE AVERAGE TEMPERATURES
WILL CONTINUE THROUGH FRIDAY OVER THE ENTIRE FORECAST AREA. GOES
SATELLITE IMAGERY REVEALS A CLOSED UPPER LEVEL LOW DRIFTING ALONG
THE WEST COAST. THIS LOW WILL BEGIN TO LIFT NORTHEAST THROUGH THE
PACIFIC NORTHWEST BEGINNING FRIDAY. SO IT WILL NOT INFLUENCE
CONDITIONS MUCH...EXCEPT TO SEND WEAK FRONTAL BOUNDARIES EAST THAT
MIGHT REACH THE LOCAL AREA BY LATE AFTERNOON. SO FOR NOW MOSTLY
HAVE SLIGHT CHANCE POPS IN THE FRIDAY AFTERNOON GRIDS.
TONIGHT...AN UNDER-CUTTING EMBEDDED SHORT-WAVE LOW RIDES THE
UPPER FLOW... PUSHING MONSOONAL MOISTURE INTO THE AREA TO BRING A
CHANCE FOR THUNDERSTORMS TONIGHT TO THE REGION. ADJUSTED POPS UP
AND SPREAD ACROSS THE CWA.
THURSDAY...WILL BE A DRIER DAY AND JUST AS HOT WITH 700MB
TEMPERATURES RANGING FROM 12C TO 15C DEGREES. UPPER FLOW WILL BE
NORTHWESTERLY TO KEEP THE AREA DRY. EXPECT CONTINUED LIGHT WIND.
FRIDAY...AS THE WESTERN TROUGH BEGINS TO LIFT INTO THE PAC-NW
LOCAL FLOW ALOFT BACKS AROUND TO THE SOUTHWEST AGAIN AND THE
SURFACE FLOW INCREASES TO AROUND 10-15KT...MOSTLY IN THE EAST.
HOWEVER...THERE IS A POTENTIAL FOR WIND TO BE STRONG ENOUGH FOR
AN ADVISORY OVER FORT PECK LAKE AND A FIRE WX HEADLINES DUE TO
LOW RH WITH WIND. SO EXPECT A FINAL HOT DAY WITH SIMILAR 700MB
TEMPERATURES. THUNDERSTORMS COULD DEVELOP AHEAD OF THE FRONT
ASSOCIATED WITH THE WESTERN TROUGH...ALTHOUGH HEAT OF THE AIR-
MASS WILL PROVIDE SOME CAPPING. ANY THUNDERSTORM WOULD HAVE THE
POTENTIAL FOR FIRE STARTS WHICH WOULD ALSO ADD TO FIRE WX
CONCERNS.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
MODELS ARE COMING INTO AGREEMENT WITH A DRY PERIOD LATE SATURDAY
THROUGH MONDAY. ANOTHER CHANCE OF SHOWERS COME ABOUT TUESDAY AS AN
UPPER LOW MOVES IN. TFJ
PREVIOUS DISCUSSION...
SYNOPTIC SET UP... LONG RANGE BEGINS WITH HOT HIGH PRESSURE OVER
THE FOUR CORNERS AND A RIDGE EXTENDING OUT OF IT INTO WYOMING....
EASTERN MONTANA... AND THE DAKOTAS. A LARGE PACIFIC TROUGH EXISTS
OVER THE PACIFIC NORTHWEST. NORTHEAST MONTANA LIES ON THE EDGE OF
THESE TWO POWERFUL FEATURES UNDER UNSTABLE SOUTHWEST FLOW ALOFT.
FRIDAY NIGHT... BEGINS WITH A COLD FRONT BARRELING THROUGH THE
REGION AND CHANCES FOR SHOWERS AND THUNDERSTORMS ELEVATED DURING
THIS TIME AND POSSIBLY ENHANCED BY A PASSING SHORTWAVE.
SATURDAY THROUGH MONDAY... CONDITIONS WILL BE STABLE AS THE
EXITING COOL TROUGH AIR SLOWLY GIVES WAY TO A BUILDING RIDGE TO
THE SOUTHWEST AGAIN. PRECIPITATION SHOULD BE MINIMAL TO ISOLATED
DURING THESE PERIODS.
MONDAY NIGHT ONWARD... MASSIVE MODEL DISAGREEMENT. CONFIDENCE IS
WELL BELOW NORMAL AT THIS TIME AND CHANGES ARE EXPECTED IN FUTURE
MODEL RUNS. CURRENTLY CONDITIONS ARE ZONAL TO NORTHWEST WITH NEAR
CLIMO AVERAGES FOR TEMPS AND POPS. GAH
&&
.AVIATION...
FLIGHT CATEGORY: MAINLY VFR
SYNOPSIS: THERE REMAINS AN OUTSIDE CHANCE FOR NOCTURNAL
THUNDERSTORMS...WHICH COULD BRIEFLY IMPACT ANY OF THE TAF SITES.
OTHERWISE FLYING WEATHER WILL BE GOOD UNDER AN UPPER RIDGE.
CIGS: SCT-BKN MID AND HIGH CLOUDS TONIGHT. MAINLY SCT HIGH CLOUDS
ON THURSDAY.
WIND: MAINLY LIGHT AND VARIABLE OR LIGHT SOUTHEAST THROUGH
TONIGHT. THUNDERSTORM WINDS WILL BE UPWARDS OF 40KTS. GILCHRIST
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1001 AM MDT TUE AUG 11 2015
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
UPDATE...GOING FORECAST IN OVERALL GOOD SHAPE. ONLY TWEAKS WERE
TO TREND UP TEMPS A FEW DEGREES BASED ON THE LATEST MODEL
DATA...AND TO PUSH UP MENTION OF THUNDER AS THE HRRR AND SSEO ARE
FASTER WITH CONVECTIVE DEVELOPMENT ACROSS THE EAST THIS AFTERNOON.
GILCHRIST
PREVIOUS DISCUSSION...UPPER RIDGE WILL PERSIST ACROSS THE HIGH
PLAINS THROUGH THE END OF THE WEEK. THIS WILL RESULT IN VERY HOT
TEMPERATURES FOR THE NEXT FEW DAYS AS 850MB TEMPERATURES APPROACH
30C. THERE IS SOME POTENTIAL FOR ISOLATED THUNDERSTORMS ALONG THE
YELLOWSTONE VALLEY THIS EVENING...WITH ADDITIONAL STORMS MOVING
OFF THE SOUTHWEST MOUNTAINS AND INTO THE PLAINS LATE WEDNESDAY.
EBERT
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
THE EXTENDED PERIOD GETS UNDERWAY THURSDAY NIGHT INTO FRIDAY WITH
A LARGE AND HIGHLY AMPLIFIED RIDGE OVER MUCH OF THE WESTERN U.S.
AND INTO ADJACENT CANADA...AND RIDGE AXIS TRANSLATING EAST INTO
THE DAKOTAS IN RESPONSE TO AN UPPER SHORTWAVE ENTERING THE PACIFIC
NORTHWEST UPSTREAM. RELATIVELY HIGH HEIGHTS OVER THE NORTHERN HIGH
PLAINS WILL LEND TO ANOTHER HOT DAY ACROSS NORTHEAST MONTANA FOR
FRIDAY. IN FACT...THE LATEST ECMWF HAS 850MB TEMPERATURES IN THE
LOWER 30S CELSIUS OVER MUCH OF THE AREA...EASILY SUPPORTIVE OF
HIGHS NEAR 100 DEGREES AT THE SURFACE WITH BOUNDARY LAYER MIXING.
THE APPROACHING SHORTWAVE WILL HAVE A COLD FRONT AT THE
SURFACE...AND WITH THE CWA MAY SEE PRE-FRONTAL WARMING FRIDAY
AFTERNOON AND A NEED TO GO TOWARD THE HIGHER END OF THE GUIDANCE
ENVELOPE. AS IT STANDS...WIDESPREAD LOWER 100S COULD RATIONALLY
BE FORECAST GIVEN THESE ARGUMENTS. DECIDED TO BE SOMEWHAT MORE
CONSERVATIVE AT THIS TIME HOWEVER DUE TO UNCERTAINTIES INVOLVING
INCREASING CLOUDINESS AHEAD OF THE APPROACHING FRONT.
WILL MAINTAIN INHERITED FORECAST THINKING IN TERMS OF POPS FOR
FRIDAY EVENING WITH SHOWERS/THUNDERSTORMS POSSIBLE WITH THE FRONT.
AT THIS TIME THOUGH DO NOTE THERE IS MORE SUPPORT WITH THE GFS
THAN THE ECMWF...WHICH IS A DRIER SOLUTION. THEREFORE...WHILE
KEEPING SCATTERED POPS IN PLACE SEEMS LIKE A GOOD IDEA...DID NOT
CHOOSE TO INCREASE POPS FURTHER GIVEN SPREAD IN MODEL SOLUTIONS.
FOR SATURDAY THE CWA WILL SEE MARKEDLY COOLER...THOUGH STILL WARM
TEMPERATURES WITH POST-FRONTAL ENVIRONMENT IN PLACE.CAA WILL HELP
MIX DOWN STRONGER WINDS TO THE SURFACE AND THIS DAY MAY NEED TO BE
MONITORED FOR LAKE WIND ADVISORY CRITERIA OUT ON FORT PECK LAKE.
SATURDAY NIGHT AND BEYOND...ENSEMBLE 500MB HEIGHTS SHOW INCREASING
SPREAD BUT BROAD AGREEMENT ON RETURNING RIDGE...SO TRENDED ON THE
DRIER SIDE WHILE MAINTAINING HIGHS IN THE 80S...RATHER SEASONABLE
FOR THIS TIME OF YEAR. MALIAWCO
&&
.AVIATION...
AN UPPER LEVEL SHORT-WAVE DISTURBANCE RIDING ACROSS THE TOP OF THE
HIGH PRESSURE RIDGE COULD INITIATE A ROUND OF THUNDERSTORMS THIS
AFTERNOON AND EVENING THAT WOULD AFFECT MAINLY TERMINAL AREAS
EAST OF KGGW. IF ANY THUNDERSTORMS DO DEVELOP THERE IS A CHANCE
FOR LOCALIZED HAIL AND GUSTY WINDS.
OTHERWISE TODAY WILL BE SKC INITIALLY THEN AFTERNOON & EVENING
MID LEVEL CLOUDS MAY DEVELOP. CLEAR SKIES WILL RETURN LATE TONIGHT
AND FOR WEDNESDAY.
WIND: TODAY...EAST TO SOUTHEAST AT 5-15KT. WEDNESDAY...LIGHT AND
VARIABLE.
SCT
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
935 AM MDT TUE AUG 11 2015
.UPDATE...
WEAK SHORTWAVE WAS WORKING INTO NORTHWEST WYOMING THIS MORNING.
THIS WAVE HAD GENERATED A FEW WEAK SHOWERS AND THUNDERSTORMS
EARLIER THIS MORNING OVER NORTHEAST IDAHO. ACTIVITY HAS DIED OUT
NOW WITH JUST SOME LEFT OVER CLOUDS. WILL LEAVE POPS OUT FOR THE
MORNING OVER THE HIGHER TERRAIN. THIS WAVE WILL ROUND THE TOP OF
THE RIDGE BUILDING IN THE AREA AND KICK OFF CONVECTION OVER THE
FAR EAST LATE TODAY. MID LEVEL CAP MAY BE ABLE TO HOLD CONVECTION
AT BAY THIS AFTERNOON WITH 700MB TEMPS ABOVE 12C. CAP MAY JUST BE
WEAK ENOUGH TO BREAK LATE THIS AFTERNOON FROM FALLON TO CARTER
COUNTIES. 12Z GFS AND NAM HOLD DEVELOPMENT OFF UNTIL THIS
EVENING...SO WILL LEAVE OUT FOR NOW. HRRR DOES FIRE ISOLATED
CONVECTION OFF OVER THE FAR EAST LATE THIS AFTERNOON...SO WILL
KEEP A CLOSE EYE ON THIS. THE REST OF THE FORECAST IN GOOD SHAPE
WITH HOT TEMPERATURES IN THE 90S. TWH
&&
.SHORT TERM...VALID FOR TDY AND WED...
UPPER LEVEL RIDGE CONTINUES TO STRENGTHEN OVER THE REGION WITH
500MB HEIGHTS APPROACHING 590DAM. DESPITE CLEAR SKIES...TEMPS ARE
STRUGGLING TO FALL AT SOME LOCATIONS PER SELY LOW LEVEL JET...SEE
3AM READING OF 70F AT MLS. THIS IS INDICATIVE OF THE HOT RIDGE
BUILDING IN. LOW LEVEL JET IS ADVECTING HIGH PLAINS MOISTURE INTO
OUR EAST WITH PWATS TO NEAR AN INCH PER LATEST ANALYSIS. THERE IS
ALSO A SMALL AREA OF WEAK CONVECTION NEAR POCATELLO ALONG A WEAK
SHORTWAVE LIFTING OUT OF THE EASTERN GREAT BASIN. WILL NEED TO
WATCH THIS BUT FOR NOW AM EXPECTING THIS ACTIVITY TO DIMINISH OVER
THE COMING HOURS BEFORE IT REACHES OUR CWA.
HOT WEATHER IS THE MAIN THEME THE NEXT TWO DAYS. EXPECT TEMPS WELL
INTO THE 90S TODAY...AND SOME LOCATIONS WILL REACH TRIPLE DIGITS
ON WEDNESDAY. WEAK SHORTWAVE/WIND SHIFT WILL ADVECT DRIER AIR INTO
OUR EAST TOMORROW...AND THIS SHOULD HELP TO DEEPEN MIXING WITHIN
AN AIRMASS SUPPORTIVE OF TRIPLE DIGIT HEAT...SO HAVE TWEAKED
EXPECTED TEMPS UP A BIT MORE. MILES CITY FORECAST HIGH OF 102F IS
PLENTY HOT BUT STILL 3 DEGREES SHORT OF THE AUG 12 RECORD.
BILLINGS HAS NOT SEEN 100 DEGREES YET IN 2015 BUT IT WILL GET
CLOSE TOMORROW. 700 TEMPS OF ABOUT +15C SUGGEST UPPER 90S WITHOUT
A PUSH OF WEST WINDS AT BILLINGS...SO WILL KEEP FORECAST HIGH AT
98F FOR THE AIRPORT.
THERE APPEARS TO BE A SMALL RISK OF TSTMS ACROSS OUR FAR EAST BY
THIS EVENING AS A WEAK SHORTWAVE ROUNDS THE RIDGE AND SLIDES
ACROSS OUR EAST...INTERACTING WITH MOISTURE PLUME WHICH IS
CURRENTLY MATERIALIZING...THOUGH THIS IS NOT OBVIOUS AS BUILDING
HEIGHTS AND MID LEVEL TEMPS WILL BE WORKING AGAINST THE CONVECTIVE
POTENTIAL. SHEAR AND INSTABILITY MAY BE ENOUGH FOR A STRONG STORM
IF ONE GETS GOING SO WILL NEED TO WATCH THIS. OTHERWISE EXPECT
ONLY WEAK TSTM ACTIVITY CONFINED TO OUR WESTERN HIGH TERRAIN...NOT
TOO DISSIMILAR TO WHAT WE SAW YESTERDAY.
THERE LOOKS TO BE A SLIGHTLY BETTER CHANCE OF DIURNAL TSTMS IN OUR
WEST ON WEDNESDAY COURTESY OF A DEEPER MONSOONAL SURGE AND
ADDITIONAL WEAK SHORTWAVE ENERGY. HAVE EXPANDED LOW POPS TO COVER
A BROADER AREA OF OUR WEST AND INCLUDING LOWER ELEVATIONS SUCH AS
LIVINGSTON...BIG TIMBER...HARLOWTON AND ROUNDUP. HAVE ALSO ADDED
MENTION OF GUSTY WINDS AS THIS WILL BE THE PRIMARY THREAT WITH ANY
CONVECTION PRODUCED BY THIS HOT AND DEEPLY MIXED AIRMASS. WILL
KEEP LALS AT 2 FOR LOWER ELEVATIONS.
AS FOR FIRE WEATHER...WILL CONTINUE TO ADVERTISE HOT WEATHER AND
MAINLY ISOLATED TSTMS THRU FRIDAY...WITH BREAKDOWN OF RIDGE AND
INCREASED WINDS ANTICIPATED BY THE END OF THE WEEK. JKL
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
NOT MANY CHANGES IN THE EXTENDED PERIOD...AS MODELS ARE STILL IN
GOOD AGREEMENT WITH THE CONTINUED HOT WEATHER ACROSS THE NORTHERN
ROCKIES.
UPPER LEVEL RIDGE REMAINS FIRMLY IN PLACE UNTIL LONG WAVE TROUGH
MOVES ONSHORE ALONG THE PACIFIC COAST BY FRIDAY MORNING. AS THE
RIDGE BREAKS DOWN...ENERGY WILL MAKE ITS WAY SOUTHEAST FROM
ALBERTA AND SASKATCHEWAN. THIS WILL ALSO PULL A SURFACE FRONT
ACROSS THE TREASURE STATE DURING THE OVERNIGHT HOURS. THE FRONT
WILL BE COOL IN NATURE...AND WILL ACT TO BRING DOWN TEMPS THIS
WEEKEND...INTO THE MID 80S...WHICH WILL SEEM DOWNRIGHT PLEASANT
COMPARED TO EARLIER IN THE WEEK. THE TRICK WITH THE FRONTAL
PASSAGE WILL BE THE WINDS. EARLIER MODEL RUNS KEPT THE STRONGEST
LOW LEVEL WINDS TO THE NORTH OF THE BYZ CWA. BUT LATEST GFS RUN
SHOWS 850MB WINDS IN EXCESS OF 45 KNOTS OVER MUCH OF SOUTHEASTERN
MONTANA. SO...IN TURN...DECIDED TO BUMP UP SURFACE WIND VALUES
FROM FRIDAY NIGHT THROUGH SATURDAY MID DAY. FIRE WEATHER WILL BE
THE MAIN ISSUE OF CONCERN...WITH LITTLE TO NO WIDESPREAD RAIN AND
VERY LOW RH VALUES FOR THE SEVERAL DAYS LEADING UP TO THE FRONTAL
PASSAGE.
BY EARLY NEXT WEEK...THE UPPER LEVEL FLOW TURNS ZONAL...WITH A
FEW WAVES MOVING THROUGH THE FLOW. SINGER
&&
.AVIATION...
MOSTLY SUNNY SKIES WITH VFR CONDITIONS WILL PREVAIL TODAY.
HOWEVER...THERE WILL BE A SLIGHT CHANCE FOR A THUNDERSTORM AND
MVFR CONDITION OVER THE MOUNTAINS THROUGHOUT THE DAY...AS WELL AS
ALONG THE DAKOTA BORDERS LATE THIS AFTERNOON INTO THIS EVENING.
HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 096 064/098 067/096 066/097 062/087 057/082 057/085
0/U 01/B 11/B 11/B 11/B 11/U 11/B
LVM 095 057/094 059/093 058/093 055/085 050/083 050/082
0/U 02/T 21/B 11/B 11/B 11/U 11/U
HDN 098 061/101 063/099 064/099 061/088 055/087 057/087
0/U 00/G 10/B 11/B 11/B 11/U 11/B
MLS 098 065/102 068/100 069/100 066/090 057/086 059/088
0/U 10/G 11/B 02/T 21/B 22/T 21/U
4BQ 096 062/099 064/099 065/100 064/091 057/085 058/087
0/U 10/U 11/B 11/B 12/T 22/T 21/B
BHK 093 062/100 063/097 063/096 064/089 056/083 056/084
1/U 20/U 12/B 12/B 22/T 22/T 21/B
SHR 095 058/098 060/094 059/095 059/088 055/084 053/086
0/U 01/B 11/B 11/B 11/B 11/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
145 PM CDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 1028 AM CDT TUE AUG 11 2015
HIGH PRESSURE DOMINATING AT THE SURFACE AND ALOFT THIS MORNING.
CLOUDS LIFTING NORTHEAST AND GENERALLY DISSIPATING EAST OF HIGHWAY
83. THE SURFACE AND UPPER RIDGE BUILDS EAST TODAY WHERE ISOLATED
TO SCATTERED CONVECTION WILL BE POSSIBLE IN THE PANHANDLE AND FAR
SOUTHWEST. NO SEVERE STORMS ARE ANTICIPATED WITH ISOLATED
THUNDERSTORMS THAT DO FORM CAPABLE OF HEAVY RAINFALL AND SMALL
HAIL. FORECAST GRIDS AND TEST PRODUCTS UPDATED TO REFLECT LOW
POPS IN THE WEST THROUGH THE AFTERNOON AND INTO TONIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CDT TUE AUG 11 2015
TODAY AND TONIGHT...THE MODELS ARE HOLDING A STATIONARY FRONT ACROSS
THE PANHANDLE TODAY. THE RAP SHOWS A MODEST LOW LEVEL JET ANCHORED
OVER THAT REGION ALL DAY. MOISTURE...STEEP LAPSE RATES AND LIFT ARE
FORCING TSTMS IN THIS AREA WHICH WOULD PROBABLY DRIFT EAST TODAY.
SINCE NONE OF THE MODELS HAVE A HANDLE ON THE CONVECTION UNDERWAY...
ISOLATED POPS WITH LOCALLY HEAVY RAINFALL ARE IN PLACE THIS MORNING.
THE RAP SUGGESTED AN ISOLATED TSTM MOVING OFF THE BLACK HILLS TOWARD
VALENTINE THIS AFTERNOON. CONSALL...ALLBLEND AND OTHER DATA SETS
SUGGESTED ISOLATED POPS ACROSS WRN NEB TODAY AND FAR SWRN NEB
TONIGHT.
THE NAM...SREF...ARW AND NMM MODELS INDICATE STRATUS MAY MOVE NORTH
INTO THE PANHANDLE TONIGHT. THIS IS ASSOCIATED WITH A LOW LEVEL JET
ANCHORED ALONG A STATIONARY FRONT. THIS FEATURE WILL BE ANALYZED
MORE CAREFULLY TODAY.
HIGHS TODAY RISE INTO THE MID AND UPPER 80S...A BIT WARMER THAN
YESTERDAY WITH LOWS TONIGHT IN THE UPPER 50S TO NEAR 60. DEW POINTS
REMAIN IN THE LOW TO MID 60S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 352 AM CDT TUE AUG 11 2015
THE LONG RANGE MODELS CONTINUE TO INDICATE THE PRESENCE OF AN UPPER
LEVEL RIDGE EXTENDING NORTH FROM THE DESERT SOUTHWEST ACROSS THE
ROCKIES AND ONTO THE CENTRAL PLAINS OF SASKATCHEWAN/ALBERTA. THIS
PATTERN IS FORECAST TO REMAIN IN PLACE INTO THE WEEKEND...BUT THEN
BREAKDOWN AS A PAC NW SHORTWAVE ADVANCES NORTHEAST TOWARD THE
CANADIAN PRAIRIES. THE MODELS CONTINUE TO INDICATE PERIODIC CHANCES
OF QPF AS DISTURBANCES RIDE ATOP THE RIDGE...HOWEVER THE GREATEST
CHANCES LOOK TO REMAIN NEAR THE HIGHER TERRAIN OF EASTERN
COLORADO/WYOMING AND THE WESTERN PANHANDLE. THE BEST CHANCE OF A
RIDGE RIDER SPILLING ACROSS SOUTHWEST NEB OR THE CENTRAL SANDHILLS
WILL BE THURSDAY EVENING...BUT AT THAT...WILL ENTERTAIN NO BETTER
THAN A SLIGHT CHANCE OF THUNDER FOR NOW AS THE MODELS HAVE STRUGGLED
WITH CONSISTENCY AND TIMING OF THESE LOWER AMPLITUDE FEATURES. THE
AFOREMENTIONED SHORTWAVE WILL PULL A COLD FRONT ACROSS THE FORECAST
AREA SATURDAY INTO SUNDAY...LEADING TO THE POSSIBILITY OF STORMS
INTO EARLY NEXT WEEK. THE GFS AND ECMWF ARE AT ODDS WITH THE TIMING
OF THE FRONT /AND ASSOCIATED SHORTWAVE PASSAGE/...WITH THE GFS THE
MOST AGGRESSIVE. THE CR_INT BLENDED PROCEDURE TRIED TO INTRODUCE
WIDESPREAD LIKELY POPS INTO THE FORECAST FOR THE PASSAGE...WHICH WAS
DEEMED TOO HIGH /BEING DAYS 5-7/. THUS THE FORECAST POPS WERE
LOWERED ACCORDINGLY.
LOWER TROPOSPHERIC THERMAL ADVECTION AND INCREASING SUBSIDENCE
ASSOCIATED WITH THE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL PROMOTE
WARMING TEMPERATURES INTO THE WEEKEND. HIGHS ARE FORECAST TO BE
ABOVE CLIMO BY LATE WEEK AND REMAIN THROUGH SATURDAY. SEASONAL TO
SLIGHTLY ABOVE AVERAGE LOWS ARE FORECAST WITH THIS TYPICAL AUGUST
PATTERN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 138 PM CDT TUE AUG 11 2015
VISUAL FLIGHT RULES WILL CONTINUE FOR TERMINALS KLBF AND KVTN
THROUGH 18Z WEDNESDAY. THE SURFACE TROUGH NEAR THE FOOTHILLS WILL
HELP CHANNEL MID LEVEL MOISTURE NORTH WHERE CEILINGS BETWEEN 5
KFT TO 8 KFT ARE POSSIBLE THIS AFTERNOON. OVERNIGHT CLOUD COVERAGE
WILL BECOME MORE SCATTERED INTO THURSDAY MORNING AS THE UPPER
RIDGE BUILDS AND SHIFTS EAST. THE CHANCE FOR ISOLATED THUNDERSTORMS
WILL FOCUS MAINLY ACROSS THE SOUTHWEST FORECAST AREA.
&&
.HYDROLOGY...
ISSUED AT 351 AM CDT TUE AUG 11 2015
THE HEAVY RAIN CENTER BETWEEN KIMBLE AND SIDNEY IS SENDING AN
UNKNOWN QUANTITY OF WATER INTO LODGEPOLE CREEK WHICH DRAINS INTO
DEUEL COUNTY. THE CREEK GENERALLY FOLLOWS A ROUTE EAST BETWEEN
I-80 AND HIGHWAY 30 AND THEN HOPEFULLY CROSSES UNDER I-80
SOUTHEAST OF CHAPPELL. AT 3 AM CDT...ABOUT 2 TO 4 INCHES OF RAIN
WAS RADAR ESTIMATED WITH THE HEAVY RAIN CENTER. DAYLIGHT WILL
REVEAL THE HEIGHT OF THE WATER FLOWING EAST. NO GAGES OTHER THAN A
STAFF GAGE 6 MILES SOUTHEAST OF CHAPPELL ARE IN PLACE TO MEASURE
THE CREEK LEVEL. IT IS NORMALLY DRY. THE CHAPPELL GAGE HAS READ AS
HIGH AS 6.5 FEET IN 1968. THE STREAM TRAVEL FLOW RATE HAS BEEN
ESTIMATED AT 2 TO 4 MILES AN HOUR WHICH WOULD PUT WATER IN DEUEL
COUNTY THIS AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KECK
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...KECK
HYDROLOGY...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
ISSUED BY NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1252 PM CDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT TUE AUG 11 2015
THE SHORT TERM FORECAST REMAINS FAIRLY QUIET THROUGH THE NEXT 24
HOURS...WITH DRY CONDITIONS AND VERY LITTLE CHANGES MADE TO THE
PREVIOUS FORECAST. AN UPPER LEVEL RIDGE REMAINS DOMINATE ACROSS THE
SOUTHERN HALF OF THE CONUS...WHILE A DEEP UPPER LEVEL CLOSED LOW
TRUDGES OFF THE PACIFIC COASTLINE. AN OPEN WAVE HAS BEGUN TO SLIDE
EASTWARD ACROSS THE GREAT LAKES REGION. THE RIDGE AXIS IN THE MID
LEVELS IS SLIGHTLY MORE PRONOUNCED AND AMPLIFIED ACROSS THE FRONT
RANGE. ALONG THIS RIDGE AXIS...RETURN FLOW COMBINED WITH WARM AIR
ADVECTION HAS ALLOWED MOISTURE TO SURGE NORTHWARD ALONG THE FRONT
RANGE. AT THE SURFACE HIGH PRESSURE HAS SHIFTED ACROSS THE CENTRAL
PLAINS. LATEST OBS REFLECT THIS FEATURE AS MOST AIRPORT WINDS ARE
LIGHT TO CALM.
ALTHOUGH THIS IS NOT REFLECTED IN THE FORECAST...THERE ARE SOME
CONCERNS ABOUT PATCHY FOG DEVELOPMENT THIS MORNING. EVEN THOUGH
DEWPOINTS ARE LOWER THAN PREVIOUS DAYS...TEMPERATURES ARE ALSO
SLIGHTLY COOLER. AT THE PRESENT TIME...RELATIVE HUMIDITY VALUES ARE
ABOVE 90 PERCENT IN MOST AREAS. MODEL SOLUTIONS SUCH AS THE
NAM...RAP...AND HRRR ALL SUGGEST LOWERED VISIBILITIES ESPECIALLY FOR
LOCATIONS WEST OF 281...MAINLY ALONG THE SURFACE RIDGE AXIS. SINCE
THIS WILL LIKELY BE PATCHY IN NATURE...WILL CONTINUE TO MONITOR
LATEST TRENDS BEFORE INTRODUCING INTO GRIDS.
THE REST OF TODAY LOOKS TO REMAIN QUIET AS THE SURFACE RIDGE SLIDES
THROUGH THE AREA. LIGHT WINDS ARE EXPECTED AND HIGH TEMPERATURES
SHOULD TOP OUT NEAR NORMAL WITH HIGHS IN THE MID 80S FOR MOST
LOCATIONS. FURTHER WEST...A SMALL DISTURBANCE WILL DEVELOP ALONG THE
FRONT RANGE...AND COMBINED WITH MOISTURE AND WARM AIR ADVECTION WILL
LIKELY SPAWN THUNDERSTORMS. 0Z MODEL SOLUTIONS PULLED POPS BACK
FURTHER WEST AND THUS WENT AHEAD AND REMOVED ANY MENTION OF
THUNDERSTORMS FROM WESTERN ZONES TUESDAY NIGHT. HOWEVER...WOULD NOT
BE SURPRISED TO SEE A STORM MAKE A RUN FOR THE WESTERN ZONES DURING
THIS TIME FRAME. EVEN THE 6Z NAM...HAS NOW REVERTED BACK TO POPS IN
NORTH CENTRAL KANSAS BY EARLY MORNING WEDNESDAY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 AM CDT TUE AUG 11 2015
AN UPPER RIDGE OF HIGH PRESSURE WILL BE THE DOMINATE WEATHER FEATURE
ACROSS THE INTERIOR CONUS THROUGH THE WORKWEEK. THE PATTERN WILL BE
BLOCKY AT THE START WITH CLOSED LOWS IN THE PACIFIC OCEAN OFF THE
COAST OF CALIFORNIA AND ANOTHER TROUGH ALONG THE EAST COAST. UNDER
THE INFLUENCE OF THE RIDGE...PRECIPITATION CHANCES WILL BE
NEGLIGIBLE UNTIL THE WEEKEND TIME FRAME WHEN THE WESTERN LOW LIFTS
OUT AND BREAKS DOWN THE INTERIOR CONUS RIDGE. ALTHOUGH THE FORECAST
REMAINS DRY UNTIL SATURDAY NIGHT WILL NEED TO KEEP AN EYE ON
CONVECTION WHICH DEVELOPS ALONG THE HIGHS PLAINS AS ACTIVITY MAY TRY
TO WORK INTO OUR WESTERN ZONES.
THE PATTERN CHANGE ARRIVES OVER THE WEEKEND AS THE AFOREMENTIONED
WESTERN SYSTEM LIFTS OUT AND CROSSES THE NORTHERN CONUS. AN
ASSOCIATED COLD FRONTAL BOUNDARY ADVANCES SOUTH FROM THE DAKOTAS
LATE SATURDAY WITH CHCS FOR TSTMS RETURNING AS FRONT ARRIVES. THE
ECMWF IS SLOWER WITH BOUNDARY PROGRESSION THAN THE GFS BUT HARD TO
PINPOINT THE DETAILS THIS FAR OUT. THE BOUNDARY IS PROGGED TO STALL
OR MEANDER ACROSS OUR REGION INTO EARLY NEXT WEEK AND WITH BOUNDARY
IN THE AREA CHANCES FOR STORMS CONTINUE. TEMPERATUREWISE...READINGS
WILL BE TYPICAL OF SUMMER WITH HIGHS IN THE 80S TO LOW 90S...WITH
LOWS IN THE 60S TO LOWER 70S.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1252 PM CDT TUE AUG 11 2015
VFR CONDITIONS UNDER MOSTLY CLEAR SKIES ARE FORECAST THROUGH
WEDNESDAY MORNING. THERE IS A SMALL CHANCE MVFR FOG COULD DEVELOP AT
CENTRAL NEBRASKA TAF SITES NEAR 12Z...BUT CHANCES ARE TOO LOW TO
MENTION AT THIS TIME.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...SALTZMAN
LONG TERM...FAY
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1037 AM CDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 1028 AM CDT TUE AUG 11 2015
HIGH PRESSURE DOMINATING AT THE SURFACE AND ALOFT THIS MORNING.
CLOUDS LIFTING NORTHEAST AND GENERALLY DISSIPATING EAST OF HIGHWAY
83. THE SURFACE AND UPPER RIDGE BUILDS EAST TODAY WHERE ISOLATED
TO SCATTERED CONVECTION WILL BE POSSIBLE IN THE PANHANDLE AND FAR
SOUTHWEST. NO SEVERE STORMS ARE ANTICIPATED WITH ISOLATED
THUNDERSTORMS THAT DO FORM CAPABLE OF HEAVY RAINFALL AND SMALL
HAIL. FORECAST GRIDS AND TEST PRODUCTS UPDATED TO REFLECT LOW
POPS IN THE WEST THROUGH THE AFTERNOON AND INTO TONIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CDT TUE AUG 11 2015
TODAY AND TONIGHT...THE MODELS ARE HOLDING A STATIONARY FRONT ACROSS
THE PANHANDLE TODAY. THE RAP SHOWS A MODEST LOW LEVEL JET ANCHORED
OVER THAT REGION ALL DAY. MOISTURE...STEEP LAPSE RATES AND LIFT ARE
FORCING TSTMS IN THIS AREA WHICH WOULD PROBABLY DRIFT EAST TODAY.
SINCE NONE OF THE MODELS HAVE A HANDLE ON THE CONVECTION UNDERWAY...
ISOLATED POPS WITH LOCALLY HEAVY RAINFALL ARE IN PLACE THIS MORNING.
THE RAP SUGGESTED AN ISOLATED TSTM MOVING OFF THE BLACK HILLS TOWARD
VALENTINE THIS AFTERNOON. CONSALL...ALLBLEND AND OTHER DATA SETS
SUGGESTED ISOLATED POPS ACROSS WRN NEB TODAY AND FAR SWRN NEB
TONIGHT.
THE NAM...SREF...ARW AND NMM MODELS INDICATE STRATUS MAY MOVE NORTH
INTO THE PANHANDLE TONIGHT. THIS IS ASSOCIATED WITH A LOW LEVEL JET
ANCHORED ALONG A STATIONARY FRONT. THIS FEATURE WILL BE ANALYZED
MORE CAREFULLY TODAY.
HIGHS TODAY RISE INTO THE MID AND UPPER 80S...A BIT WARMER THAN
YESTERDAY WITH LOWS TONIGHT IN THE UPPER 50S TO NEAR 60. DEW POINTS
REMAIN IN THE LOW TO MID 60S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 352 AM CDT TUE AUG 11 2015
THE LONG RANGE MODELS CONTINUE TO INDICATE THE PRESENCE OF AN UPPER
LEVEL RIDGE EXTENDING NORTH FROM THE DESERT SOUTHWEST ACROSS THE
ROCKIES AND ONTO THE CENTRAL PLAINS OF SASKATCHEWAN/ALBERTA. THIS
PATTERN IS FORECAST TO REMAIN IN PLACE INTO THE WEEKEND...BUT THEN
BREAKDOWN AS A PAC NW SHORTWAVE ADVANCES NORTHEAST TOWARD THE
CANADIAN PRAIRIES. THE MODELS CONTINUE TO INDICATE PERIODIC CHANCES
OF QPF AS DISTURBANCES RIDE ATOP THE RIDGE...HOWEVER THE GREATEST
CHANCES LOOK TO REMAIN NEAR THE HIGHER TERRAIN OF EASTERN
COLORADO/WYOMING AND THE WESTERN PANHANDLE. THE BEST CHANCE OF A
RIDGE RIDER SPILLING ACROSS SOUTHWEST NEB OR THE CENTRAL SANDHILLS
WILL BE THURSDAY EVENING...BUT AT THAT...WILL ENTERTAIN NO BETTER
THAN A SLIGHT CHANCE OF THUNDER FOR NOW AS THE MODELS HAVE STRUGGLED
WITH CONSISTENCY AND TIMING OF THESE LOWER AMPLITUDE FEATURES. THE
AFOREMENTIONED SHORTWAVE WILL PULL A COLD FRONT ACROSS THE FORECAST
AREA SATURDAY INTO SUNDAY...LEADING TO THE POSSIBILITY OF STORMS
INTO EARLY NEXT WEEK. THE GFS AND ECMWF ARE AT ODDS WITH THE TIMING
OF THE FRONT /AND ASSOCIATED SHORTWAVE PASSAGE/...WITH THE GFS THE
MOST AGGRESSIVE. THE CR_INT BLENDED PROCEDURE TRIED TO INTRODUCE
WIDESPREAD LIKELY POPS INTO THE FORECAST FOR THE PASSAGE...WHICH WAS
DEEMED TOO HIGH /BEING DAYS 5-7/. THUS THE FORECAST POPS WERE
LOWERED ACCORDINGLY.
LOWER TROPOSPHERIC THERMAL ADVECTION AND INCREASING SUBSIDENCE
ASSOCIATED WITH THE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL PROMOTE
WARMING TEMPERATURES INTO THE WEEKEND. HIGHS ARE FORECAST TO BE
ABOVE CLIMO BY LATE WEEK AND REMAIN THROUGH SATURDAY. SEASONAL TO
SLIGHTLY ABOVE AVERAGE LOWS ARE FORECAST WITH THIS TYPICAL AUGUST
PATTERN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 623 AM CDT TUE AUG 11 2015
A WARM FRONT STRETCHED NORTH AND SOUTH ACROSS WESTERN NEBRASKA
REMAINS STATIONARY TODAY AND TONIGHT. THE FRONT WILL BE THE FOCUS
FOR ISOLATED SHOWERS AND THUNDERSTORMS.
OTHERWISE VFR IS EXPECTED. STRATUS IS POSSIBLE LATE TONIGHT
ACROSS THE PANHANDLE. MVFR CIGS WOULD SPREAD FROM SOUTH TO NORTH
09Z-12Z.
&&
.HYDROLOGY...
ISSUED AT 351 AM CDT TUE AUG 11 2015
THE HEAVY RAIN CENTER BETWEEN KIMBLE AND SIDNEY IS SENDING AN
UNKNOWN QUANTITY OF WATER INTO LODGEPOLE CREEK WHICH DRAINS INTO
DEUEL COUNTY. THE CREEK GENERALLY FOLLOWS A ROUTE EAST BETWEEN
I-80 AND HIGHWAY 30 AND THEN HOPEFULLY CROSSES UNDER I-80
SOUTHEAST OF CHAPPELL. AT 3 AM CDT...ABOUT 2 TO 4 INCHES OF RAIN
WAS RADAR ESTIMATED WITH THE HEAVY RAIN CENTER. DAYLIGHT WILL
REVEAL THE HEIGHT OF THE WATER FLOWING EAST. NO GAGES OTHER THAN A
STAFF GAGE 6 MILES SOUTHEAST OF CHAPPELL ARE IN PLACE TO MEASURE
THE CREEK LEVEL. IT IS NORMALLY DRY. THE CHAPPELL GAGE HAS READ AS
HIGH AS 6.5 FEET IN 1968. THE STREAM TRAVEL FLOW RATE HAS BEEN
ESTIMATED AT 2 TO 4 MILES AN HOUR WHICH WOULD PUT WATER IN DEUEL
COUNTY THIS AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KECK
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
HYDROLOGY...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
623 AM CDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CDT TUE AUG 11 2015
TODAY AND TONIGHT...THE MODELS ARE HOLDING A STATIONARY FRONT ACROSS
THE PANHANDLE TODAY. THE RAP SHOWS A MODEST LOW LEVEL JET ANCHORED
OVER THAT REGION ALL DAY. MOISTURE...STEEP LAPSE RATES AND LIFT ARE
FORCING TSTMS IN THIS AREA WHICH WOULD PROBABLY DRIFT EAST TODAY.
SINCE NONE OF THE MODELS HAVE A HANDLE ON THE CONVECTION UNDERWAY...
ISOLATED POPS WITH LOCALLY HEAVY RAINFALL ARE IN PLACE THIS MORNING.
THE RAP SUGGESTED AN ISOLATED TSTM MOVING OFF THE BLACK HILLS TOWARD
VALENTINE THIS AFTERNOON. CONSALL...ALLBLEND AND OTHER DATA SETS
SUGGESTED ISOLATED POPS ACROSS WRN NEB TODAY AND FAR SWRN NEB
TONIGHT.
THE NAM...SREF...ARW AND NMM MODELS INDICATE STRATUS MAY MOVE NORTH
INTO THE PANHANDLE TONIGHT. THIS IS ASSOCIATED WITH A LOW LEVEL JET
ANCHORED ALONG A STATIONARY FRONT. THIS FEATURE WILL BE ANALYZED
MORE CAREFULLY TODAY.
HIGHS TODAY RISE INTO THE MID AND UPPER 80S...A BIT WARMER THAN
YESTERDAY WITH LOWS TONIGHT IN THE UPPER 50S TO NEAR 60. DEW POINTS
REMAIN IN THE LOW TO MID 60S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 352 AM CDT TUE AUG 11 2015
THE LONG RANGE MODELS CONTINUE TO INDICATE THE PRESENCE OF AN UPPER
LEVEL RIDGE EXTENDING NORTH FROM THE DESERT SOUTHWEST ACROSS THE
ROCKIES AND ONTO THE CENTRAL PLAINS OF SASKATCHEWAN/ALBERTA. THIS
PATTERN IS FORECAST TO REMAIN IN PLACE INTO THE WEEKEND...BUT THEN
BREAKDOWN AS A PAC NW SHORTWAVE ADVANCES NORTHEAST TOWARD THE
CANADIAN PRAIRIES. THE MODELS CONTINUE TO INDICATE PERIODIC CHANCES
OF QPF AS DISTURBANCES RIDE ATOP THE RIDGE...HOWEVER THE GREATEST
CHANCES LOOK TO REMAIN NEAR THE HIGHER TERRAIN OF EASTERN
COLORADO/WYOMING AND THE WESTERN PANHANDLE. THE BEST CHANCE OF A
RIDGE RIDER SPILLING ACROSS SOUTHWEST NEB OR THE CENTRAL SANDHILLS
WILL BE THURSDAY EVENING...BUT AT THAT...WILL ENTERTAIN NO BETTER
THAN A SLIGHT CHANCE OF THUNDER FOR NOW AS THE MODELS HAVE STRUGGLED
WITH CONSISTENCY AND TIMING OF THESE LOWER AMPLITUDE FEATURES. THE
AFOREMENTIONED SHORTWAVE WILL PULL A COLD FRONT ACROSS THE FORECAST
AREA SATURDAY INTO SUNDAY...LEADING TO THE POSSIBILITY OF STORMS
INTO EARLY NEXT WEEK. THE GFS AND ECMWF ARE AT ODDS WITH THE TIMING
OF THE FRONT /AND ASSOCIATED SHORTWAVE PASSAGE/...WITH THE GFS THE
MOST AGGRESSIVE. THE CR_INT BLENDED PROCEDURE TRIED TO INTRODUCE
WIDESPREAD LIKELY POPS INTO THE FORECAST FOR THE PASSAGE...WHICH WAS
DEEMED TOO HIGH /BEING DAYS 5-7/. THUS THE FORECAST POPS WERE
LOWERED ACCORDINGLY.
LOWER TROPOSPHERIC THERMAL ADVECTION AND INCREASING SUBSIDENCE
ASSOCIATED WITH THE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL PROMOTE
WARMING TEMPERATURES INTO THE WEEKEND. HIGHS ARE FORECAST TO BE
ABOVE CLIMO BY LATE WEEK AND REMAIN THROUGH SATURDAY. SEASONAL TO
SLIGHTLY ABOVE AVERAGE LOWS ARE FORECAST WITH THIS TYPICAL AUGUST
PATTERN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 623 AM CDT TUE AUG 11 2015
A WARM FRONT STRETCHED NORTH AND SOUTH ACROSS WESTERN NEBRASKA
REMAINS STATIONARY TODAY AND TONIGHT. THE FRONT WILL BE THE FOCUS
FOR ISOLATED SHOWERS AND THUNDERSTORMS.
OTHERWISE VFR IS EXPECTED. STRATUS IS POSSIBLE LATE TONIGHT
ACROSS THE PANHANDLE. MVFR CIGS WOULD SPREAD FROM SOUTH TO NORTH
09Z-12Z.
&&
.HYDROLOGY...
ISSUED AT 351 AM CDT TUE AUG 11 2015
THE HEAVY RAIN CENTER BETWEEN KIMBLE AND SIDNEY IS SENDING AN
UNKNOWN QUANTITY OF WATER INTO LODGEPOLE CREEK WHICH DRAINS INTO
DEUEL COUNTY. THE CREEK GENERALLY FOLLOWS A ROUTE EAST BETWEEN
I-80 AND HIGHWAY 30 AND THEN HOPEFULLY CROSSES UNDER I-80
SOUTHEAST OF CHAPPELL. AT 3 AM CDT...ABOUT 2 TO 4 INCHES OF RAIN
WAS RADAR ESTIMATED WITH THE HEAVY RAIN CENTER. DAYLIGHT WILL
REVEAL THE HEIGHT OF THE WATER FLOWING EAST. NO GAGES OTHER THAN A
STAFF GAGE 6 MILES SOUTHEAST OF CHAPPELL ARE IN PLACE TO MEASURE
THE CREEK LEVEL. IT IS NORMALLY DRY. THE CHAPPELL GAGE HAS READ AS
HIGH AS 6.5 FEET IN 1968. THE STREAM TRAVEL FLOW RATE HAS BEEN
ESTIMATED AT 2 TO 4 MILES AN HOUR WHICH WOULD PUT WATER IN DEUEL
COUNTY THIS AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
HYDROLOGY...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
615 AM CDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT TUE AUG 11 2015
THE SHORT TERM FORECAST REMAINS FAIRLY QUIET THROUGH THE NEXT 24
HOURS...WITH DRY CONDITIONS AND VERY LITTLE CHANGES MADE TO THE
PREVIOUS FORECAST. AN UPPER LEVEL RIDGE REMAINS DOMINATE ACROSS THE
SOUTHERN HALF OF THE CONUS...WHILE A DEEP UPPER LEVEL CLOSED LOW
TRUDGES OFF THE PACIFIC COASTLINE. AN OPEN WAVE HAS BEGUN TO SLIDE
EASTWARD ACROSS THE GREAT LAKES REGION. THE RIDGE AXIS IN THE MID
LEVELS IS SLIGHTLY MORE PRONOUNCED AND AMPLIFIED ACROSS THE FRONT
RANGE. ALONG THIS RIDGE AXIS...RETURN FLOW COMBINED WITH WARM AIR
ADVECTION HAS ALLOWED MOISTURE TO SURGE NORTHWARD ALONG THE FRONT
RANGE. AT THE SURFACE HIGH PRESSURE HAS SHIFTED ACROSS THE CENTRAL
PLAINS. LATEST OBS REFLECT THIS FEATURE AS MOST AIRPORT WINDS ARE
LIGHT TO CALM.
ALTHOUGH THIS IS NOT REFLECTED IN THE FORECAST...THERE ARE SOME
CONCERNS ABOUT PATCHY FOG DEVELOPMENT THIS MORNING. EVEN THOUGH
DEWPOINTS ARE LOWER THAN PREVIOUS DAYS...TEMPERATURES ARE ALSO
SLIGHTLY COOLER. AT THE PRESENT TIME...RELATIVE HUMIDITY VALUES ARE
ABOVE 90 PERCENT IN MOST AREAS. MODEL SOLUTIONS SUCH AS THE
NAM...RAP...AND HRRR ALL SUGGEST LOWERED VISIBILITIES ESPECIALLY FOR
LOCATIONS WEST OF 281...MAINLY ALONG THE SURFACE RIDGE AXIS. SINCE
THIS WILL LIKELY BE PATCHY IN NATURE...WILL CONTINUE TO MONITOR
LATEST TRENDS BEFORE INTRODUCING INTO GRIDS.
THE REST OF TODAY LOOKS TO REMAIN QUIET AS THE SURFACE RIDGE SLIDES
THROUGH THE AREA. LIGHT WINDS ARE EXPECTED AND HIGH TEMPERATURES
SHOULD TOP OUT NEAR NORMAL WITH HIGHS IN THE MID 80S FOR MOST
LOCATIONS. FURTHER WEST...A SMALL DISTURBANCE WILL DEVELOP ALONG THE
FRONT RANGE...AND COMBINED WITH MOISTURE AND WARM AIR ADVECTION WILL
LIKELY SPAWN THUNDERSTORMS. 0Z MODEL SOLUTIONS PULLED POPS BACK
FURTHER WEST AND THUS WENT AHEAD AND REMOVED ANY MENTION OF
THUNDERSTORMS FROM WESTERN ZONES TUESDAY NIGHT. HOWEVER...WOULD NOT
BE SURPRISED TO SEE A STORM MAKE A RUN FOR THE WESTERN ZONES DURING
THIS TIME FRAME. EVEN THE 6Z NAM...HAS NOW REVERTED BACK TO POPS IN
NORTH CENTRAL KANSAS BY EARLY MORNING WEDNESDAY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 AM CDT TUE AUG 11 2015
AN UPPER RIDGE OF HIGH PRESSURE WILL BE THE DOMINATE WEATHER FEATURE
ACROSS THE INTERIOR CONUS THROUGH THE WORKWEEK. THE PATTERN WILL BE
BLOCKY AT THE START WITH CLOSED LOWS IN THE PACIFIC OCEAN OFF THE
COAST OF CALIFORNIA AND ANOTHER TROUGH ALONG THE EAST COAST. UNDER
THE INFLUENCE OF THE RIDGE...PRECIPITATION CHANCES WILL BE
NEGLIGIBLE UNTIL THE WEEKEND TIME FRAME WHEN THE WESTERN LOW LIFTS
OUT AND BREAKS DOWN THE INTERIOR CONUS RIDGE. ALTHOUGH THE FORECAST
REMAINS DRY UNTIL SATURDAY NIGHT WILL NEED TO KEEP AN EYE ON
CONVECTION WHICH DEVELOPS ALONG THE HIGHS PLAINS AS ACTIVITY MAY TRY
TO WORK INTO OUR WESTERN ZONES.
THE PATTERN CHANGE ARRIVES OVER THE WEEKEND AS THE AFOREMENTIONED
WESTERN SYSTEM LIFTS OUT AND CROSSES THE NORTHERN CONUS. AN
ASSOCIATED COLD FRONTAL BOUNDARY ADVANCES SOUTH FROM THE DAKOTAS
LATE SATURDAY WITH CHCS FOR TSTMS RETURNING AS FRONT ARRIVES. THE
ECMWF IS SLOWER WITH BOUNDARY PROGRESSION THAN THE GFS BUT HARD TO
PINPOINT THE DETAILS THIS FAR OUT. THE BOUNDARY IS PROGGED TO STALL
OR MEANDER ACROSS OUR REGION INTO EARLY NEXT WEEK AND WITH BOUNDARY
IN THE AREA CHANCES FOR STORMS CONTINUE. TEMPERATUREWISE...READINGS
WILL BE TYPICAL OF SUMMER WITH HIGHS IN THE 80S TO LOW 90S...WITH
LOWS IN THE 60S TO LOWER 70S.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 612 AM CDT TUE AUG 11 2015
WHILE VFR CONDITIONS ARE FORECAST FOR THE TAF SITES THROUGHOUT THE
PERIOD...SOME UNCERTAINTY EXISTS REGARDING CEILINGS THIS MORNING.
A FEW SHOWERS HAVE DEVELOPED ACROSS SOUTHWEST NEBRASKA WHICH HAVE
RESULTED IN BKN OR OVC CEILINGS NEAR 5000 FT. DEBATED ON ADDING
AT LEAST A MENTION OF THIS CEILING IN THE KEAR TAF...BUT
CONFIDENCE IS NOT HIGH THESE CEILINGS WILL ACTUALLY MAKE IT THIS
FAR EAST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...SALTZMAN
LONG TERM...FAY
AVIATION...SALTZMAN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
351 AM CDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CDT TUE AUG 11 2015
TODAY AND TONIGHT...THE MODELS ARE HOLDING A STATIONARY FRONT ACROSS
THE PANHANDLE TODAY. THE RAP SHOWS A MODEST LOW LEVEL JET ANCHORED
OVER THAT REGION ALL DAY. MOISTURE...STEEP LAPSE RATES AND LIFT ARE
FORCING TSTMS IN THIS AREA WHICH WOULD PROBABLY DRIFT EAST TODAY.
SINCE NONE OF THE MODELS HAVE A HANDLE ON THE CONVECTION UNDERWAY...
ISOLATED POPS WITH LOCALLY HEAVY RAINFALL ARE IN PLACE THIS MORNING.
THE RAP SUGGESTED AN ISOLATED TSTM MOVING OFF THE BLACK HILLS TOWARD
VALENTINE THIS AFTERNOON. CONSALL...ALLBLEND AND OTHER DATA SETS
SUGGESTED ISOLATED POPS ACROSS WRN NEB TODAY AND FAR SWRN NEB
TONIGHT.
THE NAM...SREF...ARW AND NMM MODELS INDICATE STRATUS MAY MOVE NORTH
INTO THE PANHANDLE TONIGHT. THIS IS ASSOCIATED WITH A LOW LEVEL JET
ANCHORED ALONG A STATIONARY FRONT. THIS FEATURE WILL BE ANALYZED
MORE CAREFULLY TODAY.
HIGHS TODAY RISE INTO THE MID AND UPPER 80S...A BIT WARMER THAN
YESTERDAY WITH LOWS TONIGHT IN THE UPPER 50S TO NEAR 60. DEW POINTS
REMAIN IN THE LOW TO MID 60S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 352 AM CDT TUE AUG 11 2015
THE LONG RANGE MODELS CONTINUE TO INDICATE THE PRESENCE OF AN UPPER
LEVEL RIDGE EXTENDING NORTH FROM THE DESERT SOUTHWEST ACROSS THE
ROCKIES AND ONTO THE CENTRAL PLAINS OF SASKATCHEWAN/ALBERTA. THIS
PATTERN IS FORECAST TO REMAIN IN PLACE INTO THE WEEKEND...BUT THEN
BREAKDOWN AS A PAC NW SHORTWAVE ADVANCES NORTHEAST TOWARD THE
CANADIAN PRAIRIES. THE MODELS CONTINUE TO INDICATE PERIODIC CHANCES
OF QPF AS DISTURBANCES RIDE ATOP THE RIDGE...HOWEVER THE GREATEST
CHANCES LOOK TO REMAIN NEAR THE HIGHER TERRAIN OF EASTERN
COLORADO/WYOMING AND THE WESTERN PANHANDLE. THE BEST CHANCE OF A
RIDGE RIDER SPILLING ACROSS SOUTHWEST NEB OR THE CENTRAL SANDHILLS
WILL BE THURSDAY EVENING...BUT AT THAT...WILL ENTERTAIN NO BETTER
THAN A SLIGHT CHANCE OF THUNDER FOR NOW AS THE MODELS HAVE STRUGGLED
WITH CONSISTENCY AND TIMING OF THESE LOWER AMPLITUDE FEATURES. THE
AFOREMENTIONED SHORTWAVE WILL PULL A COLD FRONT ACROSS THE FORECAST
AREA SATURDAY INTO SUNDAY...LEADING TO THE POSSIBILITY OF STORMS
INTO EARLY NEXT WEEK. THE GFS AND ECMWF ARE AT ODDS WITH THE TIMING
OF THE FRONT /AND ASSOCIATED SHORTWAVE PASSAGE/...WITH THE GFS THE
MOST AGGRESSIVE. THE CR_INT BLENDED PROCEDURE TRIED TO INTRODUCE
WIDESPREAD LIKELY POPS INTO THE FORECAST FOR THE PASSAGE...WHICH WAS
DEEMED TOO HIGH /BEING DAYS 5-7/. THUS THE FORECAST POPS WERE
LOWERED ACCORDINGLY.
LOWER TROPOSPHERIC THERMAL ADVECTION AND INCREASING SUBSIDENCE
ASSOCIATED WITH THE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL PROMOTE
WARMING TEMPERATURES INTO THE WEEKEND. HIGHS ARE FORECAST TO BE
ABOVE CLIMO BY LATE WEEK AND REMAIN THROUGH SATURDAY. SEASONAL TO
SLIGHTLY ABOVE AVERAGE LOWS ARE FORECAST WITH THIS TYPICAL AUGUST
PATTERN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1142 PM CDT MON AUG 10 2015
WITH LIGHT EAST TO SOUTHEAST WIND AND SURFACE DEWPOINTS IN THE LOW
TO MID 60S...CONDITIONS MIGHT BE FAVORABLE FOR PATCHY SHALLOW FOG TO
DEVELOP. HOWEVER...THE DEWPOINT JUST ABOVE THE SURFACE WOULD
INDICATE THAT THE LOW TEMPERATURES WOULD NEED TO REACH THE MID 50S
FOR FOG TO BECOME WIDESPREAD AND TO LIMIT THE VISIBILITY
SIGNIFICANTLY. THE SHORT TERM MODELS DO NOT INDICATE THAT SUCH A
SCENARIO IS LIKELY TO OCCUR. THERE IS A SLIGHTLY HIGHER PROBABILITY
THAT STRATUS CEILINGS LESS THAN 1000 FEET AGL COULD DEVELOP ALONG
AND WEST OF AN IEN-OGA-IML LINE BUT THERE IS NO MODEL INDICATION
THAT THE STRATUS CEILINGS WILL REACH AS FAR EAST AS VTN-TIF-LBF.
OTHERWISE...UNLIMITED CEILING AND VISIBILITY CAN BE EXPECTED IN MOST
OF CENTRAL AND WESTERN NEBRASKA. IN NORTHERN NEBRASKA...SOME MIDDLE
CLOUD CEILINGS ARE EXPECTED TO DEVELOP LATE TUESDAY MORNING OR EARLY
AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 351 AM CDT TUE AUG 11 2015
THE HEAVY RAIN CENTER BETWEEN KIMBLE AND SIDNEY IS SENDING AN
UNKNOWN QUANTITY OF WATER INTO LODGEPOLE CREEK WHICH DRAINS INTO
DEUEL COUNTY. THE CREEK GENERALLY FOLLOWS A ROUTE EAST BETWEEN
I-80 AND HIGHWAY 30 AND THEN HOPEFULLY CROSSES UNDER I-80
SOUTHEAST OF CHAPPELL. AT 3 AM CDT...ABOUT 2 TO 4 INCHES OF RAIN
WAS RADAR ESTIMATED WITH THE HEAVY RAIN CENTER. DAYLIGHT WILL
REVEAL THE HEIGHT OF THE WATER FLOWING EAST. NO GAGES OTHER THAN A
STAFF GAGE 6 MILES SOUTHEAST OF CHAPPELL ARE IN PLACE TO MEASURE
THE CREEK LEVEL. IT IS NORMALLY DRY. THE CHAPPELL GAGE HAS READ AS
HIGH AS 6.5 FEET IN 1968. THE STREAM TRAVEL FLOW RATE HAS BEEN
ESTIMATED AT 2 TO 4 MILES AN HOUR WHICH WOULD PUT WATER IN DEUEL
COUNTY THIS AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...SPRINGER
HYDROLOGY...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
342 AM CDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT TUE AUG 11 2015
THE SHORT TERM FORECAST REMAINS FAIRLY QUIET THROUGH THE NEXT 24
HOURS...WITH DRY CONDITIONS AND VERY LITTLE CHANGES MADE TO THE
PREVIOUS FORECAST. AN UPPER LEVEL RIDGE REMAINS DOMINATE ACROSS THE
SOUTHERN HALF OF THE CONUS...WHILE A DEEP UPPER LEVEL CLOSED LOW
TRUDGES OFF THE PACIFIC COASTLINE. AN OPEN WAVE HAS BEGUN TO SLIDE
EASTWARD ACROSS THE GREAT LAKES REGION. THE RIDGE AXIS IN THE MID
LEVELS IS SLIGHTLY MORE PRONOUNCED AND AMPLIFIED ACROSS THE FRONT
RANGE. ALONG THIS RIDGE AXIS...RETURN FLOW COMBINED WITH WARM AIR
ADVECTION HAS ALLOWED MOISTURE TO SURGE NORTHWARD ALONG THE FRONT
RANGE. AT THE SURFACE HIGH PRESSURE HAS SHIFTED ACROSS THE CENTRAL
PLAINS. LATEST OBS REFLECT THIS FEATURE AS MOST AIRPORT WINDS ARE
LIGHT TO CALM.
ALTHOUGH THIS IS NOT REFLECTED IN THE FORECAST...THERE ARE SOME
CONCERNS ABOUT PATCHY FOG DEVELOPMENT THIS MORNING. EVEN THOUGH
DEWPOINTS ARE LOWER THAN PREVIOUS DAYS...TEMPERATURES ARE ALSO
SLIGHTLY COOLER. AT THE PRESENT TIME...RELATIVE HUMIDITY VALUES ARE
ABOVE 90 PERCENT IN MOST AREAS. MODEL SOLUTIONS SUCH AS THE
NAM...RAP...AND HRRR ALL SUGGEST LOWERED VISIBILITIES ESPECIALLY FOR
LOCATIONS WEST OF 281...MAINLY ALONG THE SURFACE RIDGE AXIS. SINCE
THIS WILL LIKELY BE PATCHY IN NATURE...WILL CONTINUE TO MONITOR
LATEST TRENDS BEFORE INTRODUCING INTO GRIDS.
THE REST OF TODAY LOOKS TO REMAIN QUIET AS THE SURFACE RIDGE SLIDES
THROUGH THE AREA. LIGHT WINDS ARE EXPECTED AND HIGH TEMPERATURES
SHOULD TOP OUT NEAR NORMAL WITH HIGHS IN THE MID 80S FOR MOST
LOCATIONS. FURTHER WEST...A SMALL DISTURBANCE WILL DEVELOP ALONG THE
FRONT RANGE...AND COMBINED WITH MOISTURE AND WARM AIR ADVECTION WILL
LIKELY SPAWN THUNDERSTORMS. 0Z MODEL SOLUTIONS PULLED POPS BACK
FURTHER WEST AND THUS WENT AHEAD AND REMOVED ANY MENTION OF
THUNDERSTORMS FROM WESTERN ZONES TUESDAY NIGHT. HOWEVER...WOULD NOT
BE SURPRISED TO SEE A STORM MAKE A RUN FOR THE WESTERN ZONES DURING
THIS TIME FRAME. EVEN THE 6Z NAM...HAS NOW REVERTED BACK TO POPS IN
NORTH CENTRAL KANSAS BY EARLY MORNING WEDNESDAY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 AM CDT TUE AUG 11 2015
AN UPPER RIDGE OF HIGH PRESSURE WILL BE THE DOMINATE WEATHER FEATURE
ACROSS THE INTERIOR CONUS THROUGH THE WORKWEEK. THE PATTERN WILL BE
BLOCKY AT THE START WITH CLOSED LOWS IN THE PACIFIC OCEAN OFF THE
COAST OF CALIFORNIA AND ANOTHER TROUGH ALONG THE EAST COAST. UNDER
THE INFLUENCE OF THE RIDGE...PRECIPITATION CHANCES WILL BE
NEGLIGIBLE UNTIL THE WEEKEND TIME FRAME WHEN THE WESTERN LOW LIFTS
OUT AND BREAKS DOWN THE INTERIOR CONUS RIDGE. ALTHOUGH THE FORECAST
REMAINS DRY UNTIL SATURDAY NIGHT WILL NEED TO KEEP AN EYE ON
CONVECTION WHICH DEVELOPS ALONG THE HIGHS PLAINS AS ACTIVITY MAY TRY
TO WORK INTO OUR WESTERN ZONES.
THE PATTERN CHANGE ARRIVES OVER THE WEEKEND AS THE AFOREMENTIONED
WESTERN SYSTEM LIFTS OUT AND CROSSES THE NORTHERN CONUS. AN
ASSOCIATED COLD FRONTAL BOUNDARY ADVANCES SOUTH FROM THE DAKOTAS
LATE SATURDAY WITH CHCS FOR TSTMS RETURNING AS FRONT ARRIVES. THE
ECMWF IS SLOWER WITH BOUNDARY PROGRESSION THAN THE GFS BUT HARD TO
PINPOINT THE DETAILS THIS FAR OUT. THE BOUNDARY IS PROGGED TO STALL
OR MEANDER ACROSS OUR REGION INTO EARLY NEXT WEEK AND WITH BOUNDARY
IN THE AREA CHANCES FOR STORMS CONTINUE. TEMPERATUREWISE...READINGS
WILL BE TYPICAL OF SUMMER WITH HIGHS IN THE 80S TO LOW 90S...WITH
LOWS IN THE 60S TO LOWER 70S.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1231 AM CDT TUE AUG 11 2015
VFR CONDITIONS ARE EXPECTED THROUGHOUT THE TAF PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...SALTZMAN
LONG TERM...FAY
AVIATION...SALTZMAN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1155 PM CDT MON AUG 10 2015
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 315 PM CDT MON AUG 10 2015
THE FORECAST CHALLENGES WILL BE ANY SPOTTY PRECIPITATION AND
PATCHY FOG...OTHERWISE...MAINLY QUIET AND SEASONABLE WEATHER WITH
SURFACE HIGH PRESSURE OVER THE AREA FOR THE NEXT COUPLE OF DAYS.
ON THIS MORNING/S UPPER AIR MAPS...AN H3 JET WAS STRETCHED ACROSS
NEBRASKA. THE H5 RIDGE WAS OVER THE ROCKIES WITH A CLOSED LOW OFF
THE WEST COAST AND A SHORTWAVE TROF OVER SOUTHERN MINNESOTA INTO
SOUTH DAKOTA. THE BEST H7 DEWPOINTS WERE POOLED TO THE SOUTH FROM
THE TEXAS PANHANDLE INTO OKLAHOMA AND PARTS OF SOUTHERN COLORADO AND
NEW MEXICO AND MEXICO. 14-16 DEGREE H85 DEWPOINTS STRETCHED IN THIS
SAME AREA...BUT ALSO EXTENDED INTO KANSAS...WITH A 13 DEGREE H85
DEWPOINT LINGERING AT OAX.
THE HRRR AND HIRESW ARW/NMM HAVE SOME SPOTTY PRECIP PRIOR TO
00Z...AND THE HRRR LINGERS IT INTO THE EVENING...WHILE THE NAM/GFS
ARE MOSTLY DRY. CONVECTIVE TEMPERATURES ARE IN THE LOWER 80S...
THUS WILL CONTINUE TO MONITOR CU FIELDS FOR ANY SPOTTY POP UP
SHOWERS. THE DMX RADAR HAS A FEW SHOWERS WITH THE SHORTWAVE
PASSING THROUGH SOUTHERN IOWA. DRIER DEWPOINTS HAD MOVED INTO
EASTERN NEBRASKA...HOWEVER SOME HIGHER 14 DEG DEWPOINTS WERE STILL
IN WESTERN IOWA ALONG WITH SOME MOISTURE CONVERGENCE IN THIS AREA.
THE BEST MLCAPES PER THE SPC MESOANALYSIS WAS OVER KANSAS AND
MISSOURI WITH 500 J/KG MLCAPES OVER EASTERN NEBRASKA/WESTERN IOWA.
WITH THE WET GROUND IN SPOTS AND LIGHT WINDS TONIGHT...SOME HINTS
OF PATCHY FOG IN LOW LYING AREAS/RIVER VALLEYS WITH 1 TO 2 DEGREE
DEWPOINT DEPRESSIONS.
THE NAM HAS SOME SPOTTY PRECIP AGAIN TUESDAY EVENING MAINLY JUST
WEST OF THE FORECAST AREA AND TOWARD HARLAN WITH CONVECTION THAT
FORMS WITH THE INCREASING LOW LEVEL JET IN THE HIGH PLAINS/THETA-E
ADVECTION. THE GFS IS GENERALLY DRY THROUGH THURSDAY. WILL
MAINTAIN A MAINLY DRY FORECAST THROUGH THE SHORT TERM UNTIL THERE
IS BETTER AGREEMENT ON SUBTLE FORCING FEATURES FOR PLACEMENT OF
ANY ISOLATED PRECIPITATION.
LOWS TONIGHT SHOULD DROP BACK INTO THE 50S TO LOWER 60S TUESDAY
MORNING. HIGHS SHOULD BE IN THE 80S TUESDAY AND WEDNESDAY WITH
WARMER 80S TO LOWER 90S THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 PM CDT MON AUG 10 2015
A RIDGE OF HIGH PRESSURE ALOFT WILL KEEP TEMPERATURES ABOVE NORMAL
IN THE UPPER 80S TO LOWER 90S FRIDAY AND SATURDAY. THE RIDGE
BREAKS DOWN FOR THE WEEKEND INTO EARLY NEXT WEEK AS A COLD FRONT
SLIPS INTO THE AREA AND STALLS. FOR NOW...DO HAVE A CHANCE FOR
THUNDERSTORMS WITH THE FRONT SATURDAY NIGHT INTO MONDAY. THERE ARE
SOME TIMING DIFFERENCES WITH THE EC BEING SLOWER.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1154 PM CDT MON AUG 10 2015
THE COMBINATION OF MOISTURE AT THE SURFACE AND LIGHT WINDS COULD
CREATE SOME PATCHY FOG AT KOFK AND KOMA EARLY TUESDAY MORNING.
OTHERWISE VFR CONDITIONS WILL PREVAIL.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...KG
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1017 AM PDT TUE AUG 11 2015
.SYNOPSIS...BREEZY CONDITIONS ARE EXPECTED TODAY IN THE OWENS
VALLEY WHILE MONSOON MOISTURE WORKING BACK INTO THE AREA WILL
INCREASE THUNDERSTORM CHANCES IN MOHAVE COUNTY. THUNDERSTORM CHANCES
THEN SPREAD INTO CLARK...LINCOLN...AND SAN BERNARDINO COUNTIES BY
WEDNESDAY. TEMPERATURES WILL BE RUNNING NEAR NORMAL TO SLIGHTLY
BELOW NORMAL WHERE MOISTURE AND CLOUD COVER ARE ENHANCED...BEFORE
WARMING TO ABOVE NORMAL INTO NEXT WEEK.
&&
.UPDATE...
A NORTHWESTERLY MOVING DISTURBANCE VISIBLE ON WATER VAPOR IMAGERY
IS CURRENTLY GENERATING FAST MOVING SHOWERS AND THUNDERSTORMS OVER
PINAL AND MARICOPA COUNTIES THIS MORNING. THIS ACTIVITY IS
EXPECTED TO MOVE NORTHWESTWARD AND WILL ACT UPON AVAILABLE
MOISTURE TO GENERATE SHOWERS AND THUNDERSTORMS OVER MAINLY MOHAVE
COUNTY THIS AFTERNOON. HAVE RAISED POPS TO INCLUDE LIKELY WORDING
FOR THUNDERSTORMS...ESPECIALLY OVER NORTHERN PORTIONS OF THE
COUNTY...WITH CHANCES FURTHER WEST INTO EASTERN CLARK AND LINCOLN
COUNTIES. THE LAST SEVERAL RUNS OF THE HRRR AND LOCAL HIGH RES
MODELS CONTINUE TO SHOW A SECOND WAVE OF SHOWERS AND STORMS MOVING
INTO THE AREA OVERNIGHT INTO WEDNESDAY MORNING. POPS HAVE BEEN
ADJUSTED WESTWARD TO INCLUDE A CHANCE FOR THUNDERSTORMS IN EASTERN
PORTIONS OF SAN BERNARDINO...CLARK AND MOST OF LINCOLN COUNTIES
WEDNESDAY MORNING.
&&
.PREV DISCUSSION...327 AM PDT TUE AUG 11 2015
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT.
AN UPPER LEVEL LOW DEVELOPING SOUTHWARD OF THE WEST COAST AND HIGH
PRESSURE OVER NM/TX WILL TURN FLOW MORE SOUTHERLY WILL BRING
MONSOONAL MOISTURE FIRST MAINLY TO MOHAVE COUNTY TODAY...THEN
SPREADING FURTHER WEST OVER CLARK...LINCOLN...AND EASTERN SAN
BERNARDINO COUNTIES BY WEDNESDAY. THE SHORTWAVE MODELS HAD ROTATING
AROUND THE HIGH THIS MORNING IS MORE DIFFUSE AND FURTHER WEST WITH
THE MOST RECENT RUNS. THIS HAS RESULTED IN LESS ACTIVITY IN THE
MODELS AND LOWER CONFIDENCE IN ANY SUBSTANTIAL ACTIVITY DEVELOPING THIS
MORNING ACROSS MOHAVE COUNTY. HIGH RESOLUTION MODELS ARE IN DECENT
AGREEMENT WITH DEVELOPING MORE SUBSTANTIAL CONVECTION ACROSS MOHAVE
COUNTY THIS AFTERNOON WITH SIGNALS OF EITHER A COMPLEX OR OUTFLOW
DRIVEN ACTIVITY LINGERING UNTIL MIDNIGHT. ADDITIONALLY...ENOUGH
MOISTURE MAY HAVE SPREAD INTO CLARK COUNTY BY AROUND MIDNIGHT SUCH
THAT IF ANY OUTFLOW DOES MAKE IT AS FAR WEST...THUNDERSTORM
DEVELOPMENT CANNOT BE RULED OUT...THUS HAVE ADDED SLIGHT CHANCE OF
THUNDERSTORMS FOR THE LAS VEGAS VALLEY OVERNIGHT.
BY WEDNESDAY...MOISTURE WILL HAVE INCREASED OVER MUCH OF EASTERN SAN
BERNARDINO...CLARK...AND LINCOLN COUNTIES...WITH THE BEST MOISTURE
AND HEAVY RAIN SIGNALS STILL REMAINING OVER NORTHERN MOHAVE COUNTY.
COVERAGE ON WEDNESDAY WILL DEPEND HEAVILY ON ANY ACTIVITY TONIGHT
AND FEATURES YET TO BE RESOLVED IN THE MODELS. CURRENT FORECAST IN
GOOD SHAPE WITH MORE WIDESPREAD CHANCES INTO WEDNESDAY NIGHT.
.LONG TERM...THURSDAY THROUGH MONDAY.
MODELS ARE IN REASONABLY GOOD AGREEMENT THAT LOW TO MODERATE GRADE
MONSOON MOISTURE WILL BE IN PLACE ACROSS THE EASTERN HALF TO 2/3RDS
OF THE FORECAST AREA ON THURSDAY. WEAK CAPPING UNTIL THE AFTERNOON
AND A LACK OF DYNAMIC FEATURES (AT LEAST IN THE CURRENT GUIDANCE)
MEANS THAT STORMS WILL LIKELY BE TERRAIN DRIVEN AND ISOLATED MOVING
NORTH AT 15-20 MPH. GRADUAL DRYING TAKES PLACE THROUGH THE REMAINDER
OF THE LONG TERM...BUT THINGS NEVER DRY OUT COMPLETELY. HAVE LEFT IN
AT LEAST A SLIGHT CHANCE OF STORMS OVER AT LEAST THE HIGHER TERRAIN
OF MOHAVE COUNTY EACH DAY THROUGH MONDAY.
THE OTHER CONCERN IN THE LONG TERM PERIOD IS THE VERY HOT
TEMPERATURES THAT WILL DEVELOP BY THE WEEKEND. THE ECMWF AND GFS
GUIDANCE HAVE BOTH JUMPED UP WITH TEMPERATURES WITH THE 00Z
GUIDANCE. I RAISED TEMPERATURES TO REFLECT THAT...INTRODUCING A HIGH
OF 110F AT MCCARRAN ON SUNDAY. 110F IS THE CRITERIA AT MCCARRAN FOR
AN EXCESSIVE HEAT WATCH/WARNING DURING THIS PART OF AUGUST. HOWEVER
STILL BEING QUITE A FEW DAYS OUT AND BELOW AVERAGE INTER-MODEL AND
RUN-TO-RUN AGREEMENT I HAVE OPTED TO HOLD OFF ON ISSUING AN
EXCESSIVE HEAT WATCH WITH THIS MORNING`S FORECAST. HOWEVER THE
SATURDAY THROUGH MONDAY TIME FRAME WILL NEED TO BE MONITORED OVER
THE NEXT COUPLE DAYS.
.AVIATION...FOR MCCARRAN...CLOUDS MAY BECOME THINNER BY LATE MORNING
BEFORE INCREASING IN COVERAGE AND LOWERING TO AROUND 10K FEET THIS
EVENING. THERE IS A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM
DEVELOPING ON THE MOUNTAINS. OTHERWISE SIMILAR CONDITIONS TO
YESTERDAY ARE EXPECTED WITH GUSTY WINDS POSSIBLE AGAIN THIS
AFTERNOON AND EVENING.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...GENERAL SOUTHERLY WINDS WILL PERSIST TODAY...WITH
LOCALLY GUSTY WINDS ONCE AGAIN...ESPECIALLY IN THE OWENS VALLEY.
AREAS OF SMOKE ARE STILL POSSIBLE FROM THE WILLOW FIRE ALONG THE
COLORADO RIVER VALLEY. INCREASING MOISTURE WILL LEAD TO INCREASING
CLOUD COVER...ESPECIALLY IN WESTERN ARIZONA AND SOUTHERN NEVADA
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE...PULLIN
SHORT TERM/AVIATION...STEELE
LONG TERM...WOLCOTT
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1012 PM EDT WED AUG 12 2015
.SYNOPSIS...HIGH PRESSURE WILL GRADUALLY BUILD INTO THE REGION FROM
THE NORTHWEST THROUGH THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1010 PM WEDNESDAY...
DIURNAL CU HAS DIMINISHED AND RESULTED IN A MOSTLY CLEAR SKY ACROSS
CENTRAL NC THIS EVENING...ALTHOUGH SATELLITE IMAGERY REVEALS AN AREA
OF UPSTREAM SCT TO BKN ALTOCUMULUS IN A RELATIVE MAXIMUM OF MID-
LEVEL MOISTURE CENTERED OVER THE CENTRAL APPALACHIANS PER 00Z RAOB
DATA - MOST NOTABLE AT RNK. THIS AREA OF MOISTURE IS EXPECTED TO
DRIFT SOUTHEAST ACROSS VA AND NC IN CYCLONIC FLOW ALOFT OVERNIGHT...
WHICH WILL LIKELY RESULT IN OCCASIONAL PATCHES OF CLOUDS THAT WILL
INTERRUPT OTHERWISE EXCELLENT VIEWING CONDITIONS FOR THE PEAK OF THE
PERSEID METEOR SHOWER.
INTERESTINGLY...THE HRRR HAS INSISTED FOR SEVERAL RUNS NOW THAT
SHOWERS WILL DEVELOP IN THE LEE OF THE APPALACHIANS AS THE
AFOREMENTIONED POCKET OF MID LEVEL MOISTURE PIVOTS EAST.
HOWEVER...SUCH DEVELOPMENT WOULD BE SURPRISING OWING TO UNSEASONABLY
LOW OBSERVED PRECIPITABLE WATER VALUES OF EIGHT TO NINE TENTHS OF AN
INCH; A LACK OF ANY NOTABLE FORCING FOR ASCENT ASIDE FROM WEAK
PERTURBATIONS IN CYCLONIC FLOW ALOFT; AND THE PRESENCE OF A STOUT
CAPPING INVERSION CENTERED NEAR 700 MB. WILL CONSEQUENTLY KEEP THE
FORECAST DRY...AT LEAST UNTIL OBSERVATIONAL TRENDS SUGGEST
OTHERWISE.
THE COMBINATION OF AN UNSEASONABLY DRY AIR MASS...AND CALM
CONDITIONS...SHOULD SUPPORT COOL TEMPERATURES MOSTLY IN THE LOWER TO
MIDDLE 60S BY MORNING.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 245 PM WEDNESDAY...
THE OVERALL SYNOPTIC PATTERN WILL REMAIN LARGELY UNCHANGED ON
THURSDAY...WITH AN UPPER LEVEL TROUGH OVER THE EAST COAST AND HIGH
PRESSURE AT THE SURFACE. HOWEVER...MODELS DO INDICATE A WEAK
INVERTED TROUGH DRIFTING OVER THE REGION BY THURSDAY AFTERNOON.
REGARDLESS...GIVEN THE VERY DRY AIR AND LACK OF INSTABILITY...STILL
AM EXPECTING A MOSTLY DRY DAY. TEMPS WILL ALSO BE SIMILAR TO WHAT IS
FORECAST FOR TODAY (WEDNESDAY)...WITH HIGHS IN THE MID/UPPER
80S...MAYBE RIGHT AROUND 90 DEGREES ACROSS THE SOUTH AND OVERNIGHT
LOWS GENERALLY IN THE MID 60S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 205 PM WEDNESDAY...
THROUGH THE WEEKEND: AN UPPER LEVEL TROUGH WILL LINGER OVER THE
ATLANTIC COAST THROUGH THE WEEKEND...WITH GENERALLY SW FLOW ALOFT.
AT THE SURFACE...HIGH PRESSURE WILL DOMINATE...WITH GENERALLY
NORTHEASTERLY OR EASTERLY LIGHT WINDS. DURING THIS TIME...EXPECT DRY
WEATHER...WITH THE BEST CHANCES OF RAIN ALONG THE COAST (IN THE
VICINITY OF THE SURFACE BOUNDARY LINGERING OFF THE COAST) OR IN THE
MOUNTAINS. HIGHS WILL BE IN THE MID 80S TO AROUND 90 DEGREES...WITH
OVERNIGHT LOWS IN THE LOW TO MID 60S.
EARLY NEXT WEEK: RETURN FLOW AROUND THE HIGH WILL BECOME MORE
SOUTHERLY...ADVECTING RELATIVELY WARMER AND MORE MOIST AIR INTO
CENTRAL NC. MEANWHILE...THE AFOREMENTIONED TROUGH WEAKENS AS ANOTHER
APPROACHES FROM THE WEST. CLOUD COVER...ALONG WITH CHANCES FOR
SHOWERS AND STORMS WILL INCREASE THROUGH WEDNESDAY...ALTHOUGH THERE
IS A CHANCE MUCH OF THE AREA COULD REMAIN DRY OR SEE VERY LITTLE
PRECIPITATION. REGARDLESS...WILL CONTINUE TO FORECAST AT LEAST A
SLIGHT CHANCE FOR AFT/EVE SHOWERS/STORMS DURING THIS PERIOD. HIGHS
IN THE UPPER 80S TO LOW 90S EXPECTED...WITH GRADUALLY INCREASING
OVERNIGHT LOWS IN THE UPPER 60S TO LOW 70S.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 735 PM WEDNESDAY...
DRIER AIR HAS FILTERED OVER CENTRAL NC TODAY AS HIGH PRESSURE SLOWLY
BUILDS IN BEHIND LAST NIGHTS COLD FRONT. DEWPOINTS ARE A LITTLE
HIGHER OVER THE COASTAL PLAIN...WHERE MVFR VSBYS MAY DEVELOP LATE
TONIGHT UNDER CLEAR SKIES AND LIGHT WIND. OTHERWISE...VFR
CONDITIONS WILL PREVAIL THROUGH THE TAF.
OUTLOOK...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH EARLY NEXT
WEEK AS HIGH PRESSURE DOMINATES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...RAH
SHORT TERM...KRD
LONG TERM...RAH
AVIATION...22
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
732 PM EDT WED AUG 12 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN THROUGH FRIDAY. A COASTAL TROUGH
OF LOW PRESSURE WILL DRIFT TOWARDS THE AREA OVER THE WEEKEND.
HIGH PRESSURE WILL LINGER OVERHEAD EARLY NEXT WEEK WITH THE
POTENTIAL FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 700 PM WEDNESDAY...DIURNAL HEATING FADING QUICK AS THE
EVENING PROGRESSES. THIS REFLECTED IN THE DISSIPATING CU/MOD CU
FIELDS ACROSS THE FA VIA LATEST SAT IMAGERY...AND THE DECREASING
COVERAGE OF THE RESULTANT WIND BOUNDARY INDUCED POPCORN
-TSRA/-SHRA. HAVE BASICALLY TOOK OUT ALL REMAINING POPS BY SUNSET
...AND THE HOURS THERE-AFTER. BASED ON LATEST SAT IMAGERY TRENDS
HAVE ALSO REDUCED CLOUD COVERAGE TO BASICALLY BELOW 10 PERCENT
AFTER SUNSET. EXPECT FEW/SCT THIN CI TO ADVECT ACROSS OVERNIGHT
...AND/OR FEW/SCT LOW LEVEL SC MAY PUSH ONSHORE DURING THE PRE-
DAWN THU HOURS. NEVERTHELESS...IT SHOULD NOT PREVENT A DECENT
VIEWING OF THE PERSEID METEOR SHOWERS WHICH PEAKS TONIGHT AND THU
NIGHT. UP TO 100+ METEORS PER HOUR MAY BE VIEWED DURING THE NEXT 2
NIGHTS...AND WITH A NEW MOON UPON US MAKING THE SKIES DARKER AND
EASIER TO VIEW THE METEOR SHOWERS. TWEAKED MIN TEMPS A DEGREE OR 2
LOWER BASED ON THE CLEAR SKIES AND THE POSSIBILITY OF WINDS
DECOUPLING DUE TO THE SFC BASED INVERSION. WILL CONTINUE WITH
PATCHY FOG AFTER MIDNIGHT THRU DAYBREAK...ESPECIALLY ACROSS THE
NORMALLY PRONE LOCATIONS.
PREVIOUS.......................................................
AS OF 3 PM WEDNESDAY...VERY FEW SHOWERS HAVE TRIED TO MATERIALIZE
TODAY. A FEW HOURS AGO THIS OCCURRED IN FAR EASTERN BRUNSWICK
COUNTY AND NOW THEY ARE TRYING TO PERCOLATE NEAR SOUTHPORT. THE
END RESULT APPEARS TO BE THE SAME BOTH TIMES...NON- MEASURABLE
SPRINKLES THAT THEN SUCCUMB TO THE IMPRESSIVELY DRY AIR THAT
CONTINUES TO SEEP INTO THE AREA. DESPITE THIS I HAVE LEFT THE
20-ISH POPS ALONG THE COAST SINCE THE HIGHER REFRESH MODELS LIKE
THE HRRR AND RAP CONTINUE TO LIKE THE IDEA OF SEA BREEZE
PRECIPITATION ESPECIALLY OVER SOUTH CAROLINA AND THE CU FIELDS
SEEM TO INCREASE IN VIGOR ESPECIALLY ALONG THE SEA BREEZE FRONT. A
FACET OF THE FORECAST THAT IS OF SLIGHTLY ELEVATED INTEREST
TONIGHT IS CLOUD COVER SINCE THE PERSEID METEOR SHOWER PEAKS.
VIEWING FOR THE METEORS WILL NOT BE TERRIBLE BY ANY MEANS BUT A
PARTLY CLOUDY SKY FOR MOST IF NOT ALL OF THE OVERNIGHT MEANS THEY
SIMPLY WON`T BE IDEAL. THIS MAY HOLD TRUE MORE EARLIER RATHER THAN
LATER DEPENDING ON HOW QUICKLY THE CLOUDS DISSIPATE. AT LEAST THE
MOON WILL BE COOPERATIVE...ITS PHASE WILL BE A MERE SLIVER THAT
WON`T EVEN RISE TIL AFTER 4 AM. SLIGHTLY LOWER DEWPOINTS INLAND
COULD MEAN CLEARER SKIES OVER FAR INLAND ZONES.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...THURSDAY WILL BEGIN WITH A MID-LEVEL
TROUGH AXIS ALIGNED ACROSS THE CENTRAL CAROLINAS AND THE SWATH OF
DEEPEST MOISTURE OFFSHORE. THE CENTER OF A WEAK SURFACE HIGH WILL
SHIFT EASTWARD ACROSS THE MID-ATLANTIC STATES ALLOWING WINDS TO
VEER FROM NORTH-NORTHEAST TO EAST BY THURSDAY AFTERNOON. MODEL
TIME-HEIGHT CROSS SECTIONS DO SHOW ENOUGH MOISTURE LINGERING BELOW
700 MB TO SUPPORT AN ISOLATED SHOWER OR THUNDERSTORM
THURSDAY...HOWEVER SURFACE-BASED INSTABILITY WILL BE MINIMAL.
THINK THE CHANCE IS TOO SMALL TO WARRANT INCLUSION AT THIS TIME.
INSTABILITY WILL BE A LITTLE MORE FAVORABLE FOR CONVECTION ON
FRIDAY AFTERNOON GENERALLY SOUTH AND EAST OF A FLORENCE TO BURGAW
LINE SO WILL MAINTAIN THE SLIGHT CHANCE POP THERE. THE MID-LEVEL
TROUGH WILL WEAKEN LATE IN THE PERIOD. THIS WILL ALLOW THE DEEPER
MOISTURE AND INVERTED TROUGH OFFSHORE TO SHIFT BACK TOWARDS THE
COAST FRIDAY NIGHT AND WARRANTS THE INCLUSION OF LOW POPS ACROSS
THE COASTAL COUNTIES.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...H5 PATTERN INDICATES A WEAK TROUGH ACROSS
THE SE THROUGH THE WEEKEND WITH A STATIONARY BOUNDARY OFF THE SE
COAST. THIS BOUNDARY WILL HAVE A FEW WEAK WAVES OF LOW PRESSURE
FORM AND MOVE ALONG THIS BOUNDARY OFF THE COAST THIS WEEKEND.
GFS/ECMWF KEEP A CHANCE OF POPS ACROSS THE CWA AT TIMES SO WILL
INTRODUCE CHANCE POPS FOR THE WEEKEND. WITH SOME MID LEVEL FORCING
AND THE INTERACTION WITH THE AFTERNOON SEA BREEZE SOME ISOLATED TO
SCATTERED CONVECTION IS POSSIBLE BOTH DAYS. AS THE NEXT WEEK
BEGINS WITH THE DEVELOPMENT OF A TROUGH ACROSS THE SE WHICH BRINGS
A RETURN FLOW OF MOISTURE INTO THE REGION ALONG WITH AN INCREASED
CHANCE OF POPS FOR MONDAY AND TUESDAY AFTERNOONS WITH A GREATER
LIKELIHOOD OR POPS ON WEDNESDAY WITH AN AREA OF LOW PRESSURE
DEVELOPING ACROSS THE GULF COAST STATES AND MOVING TOWARDS THE
CAROLINAS. WILL INTRODUCE A BETTER CHANCE OF POPS FOR WED.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...POTENTIAL FOR FOG DEVELOPMENT OVERNIGHT WHICH COULD
CREATE PERIODS OF MVFR/IFR INTO THE EARLY MORNING HOURS. OTHERWISE
EXPECT VFR THROUGH THE VALID TAF PERIOD AS HIGH PRESSURE BUILDS IN.
LATEST RADAR IMAGERY DEPICTS A FEW SHRA/TSRA WHICH HAVE RECENTLY
DEVELOPED ALONG THE COAST...ONE -TSRA IN PARTICULAR CLOSE TO THE
KCRE/KMYR TERMINALS. THOUGH WILL NOT RULE OUT SOME PATCHY
DRIZZLE/LIGHT RAIN ELSEWHERE AT THE COASTAL TERMINALS THIS
EVENING...OVERALL EXPECT FAIRLY QUIET CONDITIONS WITH SKY COVERAGE
DECREASING IN OPACITY. WINDS WILL BECOME LIGHT OVERNIGHT...AND
THOUGH DRIER AIR IS INFILTRATING INTO THE AREA...DO ANTICIPATE FOG
DEVELOPMENT TO CREATE MVFR/POSSIBLE IFR CONDITIONS INTO THE EARLY
MORNING HOURS. AFTER DAYBREAK...EXPECT CONDITIONS TO IMPROVE TO
VFR...PERSISTING THROUGH THE REMAINDER OF THE VALID TAF PERIOD WITH
EASTERLY WINDS AOB 10 KTS. WILL NOT ENTIRELY RULE OUT ISOLATED
SHRA/TSRA THURSDAY AFTERNOON...BUT CONFIDENCE IS LOW ATTM.
EXTENDED OUTLOOK...ISOLATED SHRA/TSRA POSSIBLE THURSDAY AND FRIDAY.
OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 700 PM WEDNESDAY...THE MESOSCALE INDUCED RESULTANT WIND
BOUNDARY HAS MADE WINDS NEARSHORE A BIT OF A CHALLENGE...
DIRECTION-WISE...FOR THIS EVENING. OTHERWISE...SYNOPTIC EASTERLY
WINDS TO PREVAIL BY OR JUST AFTER MIDNIGHT AS RIDGING FROM HIGH
PRESSURE CENTERED ACROSS THE OHIO RIVER VALLEY RIDGES IN. THE SFC
PRESSURE GRADIENT REMAINS SOMEWHAT RELAXED RESULTING IN AROUND 10
KT FOR WIND SPEEDS ACROSS ALL WATERS. SIGNIFICANT SEAS WILL RUN 2
FT...EXCEPT OCCASIONALLY UP TO 3 FT OFF CAPE FEAR. MAINLY LOOKING
AT 3.5 TO 5.5 SECOND PERIOD WIND WAVES GOVERNING THE SIGNIFICANT
SEAS SPECTRUM. NO IDENTIFIABLE GROUND SWELL TO MENTION VIA LATEST
BUOY REPORTS AND WAVEWATCH3 OUTPUT.
PREVIOUS........................................................
AS OF 3 PM WEDNESDAY...VERY LIGHT SOUTH-SOUTHWESTERLY WINDS AHEAD
OF A WEAKENING COLD FRONT FOR MOST OF THE OVERNIGHT. LATE IN THE
PERIOD WHILST SPEEDS REMAIN SIMILARLY LIGHT THERE COULD BE A
BACKING OF THE FLOW AS THE BOUNDARY SINKS FURTHER SOUTH AND A WEAK
PUSH OF HIGH PRESSURE COMES IN FROM OUR NORTH. SEAS ALREADY JUST
2-2.5 FT...LIKELY SETTLING SLIGHTLY BELOW THE LATTER VALUE THROUGH
THE PERIOD.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...THE CENTER OF SURFACE HIGH PRESSURE WILL
BUILD ACROSS THE MID-ATLANTIC STATES ON THURSDAY AND PUSH OFF THE
DELMARVA PENINSULA ON FRIDAY. A WEAK SURFACE TROUGH OFF THE GA
COAST THURSDAY IS EXPECTED TO SLOWLY DRIFT TOWARDS THE AREA
THROUGH THE PERIOD. THE RESULT WILL BE NORTHEAST WINDS BECOMING
EASTERLY THURSDAY AFTERNOON...BUT BACKING TO THE NORTHEAST AGAIN
THURSDAY NIGHT. SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO
REMAIN WELL OFFSHORE THURSDAY...BUT MAY DRIFT WESTWARD INTO THE
COASTAL WATERS LATE FRIDAY WITH THE APPROACH OF THE SURFACE
TROUGH.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...CONDITIONS WILL CHANGE VERY LITTLE FOR THE
MARINE COMMUNITY FOR THE WEEKEND. WINDS WILL PRIMARILY BE OUT OF
THE NE WITH A SHIFT TO THE ESE BY THE END OF THE WEEKEND AND BECOME
MORE S TO SW DURING THE BEGINNING OF NEXT WEEK. EXPECT 10 KTS OR
LESS THROUGHOUT THE PERIOD WITH SEAS RUNNING 1-3 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CRM
NEAR TERM...DCH/MBB
SHORT TERM...CRM
LONG TERM...MAC
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
352 PM EDT TUE AUG 11 2015
.SYNOPSIS...
RAIN CHANCES WILL INCREASE TONIGHT AND INTO WEDNESDAY AS A COLD
FRONT MAKES ITS WAY THROUGH THE AREA. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT LATE WEDNESDAY...OFFERING SEASONABLE AND MAINLY
DRY CONDITIONS INTO THE WEEKEND. A CHANCE OF RAIN MAY RETURN EARLY
NEXT WEEK AS HIGH PRESSURE MOVES OFFSHORE AND DIRECTS MOISTURE
ONSHORE.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 300 PM TUESDAY...A TWEAK OR 2 HERE AND THERE WITH POPS FOR THE
REMAINDER OF THIS AFTN AND NIGHT...BUT OVERALL WILL CONTINUE WITH
GOOD CHANCE POPS WITH THE DAYS INSOLATION FINALLY AIDING THE
DESTABILIZING OF THE ATM WITH CONVECTION NOW FIRING ACROSS PORTIONS
OF THE ILM CWA. ONCE THE DAYS INSOLATION ENDS...GO SEE A BRIEF LULL
WITH CONVECTION THIS EVENING. AS INDICATED EARLIER...BUT THEN RAMP
BACK UP LATER THIS EVENING AND OVERNIGHT DUE TO THE APPROACH AND
PASSAGE OF CONVECTION THAT ORIGINATED UPSTREAM EARLIER THIS EVENING.
WILL CONTINUE TO MENTION 25 TO 45 MPH WIND GUSTS POSSIBLE FROM THE
STRONGER STORMS WITHIN THE HAZARDOUS WX OUTLOOK.
PREVIOUS..........................................................
AS OF 130 PM TUESDAY...HAVE TWEAKED THIS AFTN MAX TEMPS A DEGREE OR
2 LOWER FOR BASICALLY THE ILM NC COUNTIES DUE TO THE EXTENDED PERIOD
OF OVERCAST SKIES. THE ILM SC COUNTIES ACTUALLY NEEDED A DEGREE OR 2
ADJUSTMENTS HIER...MAINLY CLOSER TO THE IMMEDIATE COAST DUE TO A
SOMEWHAT PINNED SEA BREEZE DUE TO SW-WSW WINDS 25-35 KT IN THE LOWER
LEVELS...SFC THRU 700MB. STILL THINK CONVECTION WILL FIRE LATER THIS
AFTN AND EVENING DUE TO THE DAYS INSOLATION. LATEST HRRR AND WRF
INDICATE THAT CONVECTION WILL DEVELOP UPSTREAM CLOSER TO THE COLD
FRONT LATE THIS AFTN...AND MAKE A BEE-LINE TO THE ILM CWA LATER THIS
EVENING AND INTO THE PRE-DAWN WED HRS. AND ACTUALLY MAY INCREASE
INTENSITY AND/OR COVERAGE AS IT PUSHES TO THE COAST. WITH THAT ON
THE TABLE NOW...HAVE DECIDED TO KEEP THE GOOD CHANCE POPS ACROSS THE
FA WELL INTO THE NIGHT TIME HRS. HAVE BACKED OFF WITH THE COLD
FRONTS PROGRESSION TO THE COAST OVERNIGHT...AND BASICALLY NOW HAVE
IT REACHING THE I-95 CORRIDOR BY DAYBREAK WED. SOME RE-ADJUSTMENTS
TO MIN TEMPS HAVE NOW BEEN APPLIED TO ACCOUNT FOR THE COLD FRONTS
SLOWER PROGRESSION.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...TRICKY FORECAST FOR MID-WEEK DUE TO TIMING OF
A COLD FRONT WHICH WILL BE DRIFTING ACROSS THE CWA ON WEDNESDAY. GFS
SEEMS TO BE A FAST OUTLIER AND IS NOT PREFERRED...AND INSTEAD RELY
ON A NAM/ARW/WPC BLEND FOR THE PERIOD.
COLD FRONT...DRIVEN BY AN ANOMALOUSLY STRONG UPPER TROUGH ACROSS THE
EAST...WILL BE ALONG OR JUST WEST OF I-95 AT FIRST LIGHT WEDNESDAY.
THIS FRONT WILL THEN SLOWLY PUSH SE THROUGH THE DAY...LIKELY MOVING
OFFSHORE WEDNESDAY EVENING. IN THIS SETUP...CONVERGENCE WILL BE
MAXIMIZED ALONG THE FRONT WHERE NW WINDS INTERSECT SW RETURN FLOW
WINDS. GUIDANCE IS PRETTY AGGRESSIVE DEVELOPING CONVECTION ALONG
THIS BOUNDARY ACROSS THE EASTERN HALF OF THE CWA ON WEDNESDAY...IN A
REGION CHARACTERIZED BY 1000 J/KG OF SBCAPE AND PWATS AROUND 2
INCHES. HOWEVER...THE MID-LEVEL W/NW FLOW DRIVING THE FRONT WILL
CREATE VERY DRY AIR ABOVE 700MB...AND MOST OF THE HIGH-RH AIR IS IN
THE 1000-800MB LAYER. WHILE THIS SUPPORTS AT LEAST A GOOD CHC FOR
SHOWERS...THUNDERSTORMS WILL BE DIFFICULT TO COME BY THANKS TO THE
CHARGE SEPARATION LAYER BEING VERY DRY. HOWEVER...STRONG SURFACE
CONVERGENCE AND SOME PVA WILL ALLOW AT LEAST SOME UPDRAFTS TO BE
STRONG ENOUGH TO CAUSE LIGHTNING. WILL RAMP POP TO HIGH-CHC THE
EASTERN HALF OF THE CWA...WITH LOW LIKELY ALONG THE IMMEDIATE COAST.
PRECIP WILL COME TO AN END AS THE FRONT MOVES OFFSHORE LATE
WEDNESDAY.
THIS FRONT WILL REMAIN STALLED OFFSHORE ON THURSDAY...WITH DRIER AND
COOLER AIR ADVECTING INTO THE CWA BEHIND IT. MUCH OF THE DAY SHOULD
BE DRY...BUT AS WINDS SHIFT TO NE AND THEN E...SOME ATLANTIC
MOISTURE MAY ADVECT BACK ONSHORE. THIS WILL OCCUR WHILE MID-LEVEL
LAPSE RATES REMAIN STEEP THANKS TO THE UPPER TROUGH...AND A FEW
SHOWERS OR THUNDERSTORMS CANNOT BE RULED OUT THURSDAY...MOST LIKELY
WITHIN THE SOUTHERN COASTAL ZONES. TOTAL COVERAGE IS EXPECTED TO BE
ISOLATED AT WORST HOWEVER.
TEMPS WEDNESDAY AHEAD OF THE FRONT WILL RISE INTO THE UPPER 80S TO
LOWER 90S...WITH MAXIMUMS A FEW DEGREES COOLER BEHIND IT ON
THURSDAY. LOWS WEDNESDAY NIGHT WILL FALL INTO THE UPPER 60S
INLAND/LOW 70S AT THE COAST WED NIGHT...WITH MINS AGAIN A BIT COOLER
THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY... UPPER TROUGHINESS REMAINS IN PLACE ON
FRIDAY WITH DEEP, PRECIP SUPPORTING MOISTURE JUST OFFSHORE. THE
WRF IS RATHER ALONE IN ITS SOLUTION OF A MORE CUTOFF UPPER LOW
NEAR KSAV THAT COULD FLING MOISTURE INTO COASTAL COUNTIES ESP SC.
HAVE RAISE FORECAST POPS SLIGHTLY IN DEFERENCE TO THIS SOLUTION
ESPECIALLY GIVEN THE SATELLITE PRESENTATION ACROSS THE UPSTREAM
PACIFIC OCEAN. BY SATURDAY THE MID LEVEL REPRESENTATION OF THE
TROUGH WILL BE A MERE SHEAR LINE AND LIKELY HAVE LITTLE EFFECT ON
THE FORECAST. SURFACE FLOW REMAINS VERY LIGHT DUE TO A POORLY
DEFINED PRESSURE PATTERN-BOTH NOT VERY CONDUCIVE OF RAINFALL.
SUNDAY AND MONDAY THIS FEATURE IS MAINTAINED DESPITE ITS WEAKNESS
AND IT DRIFTS WESTWARD. NORMAL THIS ALLOW FOR SOME DEEPER MOISTURE
TO ADVECT INTO THE CAROLINAS AS THEY FIND THEMSELVES DOWNSTREAM OF
THE TROUGH. MODELS ARE NOT TOO IMPRESSED WITH THE MOISTURE RETURN
AND POPS WILL BE CAPPED AT VERY LOW VALUES. TUESDAY APPEARS TO BE
THE DAY WHEN THE MOISTURE GROWS DEEP ENOUGH FOR POPS TO RISE ABOVE
THE SILENT 20/ISO VALUE.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...TEMPO SHRA/MVFR AND POSSIBLY VCTS WILL AFFECT
KFLO/KLBT MAINLY THIS AFTERNOON. BEST CONFIDENCE OF OCCURRENCE IS
AT KFLO. THE COASTAL TERMINALS WILL HAVE A BETTER CHANCE SHRA/MVFR
WITH TSRA/TEMPO IFR ESPECIALLY KCRE/KMYR DUE TO A PINNED SEA
BREEZE. WINDS WILL BE SW-SSW WITH GUSTS TO AROUND 20 KTS MAINLY AT
THE COASTAL TERMINALS. ACTIVITY SHOULD DISSIPATE TO ISOLATED
THUNDER SHOWERS EARLY EVENING BUT LOOKS LIKE TSRA COVERAGE MAY
INCREASE DURING THE MID TO LATE EVENING HRS AND POSSIBLY EXTEND
INTO THE PRE-DAWN WED HRS ACROSS THE COASTAL TERMS AS NEAR TERM
MODELS THINK UPSTREAM CONVECTION MAY HOLD TOGETHER AS IT DROPS TO
THE SE OVERNIGHT.
WINDS WILL SHIFT TO THE NW-N AT KLBT/KFLO OVERNIGHT INTO DAYLIGHT
WED...BUT REMAIN SW AT THE COASTAL TERMINALS INTO DAYLIGHT WED.
THERE IS A CHANCE OF MVFR ST/FOG IN THE EARLY MORNING HOURS
ACROSS KLBT. CONFIDENCE IS LOW ATTM. OTHERWISE...VFR 13Z-18Z WED.
EXTENDED OUTLOOK...VFR WITH ISOLATED SHOWERS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM TUESDAY...PREVIOUS WINDS UPDATE STILL AOK...AND WILL
CONTINUE TO ILLUSTRATE WINDS INCREASING TO 15 TO 20 KT BY EARLY
EVENING AND CONTINUING OVERNIGHT. HOWEVER...LATEST IN-HOUSE SWAN
MODEL RUN NOW INDICATES A FEW 5 FOOTERS POSSIBLE OVERNIGHT
ESPECIALLY OFF CAPE FEAR...AS PREVIOUSLY MENTIONED. AS A
RESULT...HAVE UPPED THE SIGNIFICANT SEAS TO A SOLID 4 FOOT FOR THE
WATERS FROM CAPE FEAR SOUTH TO LITTLE RIVER INLET...AND THE
PHRASEOLOGY OF 5 FOOTERS POSSIBLE ACROSS THE OUTERS OFF CAPE FEAR.
INITIALLY...THE ENE 1.5 FOOT LAZY GROUND SWELL WILL DOMINATE THE
SIG. SEAS SPECTRUM...ENERGY-WISE...BUT GIVE WAY TO THE 3 TO 5 SECOND
SW WIND DRIVEN CHOP LATER THIS EVENING AND OVERNIGHT. BOTH WINDS
AND SIG. SEAS COMBINED REMAIN JUST BELOW SCEC CONDITIONS. IF THE 5
FOOTERS BECOME MORE COMMON THAN WILL HAVE TO RE-VISIT THE ISSUANCE
OF A POSSIBLE SCEC.
PREVIOUS..........................................................
AS OF 130 PM TUESDAY...MODEL SFC PRESSURE PATTERN AND GRADIENT AHEAD
OF THE APPROACHING COLD FRONT CONTINUE TO ILLUSTRATE SW WINDS
INCREASING TO 15-20 KT BY LATE THIS AFTERNOON AND CONTINUING THRU
TONIGHT. SIGNIFICANT SEAS WILL RESPOND AND BUILD TO AROUND 3 FT LATE
THIS AFTERNOON...AND A SOLID 3 TO 4 FT TONIGHT. IF A SOLID 12 HRS OF
15-20 KT SW WINDS OCCUR...THE AREA WATERS WILL LIKELY SEE 5 FOOTERS
ESPECIALLY OFF CAPE FEAR. AT THIS POINT...HAVE NO RECEIVED A SEAS
UPDATE WITH THE LOCAL SWAN RUN AND THUS WILL HOLD OFF WITH THE 5
FOOTERS FOR NOW. CONVECTION MOVING OFF THE MAINLAND MAY BECOME MORE
COMMON LATER THIS EVENING AND OVERNIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...COLD FRONT APPROACHING FROM THE WEST WILL
MOVE SLOWLY TOWARDS THE WATERS DURING WEDNESDAY...BEFORE STALLING
OFFSHORE THROUGH THURSDAY. WINDS EARLY WEDNESDAY WILL BE AROUND 15
KTS FROM THE SW AHEAD OF THE FRONT...BUT WILL THEN EASE AS THE FRONT
APPROACHES THANKS TO THE WEAKENING GRADIENT. WINDS REMAIN OUT OF THE
SW INTO TUESDAY NIGHT BEFORE THE FRONT CROSS THE WATERS...CREATING A
WIND SHIFT TO THE NORTH BY THURSDAY MORNING AT LESS THAN 10 KTS. AS
THIS FRONT SINKS SOUTHWARD AND STALLS THURSDAY...WINDS WILL VEER
FURTHER TO THE EAST MOST OF THE DAY...BUT AT STILL LIGHT SPEEDS
AROUND 10 KTS. HIGHEST SEAS THIS PERIOD WILL BE THE FIRST FEW HOURS
ON WEDNESDAY ON THE STRONGER SW WINDS...REACHING 3-5 FT...BEFORE
FALLING OFF TO 2-3 FT LATE WEDNESDAY AND THROUGH THE REMAINDER OF
THE PERIOD.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 300 PM TUESDAY... THERE WILL NOT BE MUCH OF A PRESSURE
GRADIENT IN PLACE FOR MOST OF IF NOT THE ENTIRE PERIOD. AS SUCH WE
ONLY EXPECT A LIGHT/LESS THAN 10 KT WIND FOR THE MOST PART BLOWING
ONSHORE LARGELY DRIVEN BY THE SEA BREEZE. IN THE ABSENCE OF ANY
SWELL OVER THE OCEAN DUE TO NO STRONG ESTABLISHED FETCHES LOCAL
SEAS WILL BE MINIMAL AND GENERALLY CAPPED AT 2 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...DCH
SHORT TERM...JDW
LONG TERM...MBB
AVIATION...DCH/MRR
MARINE...DCH/JDW/MBB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
216 PM EDT TUE AUG 11 2015
.SYNOPSIS...
RAIN CHANCES WILL INCREASE TODAY AND MAY EXTEND INTO WEDNESDAY AS
A COLD FRONT MAKES ITS WAY THROUGH THE AREA. HIGH PRESSURE WILL
BUILD IN BEHIND THE FRONT WEDNESDAY...OFFERING SEASONABLE AND
MAINLY DRY CONDITIONS INTO THE WEEKEND. A CHANCE OF RAIN MAY
RETURN EARLY NEXT WEEK AS HIGH PRESSURE MOVES OFFSHORE AND DIRECTS
MOISTURE ONSHORE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM TUESDAY...HAVE TWEAKED THIS AFTN MAX TEMPS A DEGREE
OR 2 LOWER FOR BASICALLY THE ILM NC COUNTIES DUE TO THE EXTENDED
PERIOD OF OVERCAST SKIES. THE ILM SC COUNTIES ACTUALLY NEEDED A
DEGREE OR 2 ADJUSTMENTS HIER...MAINLY CLOSER TO THE IMMEDIATE
COAST DUE TO A SOMEWHAT PINNED SEA BREEZE DUE TO SW-WSW WINDS
25-35 KT IN THE LOWER LEVELS...SFC THRU 700MB. STILL THINK
CONVECTION WILL FIRE LATER THIS AFTN AND EVENING DUE TO THE DAYS
INSOLATION. LATEST HRRR AND WRF INDICATE THAT CONVECTION WILL
DEVELOP UPSTREAM CLOSER TO THE COLD FRONT LATE THIS AFTN...AND
MAKE A BEE-LINE TO THE ILM CWA LATER THIS EVENING AND INTO THE
PRE-DAWN WED HRS. AND ACTUALLY MAY INCREASE INTENSITY AND/OR
COVERAGE AS IT PUSHES TO THE COAST. WITH THAT ON THE TABLE
NOW...HAVE DECIDED TO KEEP THE GOOD CHANCE POPS ACROSS THE FA WELL
INTO THE NIGHT TIME HRS. HAVE BACKED OFF WITH THE COLD FRONTS
PROGRESSION TO THE COAST OVERNIGHT...AND BASICALLY NOW HAVE IT
REACHING THE I-95 CORRIDOR BY DAYBREAK WED. SOME RE-ADJUSTMENTS TO
MIN TEMPS HAVE NOW BEEN APPLIED TO ACCOUNT FOR THE COLD FRONTS
SLOWER PROGRESSION.
PREVIOUS.......................................................
AS OF 1000 AM TUESDAY...HAVE MODIFIED PCPN TYPE FOR THE REMAINDER
OF THIS MORNING AND AFTERNOON TO REFLECT ONGOING SPOTTY LIGHT RAIN
AND/OR SHOWERS VIA 88D RADAR TRENDS...AND INTRODUCING THUNDER BY
MIDDAY. HAVE TONED DOWN THE REMAINING MORNING POPS INTO THE AFTN
TO ACCOUNT FOR THE DELAY IN THE ATM DESTABILIZING DUE TO THE
WIDESPREAD CLOUDINESS AND SPOTTY LIGHT PCPN. STILL EXPECT CLOUDS
TO THIN ENOUGH FOR INSOLATION TO FINALLY AID DESTABILIZATION LATER
THIS AFTN AND EVENING. HAVE ALSO TWEAKED MAX TEMPS BY A DEGREE OR
2 TODAY...MAINLY LOWER TO ACCOUNT FOR THE OVERALL LOWER AMOUNT OF
INSOLATION MAKING IT TO THE SFC.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...COLD FRONT WILL BE MAKING ITS WAY OFF THE
COAST ON WEDNESDAY...BUT MAY GET HUNG UP RIGHT ALONG THE COAST
LONG ENOUGH TO PRODUCE SOME CONVECTION AS W-NW WINDS BEHIND FRONT
COME UP AGAINST ON SHORE SEA BREEZE FLOW. THEREFORE WILL KEEP SOME
POTENTIAL FOR SHWRS/TSTMS THROUGH WED AFTN MAINLY ALONG AND NEAR
THE COAST. PCP WATER VALUES DROP DOWN TO 1.5 INCHES THROUGH EARLY
WED AND CONTINUE TO FALL TO LESS THAN 1.25 INCHES BY LATE WED INTO
THURS. INLAND WILL SEE DRIER AIR COME EARLIER IN THE DAY WITH
VALUES DOWN TO 1.25 INCHES BY NOON. MID TO UPPER TROUGH WILL DIG
DOWN REMAINING ALIGNED DOWN THE EAST COAST WITH TROUGH AXIS
SHIFTING OFF THE COAST LEAVING A DEEPER DRIER NORTHERLY FLOW
ACROSS THE CAROLINAS THROUGH MID WEEK. OVERALL EXPECT CLEARING
SKIES THROUGH EARLY WED BUT RESIDUAL LOW LEVEL MOISTURE WILL
COMBINE WITH LOCALIZED CONVERGENCE TO PRODUCE SOME CLOUDS AND A
POSSIBLE SHWR/TSTM OR TWO ONCE SEA BREEZE KICKS UP CLOSER TO THE
COAST. DEWPOINT TEMPS WILL DROP OFF AS DRIER AIR FILTERS IN WITH
READINGS DOWN IN THE MID 60S BY WED AFTN INLAND. THIS DRIER AIR
WILL FILTER TOWARD THE COAST BY WED NIGHT. THE LESS HUMID AIR
WILL ALLOW FOR GREATER DIURNAL SWINGS AND EXPECT TEMPS TO RUN
SLIGHTLY BELOW NORMAL BY THURS...BUT TEMPS SHOULD RUN WARMER IN
DOWNSLOPE FLOW ON WED.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 330 AM TUESDAY...MID TO UPPER TROUGH CONTINUES TO HANG
DOWN THE EAST COAST WITH TROUGH AXIS FAR ENOUGH EAST TO KEEP BEST
LIFT AND MOISTURE OFF THE COAST THROUGH MUCH OF THE LATE WEEK
PERIOD. WEAK HIGH PRESSURE WILL KEEP LIGHT AND VARIABLE WINDS WITH
A GENERAL NORTHERLY COMPONENT TO THE FLOW. WITH SUCH LIGHT
PREVAILING WINDS AND PLENTY OF SUNSHINE...EXPECT SEA BREEZE TO
DRIVE THE WINDS EACH AFTERNOON. MODELS SHOW TROUGH ALOFT SHIFTING
BACK TO THE WEST ALLOWING FOR A DEEPER SOUTHERLY FLOW TO DEVELOP
LATE SUN INTO MONDAY. ALSO...SFC HIGH PRESSURE WILL SHIFT OFF THE
COAST BY LATE SUNDAY ALLOWING WINDS TO COME AROUND TO A MORE
SOUTHERLY DIRECTION...ALTHOUGH REMAINING LIGHT. THIS SHOULD BRING
AN INCREASING CHC OF CONVECTION BACK INTO THE FORECAST FOR LATE
SUNDAY INTO MONDAY. BUT OTHERWISE EXPECT CLEARING THROUGH EARLY
THURS AND THEN PLENTY OF SUNSHINE AND NEAR SEASONABLE TEMPS
THROUGH THE WEEKEND. WITH LESS HUMID AIR MASS IN PLACE...TEMPS
WILL HAVE GREATER DIURNAL SWINGS.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...TEMPO SHRA/MVFR AND POSSIBLY VCTS WILL AFFECT
KFLO/KLBT MAINLY THIS AFTERNOON. BEST CONFIDENCE OF OCCURRENCE IS
AT KFLO. THE COASTAL TERMINALS WILL HAVE A BETTER CHANCE SHRA/MVFR
WITH TSRA/TEMPO IFR ESPECIALLY KCRE/KMYR DUE TO A PINNED SEA
BREEZE. WINDS WILL BE SW-SSW WITH GUSTS TO AROUND 20 KTS MAINLY AT
THE COASTAL TERMINALS. ACTIVITY SHOULD DISSIPATE TO ISOLATED
THUNDER SHOWERSEARLY EVENING BUT LOOKS LIKE TSRA COVERAGE MAY
INCREASE DURING THE MID TO LATE EVENING HRS AND POSSIBLY EXTEND
INTO THE PRE-DAWN WED HRS ACROSS THE COASTAL TERMS AS NEAR TERM
MODELS THINK UPSTREAM CONVECTION MAY HOLD TOGETHER AS IT DROPS TO
THE SE OVERNIGHT.
WINDS WILL SHIFT TO THE NW-N AT KLBT/KFLO OVERNIGHT INTO DAYLIGHT
WED...BUT REMAIN SW AT THE COASTAL TERMINALS INTO DAYLIGHT WED.
THERE IS A CHANCE OF MVFR ST/FOG IN THE EARLY MORNING HOURS
ACROSS KLBT. CONFIDENCE IS LOW ATTM. OTHERWISE...VFR 13Z-18Z WED.
EXTENDED OUTLOOK...VFR WITH ISOLATED SHOWERS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM TUESDAY...MODEL SFC PRESSURE PATTERN AND
GRADIENT AHEAD OF THE APPROACHING COLD FRONT CONTINUE TO
ILLUSTRATE SW WINDS INCREASING TO 15-20 KT BY LATE THIS
AFTERNOON AND CONTINUING THRU TONIGHT. SIGNIFICANT SEAS WILL
RESPOND AND BUILD TO AROUND 3 FT LATE THIS AFTERNOON...AND A SOLID
3 TO 4 FT TONIGHT. IF A SOLID 12 HRS OF 15-20 KT SW WINDS
OCCUR...THE AREA WATERS WILL LIKELY SEE 5 FOOTERS ESPECIALLY OFF
CAPE FEAR. AT THIS POINT...HAVE NO RECEIVED A SEAS UPDATE WITH
THE LOCAL SWAN RUN AND THUS WILL HOLD OFF WITH THE 5 FOOTERS FOR
NOW. CONVECTION MOVING OFF THE MAINLAND MAY BECOME MORE COMMON
LATER THIS EVENING AND OVERNIGHT.
PREVIOUS.......................................................
AS OF 1015 AM TUESDAY...ATTM ONLY CHANGE WAS MADE TO THE POTENTIAL
PCPN MOVING ACROSS THE FA. THIS IS IN REGARD TO AREAL COVERAGE AND
OVERALL POPS LATE THIS MORNING THRU TONIGHT. EXPECT SEAS TO BUILD
TO 2 TO 4 FT...WITH THE 4 FOOTERS PRIMARILY OFF CAPE FEAR THIS
AFTN...PEAKING DURING THE PREDAWN WED HRS. WIND DRIVEN WAVES TO
DOMINATE SIG. SEAS WITH 3 TO 5 SECOND PERIODS. WILL HAVE TO TAKE
ANOTHER LOOK AT THE LATEST VARIOUS MODEL SFC PRESSURE FIELDS AND
GRADIENTS FOR TONIGHTS WINDS WHICH MAY BE SLIGHTLY UNDER-DONE.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...COLD FRONT MAY GET HUNG UP RIGHT ALONG THE
COAST ON WED PRODUCING A MORE VARIABLE WIND FLOW...BUT AS SOON AS
ON SHORE SEA BREEZE SETTLES DOWN WED NIGHT...FRONT WILL GET A PUSH
OFF SHORE AS HIGH PRESSURE BUILDS DOWN BEHIND IT. OVERALL EXPECT
WINDS TO VEER AROUND TO THE W-NW EARLY WED AND THEN BECOME MORE
VARIABLE WED AFTN BEFORE INCREASING SLIGHTLY OUT OF THE N-NE
THURS NIGHT AS HIGH PRESSURE BUILDS IN. SEAS WILL SETTLE TO 2-3
FT WED AFTN AND EVENING AS WINDS LIGHTEN UP...BUT SHOULD RISE A
LITTLE THURS NIGHT INTO EARLY FRI AS HIGH BUILDS IN. A LONGER
PERIOD EASTERLY SWELL UP TO 9 SEC WILL MIX IN WITH GENERALLY LOW
END SHORTER PERIOD WINDS WAVES. SEAS MAY REACH BACK UP TO 4 FT
THURS NIGHT...MAINLY IN OUTER WATERS.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 330 AM TUESDAY...WEAK HIGH PRESSURE OVER THE SOUTHEAST WILL
BECOME MORE DIFFUSE LEAVING FAIRLY LIGHT PREVAILING WINDS. OVERALL
EXPECT NORTHERLY FLOW TO VEER AROUND BECOMING MORE EASTERLY AS
WEAK HIGH PRESSURE REMAINS STRETCHED ACROSS THE REGION WITH
CENTER TO THE NORTH. WINDS WILL REMAIN LESS THAN 15 KTS FOR THE
MOST PART. EXPECT SPIKE IN WINDS EACH AFTN DUE TO SEA BREEZE. A
LONGER PERIOD EASTERLY SWELL WILL BEGIN TO DOMINATE AS SHORTER
PERIOD WIND WAVES DIMINISH INTO THE WEEKEND.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...DCH/REK
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
120 AM EDT TUE AUG 11 2015
.SYNOPSIS...
RAIN CHANCES WILL INCREASE TUESDAY AND MAY EXTEND INTO WEDNESDAY
AS A COLD FRONT MAKES ITS WAY THROUGH THE AREA. HIGH PRESSURE
WILL BUILD IN BEHIND THE FRONT WEDNESDAY...OFFERING SEASONABLE
AND MAINLY DRY CONDITIONS INTO THE WEEKEND. A CHANCE OF RAIN MAY
RETURN EARLY NEXT WEEK AS HIGH PRESSURE MOVES OFFSHORE AND DIRECTS
MOISTURE ONSHORE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 115 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSIONS FOLLOW:
TRIMMED BACK FORECAST SHOWER CHANCES A LITTLE MORE AS ONLY A FEW
SPOTTY RETURNS ARE NOTED UPSTREAM ON RADAR ACROSS SOUTH CAROLINA.
THE HEAVIER ACTIVITY WHICH AFFECTED THE CHARLOTTE/LAKE NORMAN AREA
EARLIER THIS EVENING IS TAKING OFF TO THE NE ACROSS
ASHEBORO/BURLINGTON AND WILL MISS MY FORECAST AREA WELL TO THE
NORTH. THE MODELS WHICH SEEM TO HAVE A GOOD HANDLE ON THE EASTERN
EDGE OF THE PRECIP INCLUDE THE 12Z ECMWF...00Z NAM...AND 12Z NMM-
ARW. NO SIGNIFICANT CHANGES HAVE BEEN MADE TO TEMPERATURES.
DISCUSSION FROM 300 PM FOLLOWS...
CLOUD COVER HAS BEEN PRETTY EXTENSIVE ACROSS THE INLAND HALF OF
THE CWA...BUT COASTAL SECTIONS HAVE ONCE AGAIN EXPERIENCED A GREAT
EARLY-AUGUST DAY. MOISTURE WILL CONTINUE TO INCREASE IN BOTH THE
MID-LEVELS AND AT THE SURFACE...FINALLY OVERCOMING THE VERY DRY
AIR IN PLACE AS THE SURFACE RIDGE OVERHEAD SHIFTS OFFSHORE.
SHOWERS THAT HAD DEVELOPED WEST OF THE CWA HAVE ERODED AS EXPECTED
THANKS TO ENCOUNTERING DRY AIR...AND HIGH RES GUIDANCE INCLUDING
THE HRRR AND NSSL WRF BOTH KEEP THE CWA DRY THROUGH TONIGHT. HAVE
REMOVED MENTION OF POP FROM EVEN IN THE FAR INLAND ZONES THROUGH
DARK TO ACCOUNT FOR TRENDS IN SATELLITE AND RADAR.
TONIGHT...COLUMN SATURATION WILL CONTINUE TO INCREASE WITH PWATS
RISING TOWARDS 2 INCHES BY TUESDAY MORNING. COLD FRONT APPROACHING
FROM THE WEST WILL BE NEAR THE CWA BY MORNING...WITH SHOWERS AND
THUNDERSTORMS INCREASING AHEAD OF IT. FORECAST PROFILES SUGGEST
ENOUGH SATURATION INLAND THAT POP HAS BEEN RAMPED UP TO HIGH CHC
FROM I-95 WESTWARD BY 8AM TUESDAY...WITH JUST SCHC ALONG THE
COAST...BUT MOST OF THE PRECIP WILL HOLD OFF UNTIL AFTER THIS PERIOD.
INCREASING CLOUD COVER AND CONTINUED LIGHT SOUTHERLY WINDS WILL KEEP
MINS ELEVATED TO ABOVE SEASONABLE NORMS TONIGHT. THE MAV AND MET ARE
IN GOOD AGREEMENT...AND HAVE FORECAST MORE CLOSELY TO THE SLIGHTLY
WARMER MAV NUMBERS. EXPECT LOWS IN THE 72-75 DEGREE RANGE THROUGHOUT
THE AREA.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...THE PRIME WEATHER CAPTION FOR TUE/WED IS RAIN
AS AN APPROACHING FRONTAL SYSTEM WITH RELATIVELY HIGH AMOUNTS OF
INGESTED PRECIPITABLE WATER...CROSSES THE APPALACHIAN MOUNTAINS
EARLY TUESDAY AND MOVES TO THE COAST TUESDAY NIGHT. IT APPEARS A
WEAK WAVE OF LOW PRESSURE MOVING NNE ALONG THE FRONT MAY SUSTAIN
ISOLATED COASTAL SHOWERS SLIGHTLY BEHIND THE DECAYING FRONTAL SYSTEM
ON WEDNESDAY. BEST FIT AND CONSENSUS QPF DEPICTIONS OF STORM/SYSTEM
TOTAL POINTS GENERALLY TO 0.50-0.75 INCHES OF RAIN TUE/WED AND
HIGHEST ALONG AREAS IN PROXIMITY TO THE COAST. A TREND OF DRYING
WILL PREVAIL ON WEDNESDAY ESPECIALLY INLAND...IN THE FACE OF
ISOLATED COASTAL SHOWERS.
POST-FRONTAL DOWNSLOPE WIND FLOW WEDNESDAY WITH LITTLE COLD AIR
ADVECTION WILL LIKELY RESULT IN A SEASONABLY WARM DAY WEDNESDAY
ALTHOUGH WE WILL OBSERVE SEVERAL DEGREES OF DEWPOINT DROPS THROUGH
WEDNESDAY...TAKING A SLIGHT EDGE OFF THE HUMIDITY LEVELS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MID LEVEL TROUGHING WILL PERSIST ACROSS THE
EAST/SOUTHEAST THROUGH SATURDAY WITH MORE OF A ZONAL PATTERN
DEVELOPING THEREAFTER. GENERALLY QUIET WEATHER IS EXPECTED AS HIGH
PRESSURE MOVES FROM THE MIDWEST TO THE APPALACHIANS THROUGH THE
PERIOD. THE HIGH WILL WEAKEN WITH THE MID LEVEL TROUGH THUS LEAVING
A WEAK PRESSURE PATTERN BOTH AT THE SURFACE AND ALOFT. HAVE
CONTINUED THE SLIGHT CHANCE POPS WHICH ARE MOSTLY CONFINED TO THE
COASTAL AND OFFSHORE ZONES. THE TEMPERATURE CURVE FOLLOWS THE SAME
PROGRESSION WITH COOL READINGS EARLY ON...FRIDAY SHOULD BE THE
COOLEST WITH 850MB TEMPERATURES NEAR 15 DEGREES C. THERMAL PROFILES
SLOWLY MODIFY FROM THAT POINT ON. READINGS MAY ECLIPSE CLIMATOLOGY
JUST BY A DEGREE OR TWO BY THE END OF THE PERIOD.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...OUTSIDE OF CONVECTIVE DEBRIS...REMAINDER OF THE NIGHT
SHOULD BE QUIET WITH MAINLY VFR CONDITIONS EXPECTED. AFT
12Z...SHOWERS SHOULD BE ON THE INCREASE AS A COLD FRONT
APPROACHES. TERMINALS MAINTAIN VFR CONDITIONS THROUGH 18Z WITH
VCSH WITH SCT SHRA IN THE AREA. AFT 18Z...ALL TERMINALS SHOWING
RAMP UP FROM PROB30 FOR TSRA WITH MVFR CIGS TO TEMPO FOR SIMILAR
CONDITIONS FROM 00Z WEDNESDAY THROUGH 04Z. SHORT DURATION IFR IS
POSSIBLE WITH TSRA BUT CONFIDENCE IN EXACT TIMING AT EACH TERMINAL
IS LOW ATTM.
EXTENDED OUTLOOK...SCATTERED SHOWERS AND STORMS TUESDAY NIGHT
WITH INTERMITTENT MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY WITH
ISOLATED MORNING CONVECTION POSSIBLE. VFR THURSDAY THROUGH
SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 115 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSIONS FOLLOW:
WINDS ARE QUITE A BIT STRONGER AT THE BEACHES THAN THEY ARE WAY
OUT AT THE FRYING PAN SHOALS BUOY. THIS IS ACTUALLY EXPECTED AS A
WEAKER PRESSURE GRADIENT EXISTS OFFSHORE NEAR THE HIGH PRESSURE
RIDGE. MODELS REMAIN IN GOOD AGREEMENT ABOUT GRADUALLY BUILDING
WIND SPEEDS AS THE RIDGE SCOOTS OUT TO THE SEAS. SEAS ARE
CURRENTLY 2 FEET...BUT WON`T BEGIN TO BUILD UNTIL AFTER DAYBREAK.
DISCUSSION FROM 300 PM FOLLOWS...
WEAK RIDGE OF HIGH PRESSURE WILL SLOWLY SHIFT OFFSHORE
TONIGHT...SO ALTHOUGH THE GRADIENT WILL REMAIN LIGHT KEEPING WIND
SPEEDS TO 10 KTS OR LESS...DIRECTION WILL CONTINUE TO VEER THROUGH
TONIGHT...FROM CURRENT ESE ALL THE WAY TO SSW LATE. CURRENT BUOY
OBS SHOW A MIX OF 5 SEC AND 10 SEC WAVES...WITH THE 10 SEC WAVE
DOMINANT DUE TO THE LIGHT WINDS...AND THESE WILL PERSIST THROUGH
THE PERIOD MAINTAINING WAVE HEIGHTS OF 2-3 FT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...MAIN MARINE HEADLINE THIS PERIOD REMAINS
APPROACH AND DECAY OF A COLD FRONTAL SYSTEM OVER THE COASTAL
WATERS DURING THE DAY WEDNESDAY. THIS MAY BRING A BRIEF PERIOD
OF N-NW WINDS WEDNESDAY...PRECEDED BY COASTAL RAIN SHOWERS AND
ISOLATED TSTMS TUESDAY NIGHT. A FEW TSTMS MAY IMPACT THE OUTER
WATERS ON WEDNESDAY AS WELL SINCE THE FRONT MAY SLOWLY DISSIPATE
THERE MID-WEEK. SEAS WILL BUILD TO 3-4 FT TUESDAY NIGHT AHEAD OF
THE COLD FRONT IN 15-20 KT SW WINDS...POSSIBLY 5 FT VERY OUTER
PORTION. SEAS SETTLING TO 2-3 FT WED AFTN AND EVENING AS WIND
SPEEDS GO LIGHT.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...HIGH PRESSURE WILL MOVE FROM THE MIDWEST TO THE
APPALACHIANS THROUGH THE PERIOD. THE HIGH WILL SLOWLY WEAKEN LEAVING
A BENIGN PRESSURE PATTERN BY SATURDAY. FOR THURSDAY AND FRIDAY
WINDS WONT BE OVERWHELMING AND EXPECT A EAST/NORTHEAST DIRECTION IN
A RANGE OF 10-15 KNOTS...MOSTLY HOVERING IN THE LOWER END OF THE
RANGE. SPEEDS DROP TO TEN KNOTS AND BELOW BY SATURDAY. SIGNIFICANT
SEAS WILL BE 1-3 FEET WITH AN EQUAL MIX OF A SHORTER PERIOD WIND
WAVE AND SWELL COMPONENT.
&&
.EQUIPMENT...
AS OF 130 PM MONDAY...POWER TO THE ILM ASOS HAS BEEN LOST DUE TO
A POWER SURGE. A REPLACEMENT IS ON ORDER...BUT IT IS LIKELY THAT
ILM ASOS WILL BE WITHOUT AUTOMATED OBSERVATIONS THROUGH TODAY AND
PART OF TUESDAY. THE ILM TOWER SHOULD AMEND OBSERVATIONS UNTIL 11
PM TONIGHT...AND RESUME EARLY TUESDAY MORNING. OVERNIGHT OBS MAY
WILL BE MISSING FOR ALL PARAMETERS. AMD NOT SKED HAS BEEN APPENDED
TO THE ILM TAF AND WILL REMAIN AS SUCH UNTIL POWER IS RESTORED TO
THE SITE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...REK/TRA
SHORT TERM...99
LONG TERM...99
AVIATION...REK/RAN
MARINE...99/REK/TRA
EQUIPMENT...99
AREA FORECAST DISCUSSION
NWS RALEIGH NC
100 AM EDT TUE AUG 11 2015
.SYNOPSIS...A MOIST SOUTHWEST FLOW WILL HOLD OVER THE REGION THROUGH
TONIGHT. A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY...
AND PUSH SOUTHEAST THROUGH THE AREA THIS EVENING. HIGH PRESSURE WILL
BUILD IN FROM THE NORTHWEST WEDNESDAY THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 925 PM MONDAY...
WATER VAPOR IMAGERY AND RAP 500MB VORT ANALYSIS SHOW SEVERAL
DISTURBANCES ALOFT THAT CONTINUE TO SUPPORT BROKEN BANDS OF MOSTLY
WEAK CONVECTION FROM WESTERN VIRGINIA SOUTH INTO GEORGIA AND
ALABAMA. LOCALLY...A BRIEF PERIOD OF HEATING/DESTABILIZATION OVER
THE WESTERN PIEDMONT AND THE DEVELOPMENT OF SOME MODERATE DCAPE
EARLIER THIS AFTERNOON ALSO APPEARS TO BE SUPPORTING A DISORGANIZED
COLD POOL AND SLOWLY WEAKENING SHOWERS/STORMS FROM THE TRIAD TO NEAR
ALBEMARLE. NOCTURNAL COOLING WILL FAVOR A CONTINUED WEAKENING OF
THIS CONVECTION...BUT RAP FORECAST SOUNDINGS SHOW A 35-40KT LOW
LEVEL JET FROM CLT TO RDU AFTER MIDNIGHT THAT MAY HELP TO TAP
WHATEVER WEAK MUCAPE IS LEFT AND MAINTAIN SOME SCATTERED SHOWERS.
THIS IS LOOSELY SUPPORTED BY RECENT HRRR RUNS. THE FORECAST UPDATE
WILL HAVE A CHANCE POP OVERNIGHT BECOMING INCREASINGLY FOCUSED TO
THE EAST TOWARD 12Z. OTHERWISE...REGIONAL SATELLITE IMAGERY SHOWS
PLENTY OF CONVECTIVE DEBRIS CLOUDINESS AND SKIES MOSTLY CLOUDY FOR A
MAJORITY OF THE AREA. LOWS IN THE LOW TO MID 70S.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 320 PM MONDAY...
STILL APPEARS TO BE THE WETTEST DAY... WITH ALL LARGE-SCALE MODELS
INCLUDING THE SREF MEAN INDICATING NUMEROUS SHOWERS AND STORMS...
ALTHOUGH DETAILS OF THE TIMING AND WHAT LOCATIONS WILL SEE THE
GREATEST AMOUNTS AND COVERAGE ARE STILL MURKY. FALLING MID LEVEL
HEIGHTS WITH THE DIGGING TROUGH ALONG WITH MID LEVEL DPVA...
INCREASING UPPER DIVERGENCE ASSOCIATED WITH A STRENGTHENING JET
STREAK OVER IA/IL... AND DECENT LOW LEVEL MOISTURE TRANSPORT WILL
WORK WITH 1000-2000 J/KG OF MUCAPE (ON THE GFS... ALTHOUGH THIS MAY
BE OVERDONE GIVEN EXTENSIVE MORNING CLOUD COVER) AND IMPROVING DEEP
LAYER SHEAR OF 25-30 KT TO FORCE SHOWERS AND STORMS... PEAKING
DURING THE AFTERNOON INTO MID EVENING... AHEAD OF THE APPROACHING
SURFACE COLD FRONT. THE SEVERE THREAT STILL LOOKS MARGINAL... GIVEN
THAT THE BETTER DYNAMIC FORCING FOR ASCENT SHOULD BE JUST TO OUR
NORTH AND NE ALONG THE MIDATLANTIC COAST WITH THE BETTER
INSTABILITY/SHEAR COMBINATION TO OUR SOUTH AND SW OVER UPSTATE SC
AND GA... BUT A FEW DAMAGING WIND REPORTS ARE STILL POSSIBLE IN THIS
INCREASINGLY VOLATILE ENVIRONMENT. EXPECT HIGHS MOSTLY IN THE MID
80S. POPS SHOULD LOWER FROM NW TO SE TUE NIGHT... TRENDING DOWN TO
JUST A SLIGHT CHANCE IN THE SE BY LATE TUE NIGHT. LOWS 65-70. -GIH
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 250 PM MONDAY...
THE MAIN FRONT WILL SHIFT OFFSHORE ON WEDNESDAY...WITH GENERAL UPPER
LEVEL TROUGHINESS LINGERING OVER THE CAROLINAS THROUGH MONDAY. AT
THE SURFACE...HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND
REMAIN OVERHEAD THROUGH MONDAY. WITH THAT IN MIND...MOST OF THE
EXTENDED PERIOD WILL REMAIN DRY...WITH JUST A SLIGHT CHANCE FOR
SHOWERS OVER THE WESTERN HALF OF THE STATE OVER THE WEEKEND.
TEMPERATURES DURING THE PERIOD WILL FEATURE HIGHS IN THE MID 80S TO
AROUND 90 DEGREES WITH OVERNIGHT LOWS GENERALLY IN THE MID 60S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 100 AM TUESDAY...
HIGH PROBABILITY THAT A PERIOD MVFR/IFR CONDITIONS WILL AFFECT THE
TERMINALS ACROSS CENTRAL NC TODAY AS A SERIES OF UPPER DISTURBANCES
AND AN APPROACHING SURFACE COLD FRONT INTERACT WITH A VERY MOIST AND
CONDITIONALLY UNSTABLE AIR MASS. CEILINGS IN THE LOW END MVFR/IFR
RANGE WILL BECOME DOMINATE AROUND DAYBREAK AND PERSIST THROUGH MUCH
OF THE MORNING. MEANWHILE SCATTERED SHOWERS WILL INITIALLY BE HIT-
AND-MISS THROUGH 09Z...BUT SHOULD BECOME MORE PROMINENT TOWARD
DAYBREAK IN THE PIEDMONT...AND BY MID-LATE MORNING IN VICINITY OF
KFAY AND KRWI
AVIATION CONDITIONS WILL BEGIN TO IMPROVE WEST-TO-EAST IN THE
AFTERNOON AS A MID LEVEL TROUGH CROSSES THE REGION. CEILINGS SHOULD
LIFT TO THE LOW END VFR CATEGORY BY EARLY-MID AFTERNOON IN THE
PIEDMONT AND BY LATE AFTERNOON ELSEWHERE. WITH AFTERNOON
HEATING...COULD SEE A FEW T-STORMS DEVELOP BUT CONFIDENCE NOT HIGH
ENOUGH AT THIS TIME TO MENTION IN THE TERMINAL FORECAST AS EXPECT
THE STORMS TO BE FAIRLY RANDOM.
A COLD FRONT WILL PROGRESSES EAST ACROSS THE REGION LATE TODAY AND
THIS EVENING. NWLY FLOW BEHIND THE BOUNDARY WILL USHER A DRIER MORE
STABLE AIR MASS...LEADING TO A PROLONGED PERIOD OF VFR CONDITIONS
WEDNESDAY THROUGH SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...HARTFIELD/22
SHORT TERM...HARTFIELD
LONG TERM...RAH
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1235 AM EDT TUE AUG 11 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE THIS EVENING. A COLD FRONT WILL
APPROACH THE AREA TUESDAY AND MOVE OFFSHORE WEDNESDAY. HIGH
PRESSURE BUILDS IN FROM THE NORTH FOR LATE WEEK. A COASTAL TROUGH
MAY AFFECT THE AREA BY THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1225 AM TUESDAY...A LOOK AT THE 3KM HRRR MODEL AND OTHER
HIGHER RESOLUTION MODELS INDICATE A MINIMAL CHANCE OF
PRECIPITATION ACROSS OUR CWA THROUGH 12Z. COULD MAKE A CASE FOR
THE FAR NORTHWESTERN COUNTIES HAVING A SMALL CHANCE WITH A FEW
SHOWERS OFF TO THE WEST AND NORTH OF RALEIGH AND WILL HAVE A
SLIGHT CHC POP FAR NORTHWEST WITH NOTHING ELSEWHERE OVERNIGHT.
NO CHANGES TO OVERNIGHT TEMPERATURES WITH LOW TEMPS IN THE LOWER
70S INLAND TO MID 70S ALONG THE COAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
AS OF 300 PM MONDAY...ADDITIONAL SHRT WV ENERGY WITH DIGGING SHRT
WV TROF ALONG WITH APPROACHING COLD FRONT AND DEW POINTS
INCREASING BACK INTO LOWER 70S WILL RESULT IN INCREASING SHOWER
AND ISOLATED TSTM THREAT DURING THE DAY. CONTINUED PREVIOUS FCST
TREND OF POPS INCREASING TO LIKELY ALL AREAS BY LATE AFTN. VEERING
WIND PROFILES AND INCREASING INSTABILITY SUPPORT ISOLATED SVR
THREAT...BUT LIMITED INSOLATION WILL LIKELY PRECLUDE WDSPRD DEEP
STRONG CONVECTION. MAX TEMPS MAINLY MID 80S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
AS OF 3 PM MON...COLD FRONT WILL PASS THROUGH TUESDAY NIGHT AND
OFF THE COAST WEDNESDAY. THE FRONT THEN BECOMES STATIONARY OVER
THE ATLANTIC OFFSHORE WATERS INTO THE WEEKEND AND DISSIPATES EARLY
NEXT WEEK. GFS/ECMWF IN AGREEMENT OVERALL AND USED A CONSENSUS
BLEND. THURSDAY AND FRIDAY NOW LOOK DRY WITH AVAILABLE MOISTURE
FOR CONVECTION REMAINING WELL OFF THE COAST. MOISTURE THEN DRIFTS
BACK TOWARD THE AREA THIS WEEKEND. HAVE REINTRODUCED POPS OVER
SOUTHERN AND EASTERN SECTIONS SATURDAY AND THROUGHOUT ON SUNDAY.
ONLY ISOLATED SEABREEZE ACTIVITY EXPECTED MONDAY.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 06Z WEDNESDAY/...
AS OF 1230 AM TUESDAY...EXTENSIVE HIGH CLOUDINESS ALONG WITH LOW-
LEVEL MIXING SHOULD KEEP ANY FOG AT BAY OVERNIGHT WITH VFR
CONDITIONS PREVAILING. THIS SHOULD CONTINUE THROUGH MOST OF THE
MORNING HOURS TUESDAY. DEVELOPING SHOWERS AND THUNDERSTORMS WILL
LEAD TO LOWER CEILINGS BY TUESDAY AFTERNOON INTO TUESDAY NIGHT
WITH SOME OCCASIONAL SUB-VFR CONDITIONS POSSIBLE.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 3 PM MON...SUB-VFR IN NUMEROUS SHOWERS AND THUNDERSTORMS
TUESDAY NIGHT. ACTIVITY ENDS FROM NORTHWEST TO SOUTHEAST WEDNESDAY
AS THE COLD FRONT MOVES OFF THE COAST. DRY/VFR WEDNESDAY NIGHT
THROUGH SATURDAY. LIGHT NORTH WIND WEDNESDAY. LIGHT NORTHEAST
THURSDAY AND FRIDAY...THEN EAST ON SATURDAY.
&&
.MARINE...
SHORT TERM /THROUGH TUESDAY/...
AS OF 1235 AM TUESDAY...LIGHT SE/S WINDS ACROSS THE COASTAL WATERS
AND SOUNDS WITH SEAS RUNNING 3 TO 5 FEET. THESE LIGHT WINDS
SHOULD CONTINUE OVERNIGHT AS HIGH PRESSURE GRADUALLY SHIFTS
OFFSHORE. WINDS WILL BECOME SW AND INCREASE TO 15-20 KT TUESDAY
WITH COLD FRONT APPROACHING FROM W.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 3 PM MON...SOUTHWEST FLOW TUESDAY NIGHT WITH WINDS/SEAS
REMAINING JUST BELOW SMALL CRAFT LEVELS. WINDS VEER TO WEST THEN
NORTHWEST WEDNESDAY AS THE FRONT MOVES OFF THE COAST. LOOSENING
PRESSURE GRADIENT WILL ALLOW WINDS AND SEAS TO DECREASE. LIGHT
NORTHEAST TO EAST FLOW WEDNESDAY NIGHT INTO SATURDAY WITH WINDS NO
HIGHER THAN 5-10 KNOTS AND SEAS 2-3 FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...HSA
AVIATION...BTC/CTC/HSA
MARINE...BTC/CTC/HSA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
957 PM CDT WED AUG 12 2015
.UPDATE...
ISSUED AT 950 PM CDT WED AUG 12 2015
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE AS HIGH BASED
CONVECTION CONTINUES ACROSS SOUTHWEST NORTH DAKOTA IN ASSOCIATION
WITH AN EMBEDDED SHORTWAVE IN THE UPPER LEVEL RIDGE ACROSS FAR
SOUTHEAST MONTANA. OVERALL...THE MARGINAL SEVERE THREAT IS RAPIDLY
ENDING WITH SUNSET AS STORMS HAVE BECOME OUTFLOW DOMINATED. THE 02
UTC HRRR DOES HAVE A GOOD DEPICTION OF THE ONGOING CONVECTION AND
WILL FOLLOW ITS SOLUTION THROUGH THE REMAINDER OF THE NIGHT.
UPDATE ISSUED AT 604 PM CDT WED AUG 12 2015
AS OF 604 PM CDT...THE LONE SUPERCELL THAT WAS NEAR LAKE TSCHIDA
HAS NOW TRANSITIONED INTO A WEAKENING MULTI-CELL CLUSTER AFTER A
STORM MERGER OVER CENTRAL GRANT COUNTY. CERTAINLY CANNOT RULE OUT
ANOTHER LONE SUPERCELL THROUGH SUNSET AHEAD OF THE WEAK SURFACE
TROUGH ACROSS SOUTHWEST THROUGH NORTHEAST NORTH DAKOTA.
HOWEVER...GIVEN THE WARM TEMPERATURES...STORM COVERAGE WILL BE
VERY LOW. ALTHOUGH...ANY CELL THAT CAN BREAK THE CAP WOULD BE
CAPABLE OF DAMAGING WINDS WITH DCAPE VALUES IN EXCESS OF 1800
J/KG.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 228 PM CDT WED AUG 12 2015
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE EXCESSIVE
HEAT AND THUNDERSTORM CHANCES.
CURRENT SURFACE ANALYSIS INDICATES A SURFACE TROUGH EXTENDING FROM
MANITOBA SOUTHWEST INTO NORTHWEST NORTH DAKOTA. MUCH DRIER AIR
WITH DEWPOINTS IN THE UPPER 40S OVER FAR NORTHWEST NORTH DAKOTA
AND NORTHEAST MONTANA. AHEAD OF THE TROUGH MOISTURE POOLING HAS
RESULTED IN A BAND OF LOWER 70 DEWPOINTS FROM SOUTH CENTRAL INTO
NORTHEAST NORTH DAKOTA. SURFACE TEMPERATURES ARE IN THE 90S OVER
MOST OF THE FORECAST AREA...WITH A LARGE AREA OF UPPER 90S ALONG
AND WEST OF THE HIGHWAY 83 CORRIDOR.
APPARENT TEMPERATURES HAVE CLIMBED INTO THE LOWER 100S ACROSS
THE SOUTH CENTRAL INTO THE JAMES RIVER VALLEY. WILL ADD A MENTION
OF HEAT INDEX VALUES ABOVE 100 DEGREES THIS AFTERNOON. IT LOOKS
LIKE MAYBE A 3 HOUR PERIOD OR SO...THUS NO HEAT ADVISORY WILL BE
ISSUED.
UPPER LEVEL RIDGE REMAINS SITUATED OVER THE MONDAY AREA WITH A
SHORTWAVE IMPULSE RIDING DOWN THE RIDGE THROUGH SOUTHERN MANITOBA.
WE REMAIN VERY UNSTABLE ACROSS CENTRAL NORTH DAKOTA WITH ML CAPES
OVER 3000 J/KG AND DECENT BULK LAYER SHEAR. HOWEVER WE REMAIN
CAPPED UNDER THE WARM THERMAL RIDGE. LATEST ITERATIONS OF THE
RAP/HRRR HAVE INDICATED CONVECTION OVER THE FAR SOUTH CENTRAL AND
JAMES RIVER VALLEY FROM AROUND 5 TO 7 PM...BUT KEEP THE STRONGEST
CONVECTION ASSOCIATED WITH THE MANITOBA SHORTWAVE EAST OF THE
FORECAST AREA LATE THIS AFTERNOON AND THIS EVENING. WILL CERTAINLY
NEED TO MONITOR AS ANY THUNDERSTORM DEVELOPMENT COULD QUICKLY
BECOME STRONG TO SEVERE GIVEN THE VERY STRONG INSTABILITY. AS FAR
AS THE FORECAST...HAVE KEPT A SLIGHT CHANCE OVER THIS AREA THROUGH
MID EVENING.
TO THE WEST IT LOOKS LIKE THE RAP/HRRR ARE BRINGING IN CONVECTION
TOO EARLY AND ARE TOO WIDESPREAD WITH THIS CONVECTION. FORECAST
MODELS ARE FAIRLY CONSISTENT IN BRINGING AN AREA OF SHOWERS AND
ISOLATED THUNDERSTORMS INTO WESTERN NORTH DAKOTA TONIGHT AND
TRACKING SOUTHEAST...EXITING THE FAR SOUTH CENTRAL BY LATE
THURSDAY MORNING. THIS WAVE TRACKS BEHIND THE AFOREMENTIONED
SURFACE TROUGH SO THE LACK OF DEEP MOISTURE...COMBINED WITH THE
LACK OF SURFACE HEATING DUE TO THE TIMING...THE THREAT OF STRONGER
STORMS IS EXPECTED TO BE MINIMAL. THE ADDED CLOUD COVER SHOULD
KEEP TEMPERATURES A BIT LOWER MOST AREAS...BUT WE ARE STILL
LOOKING AT LOW TO MID 90S MOST AREAS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 228 PM CDT WED AUG 12 2015
THE LARGE AND PERSISTENT H500 RIDGE OVER THE CENTRAL US IS
FORECAST TO BREAK DOWN BY THE WEEKEND BY AN UPPER LEVEL LOW
CURRENTLY ACROSS THE EASTERN PACIFIC. THE LOW WILL RIDE UP AND
EVENTUALLY BEAT DOWN THE RIDGE BRINGING AN END TO OUR VERY WARM
WEATHER BY SUNDAY.
FOR THURSDAY NIGHT AND FRIDAY CONDITIONS WILL CONTINUE TO BE VERY
WARM WITH LOWS THURSDAY NIGHT IN THE MID TO UPPER 60S...AND HIGHS
FRIDAY FROM THE LOWER 90S FRONT THE TURTLE MOUNTAINS THROUGH THE
JAMES VALLEY...TO THE UPPER 90S IN THE WEST. SURFACE MOISTURE WILL
BE LIMITED BY THE RECENT LACK OF RAIN AND CURING VEGETATION AND AS A
RESULT SURFACE DEWPOINTS WILL NOT BE HIGH ENOUGH TO CREATE CRITICAL
HEAT INDEX VALUES.
AHEAD OF THE FRONT ON FRIDAY...GUSTY SOUTHERLY WINDS OF AROUND 20
MPH ARE EXPECTED. MINIMUM RELATIVE HUMIDITY OF AROUND 20 PERCENT
EXPECTED IN NORTHWESTERN NORTH DAKOTA. HOWEVER...FIRE MANAGERS HAVE
SAID THAT GRASSES ARE NOT CURED ENOUGH IN THE NORTHWEST FOR FIRE
WEATHER CONCERNS AS OF YET.
SOME FIRE WEATHER CONCERNS MAY POP UP IN THE SOUTHWEST ON SATURDAY
WITH GUSTY WEST WINDS OF 15 TO 20 MPH AND RELATIVE HUMIDITY OF 20 TO
25 PERCENT BEHIND THE COLD FRONT ON SATURDAY. THOSE CONDITIONS WOULD
STILL BE JUST BELOW RED FLAG CRITERIA FOR THE SOUTHWEST...WHERE FIRE
MANAGERS SAY THE GRASSES ARE CURING QUICKLY.
A CHANCE OF THUNDERSTORMS CAN BE EXPECTED AHEAD OF THE FRONT FRIDAY
NIGHT IN THE WEST...AND OVER WESTERN AND CENTRAL NORTH DAKOTA
SATURDAY INTO SATURDAY NIGHT ON EITHER SIDE OF THE FRONT AS IT
PASSES THROUGH THE STATE.
BY SUNDAY MUCH COOLER AIR WILL FLOW IN WITH HIGH TEMPERATURES IN THE
70S TO AROUND 80. COOLER AND MORE PLEASANT WEATHER WILL REMAIN IN
PLACE MONDAY TROUGH WEDNESDAY WITH HIGHS MAINLY IN THE MID TO UPPER
70S. SCATTERED THUNDERSTORMS WILL REMAIN IN THE FORECAST WITH
CYCLONIC FLOW AND SHORTWAVE ENERGY MOVING THROUGH SOUTHERN CANADA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 950 PM CDT WED AUG 12 2015
THUNDERSTORMS ARE EXPECTED TO IMPACT KDIK BETWEEN 04-06
UTC...POSSIBLY APPROACHING KBIS BY 07-09 UTC. ADDITIONAL ISOLATED
TO SCATTERED SHOWERS AND STORMS ARE POSSIBLE AT KISN/KMOT
TONIGHT. HOWEVER...GIVEN LOW COVERAGE AND CONFIDENCE...WILL NOT
ADD TEMPO GROUPS FOR THESE TERMINALS FOR NOW AND MONITOR RADAR
TRENDS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...TWH
LONG TERM...JV
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
138 PM EDT TUE AUG 11 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER PLAINS WILL GRADUALLY MOVE UP THE
OHIO VALLEY THROUGH THURSDAY. A WEAK COLD FRONT SHOULD MOVE
THROUGH THE REGION LATE FRIDAY THEN HIGH PRESSURE WILL REBUILD
OVER THE AREA FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN UPPER LEVEL TROUGH OVER THE AREA
WILL KEEP CONDITIONS UNSETTLED THRU TONIGHT. BREAKS IN CLOUDS WILL
OCCUR ESPECIALLY OVER THE WEST HALF OF THE AREA.
THE NEAR TERM...HIGH RES MODELS...ESPECIALLY THE HRRR INDICATE A
POTENTIAL FOR LIGHT SHRA TODAY OVER THE EAST 2/3 OF THE CWA. AN
UPPER S/W DROPPING INTO THE AREA TONIGHT WILL BRING AN ADDITIONAL
THREAT FOR LIGHT SHRA WITH EMPHASIS FOR THE SNOWBELT AS LAKE EFFECT
CONDITIONS BECOME A LITTLE MORE FAVORABLE.
TEMPS WILL BE COOLER TODAY AND TONIGHT AS WEAK COLD ADVECTION OCCURS.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
EARLY WEDNESDAY LAKE INDUCED RAIN SHOWERS COULD BECOME A BIT MORE
PERSISTENT IN RESPONSE TO THE LAST BIT OF ENERGY THAT WILL DROP OUT
OF THE MAIN TROF. THESE SHOWERS WILL PRIMARILY AFFECT PRIMARY AND
SECONDARY SNOWBELT COUNTIES. DECREASE POPS THROUGH THE REST OF THE
DAY AS THE HIGH BECOMES BETTER ESTABLISHED. EVEN THOUGH THE MODELS
SHOW PRECIP OVER THE LAKE MICHIGAN AREA LATE WEDNESDAY INTO
THURSDAY TRENDING ESE TOWARDS NORTHERN OHIO...KEPT THE FORECAST
DRY GIVEN LIMITED MOISTURE. A BETTER CHANCE FOR RAIN WILL COME
FRIDAY MORNING WITH A WEAK COLD FRONT THAT WILL LIKELY DISSIPATE
ACROSS NORTHERN OHIO. TEMPERATURES WILL RUN ABOUT 10 DEGREES BELOW
NORMAL ON WEDNESDAY THEN START TO MODERATE SOME ON THURSDAY AS WE
GET INTO SOME WEAK WAA.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
A WEAKENING COLD FRONT SHOULD JUST ABOUT BE OUT OF THE
AREA AT THE START OF THE PERIOD. ALL OF THE GUIDANCE CONTINUES TO
SUGGEST THAT THERE COULD BE SOME RESIDUAL SHOWER ACTIVITY ON
SATURDAY IN THE WAKE OF THIS FRONT. HAVE ACTUALLY BUMPED UP PRECIP
CHANCES A LITTLE AS BOTH THE ECMWF AND GFS ARE NOW SHOWING PRECIP.
THE SECOND HALF OF THE WEEKEND WILL BE QUIET AS HIGH PRESSURE
BRIEFLY BUILDS OVER THE REGION. ANOTHER COLD FRONT WILL APPROACH
FROM THE NORTHWEST AT THE END OF THE PERIOD. ALREADY HAVE CHANCE
WORDING IN THE MONDAY FORECAST AND THAT SEEMS REASONABLE.
TEMPERATURES DURING THE PERIOD WILL AVERAGE A COUPLE OF DEGREES
ABOVE NORMAL.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
A FALL-LIKE PATTERN WITH A COOL NORTHWEST FLOW ACROSS LAKE ERIE.
HIGH PRESSURE TRYING TO BUILD IN FROM THE WEST BUT A WEAK TROUGH
OF LOW PRESSURE WILL DROP ACROSS THE LAKE TONIGHT AND WILL LIKELY
REESTABLISH MVFR CEILINGS ACROSS NORTHEAST OHIO AND NORTHWEST
PENNSYLVANIA. A SHOWER OR TWO POSSIBLE ESPECIALLY IN THE SNOWBELT
OF EXTREME NE OH/NW PA TONIGHT OR WED MORNING BUT NOT ENOUGH OF A
THREAT TO PUT INTO THE TAF FORECASTS. CEILINGS WILL IMPROVE TO VFR
ON WEDNESDAY WITH CLEARING FROM WEST TO EAST IN THE LATE
AFTERNOON/EVENING.
OUTLOOK...A CHANCE OF NON-VFR CONDITIONS FRIDAY NIGHT INTO
SATURDAY IN SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
LIGHT NORTHWEST TO NORTH WINDS WILL INCREASE TODAY.
EXPECT PEAK SUSTAINED WINDS TO BE ABOUT 15 KNOTS WHICH IS JUST BELOW
WHAT IS NEEDED FOR SMALL CRAFT CONDITIONS. DAY CREW WILL HAVE TO
KEEP ON EYE ON THINGS BUT WILL HOLD OFF ON HEADLINES FOR NOW.
NORTHERLY WINDS WILL CONTINUE THROUGH LATE WEDNESDAY AND THEN BECOME
SOUTHWESTERLY ON THURSDAY AS HIGH PRESSURE MOVES OFF TO THE
SOUTHEAST. MAINLY SOUTHWEST FLOW IS THEN EXPECTED TILL ANOTHER COLD
FRONT CROSSES THE LAKE ON SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAYERS
NEAR TERM...MAYERS
SHORT TERM...ADAMS/MAYERS
LONG TERM...KUBINA
AVIATION...KOSARIK
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
907 AM EDT TUE AUG 11 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER PLAINS WILL GRADUALLY MOVE UP THE
OHIO VALLEY THROUGH THURSDAY. A WEAK COLD FRONT SHOULD MOVE
THROUGH THE REGION LATE FRIDAY THEN HIGH PRESSURE WILL REBUILD
OVER THE AREA FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/... AN UPPER LEVEL TROUGH OVER THE AREA
WILL KEEP CONDITIONS UNSETTLED THRU TONIGHT. BREAKS IN CLOUDS WILL
OCCUR ESPECIALLY OVER THE WEST HALF OF THE AREA.
THE NEAR TERM...HIGH RES MODELS...ESPECIALLY THE HRRR INDICATE A
POTENTIAL FOR LIGHT SHRA TODAY OVER THE EAST 2/3 OF THE CWA. AN
UPPER S/W DROPPING INTO THE AREA TONIGHT WILL BRING AN ADDITIONAL
THREAT FOR LIGHT SHRA WITH EMPHASIS FOR THE SNOWBELT AS LAKE EFFECT
CONDITIONS BECOME A LITTLE MORE FAVORABLE.
TEMPS WILL BE COOLER TODAY AND TONIGHT AS WEAK COLD ADVECTION OCCURS.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
EARLY WEDNESDAY LAKE INDUCED RAIN SHOWERS COULD BECOME A BIT MORE
PERSISTENT IN RESPONSE TO THE LAST BIT OF ENERGY THAT WILL DROP OUT
OF THE MAIN TROF. THESE SHOWERS WILL PRIMARILY AFFECT PRIMARY AND
SECONDARY SNOWBELT COUNTIES. DECREASE POPS THROUGH THE REST OF THE
DAY AS THE HIGH BECOMES BETTER ESTABLISHED. EVEN THOUGH THE MODELS
SHOW PRECIP OVER THE LAKE MICHIGAN AREA LATE WEDNESDAY INTO
THURSDAY TRENDING ESE TOWARDS NORTHERN OHIO...KEPT THE FORECAST
DRY GIVEN LIMITED MOISTURE. A BETTER CHANCE FOR RAIN WILL COME
FRIDAY MORNING WITH A WEAK COLD FRONT THAT WILL LIKELY DISSIPATE
ACROSS NORTHERN OHIO. TEMPERATURES WILL RUN ABOUT 10 DEGREES BELOW
NORMAL ON WEDNESDAY THEN START TO MODERATE SOME ON THURSDAY AS WE
GET INTO SOME WEAK WAA.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
A WEAKENING COLD FRONT SHOULD JUST ABOUT BE OUT OF THE
AREA AT THE START OF THE PERIOD. ALL OF THE GUIDANCE CONTINUES TO
SUGGEST THAT THERE COULD BE SOME RESIDUAL SHOWER ACTIVITY ON
SATURDAY IN THE WAKE OF THIS FRONT. HAVE ACTUALLY BUMPED UP PRECIP
CHANCES A LITTLE AS BOTH THE ECMWF AND GFS ARE NOW SHOWING PRECIP.
THE SECOND HALF OF THE WEEKEND WILL BE QUIET AS HIGH PRESSURE
BRIEFLY BUILDS OVER THE REGION. ANOTHER COLD FRONT WILL APPROACH
FROM THE NORTHWEST AT THE END OF THE PERIOD. ALREADY HAVE CHANCE
WORDING IN THE MONDAY FORECAST AND THAT SEEMS REASONABLE.
TEMPERATURES DURING THE PERIOD WILL AVERAGE A COUPLE OF DEGREES
ABOVE NORMAL.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
THE AMOUNT OF IFR WEATHER ACROSS THE AREA HAS DIMINISHED AS
SLIGHTLY DRIER AIR HAS WORKED IN FROM THE NW. A GRADUAL SLOW
IMPROVEMENT OF CIG HEIGHTS IS EXPECTED THIS MORNING. ALL AREAS
SHOULD BE VFR BY 18Z. EXPECTED WESTERN AREAS TO BECOME SCT THIS
AFTERNOON BUT STRATO CUMULUS CIGS WILL PERSIST TILL LATE TODAY IN
THE EAST. NW WINDS HAVE ALREADY STARTED TO PICK AND WINDS MUCH OF
THE DAY WILL BE IN THE 10 TO 15 KNOT RANGE. THE FLOW WILL BECOME N
TOWARD EVENING AND THEN WEAKEN.
OUTLOOK...A CHANCE OF NON-VFR CONDITIONS FRIDAY NIGHT INTO
SATURDAY IN SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
LIGHT NORTHWEST TO NORTH WINDS WILL INCREASE TODAY.
EXPECT PEAK SUSTAINED WINDS TO BE ABOUT 15 KNOTS WHICH IS JUST BELOW
WHAT IS NEEDED FOR SMALL CRAFT CONDITIONS. DAY CREW WILL HAVE TO
KEEP ON EYE ON THINGS BUT WILL HOLD OFF ON HEADLINES FOR NOW.
NORTHERLY WINDS WILL CONTINUE THROUGH LATE WEDNESDAY AND THEN BECOME
SOUTHWESTERLY ON THURSDAY AS HIGH PRESSURE MOVES OFF TO THE
SOUTHEAST. MAINLY SOUTHWEST FLOW IS THEN EXPECTED TILL ANOTHER COLD
FRONT CROSSES THE LAKE ON SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAYERS
NEAR TERM...MAYERS/ADAMS
SHORT TERM...ADAMS/MAYERS
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
938 PM CDT WED AUG 12 2015
.UPDATE...
ADDED/INCREASED POPS FOR OVERNIGHT AND THURSDAY MORNING.
&&
.DISCUSSION...
WITH DEEP MID-LEVEL MOIST LAYER NOT GOING ANYWHERE...OTHER THAN
SHIFTING SLIGHTLY EAST FROM WHERE IT WAS LAST NIGHT AND
TODAY...WEAK MID-LEVEL /H7/ WAA MAY RESULT IN SCATTERED SHOWER
DEVELOPMENT LATE TONIGHT. CANNOT RULE OUT A THUNDERSTORM OR TWO
BUT THEY WILL BE BRIEF AND WEAK. WE WILL INCREASE THE POPS A BIT
FOR TONIGHT ACROSS WESTERN PARTS OF CWA AND SPREAD INTO CENTRAL
OKLAHOMA AFTER DAYBREAK WITH EASTWARD PROG OF MOIST AXIS. WRF AND
RAP FAIRLY CONSISTENT ON WEAK SIGNAL BUT OTHER MODELS HAVE
NOTHING. WRF AND RAP HAVE HANDLED THE WEAKLY FORCED ACTIVITY
BETTER THE PAST FEW DAYS SO WE WILL STICK CLOSER TO THOSE
SOLUTIONS IN THIS UPDATE.
&&
.PREV DISCUSSION... /ISSUED 643 PM CDT WED AUG 12 2015/
DISCUSSION...
THE AVIATION DISCUSSION FOR THE 00Z TAFS IS BELOW.
AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD.
ISOLATED SHOWERS AND THUNDERSTORMS MAY DEVELOP ACROSS WESTERN
OKLAHOMA AFTER 09Z TONIGHT. IF THE STORMS DEVELOP....THEY WILL
INITIALLY AFFECT KGAG AND KWWR. AS THE STORMS SHIFT
SOUTHWARD...THEY MAY AFFECT KCSM/KHBR/KLAW LATER IN THE MORNING.
HOWEVER...CONFIDENCE IN STORM DEVELOPMENT IS TOO LOW TO MENTION
IN TAFS FOR NOW.
MAHALE
PREV DISCUSSION... /ISSUED 340 PM CDT WED AUG 12 2015/
DISCUSSION...
THE PERSISTENT LIGHT TO MODERATE RAIN IN WESTERN OKLAHOMA IS
EXPECTED TO LAST SEVERAL MORE HOURS BEFORE DISSIPATING THIS
EVENING. ADDITIONAL RAIN MAY DEVELOP ALONG THE ELEVATED FRONTAL
ZONE LATE TONIGHT INTO THURSDAY MORNING...BUT INDICATIONS SUGGEST
WEAKER FORCING...SO LOWER CHANCES FOR RAIN THEN.
VARIOUS WEAK FEATURES WILL RESULT IN A FEW PERIODS OF LOW RAIN
CHANCES OVER RELATIVELY SMALL GEOGRAPHIC AREAS THROUGH EARLY NEXT
WEEK. IN GENERAL...LITTLE CHANGE TO THE WEATHER IS EXPECTED
THROUGH THE PERIOD.
MEDIUM-RANGE MODELS SUGGEST A MORE POWERFUL STORM SYSTEM IN THE
NORTHERN PLAINS ABOUT MIDWEEK...AND IF THIS ACTUALLY HAPPENS...IT
COULD PUSH A RELATIVELY STRONG COLD FRONT INTO THE SOUTHERN
PLAINS WEDNESDAY OR THURSDAY OF NEXT WEEK. THIS WOULD GREATLY
INCREASE RAIN CHANCES...AND BRING RELATIVELY MILD WEATHER INTO THE
REGION...IF...IT HAPPENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 65 90 68 89 / 10 30 10 0
HOBART OK 68 94 71 92 / 20 30 0 10
WICHITA FALLS TX 70 95 72 94 / 10 40 0 10
GAGE OK 65 91 70 92 / 20 20 0 0
PONCA CITY OK 64 90 69 90 / 0 10 0 10
DURANT OK 69 94 67 94 / 0 10 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
11/10
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
645 AM CDT TUE AUG 11 2015
.AVIATION...11/12Z TAF ISSUANCE...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE ACROSS
WRN OK AND WRN N TX THROUGH THE MORNING... LINGERING INTO THE
AFTERNOON. THIS ACTIVITY WILL IMPACT WRN OK/WRN N TX TAF SITES
AT VARIOUS TIMES THROUGH THE MORNING. OVERALL... MOST SITES WILL
REMAIN AT VFR. HOWEVER... KGAG/KWWR IN NWRN OK WILL HOLD NEAR OR
AT IFR CEILINGS THROUGH THE MORNING. WINDS WILL REMAIN OUT OF THE
NORTHEAST THROUGH THE PERIOD.
JTK
&&
.PREV DISCUSSION... /ISSUED 313 AM CDT TUE AUG 11 2015/
DISCUSSION...
THIS MORNING... ACCAS DEVELOPMENT CONTINUES TO INCREASE ALONG THE
RED RIVER VALLEY IN RESPONSE TO A WEAK H850/H700 BOUNDARY AND
MOISTURE AXIS FROM THE SERN PANHANDLE INTO NRN TX. MESO GUIDANCE
FROM THE HRRR AND VARIOUS FLAVORS OF THE WRF (NMM...ARW ETC.) TRY TO
DEVELOP PRECIP ALONG THIS BOUNDARY IN ASSOCIATION WITH THE SMALL
COMPLEX OVER THE PANHANDLES. THROUGH 08Z... SCATTERED TO ISOLATED
DEVELOPMENT HAS SLOWLY INCREASED ACROSS PORTIONS OF THE EASTERN
PANHANDLES. WITH THIS IN MIND... THE HRRR MAY BE ON THE RIGHT
TRACK... BUT MOVING TOO FAST. CONFIDENCE IS GOOD THAT SOME ISOLATED
TO WIDELY SCATTERED SHOWERS/THUNDERSTORMS WILL DEVELOP E/SE ALONG
THE INCREASING MID-LVEL THETA-E AXIS INTO SWRN OK/WRN N TX THROUGH
SUNRISE.
ANY ONGOING CONVECTION ACROSS SWRN OK/WRN N TX WILL SLOWLY DISSIPATE
THROUGH THE AFTN AS THE H500 RIDGE CONTINUES TO STRENGTHEN ALONG THE
ROCKIES. THERE ARE HINTS OF A WEAK MCV ON KAMA OVER NERN NM/NWRN TX
PH... THIS WILL CONTINUE TO LIFT NWRD... AND HAS BEEN REALIZED BY
THE 11/06Z RUN OF THE HRRR. OVERALL IT IS A MESSY MESOSCALE PATTERN
FOR THE SRN PLAINS AS THE RIDGE REMAINS CENTERED OVER THE SRN
ROCKIES. HOWEVER... WILL KEEP LOW CHC PRECIP/WX GOING FOR PORTIONS
OF WRN/NWRN OK THROUGH THE EVENING INTO EARLY WED. AS THE H500 RIDGE
CONTINUES TO SLIDE WEST... A MID-LVL THETA-E AXIS INCREASES ALONG
THE WRN OK/TX PH BORDER. WITH MODEST MID-LVL ASCENT... WOULD NOT BE
SURPRISED TO SEE SOME ISO/SCT DEVELOPMENT TONIGHT INTO EARLY WED.
FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND... MUCH QUIETER AND
MORE SEASONABLE WEATHER WILL BE ON TAP. THE H500 RIDGE REMAINS IN
CONTROL... SLOWLY BECOMING MORE POSITIVELY TILTED INTO THE WEEKEND.
TEMPS OVER THE NEXT SEVERAL DAYS WILL COOLER RELATIVE TO WHAT WE/VE
RECENTLY EXPERIENCED... WITH UPPER 80S TO LOWER 90S TODAY AND SLOWLY
CLIMBING BACK INTO THE MID TO UPPER 90S BY FRI INTO THE WEEKEND.
SCATTERED SHOWERS AND THUNDERSTORMS MAY MAKE A BRIEF APPEARANCE ON
FRI AS AN WEAK SHORT WAVE SKIRTS THE SRN PLAINS... BUT IT LOOKS...
AT THE MOMENT... TO BE AN OVERALL DRY END OF THE WEEK AND WEEKEND.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 89 68 88 67 / 10 10 0 10
HOBART OK 89 70 91 68 / 30 10 10 10
WICHITA FALLS TX 94 72 93 70 / 20 10 10 10
GAGE OK 85 66 88 67 / 20 20 20 20
PONCA CITY OK 87 65 88 67 / 0 0 10 0
DURANT OK 96 71 94 68 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORMAN OK
313 AM CDT TUE AUG 11 2015
.DISCUSSION...
THIS MORNING... ACCAS DEVELOPMENT CONTINUES TO INCREASE ALONG THE
RED RIVER VALLEY IN RESPONSE TO A WEAK H850/H700 BOUNDARY AND
MOISTURE AXIS FROM THE SERN PANHANDLE INTO NRN TX. MESO GUIDANCE
FROM THE HRRR AND VARIOUS FLAVORS OF THE WRF (NMM...ARW ETC.) TRY TO
DEVELOP PRECIP ALONG THIS BOUNDARY IN ASSOCIATION WITH THE SMALL
COMPLEX OVER THE PANHANDLES. THROUGH 08Z... SCATTERED TO ISOLATED
DEVELOPMENT HAS SLOWLY INCREASED ACROSS PORTIONS OF THE EASTERN
PANHANDLES. WITH THIS IN MIND... THE HRRR MAY BE ON THE RIGHT
TRACK... BUT MOVING TOO FAST. CONFIDENCE IS GOOD THAT SOME ISOLATED
TO WIDELY SCATTERED SHOWERS/THUNDERSTORMS WILL DEVELOP E/SE ALONG
THE INCREASING MID-LVEL THETA-E AXIS INTO SWRN OK/WRN N TX THROUGH
SUNRISE.
ANY ONGOING CONVECTION ACROSS SWRN OK/WRN N TX WILL SLOWLY DISSIPATE
THROUGH THE AFTN AS THE H500 RIDGE CONTINUES TO STRENGTHEN ALONG THE
ROCKIES. THERE ARE HINTS OF A WEAK MCV ON KAMA OVER NERN NM/NWRN TX
PH... THIS WILL CONTINUE TO LIFT NWRD... AND HAS BEEN REALIZED BY
THE 11/06Z RUN OF THE HRRR. OVERALL IT IS A MESSY MESOSCALE PATTERN
FOR THE SRN PLAINS AS THE RIDGE REMAINS CENTERED OVER THE SRN
ROCKIES. HOWEVER... WILL KEEP LOW CHC PRECIP/WX GOING FOR PORTIONS
OF WRN/NWRN OK THROUGH THE EVENING INTO EARLY WED. AS THE H500 RIDGE
CONTINUES TO SLIDE WEST... A MID-LVL THETA-E AXIS INCREASES ALONG
THE WRN OK/TX PH BORDER. WITH MODEST MID-LVL ASCENT... WOULD NOT BE
SURPRISED TO SEE SOME ISO/SCT DEVELOPMENT TONIGHT INTO EARLY WED.
FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND... MUCH QUIETER AND
MORE SEASONABLE WEATHER WILL BE ON TAP. THE H500 RIDGE REMAINS IN
CONTROL... SLOWLY BECOMING MORE POSITIVELY TILTED INTO THE WEEKEND.
TEMPS OVER THE NEXT SEVERAL DAYS WILL COOLER RELATIVE TO WHAT WE/VE
RECENTLY EXPERIENCED... WITH UPPER 80S TO LOWER 90S TODAY AND SLOWLY
CLIMBING BACK INTO THE MID TO UPPER 90S BY FRI INTO THE WEEKEND.
SCATTERED SHOWERS AND THUNDERSTORMS MAY MAKE A BRIEF APPEARANCE ON
FRI AS AN WEAK SHORT WAVE SKIRTS THE SRN PLAINS... BUT IT LOOKS...
AT THE MOMENT... TO BE AN OVERALL DRY END OF THE WEEK AND WEEKEND.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 89 68 88 67 / 10 10 0 10
HOBART OK 89 70 91 68 / 30 10 10 10
WICHITA FALLS TX 94 72 93 70 / 20 10 10 10
GAGE OK 85 66 88 67 / 20 20 20 20
PONCA CITY OK 87 65 88 67 / 0 0 10 0
DURANT OK 96 71 94 68 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
859 AM PDT TUE AUG 11 2015
.UPDATE...JUST MADE AN UPDATE TO REMOVE POPS FOR THIS MORNING AND
ADJUST SKY COVER TO CURRENT TRENDS. LATEST SATELLITE SHOWS AN
UPPER LOW OFF THE COAST ALONG 130W WITH A STREAM OF CLOUDS TO ITS
EAST STREAMING IN OVER OUR AREA. THERE IS SOME LIGHTNING OCCURRING
WITHIN THE CENTER OF THE LOW, BUT NOTHING MUCH ELSE AT THE MOMENT.
RADAR IS NOT SHOWING ANY PRECIPITATION, AND WITH CLOUD COVER, I
WOULDN`T EXPECT ANYTHING IN THE NEAR TERM.
THERE IS STILL A CHANCE FOR THUNDERSTORMS TO FORM OVER THE
MOUNTAINS THIS AFTERNOON AND EVENING. THERE IS MOISTURE AND
INSTABILITY AVAILABLE, BUT WE LACK MUCH OF A TRIGGER TO GET IT
GOING. FORECAST SOUNDINGS SHOW IT BECOMING COMPLETELY UNCAPPED
OVER THE MOUNTAINS THIS AFTERNOON, SO CONVECTION WILL LIKELY
OCCUR. HOWEVER, WE WILL HAVE AN INCREASING JET ALOFT (FORECAST TO
REACH AROUND 100 KT LATE THIS AFTERNOON) WHICH SHOULD LIMIT THE
VERTICAL EXTENT OF SAID CONVECTION. WE WILL KEEP THE CHANCE FOR
THUNDERSTORMS OVER THE MOUNTAINS (AND THE ASSOCIATED RED FLAG
WARNING), BUT THE CONFIDENCE IN THIS REMAINS LOW. -WRIGHT
&&
.PREV DISCUSSION... /ISSUED 625 AM PDT TUE AUG 11 2015/
DISCUSSION...A LARGE CUTOFF LOW IS MOVING SLOWLY NORTH TO SOUTH OVER
THE OREGON OFFSHORE WATERS. THIS LOW WILL DICTATE THE CWA`S
WEATHER FOR THE NEXT SEVERAL DAYS. THE ATMOSPHERE FOR MUCH OF THE
FORECAST AREA WILL TREND DRIER TODAY...AND THIS DRIER AIR IS NOTED
ON THE MORNING WATER VAPOR IMAGERY...MOVING SOUTH TO NORTH FROM
CENTRAL CALIFORNIA. THIS DRIER AIR IS TIMED TO ARRIVE IN SOUTHERN
OREGON LATE THIS AFTERNOON. FARTHER WEST...MORE MIDLEVEL MOISTURE
IS EVIDENT AND WILL STREAM INTO THE WESTERN QUARTER OF THE
FORECAST AREA TODAY.
WE FOCUSED THIS EVENING ON THUNDERSTORM CHANCES IN SOUTHERN OREGON
AND NORTHERN CALIFORNIA. FIRST...AREAS THAT ARE TOO STABLE AND/OR
TOO DRY FOR THUNDERSTORMS INCLUDE EASTERN
SISKIYOU...MODOC...LAKE...AND CENTRAL AND SOUTHERN KLAMATH COUNTIES.
HERE...GFS FORECAST 850MB COMPUTED LI VALUES ARE POSITIVE...AND
700MB TO 500MB MOISTURE IS LESS THAN 50 PERCENT. FARTHER NORTH AND
WEST...A BROAD AREA OF NEGATIVE LIFTED INDEX VALUES...GENERALLY MORE
MOISTURE...AND AN UPPER LEVEL DISTURBANCE MOVING FROM SOUTH TO
NORTH...ALL CONTRIBUTE TO MOSTLY ISOLATED THUNDERSTORMS TODAY. THE
TRICKY AREAS WERE THE CASCADES FROM CRATER LAKE NORTHWARD...A
CLIMATOLOGICAL FAVORITE FOR LIGHTNING...AND THE HIGH TERRAIN OF
JOSEPHINE...CURRY...AND EXTREME WESTERN SISKIYOU COUNTY.
FIRST...WE HAVE CONTINUED THE RED FLAG WARNING FOR AREAS ALONG AND
NORTH OF CRATER LAKE...AS MODELS CONTINUE TO PAINT A SWATH OF
MOISTURE AND INSTABILITY THAT SUPPORTS SCATTERED THUNDERSTORMS
THERE. ADDITIONALLY...SLIGHT UPSLOPE COMPONENT TO THE WINDS MAY
ASSIST IN FORMATION OF STORMS THERE.
FURTHER TO THE SOUTHWEST...AROUND THE KALMIOPSIS WILDERNESS...MODELS
DEPICT SIGNIFICANT INSTABILITY...MOISTURE...AND SHOW A TRIGGER IN
THE FORM OF A NARROW SHORTWAVE AHEAD OF THE CUTOFF LOW. WE THINK
THE ABUNDANT MOISTURE ALOFT WILL PREVENT OPTIMAL SURFACE HEATING
AND THEREFORE KEEP ANY THUNDERSTORMS TO ISOLATED COVERAGE. THIS IS
A PLACE WORTH MONITORING FOR HRRR TRENDS IN THE MORNING...TO
DETERMINE IF ANY PRODUCTS NEED TO BE ISSUED FOR THAT AREA.
THE LATEST ARW AND NMM HIGH-RES OUTPUT...AS WELL AS HRRR MODELED
REFLECTIVITIES SUPPORT THE CURRENT FORECAST THINKING THAT LACK OF
MOISTURE SHOULD PREVENT ABUNDANT LIGHTNING IN MOST PLACES. STORMS
TODAY SHOULD NOT PRODUCE MUCH PRECIPITATION...ESPECIALLY THE
FURTHER EAST ONE GOES. CLOSER TO THE COAST...PRECIPITABLE WATER IS
HIGHER AND RAIN IS EXPECTED WITH ANY SHOWERS OR STORMS THAT DO
FORM. STORM MOTION WILL BE FROM SOUTH-SOUTHEAST TO NORTH-NORTHWEST
AT ABOUT A 20KT CLIP TODAY.
TUESDAY NIGHT...THE LATEST NAM UPPER LEVEL INSTABILITY PARAMETERS
SUCH AS MODIFIED TOTAL TOTALS AND 700MB-500MB CAPE SHOW SOME
POTENTIAL FOR THUNDERSTORMS FOR NORTHERN DOUGLAS COUNTY TOWARDS THE
COAST...AND THIS BEARS WATCHING FOR FUTURE TRENDS. EARLIER MODELS
SHOWED LESS FAVORABLE CONDITIONS...SO SHOWERS ARE IN THE CURRENT
FORECAST FOR TUESDAY NIGHT.
ON WEDNESDAY...THE UPPER LOW DRIFTS FARTHER TO THE SOUTH...AWAY FROM
THE AREA...AND DRAWS IN EVEN DRIER AIR...HELPING TO WARM THINGS UP
AND PREVENT ANY THUNDERSTORMS FROM FORMING. THERE WAS ENOUGH
INDICATION OF SHOWERS IN PORTIONS OF THE WEST SIDE TO KEEP THEM
IN THE FORECAST...BUT FUTURE SHIFTS MAY BE ABLE TO REMOVE THEM
ALTOGETHER FOR A DRY WEDNESDAY.
ALL MODELS AGREE ON THE LOW MOVING BACK TOWARDS THE COAST
THURSDAY...BUT THE SPEED OF MOVEMENT DIFFERS. THE CURRENT THINKING
IS THAT ENOUGH MOISTURE AND DYNAMICS ARRIVE ON THURSDAY TO BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. HOWEVER...EVEN ONLY
A FEW DAYS AWAY...CONFIDENCE IN THIS PORTION OF THE FORECAST IS LOW
AS THE EC KEEPS THE LOW FURTHER WEST AND THUS DIMINISHES THE CHANCE
FOR SHOWERS ON THURSDAY...AND DELAYS ANY RAIN CHANCES UNTIL
THURSDAY EVENING.
ONCE THE LOW PASSES...STABLE CONDITIONS ARE EXPECTED FRIDAY INTO THE
WEEKEND WITH WESTERLY TO SOUTHWESTERLY FLOW ALOFT.
AVIATION...FOR THE 11/12Z TAF CYCLE...ALONG THE COAST...IFR/MVFR
CIGS OFFSHORE WILL PERSIST THROUGH MID-MORNING (CLEARING AROUND 16-
18Z) EXCEPT FOR SOME LINGERING LOW CIGS POSSIBLE NEAR KBOK INTO THE
AFTERNOON. IFR CIGS ARE EXPECTED TO RETURN TO THE COAST THIS
EVENING AROUND 04Z. INLAND...VFR CONDITIONS WILL PREVAIL THROUGH
THIS MORNING...EXCEPT FOR AREAS OF MVFR VSBYS IN SMOKE. A FEW
THUNDERSTORMS ARE POSSIBLE EARLY THIS MORNING WEST OF THE CASCADES,
MAINLY NEAR THE COAST. SOUTHEAST STEERING WINDS ARE EXPECTED WITH
ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING FROM THE SOUTHERN
OREGON CASCADES INTO EASTERN DOUGLAS COUNTY AND FROM WESTERN
SISKIYOU COUNTY INTO JOSEPHINE AND CURRY COUNTIES. STORMS MAY BRING
ERRATIC AND GUSTY WINDS AND LOCAL OBSCURATION OF HIGHER TERRAIN. -CC
MARINE...UPDATED 245 AM PDT TUESDAY 11 AUGUST 2015...A WEAK SURFACE
PRESSURE PATTERN WILL RESULT IN LIGHT WINDS AND LOW SEAS OVER THE
NEXT FEW DAYS. ALTHOUGH AN UPPER LEVEL DISTURBANCE COULD BRING A FEW
THUNDERSTORMS TO THE COASTAL WATERS THIS MORNING AND OCCASIONAL
SHOWERS THROUGH THURSDAY. A THERMAL TROUGH WILL DEVELOP NEAR THE
COAST FRIDAY AND SATURDAY, BRINGING WITH IT STRONG NORTH WINDS AND
CHOPPY SEAS, ESPECIALLY IN THE OUTER WATERS SOUTH OF CAPE BLANCO.
ALTHOUGH STILL TOO FAR OUT IN RANGE TO BE CERTAIN, GALES AND VERY
STEEP SEAS ARE POSSIBLE THIS WEEKEND INTO EARLY NEXT WEEK. -CC
FIRE WEATHER...UPDATED 600 AM PDT TUESDAY 11 AUGUST 2015...A SLIGHT
CHANCE OF THUNDERSTORMS AND SHOWERS IS POSSIBLE WEST OF THE CASCADES
THIS MORNING, MAINLY NEAR THE COAST. THEN MODELS SHOW SOME MID LEVEL
MOISTURE, INSTABILITY, AND DISTURBANCES ALOFT MOVING INTO THE AREA
THIS AFTERNOON AND EVENING. THIS IS EXPECTED TO BRING MAINLY
ISOLATED STORMS TO AREAS FROM THE CASCADES WEST AND INTO NORTHERN
KLAMATH COUNTY, EXCEPT FOR SCATTERED THUNDERSTORMS WHICH ARE
EXPECTED IN EASTERN PORTIONS OF FIRE WEATHER ZONE 617 AND FAR
NORTHERN PORTIONS OF FIRE WEATHER ZONE 623 LATE THIS AFTERNOON AND
THIS EVENING. OVERALL THERE IS MODERATE CONFIDENCE FOR SCATTERED
STORMS IN THESE AREAS LATE TODAY AND THIS EVENING. OF NOTE, MODELS
ARE TRACKING THIS MORNING`S STORMS WELL COMPARED TO YESTERDAYS
EVENT. MODELS SHOW GOOD INSTABILITY AND UPPER LEVEL SUPPORT FOR
STORMS IN ZONES 617 AND NORTHERN 623. UNCERTAINTY IS MAINLY WITH THE
TRACK OF ANY DISTURBANCES INTO THE AREA AND WHETHER THEY PUSH
FURTHER NORTH. FOR AREAS WEST OF THE CASCADES, THE BEST CHANCE FOR
ISOLATED STORMS TO DEVELOP THIS AFTERNOON INTO THIS EVENING IS IN
WESTERN SISKIYOU COUNTY NORTHWARD INTO WESTERN JOSEPHINE AND EASTERN
CURRY COUNTIES. ALSO THE STORMS THAT DEVELOP IN THE OREGON CASCADES
MAY MOVE EAST-NORTHEAST AND INTO NORTHERN JACKSON AND CENTRAL
DOUGLAS COUNTY DURING THE EVENING.
ON WEDNESDAY, CONDITIONS ARE FORECAST TO BE MORE STABLE AND LESS
FAVORABLE FOR THUNDERSTORMS. THEN AS THE UPPER LOW NEARS THE COAST
ON THURSDAY, GRADUALLY MOVING ONSHORE THURSDAY EVENING AND NIGHT,
EXPECT INCREASED CHANCES FOR A MIX OF SHOWERS AND THUNDERSTORMS OVER
THE AREA. HOWEVER, MODELS ARE SHOWING CONSIDERABLE VARIABILITY ON
THE TRACK OF THE LOW AND HOW QUICKLY IT WILL PUSH INLAND. SO
CONFIDENCE IS LOWER ON THE DETAILS OF THE FORECAST FOR THURSDAY.
AS THE UPPER LOW REMAINS OFF THE COAST, GUSTY SOUTH WINDS WILL
CONTINUE OVER EASTERN PORTIONS OF THE AREA THROUGH THURSDAY...WHEN
IT MAY BE ESPECIALLY WINDY ON THE EAST OF THE CASCADES AS THE UPPER
LOW GRADUALLY MOVES ONSHORE. ALSO GUSTY SOUTH WINDS ARE ALSO LIKELY
IN THE SHASTA VALLEY TODAY AND AGAIN ON WEDNESDAY AND POSSIBLY INTO
THURSDAY AFTERNOON. DAYTIME RELATIVE HUMIDITIES WILL INCREASE
SLIGHTLY ON THURSDAY.
AFTER THE TROUGH MOVES INLAND...OFFSHORE LOW LEVEL FLOW WILL DEVELOP
OVER THE COAST RANGE FRIDAY NIGHT INTO SATURDAY NIGHT. THIS MAY
BRING MODERATE RECOVERIES WITH LOCALLY POOR RECOVERIES POSSIBLE FOR
THE RIDGES, ESPECIALLY FOR THOSE IN THE COASTAL RANGES, SISKIYOUS
AND FOR THE MOUNTAINS IN WESTERN SISKIYOU COUNTY. /CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR... RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT THIS
EVENING FOR ORZ617-623.
CA...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM PDT THIS
EVENING FOR CAZ281.
PACIFIC COASTAL WATERS...NONE.
$$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
625 AM PDT TUE AUG 11 2015
UPDATED AVIATION AND FIRE DISCUSSIONS.
.DISCUSSION...A LARGE CUTOFF LOW IS MOVING SLOWLY NORTH TO SOUTH OVER
THE OREGON OFFSHORE WATERS. THIS LOW WILL DICTATE THE CWA`S
WEATHER FOR THE NEXT SEVERAL DAYS. THE ATMOSPHERE FOR MUCH OF THE
FORECAST AREA WILL TREND DRIER TODAY...AND THIS DRIER AIR IS NOTED
ON THE MORNING WATER VAPOR IMAGERY...MOVING SOUTH TO NORTH FROM
CENTRAL CALIFORNIA. THIS DRIER AIR IS TIMED TO ARRIVE IN SOUTHERN
OREGON LATE THIS AFTERNOON. FARTHER WEST...MORE MIDLEVEL MOISTURE
IS EVIDENT AND WILL STREAM INTO THE WESTERN QUARTER OF THE
FORECAST AREA TODAY.
WE FOCUSED THIS EVENING ON THUNDERSTORM CHANCES IN SOUTHERN OREGON
AND NORTHERN CALIFORNIA. FIRST...AREAS THAT ARE TOO STABLE AND/OR
TOO DRY FOR THUNDERSTORMS INCLUDE EASTERN
SISKIYOU...MODOC...LAKE...AND CENTRAL AND SOUTHERN KLAMATH COUNTIES.
HERE...GFS FORECAST 850MB COMPUTED LI VALUES ARE POSITIVE...AND
700MB TO 500MB MOISTURE IS LESS THAN 50 PERCENT. FARTHER NORTH AND
WEST...A BROAD AREA OF NEGATIVE LIFTED INDEX VALUES...GENERALLY MORE
MOISTURE...AND AN UPPER LEVEL DISTURBANCE MOVING FROM SOUTH TO
NORTH...ALL CONTRIBUTE TO MOSTLY ISOLATED THUNDERSTORMS TODAY. THE
TRICKY AREAS WERE THE CASCADES FROM CRATER LAKE NORTHWARD...A
CLIMATOLOGICAL FAVORITE FOR LIGHTNING...AND THE HIGH TERRAIN OF
JOSPEHINE...CURRY...AND EXTREME WESTERN SISKIYOU COUNTY. FIRST...WE
HAVE CONTINUED THE RED FLAG WARNING FOR AREAS ALONG AND NORTH OF
CRATER LAKE...AS MODELS CONTINUE TO PAINT A SWATH OF MOISTURE AND
INSTABILITY THAT SUPPORTS SCATTERED THUNDERSTORMS THERE.
ADDITIONALLY...SLIGHT UPSLOPE COMPONENT TO THE WINDS MAY ASSIST IN
FORMATION OF STORMS THERE.
FURTHER TO THE SOUTHWEST...AROUND THE KALMIOPSIS WILDERNESS...MODELS
DEPICT SIGNIFICANT INSTABILITY...MOISTURE...AND SHOW A TRIGGER IN
THE FORM OF A NARROW SHORTWAVE AHEAD OF THE CUTOFF LOW. WE THINK
THE ABUNDANT MOISTURE ALOFT WILL PREVENT OPTIMAL SURFACE HEATING
AND THEREFORE KEEP ANY THUNDERSTORMS TO ISOLATED COVERAGE. THIS IS
A PLACE WORTH MONITORING FOR HRRR TRENDS IN THE MORNING...TO
DETERMINE IF ANY PRODUCTS NEED TO BE ISSUED FOR THAT AREA.
THE LATEST ARW AND NMM HIGH-RES OUTPUT...AS WELL AS HRRR MODELED
REFLECTIVITIES SUPPORT THE CURRENT FORECAST THINKING THAT LACK OF
MOISTURE SHOULD PREVENT ABUNDANT LIGHTNING IN MOST PLACES. STORMS
TODAY SHOULD NOT PRODUCE MUCH PRECIPITATION...ESPECIALLY THE
FURTHER EAST ONE GOES. CLOSER TO THE COAST...PRECIPITABLE WATER IS
HIGHER AND RAIN IS EXPECTED WITH ANY SHOWERS OR STORMS THAT DO
FORM. STORM MOTION WILL BE FROM SOUTH-SOUTHEAST TO NORTH-NORTHWEST
AT ABOUT A 20KT CLIP TODAY.
TUESDAY NIGHT...THE LATEST NAM UPPER LEVEL INSTABILITY PARAMETERS
SUCH AS MODIFIED TOTAL TOTALS AND 700MB-500MB CAPE SHOW SOME
POTENTIAL FOR THUNDERSTORMS FOR NORTHERN DOUGLAS COUNTY TOWARDS THE
COAST...AND THIS BEARS WATCHING FOR FUTURE TRENDS. EARLIER MODELS
SHOWED LESS FAVORABLE CONDITIONS...SO SHOWERS ARE IN THE CURRENT
FORECAST FOR TUESDAY NIGHT.
ON WEDNESDAY...THE UPPER LOW DRIFTS FARTHER TO THE SOUTH...AWAY FROM
THE AREA...AND DRAWS IN EVEN DRIER AIR...HELPING TO WARM THINGS UP
AND PREVENT ANY THUNDERSTORMS FROM FORMING. THERE WAS ENOUGH
INDICATION OF SHOWERS IN PORTIONS OF THE WEST SIDE TO KEEP THEM
IN THE FORECAST...BUT FUTURE SHIFTS MAY BE ABLE TO REMOVE THEM
ALTOGETHER FOR A DRY WEDNESDAY.
ALL MODELS AGREE ON THE LOW MOVING BACK TOWARDS THE COAST
THURSDAY...BUT THE SPEED OF MOVEMENT DIFFERS. THE CURRENT THINKING
IS THAT ENOUGH MOISTURE AND DYNAMICS ARRIVE ON THURSDAY TO BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. HOWEVER...EVEN ONLY
A FEW DAYS AWAY...CONFIDENCE IN THIS PORTION OF THE FORECAST IS LOW
AS THE EC KEEPS THE LOW FURTHER WEST AND THUS DIMINISHES THE CHANCE
FOR SHOWERS ON THURSDAY...AND DELAYS ANY RAIN CHANCES UNTIL
THURSDAY EVENING.
ONCE THE LOW PASSES...STABLE CONDITIONS ARE EXPECTED FRIDAY INTO THE
WEEKEND WITH WESTERLY TO SOUTHWESTERLY FLOW ALOFT.
&&
.AVIATION...FOR THE 11/12Z TAF CYCLE...ALONG THE COAST...IFR/MVFR
CIGS OFFSHORE WILL PERSIST THROUGH MID-MORNING (CLEARING AROUND 16-
18Z) EXCEPT FOR SOME LINGERING LOW CIGS POSSIBLE NEAR KBOK INTO THE
AFTERNOON. IFR CIGS ARE EXPECTED TO RETURN TO THE COAST THIS
EVENING AROUND 04Z. INLAND...VFR CONDITIONS WILL PREVAIL THROUGH
THIS MORNING...EXCEPT FOR AREAS OF MVFR VSBYS IN SMOKE. A FEW
THUNDERSTORMS ARE POSSIBLE EARLY THIS MORNING WEST OF THE CASCADES,
MAINLY NEAR THE COAST. SOUTHEAST STEERING WINDS ARE EXPECTED WITH
ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING FROM THE SOUTHERN
OREGON CASCADES INTO EASTERN DOUGLAS COUNTY AND FROM WESTERN
SISKIYOU COUNTY INTO JOSEPHINE AND CURRY COUNTIES. STORMS MAY BRING
ERRATIC AND GUSTY WINDS AND LOCAL OBSCURATION OF HIGHER TERRAIN. -CC
&&
.MARINE...UPDATED 245 AM PDT TUESDAY 11 AUGUST 2015...A WEAK SURFACE
PRESSURE PATTERN WILL RESULT IN LIGHT WINDS AND LOW SEAS OVER THE
NEXT FEW DAYS. ALTHOUGH AN UPPER LEVEL DISTURBANCE COULD BRING A FEW
THUNDERSTORMS TO THE COASTAL WATERS THIS MORNING AND OCCASIONAL
SHOWERS THROUGH THURSDAY. A THERMAL TROUGH WILL DEVELOP NEAR THE
COAST FRIDAY AND SATURDAY, BRINGING WITH IT STRONG NORTH WINDS AND
CHOPPY SEAS, ESPECIALLY IN THE OUTER WATERS SOUTH OF CAPE BLANCO.
ALTHOUGH STILL TOO FAR OUT IN RANGE TO BE CERTAIN, GALES AND VERY
STEEP SEAS ARE POSSIBLE THIS WEEKEND INTO EARLY NEXT WEEK. -CC
&&
.FIRE WEATHER...UPDATED 600 AM PDT TUESDAY 11 AUGUST 2015...A SLIGHT
CHANCE OF THUNDERSTORMS AND SHOWERS IS POSSIBLE WEST OF THE CASCADES
THIS MORNING, MAINLY NEAR THE COAST. THEN MODELS SHOW SOME MID LEVEL
MOISTURE, INSTABILITY, AND DISTURBANCES ALOFT MOVING INTO THE AREA
THIS AFTERNOON AND EVENING. THIS IS EXPECTED TO BRING MAINLY
ISOLATED STORMS TO AREAS FROM THE CASCADES WEST AND INTO NORTHERN
KLAMATH COUNTY, EXCEPT FOR SCATTERED THUNDERSTORMS WHICH ARE
EXPECTED IN EASTERN PORTIONS OF FIRE WEATHER ZONE 617 AND FAR
NORTHERN PORTIONS OF FIRE WEATHER ZONE 623 LATE THIS AFTERNOON AND
THIS EVENING. OVERALL THERE IS MODERATE CONFIDENCE FOR SCATTERED
STORMS IN THESE AREAS LATE TODAY AND THIS EVENING. OF NOTE, MODELS
ARE TRACKING THIS MORNING`S STORMS WELL COMPARED TO YESTERDAYS
EVENT. MODELS SHOW GOOD INSTABILITY AND UPPER LEVEL SUPPORT FOR
STORMS IN ZONES 617 AND NORTHERN 623. UNCERTAINTY IS MAINLY WITH THE
TRACK OF ANY DISTURBANCES INTO THE AREA AND WHETHER THEY PUSH
FURTHER NORTH. FOR AREAS WEST OF THE CASCADES, THE BEST CHANCE FOR
ISOLATED STORMS TO DEVELOP THIS AFTERNOON INTO THIS EVENING IS IN
WESTERN SISKIYOU COUNTY NORTHWARD INTO WESTERN JOSEPHINE AND EASTERN
CURRY COUNTIES. ALSO THE STORMS THAT DEVELOP IN THE OREGON CASCADES
MAY MOVE EAST-NORTHEAST AND INTO NORTHERN JACKSON AND CENTRAL
DOUGLAS COUNTY DURING THE EVENING.
ON WEDNESDAY, CONDITIONS ARE FORECAST TO BE MORE STABLE AND LESS
FAVORABLE FOR THUNDERSTORMS. THEN AS THE UPPER LOW NEARS THE COAST
ON THURSDAY, GRADUALLY MOVING ONSHORE THURSDAY EVENING AND NIGHT,
EXPECT INCREASED CHANCES FOR A MIX OF SHOWERS AND THUNDERSTORMS OVER
THE AREA. HOWEVER, MODELS ARE SHOWING CONSIDERABLE VARIABILITY ON
THE TRACK OF THE LOW AND HOW QUICKLY IT WILL PUSH INLAND. SO
CONFIDENCE IS LOWER ON THE DETAILS OF THE FORECAST FOR THURSDAY.
AS THE UPPER LOW REMAINS OFF THE COAST, GUSTY SOUTH WINDS WILL
CONTINUE OVER EASTERN PORTIONS OF THE AREA THROUGH THURSDAY...WHEN
IT MAY BE ESPECIALLY WINDY ON THE EAST OF THE CASCADES AS THE UPPER
LOW GRADUALLY MOVES ONSHORE. ALSO GUSTY SOUTH WINDS ARE ALSO LIKELY
IN THE SHASTA VALLEY TODAY AND AGAIN ON WEDNESDAY AND POSSIBLY INTO
THURSDAY AFTERNOON. DAYTIME RELATIVE HUMIDITIES WILL INCREASE
SLIGHTLY ON THURSDAY.
AFTER THE TROUGH MOVES INLAND...OFFSHORE LOW LEVEL FLOW WILL DEVELOP
OVER THE COAST RANGE FRIDAY NIGHT INTO SATURDAY NIGHT. THIS MAY
BRING MODERATE RECOVERIES WITH LOCALLY POOR RECOVERIES POSSIBLE FOR
THE RIDGES, ESPECIALLY FOR THOSE IN THE COASTAL RANGES, SISKIYOUS
AND FOR THE MOUNTAINS IN WESTERN SISKIYOU COUNTY. /CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR... RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT THIS
EVENING FOR ORZ617-623.
CA...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM PDT THIS
EVENING FOR CAZ281.
PACIFIC COASTAL WATERS...NONE.
$$
NSK/NSK/DW
AREA FORECAST DISCUSSION
NWS MEDFORD OR
350 AM PDT TUE AUG 11 2015
.DISCUSSION...A LARGE CUTOFF LOW IS MOVING SLOWLY NORTH TO SOUTH OVER
THE OREGON OFFSHORE WATERS. THIS LOW WILL DICTATE THE CWA`S
WEATHER FOR THE NEXT SEVERAL DAYS. THE ATMOSPHERE FOR MUCH OF THE
FORECAST AREA WILL TREND DRIER TODAY...AND THIS DRIER AIR IS NOTED
ON THE MORNING WATER VAPOR IMAGERY...MOVING SOUTH TO NORTH FROM
CENTRAL CALIFORNIA. THIS DRIER AIR IS TIMED TO ARRIVE IN SOUTHERN
OREGON LATE THIS AFTERNOON. FARTHER WEST...MORE MIDLEVEL MOISTURE
IS EVIDENT AND WILL STREAM INTO THE WESTERN QUARTER OF THE
FORECAST AREA TODAY.
WE FOCUSED THIS EVENING ON THUNDERSTORM CHANCES IN SOUTHERN OREGON
AND NORTHERN CALIFORNIA. FIRST...AREAS THAT ARE TOO STABLE AND/OR
TOO DRY FOR THUNDERSTORMS INCLUDE EASTERN
SISKIYOU...MODOC...LAKE...AND CENTRAL AND SOUTHERN KLAMATH COUNTIES.
HERE...GFS FORECAST 850MB COMPUTED LI VALUES ARE POSITIVE...AND
700MB TO 500MB MOISTURE IS LESS THAN 50 PERCENT. FARTHER NORTH AND
WEST...A BROAD AREA OF NEGATIVE LIFTED INDEX VALUES...GENERALLY MORE
MOISTURE...AND AN UPPER LEVEL DISTURBANCE MOVING FROM SOUTH TO
NORTH...ALL CONTRIBUTE TO MOSTLY ISOLATED THUNDERSTORMS TODAY. THE
TRICKY AREAS WERE THE CASCADES FROM CRATER LAKE NORTHWARD...A
CLIMATOLOGICAL FAVORITE FOR LIGHTNING...AND THE HIGH TERRAIN OF
JOSPEHINE...CURRY...AND EXTREME WESTERN SISKIYOU COUNTY. FIRST...WE
HAVE CONTINUED THE RED FLAG WARNING FOR AREAS ALONG AND NORTH OF
CRATER LAKE...AS MODELS CONTINUE TO PAINT A SWATH OF MOISTURE AND
INSTABILITY THAT SUPPORTS SCATTERED THUNDERSTORMS THERE.
ADDITIONALLY...SLIGHT UPSLOPE COMPONENT TO THE WINDS MAY ASSIST IN
FORMATION OF STORMS THERE.
FURTHER TO THE SOUTHWEST...AROUND THE KALMIOPSIS WILDERNESS...MODELS
DEPICT SIGNIFICANT INSTABILITY...MOISTURE...AND SHOW A TRIGGER IN
THE FORM OF A NARROW SHORTWAVE AHEAD OF THE CUTOFF LOW. WE THINK
THE ABUNDANT MOISTURE ALOFT WILL PREVENT OPTIMAL SURFACE HEATING
AND THEREFORE KEEP ANY THUNDERSTORMS TO ISOLATED COVERAGE. THIS IS
A PLACE WORTH MONITORING FOR HRRR TRENDS IN THE MORNING...TO
DETERMINE IF ANY PRODUCTS NEED TO BE ISSUED FOR THAT AREA.
THE LATEST ARW AND NMM HIGH-RES OUTPUT...AS WELL AS HRRR MODELED
REFLECTIVITIES SUPPORT THE CURRENT FORECAST THINKING THAT LACK OF
MOISTURE SHOULD PREVENT ABUNDANT LIGHTNING IN MOST PLACES. STORMS
TODAY SHOULD NOT PRODUCE MUCH PRECIPITATION...ESPECIALLY THE
FURTHER EAST ONE GOES. CLOSER TO THE COAST...PRECIPITABLE WATER IS
HIGHER AND RAIN IS EXPECTED WITH ANY SHOWERS OR STORMS THAT DO
FORM. STORM MOTION WILL BE FROM SOUTH-SOUTHEAST TO NORTH-NORTHWEST
AT ABOUT A 20KT CLIP TODAY.
TUESDAY NIGHT...THE LATEST NAM UPPER LEVEL INSTABILITY PARAMETERS
SUCH AS MODIFIED TOTAL TOTALS AND 700MB-500MB CAPE SHOW SOME
POTENTIAL FOR THUNDERSTORMS FOR NORTHERN DOUGLAS COUNTY TOWARDS THE
COAST...AND THIS BEARS WATCHING FOR FUTURE TRENDS. EARLIER MODELS
SHOWED LESS FAVORABLE CONDITIONS...SO SHOWERS ARE IN THE CURRENT
FORECAST FOR TUESDAY NIGHT.
ON WEDNESDAY...THE UPPER LOW DRIFTS FARTHER TO THE SOUTH...AWAY FROM
THE AREA...AND DRAWS IN EVEN DRIER AIR...HELPING TO WARM THINGS UP
AND PREVENT ANY THUNDERSTORMS FROM FORMING. THERE WAS ENOUGH
INDICATION OF SHOWERS IN PORTIONS OF THE WEST SIDE TO KEEP THEM
IN THE FORECAST...BUT FUTURE SHIFTS MAY BE ABLE TO REMOVE THEM
ALTOGETHER FOR A DRY WEDNESDAY.
ALL MODELS AGREE ON THE LOW MOVING BACK TOWARDS THE COAST
THURSDAY...BUT THE SPEED OF MOVEMENT DIFFERS. THE CURRENT THINKING
IS THAT ENOUGH MOISTURE AND DYNAMICS ARRIVE ON THURSDAY TO BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. HOWEVER...EVEN ONLY
A FEW DAYS AWAY...CONFIDENCE IN THIS PORTION OF THE FORECAST IS LOW
AS THE EC KEEPS THE LOW FURTHER WEST AND THUS DIMINISHES THE CHANCE
FOR SHOWERS ON THURSDAY...AND DELAYS ANY RAIN CHANCES UNTIL
THURSDAY EVENING.
ONCE THE LOW PASSES...STABLE CONDITIONS ARE EXPECTED FRIDAY INTO THE
WEEKEND WITH WESTERLY TO SOUTHWESTERLY FLOW ALOFT.
&&
.AVIATION...FOR THE 11/06Z TAF CYCLE...ALONG THE COAST...IFR/MVFR
CIGS OFFSHORE WILL MOVE BACK ONSHORE OVERNIGHT THEN PERSIST THROUGH
MID-MORNING (AROUND 18Z) TUESDAY. INLAND...VFR CONDITIONS WILL
PREVAIL THROUGH TUESDAY MORNING...EXCEPT FOR AREAS OF MVFR VSBYS IN
SMOKE. A FEW THUNDERSTORMS ARE POSSIBLE OVERNIGHT WEST OF THE
CASCADES CONTINUING INTO THE MORNING. SOUTHEAST STEERING WINDS ARE
EXPECTED WITH ISOLATED THUNDERSTORMS TUESDAY AFTERNOON AND EVENING
FROM THE SOUTHERN OREGON CASCADES INTO EASTERN DOUGLAS COUNTY AND
FROM WESTERN SISKIYOU COUNTY INTO JOSEPHINE AND CURRY COUNTIES.
STORMS MAY BRING ERRATIC AND GUSTY WINDS AND LOCAL OBSCURATION OF
HIGHER TERRAIN. -DW
&&
.MARINE...UPDATED 245 AM PDT TUESDAY 11 AUGUST 2015...A WEAK SURFACE
PRESSURE PATTERN WILL RESULT IN LIGHT WINDS AND LOW SEAS OVER THE
NEXT FEW DAYS. ALTHOUGH AN UPPER LEVEL DISTURBANCE COULD BRING A FEW
THUNDERSTORMS TO THE COASTAL WATERS THIS MORNING AND OCCASIONAL
SHOWERS THROUGH THURSDAY. A THERMAL TROUGH WILL DEVELOP NEAR THE
COAST FRIDAY AND SATURDAY, BRINGING WITH IT STRONG NORTH WINDS AND
CHOPPY SEAS, ESPECIALLY IN THE OUTER WATERS SOUTH OF CAPE BLANCO.
ALTHOUGH STILL TOO FAR OUT IN RANGE TO BE CERTAIN, GALES AND VERY
STEEP SEAS ARE POSSIBLE THIS WEEKEND INTO EARLY NEXT WEEK. -CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR... RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT THIS
EVENING FOR ORZ617-623.
CA...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM PDT THIS
EVENING FOR CAZ281.
PACIFIC COASTAL WATERS...NONE.
$$
NSK/NSK/DW
AREA FORECAST DISCUSSION
NWS MEDFORD OR
330 AM PDT TUE AUG 11 2015
.DISCUSSION...A LARGE CUTOFF LOW IS MOVING SLOWLY NORTH TO SOUTH OVER
THE OREGON OFFSHORE WATERS. THIS LOW WILL DICTATE THE CWA`S
WEATHER FOR THE NEXT SEVERAL DAYS. THE ATMOSPHERE FOR MUCH OF THE
FORECAST AREA WILL TREND DRIER TODAY...AND THIS DRIER AIR IS NOTED
ON THE MORNING WATER VAPOR IMAGERY...MOVING SOUTH TO NORTH FROM
CENTRAL CALIFORNIA. THIS DRIER AIR IS TIMED TO ARRIVE IN SOUTHERN
OREGON LATE THIS AFTERNOON. FARTHER WEST...MORE MIDLEVEL MOISTURE
IS EVIDENT AND WILL STREAM INTO THE WESTERN QUARTER OF THE
FORECAST AREA TODAY.
WE FOCUSED THIS EVENING ON THUNDERSTORM CHANCES IN SOUTHERN OREGON
AND NORTHERN CALIFORNIA. FIRST...AREAS THAT ARE TOO STABLE AND/OR
TOO DRY FOR THUNDERSTORMS INCLUDE EASTERN
SISKIYOU...MODOC...LAKE...AND CENTRAL AND SOUTHERN KLAMATH COUNTIES.
HERE...GFS FORECAST 850MB COMPUTED LI VALUES ARE POSITIVE...AND
700MB TO 500MB MOISTURE IS LESS THAN 50 PERCENT. FARTHER NORTH AND
WEST...A BROAD AREA OF NEGATIVE LIFTED INDEX VALUES...GENERALLY MORE
MOISTURE...AND AN UPPER LEVEL DISTURBANCE MOVING FROM SOUTH TO
NORTH...ALL CONTRIBUTE TO MOSTLY ISOLATED THUNDERSTORMS TODAY. THE
TRICKY AREAS WERE THE CASCADES FROM CRATER LAKE NORTHWARD...A
CLIMATOLOGICAL FAVORITE FOR LIGHTNING...AND THE HIGH TERRAIN OF
JOSPEHINE...CURRY...AND EXTREME WESTERN SISKIYOU COUNTY. FIRST...WE
HAVE CONTINUED THE RED FLAG WARNING FOR AREAS ALONG AND NORTH OF
CRATER LAKE...AS MODELS CONTINUE TO PAINT A SWATH OF MOISTURE AND
INSTABILITY THAT SUPPORTS SCATTERED THUNDERSTORMS THERE.
ADDITIONALLY...SLIGHT UPSLOPE COMPONENT TO THE WINDS MAY ASSIST IN
FORMATION OF STORMS THERE.
FURTHER TO THE SOUTHWEST...AROUND THE KALMIOPSIS WILDERNESS...MODELS
DEPICT SIGNIFICANT INSTABILITY...MOISTURE...AND SHOW A TRIGGER IN
THE FORM OF A NARROW SHORTWAVE AHEAD OF THE CUTOFF LOW. WE THINK
THE ABUNDANT MOISTURE ALOFT WILL PREVENT OPTIMAL SURFACE HEATING
AND THEREFORE KEEP ANY THUNDERSTORMS TO ISOLATED COVERAGE. THIS IS
A PLACE WORTH MONITORING FOR HRRR TRENDS IN THE MORNING...TO
DETERMINE IF ANY PRODUCTS NEED TO BE ISSUED FOR THAT AREA.
THE LATEST ARW AND NMM HIGH-RES OUTPUT...AS WELL AS HRRR MODELED
REFLECTIVITIES SUPPORT THE CURRENT FORECAST THINKING THAT LACK OF
MOISTURE SHOULD PREVENT ABUNDANT LIGHTNING IN MOST PLACES. STORMS
TODAY SHOULD NOT PRODUCE MUCH PRECIPITATION...ESPECIALLY THE
FURTHER EAST ONE GOES. CLOSER TO THE COAST...PRECIPITABLE WATER IS
HIGHER AND RAIN IS EXPECTED WITH ANY SHOWERS OR STORMS THAT DO
FORM. STORM MOTION WILL BE FROM SOUTH-SOUTHEAST TO NORTH-NORTHWEST
AT ABOUT A 20KT CLIP TODAY.
ON WEDNESDAY...THE UPPER LOW DRIFTS FARTHER TO THE SOUTH...AWAY FROM
THE AREA...AND DRAWS IN EVEN DRIER AIR...HELPING TO WARM THINGS UP
AND PREVENT ANY THUNDERSTORMS FROM FORMING. THERE WAS ENOUGH
INDICATION OF SHOWERS IN PORTIONS OF THE WEST SIDE TO KEEP THEM
IN THE FORECAST...BUT FUTURE SHIFTS MAY BE ABLE TO REMOVE THEM
ALTOGETHER FOR A DRY WEDNESDAY.
ALL MODELS AGREE ON THE LOW MOVING BACK TOWARDS THE COAST
THURSDAY...BUT THE SPEED OF MOVEMENT DIFFERS. THE CURRENT THINKING
IS THAT ENOUGH MOISTURE AND DYNAMICS ARRIVE ON THURSDAY TO BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. HOWEVER...EVEN ONLY
A FEW DAYS AWAY...CONFIDENCE IN THIS PORTION OF THE FORECAST IS LOW
AS THE EC KEEPS THE LOW FURTHER WEST AND THUS DIMINISHES THE CHANCE
FOR SHOWERS ON THURSDAY...AND DELAYS ANY RAIN CHANCES UNTIL
THURSDAY EVENING.
ONCE THE LOW PASSES...STABLE CONDITIONS ARE EXPECTED FRIDAY INTO THE
WEEKEND WITH WESTERLY TO SOUTHWESTERLY FLOW ALOFT.
&&
.AVIATION...FOR THE 11/06Z TAF CYCLE...ALONG THE COAST...IFR/MVFR
CIGS OFFSHORE WILL MOVE BACK ONSHORE OVERNIGHT THEN PERSIST THROUGH
MID-MORNING (AROUND 18Z) TUESDAY. INLAND...VFR CONDITIONS WILL
PREVAIL THROUGH TUESDAY MORNING...EXCEPT FOR AREAS OF MVFR VSBYS IN
SMOKE. A FEW THUNDERSTORMS ARE POSSIBLE OVERNIGHT WEST OF THE
CASCADES CONTINUING INTO THE MORNING. SOUTHEAST STEERING WINDS ARE
EXPECTED WITH ISOLATED THUNDERSTORMS TUESDAY AFTERNOON AND EVENING
FROM THE SOUTHERN OREGON CASCADES INTO EASTERN DOUGLAS COUNTY AND
FROM WESTERN SISKIYOU COUNTY INTO JOSEPHINE AND CURRY COUNTIES.
STORMS MAY BRING ERRATIC AND GUSTY WINDS AND LOCAL OBSCURATION OF
HIGHER TERRAIN. -DW
&&
.MARINE...UPDATED 245 AM PDT TUESDAY 11 AUGUST 2015...A WEAK SURFACE
PRESSURE PATTERN WILL RESULT IN LIGHT WINDS AND LOW SEAS OVER THE
NEXT FEW DAYS. ALTHOUGH AN UPPER LEVEL DISTURBANCE COULD BRING A FEW
THUNDERSTORMS TO THE COASTAL WATERS THIS MORNING AND OCCASIONAL
SHOWERS THROUGH THURSDAY. A THERMAL TROUGH WILL DEVELOP NEAR THE
COAST FRIDAY AND SATURDAY, BRINGING WITH IT STRONG NORTH WINDS AND
CHOPPY SEAS, ESPECIALLY IN THE OUTER WATERS SOUTH OF CAPE BLANCO.
ALTHOUGH STILL TOO FAR OUT IN RANGE TO BE CERTAIN, GALES AND VERY
STEEP SEAS ARE POSSIBLE THIS WEEKEND INTO EARLY NEXT WEEK. -CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR... RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT THIS
EVENING FOR ORZ617-623.
CA...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM PDT THIS
EVENING FOR CAZ281.
PACIFIC COASTAL WATERS...NONE.
$$
NSK/NSK/DW
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1018 PM EDT WED AUG 12 2015
.SYNOPSIS...
THE UPPER LEVEL TROUGH OVER THE REGION WILL WEAKEN OVER THE NEXT
FEW DAYS. HIGHER HEIGHTS SHOULD MOVE INTO THE REGION OVER THE
WEEKEND ALONG WITH WARMER TEMPERATURES. ANOTHER TROUGH AND SURFACE
COLD FRONT SHOULD BRING COOLER AND DRIER AIR BACK INTO THE REGION
AROUND MIDWEEK.
&&
.NEAR TERM /UNTIL 8 AM THURSDAY MORNING/...
MINOR ADJUSTMENTS TO TEMPERATURES AND WEATHER. LAST OF THE PESKY
SHOWERS FINALLY FADING OUT OVER COLUMBIA COUNTY AND SOME CLOUDS AT
LEAST WITH THE REMNANTS OF THE SHOWERS THAT AFFECTED A FEW
LOCATIONS IN THE SOUTHEAST.
MOST AREAS ARE MOSTLY CLEAR EXCEPT THE ABOVE MENTIONED AREAS.
SHOULD BECOME MOSTLY CLEAR AND COOL EVERYWHERE OVERNIGHT. PLEASANT
DRY MORNING. COULD BE SOME PATCHY AM FOG ESPECIALLY NEAR WATER
BODIES AND STREAMS.
&&
.SHORT TERM /8 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
MOST GUIDANCE SHOWS A REALLY NICE DAY LIGHT WINDS AND MOSTLY SUNNY
SKIES. THE HRRR ONLY GOES TO 15Z AND IT SHOWS A PRETTY CLEAR RADAR
SCOPE SO TO SPEAK.
THE OPERATIONAL 21Z SREF SHOWS SOME MODEST SHOWER POTENTIAL IN
NORTHWEST PA WITH ABOUT A 15 PERCENT CHANCE OF SHOWERS. THE NEWER
26 MEMBER PARALLEL SREF HAS 5 PERCENT CHANCE OVER A SMALLER
AREA...BASICALLY PARTS OF WARREN COUNTY BETWEEN 21 AND 00 UTC.
THE OVERALL CONSENSUS IS QUITE LOW FOR POPS OVER MOST OF THE
REGION PROBABLY NOT WORTH MENTIONING. PERHAPS A SLIGHT CHANCE OVER
EXTREME NORTHWESTERN PA. BUT VERY LOW PROBABILITY.
SHOULD BE A GOOD DAY TO BE OUTDOORS OVER THE ENTIRE REGION.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THE SFC HIGH PRESSURE WILL BREAK DOWN AS A SHALLOW TROUGH WILL
DEEPEN AND ALLOW A COLD FRONT TO TRAVERSE THE REGION FRIDAY
AFTERNOON INTO SATURDAY. THE MOISTURE WILL BE FOCUSED ALONG THE
NEW YORK BORDER AND NORTH. THOUGH AS THE TROUGH CONTINUES TO TILT
POSITIVE AND DEEPENS...THERE WILL BE A GREATER CHANCE FOR SHOWERS
AND THUNDERSTORMS ALONG THE CENTRAL MTNS AND THROUGH THE NORTHERN
HALF OF PA. TEMPERATURES WILL BEGIN TO REBOUND UNDER THIS MORE
WESTERLY FLOW OUT AHEAD OF THE FRONT WHICH WILL AID IN ANY
CONVECTION. THE FRONT SHOULD STALL ON SATURDAY...WHICH COULD ALLOW
FOR DAYTIME SUMMER CONVECTION BEFORE THE COLD FRONT PUSHES EAST OF
PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL RETURN FOR THE
BEGINNING OF NEXT WEEK. GIVEN THE PATTERN HAVE ADJUSTED POPS
UPWARD AND SHIFTED THE TIMING ACCORDINGLY. HAVE ADJUSTED
TEMPERATURES UPWARD AS WELL. THE ACTIVE WEATHER PATTERN WILL
CONTINUE THROUGH THE MIDDLE OF NEXT WEEK AS SUCCESSIVE TROUGHS
WILL MOVE THROUGH THE REGION WITH THE NEXT BEST CHANCE TUESDAY
INTO WEDNESDAY.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
SHOWERS ARE DECREASING IN COVERAGE AS WE MOVE TOWARD SUNSET. A FEW
ISOLATED SHOWERS ARE CREEPING THROUGH THE SOUTH CENTRAL MOUNTAINS
AND JUST OT THE NORTH OF KIPT. WITH THE LOSS OF DAYTIME
HEATING...EXPECT SKIES TO CLEAR AFTER SUNSET WITH PATCHY MVFR FOG
LATER TONIGHT.
THE UPPER TROUGH AXIS BEGINS TO PULL AWAY TO THE NORTHEAST
TOMORROW WHICH WILL ALLOW FOR GOOD VFR CONDITIONS THROUGH THE DAY.
OUTLOOK...
FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
SUN...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...CERU/HAGNER
AVIATION...DANGELO/TYBURSKI
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1027 AM EDT TUE AUG 11 2015
.SYNOPSIS...
A FRONTAL SYSTEM WILL MOVE EAST OF THE REGION TODAY. COOLER AND
DRIER AIR WILL FOLLOW FOR THE MIDWEEK PERIOD. TEMPERATURES WILL
REBOUND LATE THIS WEEK WITH HIGH PRESSURE BUILDING EAST FROM THE
MID MISSISSIPPI VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AT MID MORNING THE COLD FRONT WAS STILL WEST OF HARRISBURG MOVING
THROUGH THE LOWER SUSQ VALLEY. BREAKS IN THE CLOUDS ARE ALLOWING
SOME AIRMASS RECOVERY WITH CAPES STARTING TO INCREASE OVER THE SERN
ZONES. WHILE THE HRRR DOES TRY AND FIRE UP A SMALL CONVECTIVE
CLUSTER OVER LANCASTER AND ADAMS COUNTY OVER THE NEXT 1-3
HOURS...I STILL THINK THE SEVERE POTENTIAL WILL BE LIMITED. NEAR
TERM GUIDANCE SHOWS COLD/DRY ADVECTION DEVELOPING IN THE LOWER
LEVELS AND THE RAP INDICATES WE WILL SEE LAYER AVERAGE NEGATIVE
THETA-E ADVECTION IN THE LOW LEVELS OVERSPREAD THE AREA BY LATE
MORNING/EARLY AFTERNOON.
WITH MARGINAL INSTABILITY OVER MOST OF THE AREA COURTESY OF
FALLING UPPER HEIGHTS...WE CANNOT RULE OUT A STRAY SHOWER OR
THUNDERSTORMS TODAY BUT THE OVERALL PATTERN SUPPORTS DRYING
CONDITIONS FOR THE REGION FOR THE REST OF THE DAY.
HIGHS WILL RANGE FROM THE LOWER 70S NORTH TO THE LOWER 80S
SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
CONDITIONS IMPROVE TONIGHT AS A CONTINUAL FEED OF PROGRESSIVELY
DRIER PW ARRIVES ON NORTHWEST FLOW. FAIRLY CYCLONIC UPPER FLOW AND DEEPENING
COLD AIR ALOFT WILL KEEP ISOLD TO LOW CHC POPS IN THE FORECAST
TONIGHT AND WEDNESDAY...BUT RAIN WILL BE SHORT-LIVED AND
GENERALLY LIGHT GIVEN DRY AIR MASS OVER THE REGION. MINS WILL
RANGE FROM THE MID 50S NORTH TO THE MID 60S SOUTHEAST...WHILE
HIGHS RANGE FROM NEAR 70 NORTHWEST TO AROUND 80 SOUTHEAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
BOTH THE GEFS AND THE NAEFS CONTINUE TO FORECAST SLIGHTLY BELOW
NORMAL 850 MB TEMPERATURES OVER THE FORECAST AREA. ADDITIONALLY...
NORTHWEST FLOW ACROSS THE AREA WILL RESULT IN MOUNTAIN SHOWERS
WEDNESDAY AFTERNOON AND EVENING.
A SURFACE HIGH WILL BUILD SOUTHWEST OF THE AREA ON THURSDAY...
BRINGING CLEARER CONDITIONS. THE UPPER LEVEL TROUGH WILL BECOME
MORE SHALLOW FRIDAY AS THE SURFACE HIGH PUSHES EAST TOWARDS THE
ATLANTIC COAST AND TEMPERATURES WILL BEGIN TO REBOUND UNDER A MORE
WESTERLY FLOW.
A COLD FRONT WILL MOVE THROUGH FRIDAY AND SATURDAY...BRINGING
ANOTHER CHANCE FOR SHOWERS AND AFTERNOON THUNDERSTORMS. THE FRONT
PUSHES EAST OF PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL
RETURN FOR SUNDAY AND MONDAY.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
THE COLD FRONT HAS YET TO CLEAR THE LOWER SUSQ VALLEY...BUT MOST
OF THE FORECAST AREA IS NOW INTO A DRIER WEST-NORTHWEST FLOW AND
WILL CONTINUE TO SEE COOLER AND DRIER AIR SLIP INTO THE REGION.
WIDESPREAD MVFR/IFR IN THE POST FRONTAL ENVIRONMENT WILL SLOWLY
IMPROVE IN MOST AREAS THIS AFTERNOON BUT WITH THE THREAT OF A
STRAY SHOWER OR THUNDERSTORM REMAINING.
A SECONDARY DISTURBANCE DROPPING OUT OF THE GR LAKES TONIGHT WILL
LIKELY BRING A RETURN OF MVFR/IFR CEILINGS TO THE LAURELS AND
NORTHERN MOUNTAIN TERMINALS...WITH THE POTENTIAL FOR CEILINGS IN
THE 1000-3000` RANGE EVEN CREEPING INTO THE CENTRAL MOUNTAINS AND
UPPER SUSQ VALLEY.
OUTLOOK...
WED...MVFR/IFR WEST AND NORTH TO START THE DAY...BECOMING MOSTLY
VFR...SCT SHOWERS WEST.
THU-FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/LA CORTE
NEAR TERM...DEVOIR/LA CORTE
SHORT TERM...DEVOIR
LONG TERM...HAGNER
AVIATION...LA CORTE/LAMBERT
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1238 AM CDT TUE AUG 11 2015
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 944 PM CDT MON AUG 10 2015/
UPDATED THE ZONE FORECASTS AND GRIDS FOR TONIGHT. LEFT IN A 20
PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS...ALTHOUGH THE ACTUAL
POP MAY BE LESS THAN THAT. A FEW SHOWERS AND THUNDERSTORMS REMAIN
UPSTREAM OVER SOUTHEASTERN MO AND SOUTHERN IL. THE HRRR CONTINUES
TO SHOW THE POSSIBILITY OF A FEW SHOWERS AND THUNDERSTORMS
TONIGHT IN ASSOCIATION WITH WEAK UPPER LEVEL DISTURBANCES. LOWERED
THE MINIMUM TEMPERATURES SOME IN MOST LOCATIONS BASED ON CURRENT
TEMPERATURES. ALSO INCLUDED AREAS OF FOG AS ANY DRIER AIR AT THE
LOWER LEVELS WILL BE SLOW IN MOVING INTO THE REGION.
JCL
&&
.DISCUSSION... /ISSUED 549 PM CDT MON AUG 10 2015/
UPDATED THE ZONE FORECASTS AND GRIDS TO ADJUST THE POPS TONIGHT
BASED ON THE LATEST MODELS AND CURRENT CONDITIONS. INCLUDED
CHANCE POPS FROM EAST CENTRAL AR TO MUCH OF NORTH MS WHERE THE
INSTABILITY IS GREATEST AND IS AHEAD OF A WEAK SURFACE BOUNDARY.
ELSEWHERE INCLUDED SLIGHT CHANCE POPS FOR THIS EVENING. ALSO
ADJUSTED THE SKY COVER GRIDS FOR TONIGHT...INDICATING PARTLY
CLOUDY SKIES IN THE ZONE FORECASTS.
JCL
DISCUSSION... /ISSUED 341 PM CDT MON AUG 10 2015/
A SHORTWAVE UPSTREAM ACROSS THE MIDDLE MISSISSIPPI VALLEY WILL
CONTINUE TO PUSH SOUTHEAST INTO THE SOUTHERN OHIO AND TENNESSEE
VALLEY TONIGHT. THIS WILL HELP TO ADVANCE A COLD FRONT SOUTH
ACROSS THE REGION OVERNIGHT. THE BEST FORCING ASSOCIATED WITH THE
SHORTWAVE SHOULD BE DIRECTED TO THE EAST OF OUR REGION WITH
EASTERN AREAS HAVING THE GREATEST POTENTIAL FOR CONVECTION
OVERNIGHT. EVEN IN THESE AREAS...SCATTERED COVERAGE AT BEST CAN BE
EXPECTED. OTHERWISE...FURTHER WEST...ISOLATED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE AS THE FRONT MOVES THROUGH. AHEAD
OF THE FRONT THIS EVENING...HOT AND HUMID CONDITIONS IN NORTH
MISSISSIPPI WILL SUPPORT A FEW MORE HOURS OF HEAT INDEX VALUES
GREATER THAN 105 DEGREES. THE HEAT ADVISORY WILL CONTINUE IN THESE
LOCATIONS THROUGH 8 PM CDT.
THE COLD FRONT SHOULD EXIT SOUTHERN SECTIONS ON TUESDAY MORNING
WITH LINGERING SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS. A
DRIER AIRMASS WILL BEGIN TO FILTER INTO THE REGION BY TUESDAY
AFTERNOON BRINGING AN END TO CONVECTIVE CHANCES AND BEGIN A SLOW
FALL OF SURFACE DEWPOINTS FROM NORTH TO SOUTH.
HIGH PRESSURE BUILDING INTO THE MID SOUTH WILL REMAIN IN PLACE
THROUGH MUCH OF THE REMAINDER OF THE WEEK. DRY WEATHER ALONG WITH
COOLER TEMPERATURES AND LOWER HUMIDITY VALUES CAN BE EXPECTED.
AN INVERTED SURFACE TROUGH AND AN INFLUX OF TROPICAL MOISTURE
SHOULD MOVE BACK INTO THE FORECAST AREA FROM THE EAST BY NEXT
WEEKEND. THIS WILL LIKELY BRING INCREASED HUMIDITY LEVELS ALONG
WITH INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS.
TEMPERATURES SHOULD ALSO RETURN TO NEAR SEASONAL VALUES FOR MID
AUGUST.
JLH
&&
.AVIATION...06Z TAF CYCLE
THUNDERSTORMS ACROSS NORTH ARKANSAS AND TENNESSEE SHOULD CONTINUE
TO WEAKEN AND DISSIPATE. PATCHY 2-5SM BR IS EXPECTED AT MKL
THIS MORNING WITH OTHERWISE VFR CONDITIONS OR THE NEXT 24 HRS.
NORTH TO NORTHEAST WINDS AROUND 5KT TONIGHT...5-10 TOMORROW.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
640 PM CDT WED AUG 12 2015
.AVIATION...
/00Z TAFS/
VFR conditions expected the next 24 hours. Could see an isolated
shower or thunderstorm across the southern terminals through
sunset but any activity will quickly dissipate with the loss of
daytime heating. Expect light east to northeast wings through
the period.
&&
.PREV DISCUSSION... /ISSUED 514 PM CDT WED AUG 12 2015/
UPDATE...
Updated zones and grids to go with slight chance to chance Pops
mainly along and south of a Mertzon to San Angelo to Brownwood
line due to current radar trends. The showers and thunderstorms
should dissipate by 03Z.
PREV DISCUSSION... /ISSUED 359 PM CDT WED AUG 12 2015/
SHORT TERM...(Tonight and Thursday)
Look for showers and a few thunderstorms this evening and again
tomorrow afternoon. Showers and thunderstorms have developed this
afternoon, mainly along and south of a Big Lake to San Angelo, to
San Saba line. Short-term models indicate this will be the best area
for continued development this evening and again tomorrow afternoon.
Otherwise, dry conditions and temperatures near persistence look
good for the next 24 hours.
Huber
LONG TERM(time period)...
High temperatures will gradually fall from the upper 90s to 101
on Friday...to mid and 90s Saturday and Sunday. This occurs...as
the center high pressure aloft pushes west into the 4 corners
region. Isolated showers and thunderstorms possible Friday into
Saturday, as a weak upper shortwave moves west across the region.
Confidence is low on potential development however...as models are
showing disagreement in both timing and area of development.
Next week...the GFS and ECWF models weaken the upper ridge
further, with highs falling to near normal in the mid 90s.
Despite the fall in heights, the model are not indicating
convection over West Central Texas, and will keep next week`s
forecast dry.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 73 99 75 99 / 10 10 5 20
San Angelo 71 102 75 101 / 20 10 5 20
Junction 73 102 74 100 / 30 20 5 20
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
99/99/24
[top]
Area Forecast Discussion
National Weather Service MIDLAND/ODESSA TX
640 PM CDT WED AUG 12 2015
.DISCUSSION...
Please see the 13/00Z aviation forecast below.
&&
.AVIATION...
VFR conditions and generally light southeasterly winds will
prevail at all area terminals UFN. A weak upper level wave is
moving over west Texas at this time and helping to maintain
isolated -SHRA/TSRA. Looking at HRRR dProg/dT suggests this
activity will diminish between 02Z and 03Z; however, as surface
T/Td spreads are huge and cloud bases high, gusty winds up to 30
kts are possible from this activity. Did stick in a TEMPO for a
few hours at KMAF per current radar trends.
&&
.PREV DISCUSSION... /issued 241 PM CDT WED AUG 12 2015/
DISCUSSION...
The upper ridge that has been dominating sensible weather
patterns lately will continue to exert its influence over the
region, though the primary ridge axis has begun to shift westward,
and will become anchored near the Four Corners Region by this
weekend. This afternoon and evening, thunderstorms are possible,
mainly across the Big Bend area and the far Lower Trans Pecos in the
vicinity of a stalled but rather diffuse frontal boundary, where a
cumulus field has already begun to develop. Primary threats with
these storms are brief heavy rainfall, gusty winds, and frequent
lightning. As high pressure continues to exert its influence, expect
high clouds tonight, and seasonable lows in the 60s and 70s across
the area.
Thunderstorms will be possible once again Thursday, mainly across
the Big Bend area due to a combination of the aforementioned frontal
boundary as well as continued southeasterly surface flow. The NAM
and GFS solutions differ for the end of this week, with the NAM (and
to a lesser extent, the ECMWF) allowing for quicker and more
substantial midlevel moisture return from the Gulf, whereas the GFS
maintains drier conditions over southeast New Mexico and west Texas
through Friday. If the NAM solution were to verify, temperatures
would be several degrees cooler and precipitation chances would
increase area-wide on Friday, and moreso on Saturday invof a surface
trough that will affect the area. If the GFS solution were to verify
with less available moisture, temperatures would remain in the low
100s, with dry conditions looking to hang on through Friday.
Regardless, NAEFS and GEFS ensembles indicate PWATs of 1.25-1.50
inches across the area by Saturday, and given the presence of the
aforementioned surface trough, maintaining slight/low chance PoPs
into the first part of the weekend seems prudent. Beyond Saturday,
precipitation chances look to be confined mainly to the higher
terrain of southeast New Mexico and southwest Texas, and remain
fairly low. The hot temperatures lately have been slow to moderate,
and it looks like the trend of above normal temperatures will
continue through the extended. A little bit of relief is on the way
as temperatures should slowly drop through the weekend, with only
mid to upper 90s expected across the area by Monday. However, a
warming trend looks to then set in by the middle of next week, with
locations across the Pecos and Rio Grande Valleys climbing back over
the century mark.
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
70
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
623 PM CDT WED AUG 12 2015
.AVIATION...
VFR WITH LIGHT SE WINDS TURNING SW BY THUR AFTN.
&&
.PREV DISCUSSION... /ISSUED 339 PM CDT WED AUG 12 2015/
SHORT TERM...
MID-LEVEL MOISTURE EVIDENT ON WATER VAPOR STREAMING WESTWARD
ACROSS TRANS-PECOS AND BIG BEND THIS AFTERNOON HAS EXPANDED ITS
NORTHERN PERIPHERY INTO THE SOUTH PLAINS. MID-LEVEL MOISTURE
COUPLED WITH WEAK UPSLOPE HAS RESULTED IN CU FIELD SIMILAR TO
YESTERDAY AFTERNOON BUT WITH SOMEWHAT LESS COVERAGE AND FOR NOW
LESS VERTICAL EXTENT.
STEEP LOW LEVEL LAPSE RATES OF -10/KM OR MORE ARE RUNNING INTO
ALMOST AS IMPRESSIVE CAPPING INVERSIONS ACROSS OUR AREA THAT SHOULD
KEEP ANY SHOWERS OR TSTORMS FROM INITIATING. SHORT TERM GUIDANCE
HAS CONTINUED TO STRUGGLE WITH VERTICAL WIND PROFILES AS HIGH
PRESSURE SLOWLY MIGRATES OUT OF WEST TEXAS TOWARD THE FOUR
CORNERS. STREAMLINE SURFACE CONVERGENCE EXTENDING SOUTHWARD DOWN
THE I27 CORRIDOR AND ITS SUBSEQUENT CI CONSISTENTLY ADVERTISED BY
THE HRRR ALL MORNING HAS NOT MATERIALIZED...WHILE THE RAP HAS
STRUGGLED WITH SIMILAR ISSUES. HAVE BEEN WATCHING THE TX/NM BORDER
NEAR THE SW TEXAS PANHANDLE CLOSELY OVER THE LAST COUPLE OF HOURS
GIVEN PERSISTENT SHOWERS AND TSTORMS THE LAST COUPLE OF WEEKS BUT
HAVE DECIDED TO KEEP OUT ANY MENTIONABLE POPS ATTM. ADJUSTED
TEMPS UP A COUPLE OF DEGREES ACROSS OUR SE COUNTIES IN THE ROLLING
PLAINS GIVEN CURRENT TRENDS...OTHERWISE GUIDANCE FOR TEMPS
TODAY...TONIGHT AND TOMORROW SEEM GOOD.
CLOUDS SHOULD CLEAR AFTER SUNSET PROVIDING GOOD VIEWING OF
TONIGHT/S PERSEID METEOR SHOWER PEAKING AFTER MIDNIGHT. HAVE NO
MENTIONABLE POPS IN PLACE OVERNIGHT INTO TOMORROW BUT THERE IS A
NONZERO CHANCE OF LIGHT SHOWERS BRUSHING OUR EASTERN ZONES OFF THE
CAPROCK IF OVERNIGHT CONVECTION SIMILAR TO WHAT WE SAW LAST NIGHT
IS ABLE TO WORK ITS WAY FAR ENOUGH SOUTH OUT OF THE NORTHERN TEXAS
PANHANDLE AND WESTERN OKLAHOMA.
LONG TERM...
THE UA RIDGE IS STILL PROJECTED TO DRIFT WRD TO ACROSS THE FOUR-
CORNERS BY THIS WEEKEND...AND WILL BE PARKED THERE FOR THE MAJORITY
OF THE EXTENDED PERIOD. A FEW MODEL SOLUTIONS CONTINUE TO HINT AT
CHANCES FOR PRECIP MORE SO OFF THE CAPROCK ON FRIDAY...APPEARING TO
BE COURTESY OF A BIT OF MID-UPPER LEVEL MOISTENING AND WEAK
ISENTROPIC UPGLIDE. ALTHOUGH 1000-2000 J/KG OF SFC-BASED CAPE WILL
BE AVAILABLE...A WEAK CAP IS NOTICEABLE PER MODEL SOUNDINGS
AROUND 700 MB...THEREBY INSINUATING THE POTENTIAL FOR SHOWERY/WEAK
THUNDERSTORM ACTIVITY. BY THE WEEKEND INTO EARLY NEXT WEEK
HOWEVER...FOCUS FOR PRECIP WILL SWITCH TO LOCALES ON THE
CAPROCK...NEAREST TO A SFC TROUGH. ALTHOUGH...FLOW ALOFT WILL BE
FROM A NORTHERLY TO NORTHEASTERLY FLOW WHICH IS NOT VERY CONDUCIVE
FOR STORMS ACROSS THE HIGHER TERRAIN OF NM AND CO TO MAKE IT TO
THE SOUTH PLAINS. IT WILL BE HIGHLY DEPENDENT ON THE LOCATION OF
THE AFOREMENTIONED SFC TROUGH...WHETHER IT WILL BE CONFINED TO NM
/AS SUGGESTED BY MODEL SOLUTIONS/ OR CLOSER TO THE TX/NM BORDER.
NONETHELESS...SLIGHT CHANCE POPS PER THE SUPER-BLENDED SOLUTION
APPEARS REASONABLE ATTM. BY MID-WEEK...AN UA SHORTWAVE POISED TO
MOVE FROM THE NW PACIFIC TO THE CENTRAL/NORTHERN PLAINS WILL
RESULT IN THE DE-AMPLIFICATION OF THE UA RIDGE TO OUR WEST AND
HEIGHT FALLS ACROSS THE SOUTHERN PLAINS AS A COLD FRONT
POTENTIALLY APPROACHES THE CWA. WE WILL SEE IF THIS CHANGE IN THE
SYNOPTIC PATTERN DOES INDEED COME INTO FRUITION...AS THAT COLD
FRONT COULD BE OUR NEXT SHOT AT PRECIP.
GIVEN THE UA RIDGE WILL BE NOT BE DIRECTLY OVERHEAD...TEMPS WILL
WARM TO SEASONAL NORMS THROUGHOUT THE EXTENDED PERIOD /LOWER 90S ON
THE CAPROCK TO MIDDLE TO UPPER 90S OFF THE CAPROCK/.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
241 PM CDT TUE AUG 11 2015
.SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...MAIN ISSUE IS THE
CHANCE FOR RAIN...WHICH IS NOT STRAIGHT-FORWARD SINCE MESO-SCALE
INFLUENCES WILL PLAY SOME ROLE IN HOW FAR SOUTH AND WEST CONVECTION
GOES (AND HOW MUCH AREA GETS). MOST MODELS KEEP AT LEAST A BIT OF A
CAP/CIN BUT IT GETS CLOSE TO BREAKING AND ANY STORM WHICH BREAKS THE
CAP (GIVEN DAYTIME TEMPERATURES) COULD INITIATE MORE CONVECTION VIA
COOLING AND/OR CONVERGENCE.
FOR TONIGHT...THINK ANY CONVECTION WHICH DEVELOPS NORTH OF THE CWFA
WILL REMAIN NORTH (THIS AGREES WITH THE LATEST HRRR AND TTU SMALL
SCALE MODELS...AND TO A LESSER DEGREE THE MSSL MODEL RUN AT 11/00Z).
FOR WEDNESDAY...MOISTURE GETS BETTER AND CONVERGENCE ALONG THE
BOUNDARY (MAINLY NORTH) COULD TRIGGER CONVECTION WHICH COULD MOVE
INTO THE CWFA IN THE AFTEROOON AND EVENING BEFORE ENDING. THUS...
WILL MAINTAIN THE HIGHER POPS TO THE NORTH/NORTHEAST WEDNESDAY AND
NEAR THE COAST WEDNESDAY NIGHT...BUT WILL MENTION AT LEAST A SLIGHT
CHANCE FOR RAIN ALL LOCATIONS WEDNESDAY AFTERNOON AND WEDNESDAY
EVENING.
OTHER THAN THAT...STILL LOOKS LIKE A HOT DAY ON WEDNESDAY WITH
BOUNDARY/FRONT TO THE NORTH. HAVE GONE ON THE WARM SIDE OF GUIDANCE
FOR TEMPERATURES ON WEDNESDAY. CONCERNING LOWS...A BIT TRICKER AS
MOST MODEL 2 METER TEMPERATURES ARE QUITE WARM BUT ALSO SHOWING
LIGHT SOUTHWEST WINDS AND ABOUT THE SAME IF NOT COOLER BOUNDARY
LAYER TEMPERATURES. AM GOING WITH MORE OF A CONSENSUS FORECAST (BUT
A TAD WARMER THAN THIS MORNING DUE TO AFOREMENTIONED TEMPERATURES)
FOR WEDNESDAY`S LOW TEMPERATURES...AND EVEN A BIT WARMER WEDNESDAY
NIGHT/THURSDAY MORNING. OBVIOUSLY ANY CONVECTION OVERNIGHT (WHICH IS
NOT EXPECTED TO BE MORE THAN ISOLATED AND MAINLY IN THE EVENING)
COULD LOWER TEMPERATURES MORE THAN EXPECTED. FINALLY...GENERALLY
LIGHT WINDS AND MORE CLOUDS ON WEDNESDAY THAN TODAY.
$$
.MARINE (TONIGHT THROUGH WEDNESDAY NIGHT)...A WEAK GRADIENT WILL
PERSIST WITH FRONT/BOUNDARY TO THE NORTH. WINDS WILL HAVE TROUBLE
MAKING IT BEYOND 10-12 KNOTS THROUGH THE PERIOD...MAYBE WEDNESDAY
NIGHT. MAINLY A SLIGHT CHANCE FOR SHOWERS/STORMS WEDNESDAY AND
WEDNESDAY NIGHT...BUT DID GO A BIT HIGHER OVER THE NORTHEAST
PROXIMATE TO BETTER FORCING AND LIMITED CAP.
&&
.LONG TERM (THURSDAY THROUGH TUESDAY)...EXTENDED BEGINS WITH UPPER
RIDGE AXIS STILL FAR ENOUGH WEST TO LIMIT CONVECTIVE CAP AND
MAINTAIN RAIN CHANCES ACROSS THE COASTAL BEND. RIDGE AXIS THEN
WOBBLES EASTWARD THROUGH THE WEEKEND...RESULTING IN DRY AND WARM
WEATHER.
BY MONDAY MODELS PROJECT THE NEXT IMPULSE REACHING THE GREAT LAKES
TO EXTEND SOUTHWEST DOWN UNDER THE BULK OF THE RIDGE...COOLING
TEMPERATURES ALOFT. IF THIS PANS OUT...IT WILL HAVE THE DOUBLE
EFFECT OF REINTRODUCING LOW POPS AND COOLING TEMPERATURES BY FIVE OR
SO DEGREES.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE WEEKEND...WITH
ELEVATED HEAT INDICES AS WELL. HIGHS MAY RELAX A BIT TOWARD THE END
OF THE PERIOD...WITH READINGS CLOSER TO NORMAL FOR MID AUGUST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 76 99 77 96 77 / 10 20 20 30 10
VICTORIA 75 101 76 98 76 / 10 30 30 30 10
LAREDO 77 103 80 104 80 / 10 10 20 20 10
ALICE 75 102 76 100 76 / 10 20 20 30 10
ROCKPORT 78 96 79 93 80 / 10 30 30 30 10
COTULLA 76 104 79 103 78 / 10 20 20 20 10
KINGSVILLE 76 101 76 98 76 / 10 20 20 30 10
NAVY CORPUS 79 94 80 91 80 / 10 20 20 30 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...SHORT TERM
JV/71...LONG TERM
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1044 PM CDT WED AUG 12 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 229 PM CDT WED AUG 12 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM TEXAS TO THE GULF OF MEXICO. MID-LEVEL
WARM ADVECTION IS GENERATING A BAND OF CLOUDS OVER THE UPPER
PENINSULA AND NORTHEAST WISCONSIN WHERE A COUPLE LIGHT SHOWERS HAVE
DEVELOPED OVER THE PAST HOUR. WILL KEEP AN ISOLATED MENTION OVER NE
WI THROUGH EARLY THIS EVENING AS A RESULT. LOOKING UPSTREAM...A
SHORTWAVE TROUGH IS TRIGGERING SHOWERS AND STORMS OVER SOUTHERN
MANITOBA. AS THIS SHORTWAVE MOVES SOUTHEAST INTO THE REGION
TONIGHT...THUNDERSTORM TRENDS ARE THE MAIN FORECAST CONCERN IN THE
SHORT TERM.
TONIGHT...MID-LEVEL WARM ADVECTION WILL EXIT NORTHEAST WISCONSIN
THIS EVENING...WHICH SHOULD ENSURE DECREASING CLOUDS FOR THAT PART
OF THE STATE. OTHER LOCATIONS WILL SEE MOSTLY CLEAR CONDITIONS TO
START OUT THE EVENING...THEN WILL SEE INCREASING CLOUDS FROM THE
NORTHWEST. THESE CLOUDS WILL BE AHEAD OF A SHORTWAVE TROUGH SLIDING
SOUTHEAST OVER SOUTHEAST MANITOBA. THE SHORTWAVE ITSELF WILL NOT
ARRIVE UNTIL LATE IN THE NIGHT OVER N-C WISCONSIN. WILL HAVE A
DECENT AMOUNT OF ELEVATED INSTABILITY AND MOISTURE TRANSPORT AHEAD
OF THE WAVE...SO WILL RAISE THUNDERSTORM CHANCES. LOWS MAINLY IN
THE 60S.
THURSDAY...THE SHORTWAVE WILL MOVE ACROSS NORTHERN WISCONSIN DURING
THE MORNING HOURS...GIVING MOST LOCATION AT LEAST A SLIGHT CHANCE OF
THUNDERSTORMS. HIGHEST CHANCES WILL BE ACROSS THE NORTH. THEN
CONFIDENCE WANES IN THE WAKE OF THE SHORTWAVE. SHOULD SEE SOME
SUBSIDENCE BEHIND THE WAVE...BUT GUIDANCE SHOWS A SURFACE
TROUGH/WIND SHIFT MOVING INTO THE FORECAST AREA DURING THE
AFTERNOON. MOISTURE POOLING ALONG THE BOUNDARY WILL LEAD TO ML
CAPES APPROACHING 2000 J/KG DURING PEAK HEATING IN THE AFTERNOON.
LARGE-SCALE SUPPORT IS NOTICEABLY ABSENT...BUT IF THAT SORT OF
DESTABILIZATION OCCURS...IT WOULD NOT TAKE MUCH CONVERGENCE TO SET
OFF STORMS. 0-6KM WIND SHEARS ARE AROUND 25 KTS...SO THINK STORMS
WILL BE RATHER PULSY IN NATURE. STILL COULD SEE A FEW STRONG STORMS
DEVELOP THAT COULD CREATE STRONG GUSTY WINDS AND MARGINALLY SEVERE
HAIL. BEST TIMING WOULD BE AFTER 3 PM. WARMER AND MORE HUMID WITH
HIGHS IN THE MID TO UPPER 80S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 229 PM CDT WED AUG 12 2015
UPR RDG AXIS OVER THE CNTRL/SRN PLAINS IS FCST TO EXTEND NEWD INTO
THE WRN GREAT LAKES BY THE END OF THE WEEK BEFORE RETROGRADING AND
WEAKENING TOWARD THE SW CONUS NEXT WEEK. THIS PATTERN SHIFT WL
ALLOW FOR THE MAIN BAND OF WESTERLIES TO RUN ALONG THE NRN TIER OF
STATES AND ALLOW FOR A COUPLE OF SYSTEMS TO MOVE ACROSS WI. AFTER
THE INITIAL NW FLOW PCPN CHCS END FRI...THE PASSAGE OF A CDFNT
LATE SUNDAY INTO MON WL BRING THE NEXT CHC OF PCPN TO NE WI. A
STRONGER SYSTEM CONSISTING OF ANOTHER CDFNT AND STRONGER SHORTWAVE
TROF REACHES THE REGION TOWARD THE MIDDLE OF NEXT WEEK WITH A
HIGHER CHC OF SHWRS/TSTMS. TEMPS ARE EXPECTED TO BE ABOVE NORMAL
THRU SUNDAY...COOL A BIT BELOW NORMAL EARLY NEXT WEEK AND THEN
BEGIN TO WARM THEREAFTER.
INITIAL PRE-FRONTAL TROF TO STILL BE IN THE PROCESS OF EXITING
E-CNTRL WI THU EVENING...THUS A CHC POP IS NECESSARY FOR THIS
LOCATION. MEANWHILE...THE PRIMARY CDFNT IS FCST TO DROP SE TOWARD
NRN WI LATER THU NGT AND INTRODUCE ANOTHER CHC OF SHWRS AND TSTMS.
IN ADDITION TO THE SFC BOUNDARIES...MODELS INDICATE A MODEST
SHORTAVE TROF MOVING SE THRU THE WRN GREAT LAKES ACCOMPANIED BY
EMBEDDED SHORTWAVE ENERGY. POPS IN BOTH LOCATIONS TO BE HELD IN
THE CHC CATEGORY FOR NOW. TEMPS TO REMAIN ON THE MILD SIDE WITH
MINS IN THE LWR 60S NORTH...MID TO UPR 60S SOUTH.
THE CDFNT IS PROGGED TO CONT MOVING SE INTO WI ON FRI...ALTHO THE
MODELS DISAGREE WITH HOW FAST THE FNT WL ACTUALLY MOVE. THE NAM IS
SLOWER...BUT WITH THE NW FLOW ALOFT STILL OVERHEAD...BELIEVE A
FASTER FRONTAL MOVEMENT MAKES MORE SENSE. PCPN COVERAGE IS ANOTHER
PROBLEM AS THE ATMOSPHERE WL BECOME UNSTABLE WITH CAPES AROUND
1500 J/KG AND LI`S DOWN TO AROUND -4. DESPITE THE INSTABILITY...
MOISTURE AVAILABILITY AND FRONTAL BOUNDARY NEARBY...MODELS CONT TO
SHOW A LIMITED PCPN COVERAGE PRIMARILY DUE TO UPR HEIGHTS BUILDING
TOWARD WI AND PROVIDING A CAP TO INHIBIT TSTM GROWTH. SINCE NE WI
TO SIT ON THE EDGE OF THIS BUILDING CAP...PREFER TO KEEP CHC POPS
IN THE FCST. FRI WL BE A VERY WARM AND HUMID DAY WITH MAX TEMPS
RANGING FROM THE MID 80S NORTH AND ALONG LAKE MI...TO THE UPR 80S
TO LWR 90S ELSEWHERE.
DEPENDING ON THE EXACT TIMING OF THE CDFNT...CANNOT COMPLETELY
RULE OUT A LINGERING SHWR OR STORM OVER SRN SECTIONS OF THE FCST
AREA FRI EVENING. OTHERWISE...THE UPR RDG WL CONT TO BUILD INTO WI
FRI NGT...ALONG WITH A WEAK SFC HI OVER THE GREAT LAKES. SKIES
SHOULD BECOME MOSTLY CLEAR AND WITH LIGHT WINDS EXPECTED...WE
COULD SEE SOME PATCHY FOG DEVELOP OVRNGT. MIN TEMPS TO RANGE FROM
THE MID TO UPR 50S NORTH...LWR TO MID 60S SOUTH. THE UPR RDG WL
EXTEND FROM THE FOUR CORNERS REGION NEWD TO THE GREAT LAKES ON SAT
AND BRING ANOTHER VERY WARM/MUGGY DAY TO NE WI. THERE SHOULD BE A
SUFFICIENT CAP IN PLACE TO PREVENT ANY TSTMS FROM DEVELOPING
DESPITE THE INCREASED INSTABILITY. LOOK FOR MAX TEMPS TO AGAIN
RANGE FROM THE LWR TO MID 80S NORTH AND NEAR LAKE MI...UPR 80S TO
LWR 90S CNTRL/E-CTNRL WI.
THIS UPR RDG WL BEGIN TO LOSE ITS INFLUENCE OVER THE GREAT LAKES
DURING THE LATTER HALF OF THE WEEKEND AS A LEAD SHORTWAVE TROF
PUSHES EWD ALONG THE U.S.-CANADIAN BORDER. WHILE SAT NGT WL REMAIN
DRY/MILD/MUGGY...THE SHORTWAVE TROF IS FCST TO MOVE INTO THE UPR
MS VALLEY ON SUNDAY...PRECEDED BY A CDFNT THAT COULD REACH NW WI
AS EARLY AS LATE SUNDAY AFTERNOON. WHILE MOST OF NE WI TO STAY DRY
THRU THE DAYLIGHT HOURS...WL NEED TO MENTION A CHC OF SHWRS/TSTMS
FOR N-CNTRL WI...MAINLY DURING THE AFTERNOON. SUNDAY ALSO LOOKS TO
BE YET ANOTHER VERY WARM/HUMID DAY WITH MAX TEMPS IN THE LWR TO
MID 80S NORTH/LAKESHORE...85-90 DEG RANGE ELSEWHERE.
THIS CDFNT DOES NOT APPEAR TO BE A FAST-MOVER...MAINLY DUE TO THE
REMNANTS OF THE UPR RDG TO OUR SOUTH. LATEST TIMING HAS THE FNT
REACHING CNTRL WI BY 12Z MON AND CLEARING E-CNTRL WI AROUND 18Z
MON. ANOTHER CONCERN WL BE A TRAILING SHORTWAVE TROF/EMBEDDED
SHORTWAVE PUSHING INTO THE WRN GREAT LAKES REGION MON AFTERNOON.
THERE WL BE A GOOD CHC FOR SHWRS/TSTMS TO ACCOMPANY THE FROPA
SUNDAY NGT THRU MON MORNING WITH THE POSSIBILITY OF SOME SHWRS
LINGERING OVER E-CNTRL WI INTO MON AFTERNOON. MAX TEMPS TO BE MUCH
COOLER ON MON WITH READINGS IN THE LWR 70S N-CNTRL...MID TO UPR
70S E-CNTRL WI.
A MODEST HI PRES IS FCST TO BUILD INTO THE REGION ON TUE...THEREBY
BRINGING PARTLY CLOUDY SKIES TO THE FCST AREA. PLENTY OF ISSUES
THEN HEADED INTO WED AS THE SFC HI DEPARTS...WAA DEVELOPS AND A
RATHER SHARP SHORTWAVE TROF ENTERS THE CNTRL CONUS. MODELS ARE ALL
OVER THE PLACE AS FAR AS TIMING OF PCPN CHCS INTO NE WI RANGING
FROM TUE NGT TO WED NGT. HAVE FOLLOWED THE CONSENSUS SOLUTION FOR
NOW WHICH BRINGS PCPN CHCS TO THE ENTIRE REGION FOR THE TIME
BEING. TEMPS FOR TUE AND WED SHOULD BE AT OR SLIGHTLY BELOW
NORMAL.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1044 PM CDT WED AUG 12 2015
MIDDLE AND HIGH CLOUDS WILL INCREASE TONIGHT. LOW
LEVEL WIND SHEAR COULD BE SIGNIFICANT TO LIGHT AIRCRAFT WITH
LIGHT SOUTHWEST SURFACE WINDS AND WEST WINDS AT 25 TO 30 KTS
AROUND 500FT ABOVE GROUND. SCATTERED THUNDERSTORMS ARE EXPECTED TO
MOVE ACROSS NORTHERN WISCONSIN THURSDAY. VFR CONDITIONS EXPECTED
OUTSIDE OF ANY THUNDERSTORM ACTIVITY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
648 PM CDT WED AUG 12 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 308 PM CDT WED AUG 12 2015
MAIN FORECAST CONCERNS ARE SMALL PRECIPITATION CHANCES TONIGHT INTO
THURSDAY.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL RIDGE
AMPLIFYING OVER THE ROCKY MOUNTAINS AND UPPER LEVEL TROUGH OVER
EASTERN UNITED STATES. SHORTWAVE TROUGHS ROTATING AROUND THE UPPER
LEVEL RIDGE INTO THE NORTHERN PLAINS AND SOUTHERN CANADA...AS
EVIDENT PER WATER VAPOR SATELLITE IMAGERY. LATEST 19Z SURFACE
ANALYSIS INDICATES HIGH PRESSURE OVER IOWA INTO THE SOUTHERN PLAINS
STATES. THIS IS PROVIDING MOSTLY SUNNY SKIES ACROSS THE FORECAST
AREA PER VISIBLE SATELLITE IMAGERY.
THE 12.12Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT BUILDING SURFACE
RIDGE SOUTH OF THE FORECAST AREA INTO THE OHIO RIVER VALLEY TONIGHT
THURSDAY. FIRST IMPULSE OVER-TOPPING THE UPPER LEVEL RIDGE OVER
SOUTHERN MANITOBA WILL PUSH SOUTHEAST INTO CENTRAL WISCONSIN BY 18Z
THURSDAY. LATEST HI-RESOLUTION ARW/NMM/12.17Z HRRR SUGGEST
CONVECTION IN ASSOCIATION WITH IMPULSE WILL WEAKEN AS IT
APPROACHES THE NORTHERN SECTIONS OF THE FORECAST AREA...THIS IS
EVIDENT...WITH THE 12.12Z GFS/NAM INDICATE WEAKENING ELEVATED
INSTABILITY ALONG AND AHEAD OF THE IMPULSE. HAVE CONTINUED THE
TREND OF SMALL PRECIPITATION CHANCES AFTER 09Z THURSDAY AND INTO
THE DAYTIME HOURS THURSDAY...AS THE 12.12Z MODELS SUGGEST WEAK
MOISTURE CONVERGENCE ALONG LINGERING SURFACE FRONT WITH IMPULSE
COULD PRODUCE AN ISOLATED SHOWER OR THUNDERSTORM.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 308 PM CDT WED AUG 12 2015
FOCUS TURNS TO THE NEXT SHORTWAVE TROUGH OVER-TOPPING THE UPPER
LEVEL RIDGE THURSDAY EVENING INTO FRIDAY. THE LATEST 12.12Z
GFS/NAM/ECMWF ARE WEAKER WITH 925-850MB MOISTURE CONVERGENCE/LIFT
WITH THIS IMPULSE. WITH THE WEAK LOW LEVEL CONVERGENCE AND
INSTABILITY AXIS ALONG THE SURFACE FRONT/OVER THE FORECAST
AREA...POSSIBILITY OF A SMALL CHANCE OF SHOWERS/THUNDERSTORMS
EXIST THURSDAY NIGHT INTO FRIDAY ACROSS MUCH OF THE FORECAST AREA.
UPPER LEVEL RIDGE AXIS BUILDS INTO THE UPPER GREAT LAKES REGION
FRIDAY AFTERNOON INTO SATURDAY. THE 12.12Z GFS/NAM/ECMWF INDICATE
925MB TEMPERATURES RISING TO PLUS 25 TO PLUS 27 DEGREES CELSIUS
ACROSS THE FORECAST AREA BY 00Z SUNDAY. THE COMBINATION OF
SUBSIDENCE AND 925MB TEMPERATURES...HIGH TEMPERATURES WILL BE IN THE
MIDDLE 80S TO AROUND 90...WITH SOME LOCATIONS POSSIBLY RISING INTO
THE LOWER 90S.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES THROUGH THE PERIOD.
THE 12.12Z GFS/ECMWF/GEM ARE IN GOOD AGREEMENT IN FLATTENING UPPER
LEVEL RIDGE AND DEVELOP WEST TO EAST ZONAL FLOW ACROSS THE NORTHERN
TIER STATES. SIGNIFICANT DIFFERENCES OCCUR BETWEEN THE MODELS ON
TIMING/PLACEMENT OF THE TWO SHORTWAVE TROUGHS/SURFACE FEATURES INTO
THE UPPER GREAT LAKES REGION THROUGH THE PERIOD. FIRST IMPULSE
FLATTENS UPPER LEVEL RIDGE AND PUSHES INTO THE GREAT LAKES REGION
SUNDAY INTO MONDAY. MAIN ENERGY WITH SHORTWAVE TROUGH REMAINS
NORTH OF THE FORECAST AREA. LOW LEVEL MOISTURE CONVERGENCE WITH
SURFACE COLD FRONT WILL PROVIDE A CHANCE OF PRECIPITATION ACROSS
MUCH OF THE FORECAST MAINLY SUNDAY NIGHT INTO MONDAY MORNING. NEXT
FEATURE TO IMPACT THE FORECAST AREA TUESDAY NIGHT INTO WEDNESDAY.
DIFFERENCES OCCUR BETWEEN THE 12.12Z GFS/ECMWF ON
STRENGTH/TIMING/PLACEMENT WITH THIS FEATURE. THE MODELS SUGGEST
DECENT MOISTURE CONVERGENCE/TRANSPORT AND LIFT WITH THE SHORTWAVE
TROUGH/SURFACE FEATURE. BASED ON TIMING/PLACEMENT DIFFERENCES WITH
THE MODELS...WILL CONTINUE THE TREND OF A CHANCE OF PRECIPITATION
ACROSS THE FORECAST AREA TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 648 PM CDT WED AUG 12 2015
VFR CONDITIONS TO CONTINUE AT KRST/KLSE THROUGH 14.00Z. MOSTLY
CLEAR SKIES THIS EVENING WILL SLOWLY GIVE WAY TO INCREASING MID-
HIGH LEVEL CLOUDS ASSOCIATED WITH THUNDERSTORMS ACROSS NORTH-
CENTRAL MN. SURFACE TROUGH WILL SWING ACROSS THE REGION ON
THURSDAY...BRINGING A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS.
HOWEVER...THE THREAT IS NOT SIGNIFICANT ENOUGH AT THIS TIME TO
INCLUDE IN TAFS. COULD SEE SOME SCATTERED AFTERNOON CUMULUS IN THE
5000 TO 6000 FT AGL LAYER THURSDAY AFTERNOON. OTHERWISE...ANY
CEILINGS LIKELY TO REMAIN AT OR ABOVE 10000 FT AGL THROUGH THE
PERIOD. SOUTH-SOUTHWEST WINDS FROM 6 TO 10 KTS...COMBINED WITH
CLOUD COVER OVERNIGHT ENOUGH TO THWART ANY FOG DEVELOPMENT. WEST-
SOUTHWEST WINDS TO INCREASE THURSDAY WITH SOME GUSTS INTO THE LOW
20 KT RANGE AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...ROGERS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
635 PM CDT WED AUG 12 2015
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 229 PM CDT WED AUG 12 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM TEXAS TO THE GULF OF MEXICO. MID-LEVEL
WARM ADVECTION IS GENERATING A BAND OF CLOUDS OVER THE UPPER
PENINSULA AND NORTHEAST WISCONSIN WHERE A COUPLE LIGHT SHOWERS HAVE
DEVELOPED OVER THE PAST HOUR. WILL KEEP AN ISOLATED MENTION OVER NE
WI THROUGH EARLY THIS EVENING AS A RESULT. LOOKING UPSTREAM...A
SHORTWAVE TROUGH IS TRIGGERING SHOWERS AND STORMS OVER SOUTHERN
MANITOBA. AS THIS SHORTWAVE MOVES SOUTHEAST INTO THE REGION
TONIGHT...THUNDERSTORM TRENDS ARE THE MAIN FORECAST CONCERN IN THE
SHORT TERM.
TONIGHT...MID-LEVEL WARM ADVECTION WILL EXIT NORTHEAST WISCONSIN
THIS EVENING...WHICH SHOULD ENSURE DECREASING CLOUDS FOR THAT PART
OF THE STATE. OTHER LOCATIONS WILL SEE MOSTLY CLEAR CONDITIONS TO
START OUT THE EVENING...THEN WILL SEE INCREASING CLOUDS FROM THE
NORTHWEST. THESE CLOUDS WILL BE AHEAD OF A SHORTWAVE TROUGH SLIDING
SOUTHEAST OVER SOUTHEAST MANITOBA. THE SHORTWAVE ITSELF WILL NOT
ARRIVE UNTIL LATE IN THE NIGHT OVER N-C WISCONSIN. WILL HAVE A
DECENT AMOUNT OF ELEVATED INSTABILITY AND MOISTURE TRANSPORT AHEAD
OF THE WAVE...SO WILL RAISE THUNDERSTORM CHANCES. LOWS MAINLY IN
THE 60S.
THURSDAY...THE SHORTWAVE WILL MOVE ACROSS NORTHERN WISCONSIN DURING
THE MORNING HOURS...GIVING MOST LOCATION AT LEAST A SLIGHT CHANCE OF
THUNDERSTORMS. HIGHEST CHANCES WILL BE ACROSS THE NORTH. THEN
CONFIDENCE WANES IN THE WAKE OF THE SHORTWAVE. SHOULD SEE SOME
SUBSIDENCE BEHIND THE WAVE...BUT GUIDANCE SHOWS A SURFACE
TROUGH/WIND SHIFT MOVING INTO THE FORECAST AREA DURING THE
AFTERNOON. MOISTURE POOLING ALONG THE BOUNDARY WILL LEAD TO ML
CAPES APPROACHING 2000 J/KG DURING PEAK HEATING IN THE AFTERNOON.
LARGE-SCALE SUPPORT IS NOTICEABLY ABSENT...BUT IF THAT SORT OF
DESTABILIZATION OCCURS...IT WOULD NOT TAKE MUCH CONVERGENCE TO SET
OFF STORMS. 0-6KM WIND SHEARS ARE AROUND 25 KTS...SO THINK STORMS
WILL BE RATHER PULSY IN NATURE. STILL COULD SEE A FEW STRONG STORMS
DEVELOP THAT COULD CREATE STRONG GUSTY WINDS AND MARGINALLY SEVERE
HAIL. BEST TIMING WOULD BE AFTER 3 PM. WARMER AND MORE HUMID WITH
HIGHS IN THE MID TO UPPER 80S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 229 PM CDT WED AUG 12 2015
UPR RDG AXIS OVER THE CNTRL/SRN PLAINS IS FCST TO EXTEND NEWD INTO
THE WRN GREAT LAKES BY THE END OF THE WEEK BEFORE RETROGRADING AND
WEAKENING TOWARD THE SW CONUS NEXT WEEK. THIS PATTERN SHIFT WL
ALLOW FOR THE MAIN BAND OF WESTERLIES TO RUN ALONG THE NRN TIER OF
STATES AND ALLOW FOR A COUPLE OF SYSTEMS TO MOVE ACROSS WI. AFTER
THE INITIAL NW FLOW PCPN CHCS END FRI...THE PASSAGE OF A CDFNT
LATE SUNDAY INTO MON WL BRING THE NEXT CHC OF PCPN TO NE WI. A
STRONGER SYSTEM CONSISTING OF ANOTHER CDFNT AND STRONGER SHORTWAVE
TROF REACHES THE REGION TOWARD THE MIDDLE OF NEXT WEEK WITH A
HIGHER CHC OF SHWRS/TSTMS. TEMPS ARE EXPECTED TO BE ABOVE NORMAL
THRU SUNDAY...COOL A BIT BELOW NORMAL EARLY NEXT WEEK AND THEN
BEGIN TO WARM THEREAFTER.
INITIAL PRE-FRONTAL TROF TO STILL BE IN THE PROCESS OF EXITING
E-CNTRL WI THU EVENING...THUS A CHC POP IS NECESSARY FOR THIS
LOCATION. MEANWHILE...THE PRIMARY CDFNT IS FCST TO DROP SE TOWARD
NRN WI LATER THU NGT AND INTRODUCE ANOTHER CHC OF SHWRS AND TSTMS.
IN ADDITION TO THE SFC BOUNDARIES...MODELS INDICATE A MODEST
SHORTAVE TROF MOVING SE THRU THE WRN GREAT LAKES ACCOMPANIED BY
EMBEDDED SHORTWAVE ENERGY. POPS IN BOTH LOCATIONS TO BE HELD IN
THE CHC CATEGORY FOR NOW. TEMPS TO REMAIN ON THE MILD SIDE WITH
MINS IN THE LWR 60S NORTH...MID TO UPR 60S SOUTH.
THE CDFNT IS PROGGED TO CONT MOVING SE INTO WI ON FRI...ALTHO THE
MODELS DISAGREE WITH HOW FAST THE FNT WL ACTUALLY MOVE. THE NAM IS
SLOWER...BUT WITH THE NW FLOW ALOFT STILL OVERHEAD...BELIEVE A
FASTER FRONTAL MOVEMENT MAKES MORE SENSE. PCPN COVERAGE IS ANOTHER
PROBLEM AS THE ATMOSPHERE WL BECOME UNSTABLE WITH CAPES AROUND
1500 J/KG AND LI`S DOWN TO AROUND -4. DESPITE THE INSTABILITY...
MOISTURE AVAILABILITY AND FRONTAL BOUNDARY NEARBY...MODELS CONT TO
SHOW A LIMITED PCPN COVERAGE PRIMARILY DUE TO UPR HEIGHTS BUILDING
TOWARD WI AND PROVIDING A CAP TO INHIBIT TSTM GROWTH. SINCE NE WI
TO SIT ON THE EDGE OF THIS BUILDING CAP...PREFER TO KEEP CHC POPS
IN THE FCST. FRI WL BE A VERY WARM AND HUMID DAY WITH MAX TEMPS
RANGING FROM THE MID 80S NORTH AND ALONG LAKE MI...TO THE UPR 80S
TO LWR 90S ELSEWHERE.
DEPENDING ON THE EXACT TIMING OF THE CDFNT...CANNOT COMPLETELY
RULE OUT A LINGERING SHWR OR STORM OVER SRN SECTIONS OF THE FCST
AREA FRI EVENING. OTHERWISE...THE UPR RDG WL CONT TO BUILD INTO WI
FRI NGT...ALONG WITH A WEAK SFC HI OVER THE GREAT LAKES. SKIES
SHOULD BECOME MOSTLY CLEAR AND WITH LIGHT WINDS EXPECTED...WE
COULD SEE SOME PATCHY FOG DEVELOP OVRNGT. MIN TEMPS TO RANGE FROM
THE MID TO UPR 50S NORTH...LWR TO MID 60S SOUTH. THE UPR RDG WL
EXTEND FROM THE FOUR CORNERS REGION NEWD TO THE GREAT LAKES ON SAT
AND BRING ANOTHER VERY WARM/MUGGY DAY TO NE WI. THERE SHOULD BE A
SUFFICIENT CAP IN PLACE TO PREVENT ANY TSTMS FROM DEVELOPING
DESPITE THE INCREASED INSTABILITY. LOOK FOR MAX TEMPS TO AGAIN
RANGE FROM THE LWR TO MID 80S NORTH AND NEAR LAKE MI...UPR 80S TO
LWR 90S CNTRL/E-CTNRL WI.
THIS UPR RDG WL BEGIN TO LOSE ITS INFLUENCE OVER THE GREAT LAKES
DURING THE LATTER HALF OF THE WEEKEND AS A LEAD SHORTWAVE TROF
PUSHES EWD ALONG THE U.S.-CANADIAN BORDER. WHILE SAT NGT WL REMAIN
DRY/MILD/MUGGY...THE SHORTWAVE TROF IS FCST TO MOVE INTO THE UPR
MS VALLEY ON SUNDAY...PRECEDED BY A CDFNT THAT COULD REACH NW WI
AS EARLY AS LATE SUNDAY AFTERNOON. WHILE MOST OF NE WI TO STAY DRY
THRU THE DAYLIGHT HOURS...WL NEED TO MENTION A CHC OF SHWRS/TSTMS
FOR N-CNTRL WI...MAINLY DURING THE AFTERNOON. SUNDAY ALSO LOOKS TO
BE YET ANOTHER VERY WARM/HUMID DAY WITH MAX TEMPS IN THE LWR TO
MID 80S NORTH/LAKESHORE...85-90 DEG RANGE ELSEWHERE.
THIS CDFNT DOES NOT APPEAR TO BE A FAST-MOVER...MAINLY DUE TO THE
REMNANTS OF THE UPR RDG TO OUR SOUTH. LATEST TIMING HAS THE FNT
REACHING CNTRL WI BY 12Z MON AND CLEARING E-CNTRL WI AROUND 18Z
MON. ANOTHER CONCERN WL BE A TRAILING SHORTWAVE TROF/EMBEDDED
SHORTWAVE PUSHING INTO THE WRN GREAT LAKES REGION MON AFTERNOON.
THERE WL BE A GOOD CHC FOR SHWRS/TSTMS TO ACCOMPANY THE FROPA
SUNDAY NGT THRU MON MORNING WITH THE POSSIBILITY OF SOME SHWRS
LINGERING OVER E-CNTRL WI INTO MON AFTERNOON. MAX TEMPS TO BE MUCH
COOLER ON MON WITH READINGS IN THE LWR 70S N-CNTRL...MID TO UPR
70S E-CNTRL WI.
A MODEST HI PRES IS FCST TO BUILD INTO THE REGION ON TUE...THEREBY
BRINGING PARTLY CLOUDY SKIES TO THE FCST AREA. PLENTY OF ISSUES
THEN HEADED INTO WED AS THE SFC HI DEPARTS...WAA DEVELOPS AND A
RATHER SHARP SHORTWAVE TROF ENTERS THE CNTRL CONUS. MODELS ARE ALL
OVER THE PLACE AS FAR AS TIMING OF PCPN CHCS INTO NE WI RANGING
FROM TUE NGT TO WED NGT. HAVE FOLLOWED THE CONSENSUS SOLUTION FOR
NOW WHICH BRINGS PCPN CHCS TO THE ENTIRE REGION FOR THE TIME
BEING. TEMPS FOR TUE AND WED SHOULD BE AT OR SLIGHTLY BELOW
NORMAL.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 635 PM CDT WED AUG 12 2015
CLEAR SKIES EXPECTED THIS EVENING WITH INCREASING
MIDDLE AND HIGH CLOUDS LATE TONIGHT. LOW LEVEL WIND SHEAR COULD BE
SIGNIFICANT TO LIGHT AIRCRAFT AFTER MIDNIGHT WITH LIGHT SOUTHWEST
SURFACE WINDS AND WEST WINDS AT 25 TO 30 KTS AROUND 500FT ABOVE
GROUND. SCATTERED THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS
NORTHERN WISCONSIN THURSDAY. VFR CONDITIONS EXPECTED OUTSIDE OF
ANY THUNDERSTORM ACTIVITY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......RDM
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 242 PM CDT TUE AUG 11 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM HUDSON BAY TO THE SOUTHERN GREAT PLAINS
EARLY THIS AFTERNOON. DIURNAL CU POPPED BY 15-16Z AND SPREAD SOUTH
TO COVER SCT-BKN CONDITIONS ACROSS MUCH OF THE STATE. A SHORTWAVE
CURRENTLY OVER WESTERN LAKE SUPERIOR WILL MOVE ACROSS NORTHEAST
WISCONSIN LATE IN THE DAY AND MAY PROLONG SCT CLOUD COVER INTO THIS
EVENING. OTHERWISE...THE MAIN FOCUS INCLUDES THUNDERSTORM POTENTIAL
FROM MID-LEVEL WARM ADVECTION FOR WEDNESDAY. SCATTERED
THUNDERSTORMS OCCURRED EARLIER TODAY OVER THE LAKE WINNIPEG REGION
IN THIS WARM ADVECTION ZONE.
TONIGHT...HIGH PRESSURE WILL SLIDING SOUTHEAST ACROSS THE WESTERN
GREAT LAKES WHILE A SHORTWAVE EXITS NORTHEAST WISCONSIN DURING THE
EVENING. THE SHORTWAVE MAY PROLONG SCT CLOUD COVER ACROSS EASTERN
WISCONSIN INTO MID-EVENING...BUT THE REST OF THE AREA SHOULD SEE
CLEARING SKIES WITH LOSS OF DAYTIME HEATING. ONCE THE CLOUDS
DISSIPATE...WILL SEE A PERIOD OF CLEAR CONDITIONS UNTIL LATE IN THE
NIGHT WHEN WARM ADVECTION CLOUDS MOVE SOUTHEAST INTO NORTH-CENTRAL
WISCONSIN. WITH CLOUDS ARRIVING LATE...DO NOT THINK FOG WILL BECOME
TOO BIG OF AN ISSUE. LOWS MAINLY IN THE LOWER TO MIDDLE 50S.
WEDNESDAY...WARM ADVECTION WILL CONTINUE ACROSS THE REGION. THE
BAND OF ASSOCIATED MID-CLOUDS WILL PROCEED EAST ACROSS THE FORECAST
AREA DURING THE MORNING AND THEN EXIT NORTHEAST WI AROUND MID-
AFTERNOON. SOME ELEVATED INSTABILITY GRAZES NORTHERN WISCONSIN
DURING THIS TIME...ALONG WITH MID-LEVEL FGEN ON THE NOSE OF A LLJ.
THOUGH MOISTURE IS NOT PLENTIFUL...NOT COMFORTABLE GOING DRY IN THIS
SCENARIO. SO WILL SHOW 20-30 PCT CHANCE OF RAIN ACROSS FAR N-C AND
PARTS OF NORTHEAST WI. THE REST OF THE AREA SHOULD SEE A PERIOD A
PARTLY/MOSTLY CLOUDY SKIES. HIGHS WARMING A COUPLE DEGREES...WITH
READINGS RANGING FROM THE UPPER 70S TO MID 80S.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 242 PM CDT TUE AUG 11 2015
WITH AMPLIFICATION OF THE WESTERN RIDGE EXPECTED THE REST OF THIS
WEEK...OUR AREA WILL CONTINUE TO FALL UNDER NORTHWEST FLOW.
DESPITE THAT...ABOVE NORMAL HEIGHTS AND WARM AIR ADVECTION FROM
THE WEST SHOULD KEEP TEMPERATURES ABOVE NORMAL...PERHAPS EVEN
SIGNIFICANTLY SO.
THE MAJOR FORECAST CHALLENGE REMAINS PRECIPITATION CHANCES FROM
WEDNESDAY NIGHT THROUGH THE WEEKEND. THOUGH THE GENERAL IDEA OF
MULTIPLE WEAK SHORTWAVE TROUGHS AND AT TIMES ASSOCIATED FRONTS
REMAINS SOLID...THE EXACT DETAILS REMAIN A BIT MUDDY. WEDNESDAY
NIGHT SEEMS PARTICULARLY CHALLENGING AS MANY INGREDIENTS ARE
PRESENT...BUT IN A DISJOINTED MANNER THAT DON`T ENTIRELY SUGGEST
STRONG POTENTIAL FOR CONVECTION. A THETA-E GRADIENT NOSES THROUGH
THE REGION EARLIER IN THE DAY...AND A MIDLEVEL VORT MAX SWINGS
THROUGH IN THE EVENING ALONG WITH MODEST INSTABILITY AND SHEAR BUT
LACKING ANY SIGNIFICANT TRIGGERING MECHANISM. IN THE OVERNIGHT
HOURS TOWARDS DAYBREAK...COULD BEGIN TO SEE INFLUENCE FROM AN
APPROACHING COLD FRONT. THOUGH I GET THE FEELING THAT THE EVENING
WILL END UP DRY...CAN`T RULE DEVELOPMENT OUT AND SO SOME LOW-END
POPS REMAIN. POPS THEN BEGIN TO INCREASE TOWARDS MORNING AS THE
FRONT DRAWS NEARER IN DEFERENCE TO THE MORE PROGRESSIVE ELEMENTS
OF THE MODEL ENVELOPE.
THURSDAY PERHAPS SHOWS THE BEST POTENTIAL FOR STORMS AS THE FRONT
SWINGS INTO THE AREA ALONG WITH BETTER INSTABILITY. INDEED...THE
GFS SUGGESTS UP TO 3000 J/KG OF CAPE IN THE NORTHWOODS LATE
THURSDAY AFTERNOON INTO THE EVENING AND MARGINAL 30 KNOT SHEAR.
FORECAST SOUNDINGS AGAIN SHOW CAPPING THURSDAY WHICH COULD BE
RESTRICTIVE...BUT THE FRONT SHOULD AID IN OVERCOMING THAT...AS
LONG AS IT MOVES IN QUICKLY ENOUGH. STEEP TEMPERATURE-DEWPOINT
SPREADS AT THE SURFACE AND A STRONGLY MIXED BOUNDARY LAYER CREATE
THE POTENTIAL FOR INVERTED-V TYPE SOUNDINGS. IF CONVECTION BECOMES
STRONG ENOUGH...THERE COULD BE SOME GUSTY WINDS TO BE FOUND.
GUIDANCE DOES BEGIN TO DIVERGE BUT...EITHER DUE TO SLOWER TIMING
IN SOME MODELS...AND STALLING THE FRONT OUT OVER SOUTHERN
WISCONSIN IN OTHERS...THE CHANCE FOR LINGERING RAIN DRAGS INTO
FRIDAY IN CENTRAL AND EAST CENTRAL WISCONSIN.
WE SHOULD THEN SEE A DRYING TREND THROUGH MOST OF THE WEEKEND AS
RIDING BUILDS INTO THE REGION AND TEMPERATURES ONLY A BIT COOLER
BEHIND THE WEAK FRONT. FINALLY...THE MIDLEVEL RIDGE WILL BEGIN TO
FLATTEN AS AN UPPER TROUGH SWINGS THROUGH CANADA. THE COLD FRONT
ASSOCIATED WITH ITS SURFACE REFLECTION LOOKS TO COME THROUGH THE
AREA SUNDAY NIGHT...BRINGING OUR NEXT CHANCE OF RAIN AND
POTENTIALLY TEMPERATURES NEAR SEASONAL AVERAGES FOR THE FIRST PART
OF NEXT WEEK.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1159 AM CDT TUE AUG 11 2015
CLOUDS WILL CONTINUE TO BUILD EARLY THIS AFTERNOON BUT
REMAIN VFR. WITH LOSS OF HEATING...WILL SEE CLEARING SKIES EARLY
THIS EVENING...WHICH SHOULD LEAD TO A TRANQUIL NIGHT. WARMER AIR
WILL BE INCOMING FROM THE NORTHWEST LATE TONIGHT INTO WEDNESDAY
MORNING. THE IMPACT FROM THIS WILL BE INCREASING MID-LEVEL CLOUDS
AND A SMALL CHANCE OF SHOWERS AND STORMS ACROSS FAR NORTHERN
WISCONSIN. A VERY LOW PROBABILITY THAT ANY STORMS WILL AFFECT
RHINELANDER.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......LUCHS
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
240 PM CDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 240 PM CDT TUE AUG 11 2015
MUCH OF THE PERIOD LOOKS TO BE QUIET AS HIGH PRESSURE DOMINATES
THE REGION. THIS HIGH IS CURRENTLY CENTERED OVER NEBRASKA WITH THE
RIDGE AXIS EXTENDING NORTH WELL INTO ONTARIO. THE HIGH IS EXPECTED
TO DRIFT EAST TONIGHT AND BE OVER THE AREA SETTING UP THE
POSSIBILITY OF VALLEY FOG. THE 11.12Z NAM FORECAST SOUNDING FOR
KLSE LATE TONIGHT HAS LIGHT WINDS OF 10 KNOTS OR LESS ONLY UP
THROUGH ABOUT 3000 FEET AND WHILE IT SHOWS SATURATION OCCURRING AT
THE SURFACE...IT IMMEDIATELY BECOMES VERY DRY JUST ABOVE THE
SURFACE. THE 11.17Z RAP FORECAST SOUNDING IS EVEN MORE PESSIMISTIC
AS IT DOES NOT SHOW SATURATION OCCURRING AT THE SURFACE AND HAS A
3C TEMP/DEW POINT SPREAD AT 12.11Z. FOR NOW...WILL LEAVE THE
MENTION OF PATCHY VALLEY FOG IN THE FORECAST IN CASE THE NAM
SOUNDING ENDS UP BEING MORE CORRECT BUT WOULD TEND TO THE THINK
WITH THE LACK OF A DEEPER LAYER OF LIGHT WINDS AND SATURATION THAT
THERE WILL BE VERY LITTLE FOG IN THE VALLEYS.
ALL THE 11.12Z MODELS HAVE TRENDED TOWARD KEEPING THE SURFACE
RIDGE OVER THE REGION LONGER THAN PREVIOUS MODEL RUNS. THE UPPER
LEVEL RIDGE AXIS REMAINS OVER THE EASTERN ROCKIES INTO THE
NORTHERN HIGH PLAINS WHICH ENDS UP PUSHING THE SYSTEM CROSSING
CANADA FARTHER TO THE NORTH. THE MODELS CONTINUE TO SHOW A WEAK
SHORT WAVE TROUGH UNDERNEATH THE MAIN SYSTEM BUT THIS SHOULD NOW
PASS EVEN FARTHER TO THE NORTHEAST AND OVER THE NORTHERN GREAT
LAKES FOR WEDNESDAY NIGHT INTO THURSDAY. WITH THE STRONGER LOW
LEVEL RIDGING...THE WEAK COLD FRONT HAS A HARD TIME WORKING SOUTH
AND ALL THE MODELS NOW SHOW THIS REMAINING TO THE NORTH OF THE
AREA WEDNESDAY NIGHT. WITH THE LACK OF SIGNIFICANT FORCING AND THE
FRONT STAYING TO THE NORTH...HAVE REMOVED THE RAIN CHANCES FOR
WEDNESDAY NIGHT.
THERE IS STILL A TREND FOR THE UPPER LEVEL HEIGHTS TO LOWER SOME
THURSDAY INTO THURSDAY NIGHT AS THE UPPER LEVEL RIDGE SHIFTS
SLIGHTLY TO THE WEST. THIS MAY ALLOW A SHORT WAVE TROUGH TO TOP
THE RIDGE AXIS AND THEN SLIDE SOUTHEAST ACROSS THE REGION. IF THE
11.12Z GFS IS CORRECT...THIS WAVE COULD PRODUCE SOME MODERATE PV
ADVECTION IN THE 500-300 MB LAYER AS IT COMES ACROSS THE REGION.
WHAT LOW LEVEL MOISTURE TRANSPORT THERE IS LOOKS TO WRAP AROUND
THE LOW LEVEL RIDGE AND ACTUALLY COME BACK INTO THE AREA FROM THE
NORTHWEST. OVERALL...THE SIGNAL LOOKS PRETTY WEAK FOR RAIN AS THE
FRONT TRIES TO PUSH INTO THE REGION AND BOTH THE NAM AND 11.12Z
ECMWF KEEP THE AREA DRY WITH ANY RAIN OFF TO THE EAST. THE GFS
CONTINUES TO BE THE MOST ROBUST WITH RAIN AND WILL HONOR ITS
SOLUTION WITH SOME 20 TO 30 PERCENT RAIN CHANCES.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 240 PM CDT TUE AUG 11 2015
THERE COULD BE SOME LINGERING RAIN CHANCES ACROSS THE EAST INTO
FRIDAY FROM THIS SYSTEM...OTHERWISE IT LOOKS TO BE DRY THROUGH
SATURDAY NIGHT. THE RIDGE AXIS IS THEN EXPECTED TO GET FLATTENED
WITH A NEARLY ZONAL FLOW OVER THE UPPER MIDWEST AS A POSITIVE TILT
SYSTEM MOVES ACROSS SOUTHERN CANADA. THE CONCERN WITH THIS SYSTEM
IS HOW FAR SOUTH WILL THE TAIL OF THE SHORT WAVE TROUGH EXTEND.
THE GFS AND 11.12Z GEM ESSENTIALLY SHOW THIS SYSTEM STAYING WELL
TO THE NORTH WHILE THE ECMWF IS STRONGER WITH THE TAIL END OF THE
SYSTEM AND BRINGS A DECENT SECONDARY SHORT WAVE TROUGH ACROSS
SUNDAY AND SUNDAY NIGHT. A COLD FRONT SHOULD GET PUSHED INTO THE
AREA WITH THIS SYSTEM AND ALL THE MODELS AT LEAST SHOW SOME RAIN
CHANCES WITH THE FRONT WITH THE ECMWF HAVING THE MOST AND FOR NOW
WILL SHOW SOME 30 TO 40 PERCENT CHANCES SUNDAY AND SUNDAY NIGHT.
THE ECMWF PUSHES THE FRONT COMPLETELY THROUGH THE AREA WITH HIGH
PRESSURE BUILDING IN FOR THE START OF NEXT WEEK. HOWEVER...THE GFS
HANGS THE FRONT UP OVER THE AREA AND WOULD SUGGEST THERE WOULD BE
SOME ADDITIONAL RAIN CHANCES MONDAY INTO TUESDAY. WITH THE
UNCERTAINTY ON THAT SECONDARY SHORT WAVE TROUGH...WILL HONOR THE
GFS SOLUTION WITH SOME RAIN CHANCES FOR MONDAY THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1152 AM CDT TUE AUG 11 2015
PRIMARY AVIATION CONCERN IS POTENTIAL FOR FOG BY WEDNESDAY
MORNING. SURFACE RIDGE WILL BE RIGHT OVERHEAD WITH A COOL AIRMASS
IN PLACE. LOOKING AT BOUNDARY LAYER PROFILES VIA BUFKIT...WOULD
LIKE TO SEE A DEEPER LAYER OF LIGHT WINDS. BUT MODELS ALL SHOWING
THAT THE WINDS PICK UP ABOVE 10 KTS ALREADY BY 2-3 KFT. THIS
MIXING TYPICALLY PRECLUDES DEVELOPMENT OF FOG. LOOKING AT WHAT
OCCURRED UNDER THE RIDGE THIS MORNING...FEEL THERE IS THE
POTENTIAL FOR AT LEAST SOME FOG. SO DID MAINTAIN THE 5SM BR FOR
KRST. AT KLSE...DO NOT FEEL THE WIDESPREAD VALLEY FOG WILL REACH
THE AIRPORT EN MASSE. BUT THERE IS POTENTIAL...ESPECIALLY IF THE
LIGHT WIND LAYER ENDS UP BEING DEEPER THAN CURRENTLY DEPICTED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...MW
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1012 AM CDT TUE AUG 11 2015
.AVIATION/18Z TAFS/...VFR CU FIELD EXPECTED WITH LINGERING CHILLY
MID LEVEL CYCLONIC FLOW. KGRB 500 TEMP -14C. LOW LEVEL THERMAL
TROUGH SUPPORTIVE OF CU DEVELOPMENT AS WELL. ALREADY SEEING THIS
DEVELOPMENT BETWEEN 14-15Z ON VIS IMAGERY. MESO MODELS PAINT QPF
MAINLY IN 22-03Z TIME FRAME. LAKE BREEZE CONVERGENCE AND
32 UNIT VORT DROPPING SSE FROM NORTH OF LAKE SUPERIOR WILL HAVE
TO BE WATCHED. HOWEVER RAP SOUNDINGS SHOW VERY LITTLE IF ANY CAPE
WITH OVERALL PARCHED COLUMN. SO FOR NOW WILL NOT INTRODUCE PRECIP
CHCS AT THIS TIME.
PC
&&
.MARINE...WEAKENING PRESSURE GRADIENT OVER LAKE MICHIGAN WILL ALLOW
WINDS TO TURN TO THE NORTH TO NORTHEAST LATE THIS MORNING AND
CONTINUE THROUGH THE AFTERNOON. WIND SPEEDS WILL INCREASE BUT GUSTS
WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS. FURTHER WEAKENING OF
THE PRESSURE GRADIENT WILL ALLOW WIND SPEEDS TO DECREASE TO LESS
THAN 10 KTS TONIGHT.
MBK
&&
.BEACHES...NORTHWEST WINDS WILL TURN TO THE NORTHEAST THIS MORNING
AND INCREASE TO 10 TO 15 MPH...WITH POSSIBLY A GUST OR TWO UP TO 20
MPH. THE WINDS WILL DECREASE LATER THIS AFTERNOON AND EVENING.
THIS BRIEF PERIOD OF STRONGER ONSHORE WINDS WILL RESULT IN A
MODERATE SWIM RISK THIS AFTERNOON AND EVENING WITH WAVES BUILDING
TO 2 TO 4 FEET. BREAKING WAVES AND CURRENTS ARE EXPECTED.
MBK
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT TUE AUG 11 2015/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
DRY AIR CONTINUES TO SPREAD INTO THE REGION AS A BROAD HIGH
PRESSURE BUILDS IN. SOUNDINGS INDICATE SOME DIURNAL CUMULUS CLOUDS
BY THIS AFTERNOON...NO MORE THAN SCATTERED AT INLAND LOCATIONS.
THERE IS A POTENTIAL OF BROKEN CUMULUS IN THE EAST...WITH
CONVERGENCE AS NORTHEAST LAKE BREEZE DEVELOPS. THIS WILL ALSO COOL
OFF EASTERN LOCATIONS AFTER HIGHS IN THE MID 70S...WITH 925 MB
TEMPS SUPPORTING UPPER 70S TO LOWER 80S INLAND.
LIGHT WINDS AND CLEARING SKIES TONIGHT ALLOW GOOD RADIATIONAL
COOLING...WITH LOWS IN THE MID 50S AWAY FROM THE LAKE. EXPECT TO
SEE PATCHY FOG...ESPECIALLY IN THE RIVER VALLEYS AND LOW LYING
RURAL AREAS...BUT NOT EXPECTING TO FALL MUCH BELOW 3 TO 5 MILES
EXCEPT IN THE WI RIVER VALLEY.
SHORT TERM...WEDNESDAY THROUGH THURSDAY NIGHT...FORECAST
CONFIDENCE IS MEDIUM.
MODELS ARE IN PRETTY GOOD AGREEMENT WITH HIGH PRESSURE TO THE
SOUTHWEST OF THE AREA SLIDING SLOWLY SOUTHEASTWARD WEDNESDAY AND
WEDNESDAY NIGHT. 500 MB FLOW REMAINS NORTHWESTERLY DURING THIS
TIME...WITH A VORTICITY MAXIMUM SLIDING ACROSS NORTHEAST WISCONSIN
INTO CENTRAL LAKE MICHIGAN WEDNESDAY.
THERE IS SOME WARM AIR ADVECTION THAT DEVELOPS LATER WEDNESDAY
INTO WEDNESDAY NIGHT...WHICH HELPS GENERATE SOME LIGHT QPF OVER
AND EAST OF NORTHERN LAKE MICHIGAN. GFS TRIES TO EXTEND THIS
SOUTHWARD INTO THE FAR EASTERN COUNTIES. HOWEVER...AREA FORECAST
SOUNDINGS ARE REMAINING FAIRLY DRY DURING THIS PERIOD.
THUS...KEPT THE DRY FORECAST GOING WEDNESDAY AND WEDNESDAY NIGHT.
HIGHS IN THE LOWER 80S ARE EXPECTED AWAY FROM THE LAKE...WITH
UPPER 70S CLOSER TO SHORE. LAKE BREEZE SHOULD DEVELOP IN THE
AFTERNOON...ESPECIALLY MILWAUKEE AND SOUTHWARD.
MODELS ARE SHOWING THE WARM AIR ADVECTION CONTINUING THURSDAY INTO
THURSDAY NIGHT...WITH THE COLD FRONT APPROACHING THE AREA THURSDAY
NIGHT FROM THE NORTHWEST. GUSTY SOUTHWEST WINDS ARE EXPECTED
THURSDAY WITHIN A TIGHT PRESSURE GRADIENT. THIS SHOULD BRING HIGHS
WELL INTO THE 80S ACROSS THE ENTIRE AREA...WITH HUMID CONDITIONS.
AREA FORECAST SOUNDINGS ARE SHOWING A DECENT CAP DEVELOPING
THURSDAY WITH THE WARM AIR ADVECTION...WHICH MAY DELAY ANY SHOWERS
AND THUNDERSTORMS UNTIL THURSDAY NIGHT AS THE FRONT APPROACHES.
KEPT LOW POPS FOR THURSDAY IN THE NORTH...WITH HIGHER POPS
THURSDAY NIGHT. MEAN LAYER CAPES ARE SOLIDLY IN THE 1000 TO 1500
J/KG RANGE...THOUGH DEEP LAYER SHEAR IS FAIRLY WEAK.
LONG TERM...FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE IS
MEDIUM.
ECMWF/GFS BRINGS THE COLD FRONT THROUGH THE AREA FRIDAY...BEFORE
SLIDING SOUTHWARD BY LATER FRIDAY NIGHT. SOME TIMING DIFFERENCES
HERE...THOUGH BOTH MODELS SHOW A 500 MB VORTICITY MAXIMUM PASSING
SOUTHEAST THROUGH THE REGION. KEPT POPS GOING FOR FRIDAY INTO
FRIDAY NIGHT FOR NOW...WITH WARM AND HUMID CONDITIONS.
CONTINUED DRY FORECAST FOR SATURDAY INTO SUNDAY...AS HIGH PRESSURE
AXIS KEEPS THE AREA DRY. MODELS THEN DIFFER WITH TIMING AND
PLACEMENT OF NEXT COLD FRONT MOVING INTO THE REGION SUNDAY NIGHT
INTO MONDAY. CONTINUED CONSENSUS POPS AND TEMPERATURES FOR NOW.
AVIATION/12Z TAFS/...
EXPECT VFR CONDITIONS AFTER ANY PATCHY FOG DISSIPATES BY 14Z.
DIURNAL VFR CUMULUS WILL BE MAINLY SCATTERED AT INLAND LOCATIONS.
THERE IS A POTENTIAL OF A PERIOD OR TWO OF BROKEN CUMULUS IN THE
EAST...WITH CONVERGENCE AS NORTHEAST LAKE BREEZE DEVELOPS.
EXPECT SOME PATCHY FOG TONIGHT WITH LIGHT WINDS AND CLEAR
SKIES...BUT NOT CERTAIN IT WILL BE AT TAF SITES. THIS WOULD BE
ESPECIALLY SO AT THE EASTERN TAF SITES...WHERE WARMER TEMPS DUE
TO THE ONSHORE FLOW OFF OF THE WARMER LAKE WILL PREVENT COOLING
DOWN TO DEW POINTS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
WEDNESDAY THROUGH MONDAY...WOOD
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
452 PM MDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 237 PM MDT TUE AUG 11 2015
TONIGHT:
LATEST RADAR LOOP WAS SHOWING VERY MINIMAL COVERAGE IN SHOWERS AND
THUNDERSTORMS THIS AFTERNOON WITH THE BULK OF THEM DEVELOPING OVER
THE LARAMIE RANGE. WOULD EXPECT THIS TREND TO CONTINUE DURING THE
REMAINDER OF THE AFTERNOON. ANOTHER CONCERN IS THE POTENTIAL FOR
PATCHY FOG DEVELOPMENT IN THE SOUTHERN PANHANDLE TONIGHT. LATEST
SURFACE ANALYSIS WAS SHOWING A GOOD FETCH OF LOW LEVEL MOISTURE
BETWEEN THE SURFACE HIGH IN THE PLAINS AND THE LEE TROF EAST OF
THE LARAMIE RANGE. THE NAM BUFKIT ANALYSIS WAS SHOWING THE
BOUNDARY LAYER RH FIELDS INCREASING AFTER MIDNIGHT IN THE SOUTHERN
PANHANDLE UNDERNEATH THE LOW LEVEL INVERSION. WE WENT AHEAD AND
INTRODUCED PATCHY FOG IN THIS REGION TO REFLECT THIS POTENTIAL.
WEDNESDAY-WEDNESDAY NIGHT:
A WEAK POTENTIAL VORTICITY ANOMALY IS EXPECTED TO MOVE INTO THE
SOUTHWEST PORTION OF THE FORECAST AREA ON WEDNESDAY MORNING WITH
THIS WAVE SPREADING WEST TO EAST DURING THE COURSE OF THE DAY.
IN ADDITION...THERE IS DECENT MOISTURE TRANSPORT AROUND 310K WITH
THE BEST LIFT IN THE NORTHERN HALF OF THE AREA. ANY CONVECTION
THAT DOES DEVELOP OVER THE LARAMIE RANGE EARLY WEDNESDAY AFTERNOON
SHOULD GENERALLY SPREAD EAST-NORTHEAST DURING THE COURSE OF THE
DAY. THE BEST INSTABILITY EXISTS OVER THE PANHANDLE...BUT THE
SHEAR IS QUITE LIMITED SO NOT EXPECTING ANYTHING SEVERE. THE
CONVECTION SHOULD BEGIN TO DIMINISH THE EVENING AND OVERNIGHT DUE
TO LIMITED SHEAR.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 237 PM MDT TUE AUG 11 2015
FAIRLY STAGNANT PATTERN EXPECTED ACROSS THE CWA WEDS NIGHT INTO
SATURDAY WITH A LARGE UPPER RIDGE HOLDING ACROSS THE REGION ATOP
AN UPPER HIGH THAT WILL DRIFT SLOWLY WESTWARD ACROSS THE SOUTHERN
ROCKY MTNS. TEMPS QUITE WARM THURSDAY THROUGH SATURDAY UNDER A MID
LEVEL THERMAL RIDGE WITH 700MB TEMPS WARMING TO ABOUT 14-16C. THIS
WILL ALLOW TEMPS TO WARM INTO THE 90S OVER LOWER ELEVATIONS. WEAK
IMPULSES WILL DRIFT THROUGH THE UPPER RIDGE AND ACROSS THE REGION
AND SHOULD SET OFF ISOLATED CONVECTION FROM TIME TO TIME.
INDIVIDUAL WAVES HARD TO TIME SO TAILORED POPS TO FIT WHAT SEEMED
TO BE THE BETTER CHANCES.
SOME CHANGES MAY ARRIVE IN THE SUNDAY/MONDAY TIME PERIOD AS AN
UPPER SHORTWAVE MOVES ACROSS SRN CANADA. THIS SHOULD PUSH A COOL
FRONT ACROSS THE CWA EARLY SUNDAY BEFORE WASHING BACK OUT EAST
MONDAY. PCPN CHANCE STILL NOT TOO IMPRESSIVE HOWEVER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 450 PM MDT TUE AUG 11 2015
GOING TO CONTINUE CHANCES FOR IFR/LIFR CONDITIONS AT KCYS...KBFF
AND KSNY TONIGHT WITH SOUTHEAST WINDS CONTINUING. SUPPORTED BY
LATEST SREF AND HRRR FORECASTS AS WELL. COULD LAST ALL MORNING IF
THERE IS NO CONVECTION TO BREAK UP THE LOW LEVEL MOISTURE. WILL
TRY TO NAIL DOWN TIMING A LITTLE BETTER WITH THE 06Z TAF SUITE.
&&
.FIRE WEATHER...
ISSUED AT 237 PM MDT TUE AUG 11 2015
ONLY FIRE WEATHER CONCERN WILL BE THE LIGHTNING POTENTIAL OVER
THE MOUNTAINS DURING THE NEXT COUPLE OF DAYS WHICH COULD IGNITE A
FIRE START. OTHERWISE...RELATIVE HUMIDITIES WILL BE MARGINAL 20
TO 30 PERCENT WITH WIND SPEEDS POSSIBLY REACHING 20 TO 25 MPH IN
AREAS WEST OF THE LARAMIE RANGE WEDNESDAY AFTERNOON.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...REC
LONG TERM...JG
AVIATION...GCC
FIRE WEATHER...REC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1210 AM MDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 1157 PM MDT MON AUG 10 2015
SIGNIFICANT FLASH FLOODING REMAINS A MAJOR CONCERN EARLY THIS AM
FOR THE I80 CORRIDOR BETWEEN KIMBALL AND SIDNEY. THUNDERSTORMS W/
VERY HEAVY RAINFALL HAVE LOCKED ONTO THE CHEYENNE RIDGE OVER THE
LAST SEVERAL HOURS...REMAINING NEARLY STATIONARY. DUAL-POL RADAR
ESTIMATES ARE WELL IN EXCESS OF 4 INCHES AND NUMEROUS REPORTS OF
SUBMERGED VEHICLES WERE RECEIVED FROM KIMBALL AFTER 11 PM. NEAR
TERM CONCERNS REVOLVE AROUND DOWNSTREAM AREAS ALONG LODGEPOLE
CREEK TOWARD SIDNEY. WILL NEED TO MONITOR VERY CLOSELY AS THE
LOW-LEVEL MOISTURE FEED SHOULD CONTINUE TO SUPPORT CONVECTIVE
MAINTENANCE FOR AT LEAST THE NEXT HOUR OR TWO. HAVE UPDATED THE
GRIDS TO INCLUDE MENTION OF HEAVY STORMS AND ADDITIONAL RAINFALL
IN EXCESS OF ONE INCH.
UPDATE ISSUED AT 938 PM MDT MON AUG 10 2015
GRIDDED FORECASTS UPDATED TO ADJUST POPS THE REST OF THIS EVENING
FOR SHOWERS AND THUNDERSTORMS OVER KIMBALL COUNTY NEBRASKA AND
A FEW SHOWERS OVER WESTERN NEBRASKA. EXPECT THESE SHOWERS TO BE
OVER BY MIDNIGHT. LATEST 00Z NAM AND HRRR INDICATING LOW CLOUDS
AND FOG ALONG THE SOUTHERN LARAMIE RANGE FROM CHEYENNE TO PINE
BLUFFS AND OVER THE SUMMIT LATER TONIGHT. /SAR
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 242 PM MDT MON AUG 10 2015
WE ARE STARTING TO SEE A FEW BUILDUPS ACROSS THE SOUTHERN LARAMIE
RANGE IN WYOMING AS WELL AS IN A ZONE OF DIFFERENTIAL HEATING ON
THE NORTH SIDE OF THE NORTH PLATTE RIVER VALLEY ACROSS THE
NEBRASKA PANHANDLE NORTH OF SCOTTSBLUFF. DONT THINK MOST STORMS
WILL GET OVERLY ROWDY THIS AFTERNOON AND EVENING...ALTHOUGH WITH
SBCAPES RUNNING IN THE 1200-1600 J/KG RANGE OVER THE PANHANDLE WE
COULD SEE A FEW STRONGER UPDRAFTS TO SUPPORT ISOLATED
STRONG/BRIEFLY MARGINALLY SEVERE STORMS...ALTHOUGH TYPICAL OF
AUGUST MIDLEVELS ARE FAIRLY WARM. MOST OF THE CONVECTION IS
EXPECTED TO FIRE ALONG AND JUST EAST OF THE LARAMIE RANGE THIS
AFTERNOON WITH ISOLATED STORMS EXPECTED THROUGH MID EVENING OVER
THE PANHANDLE.
RATHER AMPLIFIED UPPER RIDGE EXTENDS NORTH ACROSS THE CENTRAL AND
NORTHERN ROCKIES WITH OUR FORECAST AREA SEEING A GRADUAL INCREASE
IN MIDLEVEL MOISTURE FROM THE SOUTHWEST THROUGH MID WEEK. WILL SEE
SCATTERED STORMS TOMORROW AFTERNOON FIRE OVER THE SIERRA MADRE,
SNOWY AND SOUTHERN LARAMIE RANGE WITH ISOLATED STORMS EAST ONTO
THE PLAINS. BOTH THE GFS AND THE NAM SUPPORT THE NOTION OF A
SHORTWAVE RIDING NORTHEAST ACROSS OUR AREA WEDNESDAY AND THAT WILL
SUPPORT AN INCREASE IN POPS FOR WEDNESDAY AFTERNOON...ESPECIALLY
OUT WEST ALONG AND WEST OF THE LARAMIE RANGE WITH ISOLATED POPS
FARTHER EAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 242 PM MDT MON AUG 10 2015
FAIRLY STAGNANT PATTERN EXPECTED ACROSS THE CWA WEDS NIGHT INTO
SATURDAY WITH A LARGE UPPER RIDGE HOLDING ACROSS THE REGION ATOP
AN UPPER HIGH THAT WILL DRIFT SLOWLY WESTWARD ACROSS THE SOUTHERN
ROCKY MTNS. TEMPS QUITE WARM THURSDAY THROUGH SATURDAY UNDER A MID
LEVEL THERMAL RIDGE WITH 700MB TEMPS WARMING TO ABOUT 14-16C. THIS
WILL ALLOW TEMPS TO WARM INTO THE 90S OVER LOWER ELEVATIONS. WEAK
IMPULSES WILL DRIFT THROUGH THE UPPER RIDGE AND ACROSS THE REGION
AND SHOULD SET OFF ISOLATED CONVECTION FROM TIME TO TIME.
INDIVIDUAL WAVES HARD TO TIME SO TAILORED POPS TO FIT WHAT SEEMED
TO BE THE BETTER CHANCES.
SOME CHANGES MAY ARRIVE IN THE SUNDAY/MONDAY TIME PERIOD AS AN
UPPER SHORTWAVE MOVES ACROSS SRN CANADA. THIS SHOULD PUSH A COOL
FRONT ACROSS THE CWA EARLY SUNDAY BEFORE WASHING BACK OUT EAST
MONDAY. PCPN CHANCE STILL NOT TOO IMPRESSIVE HOWEVER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 439 PM MDT MON AUG 10 2015
THERE IS THE POSSIBILITY OF LOWER FLIGHT CONDITIONS FOR SOME
AIRPORTS IN THE SOUTHERN PANHANDLE AND HERE AT CHEYENNE. LATEST
ALTERNATIVE HRRR AND SREF GUIDANCE IS SHOWING KSNY...KCYS AND
POSSIBLY KBFF GOING DOWN IN FOG AND STRATUS AFTER 09Z OR SO
TUESDAY MORNING. WILL TRY TO NARROW DOWN TIMING AND AIRPORTS ON
THE 06Z TAFS. BEST CHANCES LOOK TO BE HERE AT KCYS OVERNIGHT.
SOUTHEAST UPSLOPING WINDS TO CONTINUE THROUGH LATE MORNING TUESDAY
BEFORE TURNING MORE WESTERLY.
&&
.FIRE WEATHER...
ISSUED AT 242 PM MDT MON AUG 10 2015
STILL EXPECTING NO MAJOR FIRE WEATHER CONCERNS THROUGH AT LEAST
WEDNESDAY WITH WIND GUSTS (AWAY FROM THUNDERSTORMS) EXPECTED TO
REMAIN BELOW 25 MPH AND HUMIDITIES AT OR ABOVE 20 PERCENT FOR MOST
LOCATIONS. WE WILL SEE ISOLATED TO SCATTERED THUNDERSTORMS THROUGH
MID WEEK IN THE AFTERNOON AND EARLY EVENING HOURS...WITH THE MAIN
THREATS FROM THESE BEING CLOUD TO GROUND LIGHTNING AND
GUSTY/ERRATIC WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLH
SHORT TERM...JG
LONG TERM...RE
AVIATION...GCC
FIRE WEATHER...JG
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1118 PM MDT WED AUG 12 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 334 PM MDT WED AUG 12 2015
CURRENTLY...
LINE OF Q NOTED OVER THE FAR SE PLAINS. SPC ANALYSIS INDICATES 3000
J/KG MIXED CAPE OVER THIS REGION. IN ADDITION...SPC NON SUPERCELL
TORNADO INDICES ARE INCREASING OVER THIS SAME AREA.
ELSEWHERE...ISOLD CONVECTION WAS NOTED OVER THE MTNS.
THIS AFTERNOON...
MAIN SHORT TERM CONCERN IS BOUNDARY OUT EAST. GIVEN THE
CAPE...INCREASING VALUES ON THE NON SUPERCELL SPC PAGE AND HRRR
SHOWING CONVECTION INITIATING OVER THE REGION...CANT RULE OUT A WEAK
ROPE TORNADO DEVELOPING BETWEEN NOW AND LATE AFTERNOON OVER E
KIOWA...PROWERS AND POSSIBLY BACA COUNTIES. OTHER CONVECTION WILL
CONTINUE TO DEVELOP OVER THE HIGHER TRRN AND POSSIBLY THE LOWER
ELEVATIONS OF EL PASO COUNTY. CANT RULE OUT AN ISOLD STORM
DEVELOPING OVER THE REST OF THE PLAINS.
TONIGHT...
WITH LIMITED FORCING OVER THE REGION...CONVECTION THAT DOES INITIATE
SHOULD DECREASE AFTER SUNSET THIS EVENING. LATEST HRRR GUIDANCE
LOOKS A LITTLE HEAVY HANDED REGARDING CONVECTION INTENSITY AND
DURATION FOR THIS EVENING. I CANT RULE OUT AN ISOLD STORM LINGERING
INTO THE EVENING HOURS...BUT OVERALL NOT MUCH CONVECTION ANTICIPATED
TONIGHT.
LOW TEMPS TONIGHT SHOULD BE IN THE M/U60S PLAINS WITH 40S AND 50S
MTNS/VALLEYS.
TOMORROW...
WEAK BOUNDARY WILL COME DOWN THE PLAINS TOMORROW AND MONSOON MSTR
WILL LINGER OVER THE EASTERN PLAINS. ALTHOUGH THE BRUNT OF THE
DEEPER MSTR WILL BE OVER THE CONTDVD AND WESTWARD...ENOUGH FORCING
WILL BE OVER THE PLAINS AND MTNS FOR ISOLD TO SCT ACTIVITY DURING
THE LATER AFTERNOON TIME PD. NAM APPEARS TO BE THE MOST HEAVY
HANDED OF ALL THE GUIDANCE AND APPEARS OVERDONE...BUT GIVEN THE
SOMEWHAT FAVORABLE LLVL FORCING...WE MAY SEE AN UPTICK IN
CONVECTION OVER THE PLAINS LATE TOMORROW AFTERNOON.
EXPECT MAX TEMPS TOMORROW TO BE IN THE L/M90S WITH 80S IN THE COS
REGION...AND 70S AND 80S IN THE THE MTNS. HODANISH
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 334 PM MDT WED AUG 12 2015
THURSDAY NIGHT THROUGH SATURDAY...A LARGE UPPER HIGH CONTINUES TO BE
CENTERED OVER THE REGION THROUGH FRIDAY KEEPING WINDS ALOFT
LIGHT...BEFORE FLATTENING OUT AND EDGING TO THE SOUTH BEGINNING
SATURDAY. MOISTURE TRAPPED UNDER THE HIGH WILL FEED DIURNAL AFTN AND
EVE MT SHOWERS AND STORMS...AND STORMS THAT DO DEVELOP WILL BE SLOW-
MOVING AND MOVEMENT WILL BE DIFFICULT TO ANTICIPATE. LOOK FOR MAX
TEMPS TO REMAIN STEADY THROUGH THE PERIOD WITH AFTN HIGHS IN THE 80S
FOR THE HIGH VALLEYS...AND 80S TO MID 90S FOR THE E PLAINS.
SUNDAY AND MONDAY...THE UPPER HIGH GETS PUSHED TO THE SOUTH AS A
SHORTWAVE CROSSES THE NORTHERN ROCKIES LATE SAT THROUGH MON...WITH
THE HIGH CENTER SETTLING OVER AZ. THE SHORTWAVE PUSHES A COLD FRONT
DOWN INTO E CO ON SUN...WITH MODELS SAYING THE FRONTAL PASSAGE OVER
THE PALMER DVD SOMETIME IN THE LATE MORNING. AFTER A WARM DAY
SUN...THE FRONT MAY HELP TO COOL TEMPS A FEW DEGREES ON MON...WITH
HIGHS IN THE 80S TO NEAR 90 FOR THE PLAINS...AND AROUND 80 FOR THE
HIGH VALLEYS. AS FOR PCPN...THERE LOOKS TO BE A SLIGHT INCREASE IN
POPS SUN...BUT MORE SO SUN EVE AND DEFINITELY INTO MON. THE BEST
WINDOW FOR WIDESPREAD PCPN COVERAGE COMES MON AFTN AND EVE ACROSS
ALL OF THE MTS AND E PLAINS.
TUESDAY AND WEDNESDAY...THE EXTENDED PERIOD GETS INTERESTING AS
MODELS AGREE ON DROPPING A STRONG UPPER LOW DOWN ACROSS THE PAC NW
ON MON...BUT THEN THE SOLUTIONS DIVERGE. THE EC WANTS TO CONTINUE
DROPPING THE LOW INTO THE GREAT BASIN TUE AND WED...WHILE THE GFS
SWEEPS THE LOW DUE EAST ACROSS ID AND MT. FOR NOW WENT WITH ISOLATED
TO SCATTERED MT CONVECTION TUE AFTN AND EVE...THEN COOLER AND DRIER
FOR WED. MOORE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1113 PM MDT WED AUG 12 2015
ISOLATED THUNDERSTORMS IN VICINITY OF KCOS WILL MOVE TO THE EAST
OF THE TERMINAL AND DIMINISH BY 07-08Z. LIGHTNING AND BRIEF LIGHT
RAINFALL WILL BE PRIMARY STORM THREATS. OTHERWISE...SHOULD SEE
MVFR STRATUS DEVELOP ACROSS NORTHERN PORTIONS OF THE SOUTHEAST
PLAINS LATE TONIGHT...WHICH COULD SPREAD WESTWARD TO NEAR THE KPUB
TAF SITE BY EARLY THURS MORNING. SINCE STRATUS IS MORE LIKELY TO
REMAIN TO THE EAST OF KPUB...WILL ONLY PUT A SCT MVFR LAYER IN
TOWARDS 13Z. ANOTHER ROUND OF THUNDERSTORMS WILL DEVELOP OVER THE
MTS AND SPREAD EASTWARD INTO THE LOWER ELEVATIONS. CHANCES FOR
THUNDERSTORMS LOOK A LITTLE HIGHER TOMORROW AS A DISTURBANCE MOVES
THOUGH SO WILL CARRY VCTS AT ALL THREE TAF SITES. ERRATIC WIND
GUSTS TO AROUND 40 KTS ALONG WITH LOCALLY HEAVY RAINFALL WILL BE
THE PRIMARY STORM THREATS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HODANISH
LONG TERM...MOORE
AVIATION...KT
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
556 AM EDT THU AUG 13 2015
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND FROM THE OHIO VALLEY EASTWARD INTO THE
DELMARVA REGION THROUGH FRIDAY. A FRONTAL SYSTEM WILL BE NEAR THE
SOUTHEAST COAST. ASSOCIATED FRONTAL MOISTURE WILL REMAIN MAINLY
EAST OF THE FORECAST AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE RIDGE WILL CONTINUE NORTH OF THE FORECAST AREA THROUGH
TONIGHT. THE MODELS KEEP DEEP MOISTURE ASSOCIATED WITH THE FRONT
NEAR THE SOUTHEAST COAST EAST OF THE FORECAST AREA. HEATING AND
SOME LOW-LEVEL CONVERGENCE ASSOCIATED WITH THE SEA-BREEZE FRONT
AND WEAK TROUGH IN THE FORECAST AREA SHOWN BY THE NAM AND ECMWF COULD
HELP SUPPORT THUNDERSTORMS. BASED ON THE DRY WATER VAPOR IMAGERY
AND MODEL FORECAST SOUNDINGS BELIEVE MID-LEVEL CAPPING WILL
DOMINATE. EXPECT LITTLE OR NO THUNDERSTORM COVERAGE. THE HRRR AND
SPC WRF DISPLAYED JUST ISOLATED COVERAGE. WE MAINTAINED THE VERY
LOW POPS WITH HIGHER VALUES IN THE EAST PART BECAUSE OF
CONVERGENCE NEAR THE SEA-BREEZE FRONT...AND SOUTHWEST SECTION
CLOSE TO WHERE A FEW SHOWERS OCCURRED DURING THE EARLY MORNING
HOURS AND HRRR DISPLAYED GREATER COVERAGE THIS AFTERNOON. LEANED
TOWARD THE HIGHER HIGH TEMPERATURE GUIDANCE BASED ON THE RECENT
BIAS. USED THE GUIDANCE CONSENSUS FOR THE LOW TEMPERATURE
FORECAST.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
THE MODELS KEEP MOISTURE SHALLOW IN THE FORECAST AREA FRIDAY AND
FRIDAY NIGHT. DEEPER MOISTURE AND CONVERGENCE REMAIN OFF THE
COAST ALONG THE FRONT WITH HIGH PRESSURE RIDGING INTO THE FORECAST
AREA FROM THE NORTH. THERE SHOULD BE LITTLE LOW-LEVEL CONVERGENCE
EXCEPT POSSIBLY ALONG THE SEA-BREEZE FRONT WHICH MAY MOVE WELL
INLAND. WE KEPT THE POPS LOW WHICH WAS SUPPORTED BY BOTH THE NAM
AND GFS MOS. THE TEMPERATURE GUIDANCE WAS CLOSE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF DISPLAY SOME WEAK SURFACE TROUGHING IN THE
FORECAST AREA DURING MUCH OF THE MEDIUM-RANGE PERIOD. SOME UPPER
TROUGHING APPEARS TO SHIFT FARTHER WEST EARLY IN THE PERIOD...BUT
GETS REESTABLISHED LATE IN THE PERIOD. THE PATTERN SUPPORTS A
CHANCE OF THUNDERSTORMS. THE GFS...ECMWF...AND EKD MOS HAVE POPS
OF 10 TO 30 PERCENT WITH MORE CONSISTENCY FOR HIGHER POPS MONDAY
THROUGH WEDNESDAY. THE MOS HAS TEMPERATURES NEAR CLIMATOLOGY
THROUGH THE PERIOD.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
IFR/MVFR FOG EXPECTED LATE TOWARD MORNING AT FOG PRONE
SITES...AGS/OGB.
WATER VAPOR INDICATING VERY DRY AIR ALOFT. MODELS INDICATE
SHALLOW LOW-LEVEL MOISTURE. WILL CONTINUE TO MENTION MVFR TEMPO
GROUP FOR FOG AT AGS/OGB 10Z THROUGH 13Z. HIGH PRESSURE WILL
PROMOTE MOSTLY SUNNY SKIES THROUGH THE AFTERNOON. ONLY A SLIGHT
CHANCE OF AFTERNOON CONVECTION AT AGS/DNL DUE TO HEATING AND
CONVERGENCE ALTHOUGH MOISTURE WILL BE LIMITED. LIGHT AND VARIABLE
WINDS EARLY THIS MORNING WILL PICK UP OUT OF THE NORTHEAST AT
AROUND 5 TO 10 KNOTS AFTER SUNRISE.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT RESTRICTIONS TO AVIATION
ARE EXPECTED AT THIS TIME.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
552 AM EDT THU AUG 13 2015
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND FROM THE OHIO VALLEY EASTWARD INTO THE
DELMARVA REGION THROUGH FRIDAY. A FRONTAL SYSTEM WILL BE NEAR THE
SOUTHEAST COAST. ASSOCIATED FRONTAL MOISTURE WILL REMAIN MAINLY
EAST OF THE FORECAST AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE RIDGE WILL CONTINUE NORTH OF THE FORECAST AREA THROUGH
TONIGHT. THE MODELS KEEP DEEP MOISTURE ASSOCIATED WITH THE FRONT
NEAR THE SOUTHEAST COAST EAST OF THE FORECAST AREA. HEATING AND
SOME LOW-LEVEL CONVERGENCE ASSOCIATED WITH THE SEA-BREEZE FRONT
AND WEAK TROUGH IN THE FORECAST AREA SHOWN BY THE NAM AND ECMWF COULD
HELP SUPPORT THUNDERSTORMS. BASED ON THE DRY WATER VAPOR IMAGERY
AND MODEL FORECAST SOUNDINGS BELIEVE MID-LEVEL CAPPING WILL
DOMINATE. EXPECT LITTLE OR NO THUNDERSTORM COVERAGE. THE HRRR AND
SPC WRF DISPLAYED JUST ISOLATED COVERAGE. WE MAINTAINED THE VERY
LOW POPS WITH HIGHER VALUES IN THE EAST PART BECAUSE OF
CONVERGENCE NEAR THE SEA-BREEZE FRONT...AND SOUTHWEST SECTION
CLOSE TO WHERE A FEW SHOWERS OCCURRED DURING THE EARLY MORNING
HOURS AND HRRR DISPLAYED GREATER COVERAGE THIS AFTERNOON. LEANED
TOWARD THE HIGHER HIGH TEMPERATURE GUIDANCE BASED ON THE RECENT
BIAS. USED THE GUIDANCE CONSENSUS FOR THE LOW TEMPERATURE
FORECAST.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
THE MODELS KEEP MOISTURE SHALLOW IN THE FORECAST AREA FRIDAY AND
FRIDAY NIGHT. DEEPER MOISTURE AND CONVERGENCE REMAIN OFF THE
COAST ALONG THE FRONT WITH HIGH PRESSURE RIDGING INTO THE FORECAST
AREA FROM THE NORTH. THERE SHOULD BE LITTLE LOW-LEVEL CONVERGENCE
EXCEPT POSSIBLE ALONG THE SEA-BREEZE FRONT WHICH MAY MOVE WELL
INLAND. WE KEPT THE POPS LOW WHICH WAS SUPPORTED BY BOTH THE
NAM AND GFS MOS. THE TEMPERATURE GUIDANCE WAS CLOSE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF DISPLAY SOME WEAK SURFACE TROUGHING IN THE
FORECAST AREA DURING MUCH OF THE MEDIUM-RANGE PERIOD. SOME UPPER
TROUGHING APPEARS TO SHIFT FARTHER WEST EARLY IN THE PERIOD...BUT
GETS REESTABLISHED LATE IN THE PERIOD. THE PATTERN SUPPORTS A
CHANCE OF THUNDERSTORMS. THE GFS...ECMWF...AND EKD MOS HAVE POPS
OF 10 TO 30 PERCENT WITH MORE CONSISTENCY FOR HIGHER POPS MONDAY
THROUGH WEDNESDAY. THE MOS HAS TEMPERATURES NEAR CLIMATOLOGY
THROUGH THE PERIOD.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
IFR/MVFR FOG EXPECTED LATE TOWARD MORNING AT FOG PRONE
SITES...AGS/OGB.
WATER VAPOR INDICATING VERY DRY AIR ALOFT. MODELS INDICATE
SHALLOW LOW-LEVEL MOISTURE. WILL CONTINUE TO MENTION MVFR TEMPO
GROUP FOR FOG AT AGS/OGB 10Z THROUGH 13Z. HIGH PRESSURE WILL
PROMOTE MOSTLY SUNNY SKIES THROUGH THE AFTERNOON. ONLY A SLIGHT
CHANCE OF AFTERNOON CONVECTION AT AGS/DNL DUE TO HEATING AND
CONVERGENCE ALTHOUGH MOISTURE WILL BE LIMITED. LIGHT AND VARIABLE
WINDS EARLY THIS MORNING WILL PICK UP OUT OF THE NORTHEAST AT
AROUND 5 TO 10 KNOTS AFTER SUNRISE.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT RESTRICTIONS TO AVIATION
ARE EXPECTED AT THIS TIME.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
452 AM EDT THU AUG 13 2015
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND FROM THE OHIO VALLEY EASTWARD INTO THE
DELMARVA REGION THROUGH FRIDAY. A FRONTAL SYSTEM WILL BE NEAR THE
SOUTHEAST COAST. ASSOCIATED FRONTAL MOISTURE WILL REMAIN MAINLY
EAST OF THE FORECAST AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE RIDGE WILL CONTINUE NORTH OF THE FORECAST AREA THROUGH
TONIGHT. THE MODELS KEEP DEEP MOISTURE ASSOCIATED WITH THE FRONT
NEAR THE SOUTHEAST COAST EAST OF THE FORECAST AREA. HEATING AND
SOME LOW-LEVEL CONVERGENCE ASSOCIATED WITH THE SEA-BREEZE FRONT
AND WEAK TROUGH IN THE FORECAST AREA SHOWN BY THE NAM AND ECWMF COULD
HELP SUPPORT THUNDERSTORMS. THE NAM HAD MUCH MORE INSTABILITY
COMPARED TO THE GFS THIS AFTERNOON. BASED ON THE DRY WATER VAPOR
IMAGERY BELIEVE MID-LEVEL CAPPING MAY DOMINATE AND EXPECT LITTLE
THUNDERSTORM COVERAGE. THE HRRR AND SPC WRF DISPLAYED JUST
ISOLATED COVERAGE. WE MAINTAINED THE VERY LOW POPS WITH HIGHER
VALUES IN THE EAST PART BECAUSE OF CONVERGENCE NEAR THE SEA-BREEZE
FRONT...AND THE WEST PART WHERE EARLY MORNING SATELLITE INDICATED
GREATER MOISTURE AND THE HRRR DISPLAYED GREATER COVERAGE. LEANED
TOWARD THE HIGHER HIGH TEMPERATURE GUIDANCE BASED ON THE RECENT
BIAS. USED THE GUIDANCE CONSENSUS FOR THE LOW TEMPERATURE FORECAST.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
THE MODELS KEEP MOISTURE SHALLOW IN THE FORECAST AREA FRIDAY AND
FRIDAY NIGHT. DEEPER MOISTURE AND CONVERGENCE REMAIN OFF THE
COAST ALONG THE FRONT WITH HIGH PRESSURE RIDGING INTO THE FORECAST
AREA FROM THE NORTH. THERE SHOULD BE LITTLE LOW-LEVEL CONVERGENCE
EXCEPT POSSIBLE ALONG THE SEA-BREEZE FRONT WHICH MAY MOVE WELL
INLAND. WE KEPT THE POPS LOW WHICH WAS SUPPORTED BY BOTH THE
NAM AND GFS MOS. THE TEMPERATURE GUIDANCE WAS CLOSE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF DISPLAY SOME WEAK SURFACE TROUGHING IN THE
FORECAST AREA DURING MUCH OF THE MEDIUM-RANGE PERIOD. SOME UPPER
TROUGHING APPEARS TO SHIFT FARTHER WEST EARLY IN THE PERIOD...BUT
GETS REESTABLISHED LATE IN THE PERIOD. THE PATTERN SUPPORTS A
CHANCE OF THUNDERSTORMS. THE GFS...ECMWF...AND EKD MOS HAVE POPS
OF 10 TO 30 PERCENT WITH MORE CONSISTENCY FOR HIGHER POPS MONDAY
THROUGH WEDNESDAY. THE MOS HAS TEMPERATURES NEAR CLIMATOLOGY
THROUGH THE PERIOD.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
IFR/MVFR FOG EXPECTED LATE TOWARD MORNING AT FOG PRONE
SITES...AGS/OGB.
WATER VAPOR INDICATING VERY DRY AIR ALOFT. MODELS INDICATE
SHALLOW LOW-LEVEL MOISTURE. WILL CONTINUE TO MENTION MVFR TEMPO
GROUP FOR FOG AT AGS/OGB 10Z THROUGH 13Z. HIGH PRESSURE WILL
PROMOTE MOSTLY SUNNY SKIES THROUGH THE AFTERNOON. ONLY A SLIGHT
CHANCE OF AFTERNOON CONVECTION AT AGS/DNL DUE TO HEATING AND
CONVERGENCE ALTHOUGH MOISTURE WILL BE LIMITED. LIGHT AND VARIABLE
WINDS EARLY THIS MORNING WILL PICK UP OUT OF THE NORTHEAST AT
AROUND 5 TO 10 KNOTS AFTER SUNRISE.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT RESTRICTIONS TO AVIATION
ARE EXPECTED AT THIS TIME.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
240 AM EDT THU AUG 13 2015
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND FROM THE OHIO VALLEY EASTWARD INTO THE
DELMARVA REGION THROUGH FRIDAY. A FRONTAL SYSTEM WILL BE NEAR THE
SOUTHEAST COAST. ASSOCIATED FRONTAL MOISTURE WILL REMAIN MAINLY
EAST OF THE FORECAST AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE RIDGE WILL CONTINUE NORTH OF THE FORECAST AREA THROUGH
TONIGHT. THE MODELS KEEP DEEP MOISTURE ASSOCIATED WITH THE FRONT
NEAR THE SOUTHEAST COAST EAST OF THE FORECAST AREA. HEATING AND
SOME LOW-LEVEL CONVERGENCE ASSOCIATED WITH THE SEA-BREEZE FRONT
AND WEAK TROUGH IN THE FORECAST AREA SHOWN BY THE NAM AND ECWMF COULD
HELP SUPPORT THUNDERSTORMS. THE NAM HAD MUCH MORE INSTABILITY
COMPARED TO THE GFS THIS AFTERNOON. BASED ON THE DRY WATER VAPOR
IMAGERY BELIEVE MID-LEVEL CAPPING MAY DOMINATE AND EXPECT LITTLE
THUNDERSTORM COVERAGE. THE HRRR AND SPC WRF DISPLAYED JUST
ISOLATED COVERAGE. WE MAINTAINED THE VERY LOW POPS WITH HIGHER
VALUES IN THE EAST PART BECAUSE OF CONVERGENCE NEAR THE SEA-BREEZE
FRONT...AND THE WEST PART WHERE EARLY MORNING SATELLITE INDICATED
GREATER MOISTURE AND THE HRRR DISPLAYED GREATER COVERAGE. LEANED
TOWARD THE HIGHER HIGH TEMPERATURE GUIDANCE BASED ON THE RECENT
BIAS. USED THE GUIDANCE CONSENSUS FOR THE LOW TEMPERATURE FORECAST.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
THE MODELS KEEP MOISTURE SHALLOW IN THE FORECAST AREA FRIDAY AND
FRIDAY NIGHT. DEEPER MOISTURE AND CONVERGENCE REMAIN OFF THE
COAST ALONG THE FRONT WITH HIGH PRESSURE RIDGING INTO THE FORECAST
AREA FROM THE NORTH. THERE SHOULD BE LITTLE LOW-LEVEL CONVERGENCE
EXCEPT POSSIBLE ALONG THE SEA-BREEZE FRONT WHICH MAY MOVE WELL
INLAND. WE KEPT THE POPS LOW WHICH WAS SUPPORTED BY BOTH THE
NAM AND GFS MOS. THE TEMPERATURE GUIDANCE WAS CLOSE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF DISPLAY SOME WEAK SURFACE TROUGHING IN THE
FORECAST AREA DURING MUCH OF THE MEDIUM-RANGE PERIOD. SOME UPPER
TROUGHING APPEARS TO SHIFT FARTHER WEST EARLY IN THE PERIOD...BUT
GETS REESTABLISHED LATE IN THE PERIOD. THE PATTERN SUPPORTS A
CHANCE OF THUNDERSTORMS. THE GFS...ECMWF...AND EKD MOS HAVE POPS
OF 10 TO 30 PERCENT WITH MORE CONSISTENCY FOR HIGHER POPS MONDAY
THROUGH WEDNESDAY. THE MOS HAS TEMPERATURES NEAR CLIMATOLOGY
THROUGH THE PERIOD.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS EXPECTED THROUGH 06Z. IFR/MVFR FOG EXPECTED LATE
TOWARD MORNING AT FOG PRONE SITES...AGS/OGB.
WATER VAPOR INDICATING VERY DRY AIR ALOFT. MODELS INDICATE
SHALLOW LOW-LEVEL MOISTURE. LATEST HRRR/LAMP GUIDANCE SUGGESTS
SOME POTENTIAL FOR FOG LATE TONIGHT...MAINLY AT AGS/OGB. THIS IS
SUPPORTED BY CLIMATOLOGY. WILL MENTION MVFR LATE WITH TEMPO IFR AT
AGS THROUGH 13Z AND A MVFR TEMPO GROUP AT OGB THROUGH 13Z. AIR
MASS OVER THE CAE TERMINAL AREA IS A LITTLE DRIER. FOG IS EXPECTED
TO DISSIPATE BY 13Z. DRY HIGH PRESSURE WILL PROMOTE MOSTLY SUNNY
SKIES THROUGH THE AFTERNOON. LIGHT AND VARIABLE WINDS EARLY THIS
MORNING WILL PICK UP OUT OF THE NORTHEAST AT AROUND 5 TO 10 KNOTS
AFTER SUNRISE.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT RESTRICTIONS TO AVIATION
ARE EXPECTED AT THIS TIME.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS LINCOLN IL
311 AM CDT THU AUG 13 2015
.SHORT TERM...(TODAY)
ISSUED AT 311 AM CDT THU AUG 13 2015
RIDGE OF HIGH PRESSURE EXTENDING FROM THE MID-ATLANTIC STATES TO THE
CENTRAL PLAINS IS PROVIDING CLEAR SKIES AND NEARLY CALM WINDS TO
CENTRAL ILLINOIS TONIGHT. 07Z/2AM SURFACE OBS ARE SHOWING DEWPOINT
DEPRESSIONS OF 0-3F IN MANY LOCATIONS...WHICH IS BEGINNING TO LEAD
TO PATCHY FOG. LATEST HRRR EVEN SUGGESTS A FEW SPOTS MAY SEE
VISIBILITIES REDUCED TO AROUND 1/4 MILE AT TIMES...HOWEVER IT DOES
NOT APPEAR THERE WILL BE WIDESPREAD DENSE FOG. GIVEN CURRENT TRENDS
AND CONSISTENT HRRR FORECAST...WILL INCLUDE PATCHY FOG DURING THE
EARLY MORNING HOURS. ONCE ANY FOG DISSIPATES...MOSTLY SUNNY
CONDITIONS WILL PREVAIL FOR THE BALANCE OF THE DAY. HIGH/THIN
CIRRUS BLOW OFF FROM CONVECTION ACROSS THE UPPER MIDWEST WILL STREAM
ACROSS THE SKY AND SCT DIURNAL CLOUDS WILL DEVELOP AS WELL...HOWEVER
OVERALL CONDITIONS WILL REMAIN MOSTLY SUNNY. AFTERNOON HIGH
TEMPERATURES WILL TOP OUT IN THE MIDDLE 80S.
&&
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 311 AM CDT THU AUG 13 2015
WEAK COLD FRONT CURRENTLY OVER NORTH DAKOTA/MINNESOTA WILL TRY TO
SETTLE SOUTHWARD INTO ILLINOIS OVER THE NEXT 24-48 HOURS...HOWEVER
IT WILL BE PUSHING DIRECTLY INTO A PERSISTENT RIDGE OF HIGH PRESSURE
AND WILL NEVER PASS THROUGH THE KILX CWA. MODELS HAVE BEEN SHOWING
THE BOUNDARY SAGGING INTO NORTHERN SECTIONS OF ILLINOIS AND INDIANA
FRIDAY NIGHT INTO SATURDAY THEN DISSIPATING COMPLETELY OVER THE
WEEKEND. DUE TO SYNOPTIC SUBSIDENCE AND A LACK OF DEEP-LAYER
MOISTURE...AREAL COVERAGE OF CONVECTION ALONG THE FRONT WILL BE
MINIMAL. WHILE MOST OF THIS ACTIVITY WILL REMAIN NORTH AND EAST OF
THE KILX CWA...ISOLATED THUNDERSTORMS COULD POTENTIALLY DEVELOP
ALONG/NORTH OF A BLOOMINGTON TO PARIS LINE FRIDAY NIGHT INTO
SATURDAY. DUE TO UNCERTAINTIES ABOUT THE EXACT SOUTHWARD POSITION
OF THE FRONT AND LACK OF MOISTURE...WILL MAINTAIN A DRY FORECAST
ACROSS THE BOARD AT THIS TIME.
MAIN WEATHER STORY THIS WEEKEND WILL BE THE INCREASING HEAT AND
HUMIDITY AS THE CENTRAL PLAINS UPPER RIDGE SHIFTS SOUTHEASTWARD.
AMPLE SUNSHINE AND RISING UPPER HEIGHTS WILL ALLOW HIGH TEMPERATURES
TO RISE INTO THE LOWER 90S BY SUNDAY. WHILE CONDITIONS APPEAR TO
REMAIN HOT AND DRY THIS WEEKEND...A POTENTIAL FLY-IN-THE-OINTMENT
WILL BE A WEAKNESS IN THE RIDGE AXIS SEEN PROMINENTLY ON THE ECMWF
AND TO A LESSER EXTENT ON THE GFS. THE ECMWF SHOWS THIS WEAKNESS
DEVELOPING OVER THE OHIO RIVER VALLEY ON SUNDAY...WHICH COULD
POTENTIALLY TRIGGER ISOLATED CONVECTION ACROSS THE E/SE CWA. GFS
KEEPS THE WEAKNESS FURTHER EAST AND MAINTAINS DRY WEATHER. WILL
STICK WITH A COMPLETELY DRY FORECAST FOR NOW...BUT WILL KEEP AN EYE
ON FUTURE MODEL RUNS TO SEE HOW THEY HANDLE THIS FEATURE.
THE NEXT SIGNIFICANT FRONTAL BOUNDARY IS STILL PROGGED TO ARRIVE BY
MONDAY AFTERNOON...WITH THE LATEST GFS NOW BRINGING THE BOUNDARY
FURTHER SOUTH INTO CENTRAL ILLINOIS...MUCH LIKE PREVIOUS RUNS OF THE
ECMWF/GEM HAD DONE. GIVEN GOOD MODEL CONSENSUS...CONFIDENCE IS
GROWING THAT SCATTERED THUNDERSTORMS WILL DEVELOP NORTH OF THE I-70
CORRIDOR MONDAY AFTERNOON...THEN CONTINUE EVERYWHERE MONDAY NIGHT
INTO TUESDAY AS THE FRONT STALLS. AFTER THAT...CONSIDERABLE
DISCREPANCIES DEVELOP AMONG THE 00Z AUG 13 MODELS CONCERNING THE
ARRIVAL OF A STRONGER SHORT-WAVE FOR THE MIDDLE OF NEXT WEEK.
ECMWF HAS SLOWED THE WAVE AND HAS THUS MAINTAINED THE EARLY WEEK
BAROCLINIC ZONE ACROSS THE AREA THROUGH WEDNESDAY. MEANWHILE...THE
GFS/GEM HAVE BOTH KEPT THEIR PREVIOUS SOLUTION OF BRINGING THE
WAVE IN QUICKER...THUS ALLOWING THE EARLY WEEK FRONT TO LIFT NORTH
OF THE AREA. WILL FOLLOW THE MORE CONSISTENT GFS/GEM
HERE...RESULTING IN WARM/DRY CONDITIONS TUESDAY NIGHT AND
WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1152 PM CDT WED AUG 12 2015
PREDOMINANTLY QUIET/VFR WEATHER CONDITIONS EXPECTED ACROSS THE
CENTRAL ILLINOIS TERMINALS THROUGH THE 06Z TAF VALID TIME.
HOWEVER, BASED ON ISOLATED OBSERVATIONS, AND SHORT RANGE MODEL
GUIDANCE, HAVE ADDED A TEMPO GROUP FOR MVFR FOG DURING THE
OVERNIGHT HOURS. GENERALLY LIGHT WINDS ARE EXPECTED THROUGH THE
PERIOD, AND THESE LIGHT WINDS SHOULD ALSO TEND TO KEEP ANY FOG
THAT DOES DEVELOP OVERNIGHT RATHER SHALLOW.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
242 AM MDT THU AUG 13 2015
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 212 AM MDT THU AUG 13 2015
ACROSS THE FORECAST AREA THIS MORNING...TEMPERATURES ARE MAINLY IN
THE 60S UNDER A MOSTLY/PARTLY CLOUDY SKIES MIX. OVERALL DECENT
MORNING DESPITE DEWPTS IN THE 60S AS WELL.
LOOKING AHEAD OVER THE NEXT 72-HR PERIOD...BROAD H5/H7 RIDGE STILL
REMAINS THE MAIN WX FEATURE FOR THE ENTIRE CWA...WHICH WILL PROVIDE
HOT CONDITIONS FOR THE AREA IN THE FORM OF ABOVE NORMAL
TEMPERATURES. 850 MB TEMPS TODAY THRU SATURDAY WILL RANGE FROM +28C
TO ALMOST +32C...FAIRLY CONSISTENT OVER PAST FEW MODEL RUNS. RIDGE
AXIS WILL BEGIN TO SHIFT EASTWARD OUT OVER THE PLAINS BY
SATURDAY...FURTHER AMPLIFYING ABOVE NORMAL CONDITIONS...WHICH WILL
TOP OF IN THE MID 90S FOR HIGHS FOR TODAY THRU SATURDAY. HEAT
INDICES WILL REMAIN BELOW 100 FOR ALL AREAS. OVERNIGHT LOWS NEAR THE
MID 60S.
DESPITE THE TRI STATE REGION SEEING HOT TEMPERATURES...SOME RELIEF
DURING THIS TIMEFRAME WILL COME IN THE FORM OF A COUPLE SHORTWAVES
THAT RIDE OVER TOP OF UPPER LEVEL RIDGE...SLIDING SE OUT ONTO THE
PLAINS REGION. FIRST SYSTEM ARRIVES TONIGHT LASTING INTO FRIDAY
MORNING...FOLLOWED BY ANOTHER SATURDAY NIGHT. MAIN THREAT WITH ANY
STORMS CONTINUE TO BE HEAVY RAINFALL AS PW VALUES REMAIN IN A 1.00"
TO 1.70" RANGE.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 242 AM MDT THU AUG 13 2015
AT THE BEGINNING OF THE EXTENDED PERIOD MODELS SHOW PRESSURE SYSTEM
LOCATED OVER CENTRAL CANADA... JUST NORTH OF MINNESOTA... WITH AN
ASSOCIATED FRONTAL BOUNDARY EXTENDING SOUTHWEST INTO THE PLAINS AND
OVER THE NORTHWEST PART OF OUR CWA. AS THE SYSTEM MOVES TOWARDS THE
EAST THE FRONT WILL STRETCH AND BECOME MOVE STATIONARY OVER THE TRI
STATE AREA. THIS WILL PRODUCE SHOWERS AND THUNDERSTORMS OVER THE TRI
STATE AREA THROUGH WEDNESDAY MORNING... WITH THE HEAVIEST
PRECIPITATION BEING ON SUNDAY NIGHT/MONDAY MORNING.
WEDNESDAY AFTERNOON THERE WILL BE A BRIEF PERIOD OF NO PRECIPITATION
AS HIGH PRESSURE OVER THE GREAT LAKES REGION AND DRIER AIR WILL
INFLUENCE THE AREA WITH STABLE AIR. HOWEVER, IT LOOKS LIKE A LOW
PRESSURE SYSTEM MAY DEVELOP OVER THE NORTHERN PLAINS AND BRING
PRECIPITATION BACK TO THE REGION ON THURSDAY AND BEYOND THE EXTENDED.
SO WE WILL HAVE TO WAIT FOR THE NEXT FEW MODEL RUNS TO SEE IS INDEED
THIS NEW SYSTEM DEVELOPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1121 PM MDT WED AUG 12 2015
VFR CONDITIONS WILL CONTINUE TONIGHT AND THURSDAY AT KGLD AND
KMCK. NAM BOUNDARY LAYER RH INCREASES OVER EASTERN COLORADO LATER
TONIGHT AND COULD POSSIBLY DRIFT EAST ENOUGH TO AFFECT KGLD WITH
MVFR CIGS. THE HRRR KEEPS IT OUTSIDE OF THE AREA SO WILL NOT
MENTION IN THE KGLD TAF BUT WILL NEED TO MONITOR. LATER THURSDAY
EVENING THERE IS A SLIGHT CHANCE OF THUNDERSTORMS AS A SHORTWAVE
COMES OVER THE RIDGE SO WILL INTRODUCE VICINITY STORMS AT BOTH SITES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JN
LONG TERM...BW
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
212 AM MDT THU AUG 13 2015
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 212 AM MDT THU AUG 13 2015
ACROSS THE FORECAST AREA THIS MORNING...TEMPERATURES ARE MAINLY IN
THE 60S UNDER A MOSTLY/PARTLY CLOUDY SKIES MIX. OVERALL DECENT
MORNING DESPITE DEWPTS IN THE 60S AS WELL.
LOOKING AHEAD OVER THE NEXT 72-HR PERIOD...BROAD H5/H7 RIDGE STILL
REMAINS THE MAIN WX FEATURE FOR THE ENTIRE CWA...WHICH WILL PROVIDE
HOT CONDITIONS FOR THE AREA IN THE FORM OF ABOVE NORMAL
TEMPERATURES. 850 MB TEMPS TODAY THRU SATURDAY WILL RANGE FROM +28C
TO ALMOST +32C...FAIRLY CONSISTENT OVER PAST FEW MODEL RUNS. RIDGE
AXIS WILL BEGIN TO SHIFT EASTWARD OUT OVER THE PLAINS BY
SATURDAY...FURTHER AMPLIFYING ABOVE NORMAL CONDITIONS...WHICH WILL
TOP OF IN THE MID 90S FOR HIGHS FOR TODAY THRU SATURDAY. HEAT
INDICES WILL REMAIN BELOW 100 FOR ALL AREAS. OVERNIGHT LOWS NEAR THE
MID 60S.
DESPITE THE TRI STATE REGION SEEING HOT TEMPERATURES...SOME RELIEF
DURING THIS TIMEFRAME WILL COME IN THE FORM OF A COUPLE SHORTWAVES
THAT RIDE OVER TOP OF UPPER LEVEL RIDGE...SLIDING SE OUT ONTO THE
PLAINS REGION. FIRST SYSTEM ARRIVES TONIGHT LASTING INTO FRIDAY
MORNING...FOLLOWED BY ANOTHER SATURDAY NIGHT. MAIN THREAT WITH ANY
STORMS CONTINUE TO BE HEAVY RAINFALL AS PW VALUES REMAIN IN A 1.00"
TO 1.70" RANGE.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 200 PM MDT WED AUG 12 2015
THURSDAY NIGHT-SATURDAY...UPPER LEVEL RIDGE AXIS (AROUND 597DM)
CENTERED OVER THE NEW MEXICO BORDER/TEXAS BORDER THIS AFTERNOON
(WEDNESDAY) IS FORECAST TO DRIFT TOWARD THE WEST INTO NORTH
CENTRAL NEW MEXICO/SOUTH CENTRAL COLORADO BY THURSDAY NIGHT THEN
WEST/SOUTHWEST INTO EAST CENTRAL ARIZONA BY 12Z SATURDAY REMAINING
STATIONARY THROUGH THE DAY.
FOLLOWING THE 700-500MB MOISTURE REVEALS A WEATHER DISTURBANCE
MOVING THROUGH EARLY THURSDAY NIGHT WITH DRIER AIR MOVING IN FROM
THE NORTH. THIS WOULD SUGGEST A DECREASING CHANCE OF PRECIPITATION
FROM NORTH TO SOUTH. QUITE A BIT OF DRY AIR OVER THE AREA FRIDAY
AFTERNOON THROUGH THE OVERNIGHT WITH SLIGHTLY BETTER CHANCES JUST
WEST AND OUTSIDE OF THE FORECAST AREA. FOR SATURDAY PRECIPITATION
CHANCES INCREASE A BIT ACROSS THE WESTERN 1/2 TO 1/3 OF THE AREA AS
THE MOISTURE ALONG THE FRONT RANGE SLOWLY SHIFTS EAST A BIT.
LOW TEMPERATURES THURSDAY NIGHT IN THE LOW TO MID 60S WITH HIGH
TEMPERATURES FRIDAY IN THE UPPER 80S TO LOW 90S IN FAR EASTERN
COLORADO...LOW TO MID 90S EAST OF THE CO/KS BORDER. FOR FRIDAY NIGHT
LOWS IN THE MID TO UPPER 60S WITH HIGH TEMPERATURES SATURDAY IN THE
LOW TO MID 90S.
SATURDAY NIGHT-SUNDAY NIGHT...SOME MID AND HIGH CLOUDINESS SPREAD
EAST ACROSS THE AREA DURING THE NIGHT INCREASING A BIT DURING THE
DAY. GFS AND ECWMF IN FAIR AGREEMENT BRINGING A COLD FRONT THROUGH
THE NORTHWEST HALF OF THE AREA DURING THE DAY WITH INCREASING
INSTABILITY ALONG IT. PRECIPITABLE WATER AROUND/JUST OVER 1.5 INCHES
SO SOME LOCALLY HEAVY RAINFALL POSSIBLE. CURRENT PRECIPITATION
FORECAST LOOKS PRETTY GOOD. FRONT APPEARS TO GET HUNG UP OVER THE
AREA SUNDAY NIGHT WITH PLENTIFUL MOISTURE AVAILABLE. WILL CONTINUE
TO MID CHANCE POPS FOR NOW. LOW TEMPERATURES IN THE LOW TO UPPER
60S. HIGH TEMPERATURES IN THE MID 80S TO LOW 90S WEST...LOW 90S EAST
OF THE CO/KS BORDER.
MONDAY-MONDAY NIGHT...DRIER AIR ALOFT SLOWLY MOVES IN FROM THE
NORTHWEST DURING THE DAY SUGGESTING A DECREASE IN PRECIPITATION
POTENTIAL FROM NORTHWEST TO SOUTHEAST. SHOULD BE GENERALLY PRECIP
FREE MONDAY NIGHT AS DRIER AIR ALOFT CONTINUES TO MOVE IN FROM THE
NORTHWEST. HIGH TEMPERATURES RANGE FROM THE LOW TO MID 80S IN
COLORADO WITH MID 80S TO AROUND 90 ELSEWHERE. LOWS IN THE LOW TO MID
60S.
TUESDAY-TUESDAY NIGHT...MAY SEE A SLIGHT CHANCE FOR THUNDERSTORMS IN
THE AFTERNOON ALONG AND WEST OF THE CO/KS BORDER WHERE GFS/ECMWF
BRING AN INCREASE IN MID LEVEL MOISTURE FROM THE NORTHWEST AHEAD OF
AN APPROACHING UPPER TROUGH. BETTER MID LEVEL MOISTURE SCOOTS ACROSS
THE NORTHERN 1/3 OR SO OF THE AREA EARLY TUESDAY NIGHT BEFORE
EXITING THE AREA BY 12Z WEDNESDAY AS COLD FRONT MOVES THROUGH THE
WESTERN 1/2 OF THE AREA. HIGH TEMPERATURES IN THE MID 80S TO AROUND
90 WITH LOWS IN THE UPPER 50S TO MID 60S.
WEDNESDAY...UPPER TROUGH AXIS MOVES ACROSS THE AREA DURING THE DAY
BRINGING PERHAPS SOME GUSTY NORTHWEST WINDS TO SOME. MODELS VARY ON
MOISTURE AVAILABILITY AND THUS PRECIPITATION CHANCES. HIGHS IN THE
LOW TO UPPER 80S (WEST TO EAST) WITH LOWS IN THE MID 50S TO LOW 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1121 PM MDT WED AUG 12 2015
VFR CONDITIONS WILL CONTINUE TONIGHT AND THURSDAY AT KGLD AND
KMCK. NAM BOUNDARY LAYER RH INCREASES OVER EASTERN COLORADO LATER
TONIGHT AND COULD POSSIBLY DRIFT EAST ENOUGH TO AFFECT KGLD WITH
MVFR CIGS. THE HRRR KEEPS IT OUTSIDE OF THE AREA SO WILL NOT
MENTION IN THE KGLD TAF BUT WILL NEED TO MONITOR. LATER THURSDAY
EVENING THERE IS A SLIGHT CHANCE OF THUNDERSTORMS AS A SHORTWAVE
COMES OVER THE RIDGE SO WILL INTRODUCE VICINITY STORMS AT BOTH SITES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JN
LONG TERM...99
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1130 PM MDT WED AUG 12 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 1227 PM MDT WED AUG 12 2015
FORECAST FOCUS IS ON THE POSSIBILITY OF ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING AND SPREADING ACROSS THE FORECAST AREA
LATE THURSDAY AFTERNOON THROUGH THURSDAY EVENING.
CONDITIONS ARE EXPECTED TO REMAIN DRY THROUGH THE REMAINDER OF
TODAY THROUGH MID DAY THURSDAY WITH THE APEX OF THE UPPER RIDGE
SQUARELY IN POSITION OVER THE FORECAST AREA. ISOLATED
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG AND EAST OF A SURFACE
TROUGH THAT WILL BE ADVANCING EASTWARD ACROSS THE FORECAST AREA
DURING THE DAY ON THURSDAY. A SHORT WAVE TROUGH ALOFT TOPS THE
RIDGE EXTENDING NORTH ALONG THE ROCKIES FROM A HIGH PRESSURE AREA
CENTERED OVER NEW MEXICO. THIS SHORT WAVE TROUGH WILL MOVE THROUGH
THE DAKOTAS WITH THE SOUTHERN EXTENT OF THE TROUGH CLIPPING THE
TRI-STATE REGION BY LATE AFTERNOON/EARLY EVENING. EXPECT ISOLATED
STORMS LATE IN THE AFTERNOON TO BECOME SCATTERED DURING THURSDAY
EVENING.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 200 PM MDT WED AUG 12 2015
THURSDAY NIGHT-SATURDAY...UPPER LEVEL RIDGE AXIS (AROUND 597DM)
CENTERED OVER THE NEW MEXICO BORDER/TEXAS BORDER THIS AFTERNOON
(WEDNESDAY) IS FORECAST TO DRIFT TOWARD THE WEST INTO NORTH
CENTRAL NEW MEXICO/SOUTH CENTRAL COLORADO BY THURSDAY NIGHT THEN
WEST/SOUTHWEST INTO EAST CENTRAL ARIZONA BY 12Z SATURDAY REMAINING
STATIONARY THROUGH THE DAY.
FOLLOWING THE 700-500MB MOISTURE REVEALS A WEATHER DISTURBANCE
MOVING THROUGH EARLY THURSDAY NIGHT WITH DRIER AIR MOVING IN FROM
THE NORTH. THIS WOULD SUGGEST A DECREASING CHANCE OF PRECIPITATION
FROM NORTH TO SOUTH. QUITE A BIT OF DRY AIR OVER THE AREA FRIDAY
AFTERNOON THROUGH THE OVERNIGHT WITH SLIGHTLY BETTER CHANCES JUST
WEST AND OUTSIDE OF THE FORECAST AREA. FOR SATURDAY PRECIPITATION
CHANCES INCREASE A BIT ACROSS THE WESTERN 1/2 TO 1/3 OF THE AREA AS
THE MOISTURE ALONG THE FRONT RANGE SLOWLY SHIFTS EAST A BIT.
LOW TEMPERATURES THURSDAY NIGHT IN THE LOW TO MID 60S WITH HIGH
TEMPERATURES FRIDAY IN THE UPPER 80S TO LOW 90S IN FAR EASTERN
COLORADO...LOW TO MID 90S EAST OF THE CO/KS BORDER. FOR FRIDAY NIGHT
LOWS IN THE MID TO UPPER 60S WITH HIGH TEMPERATURES SATURDAY IN THE
LOW TO MID 90S.
SATURDAY NIGHT-SUNDAY NIGHT...SOME MID AND HIGH CLOUDINESS SPREAD
EAST ACROSS THE AREA DURING THE NIGHT INCREASING A BIT DURING THE
DAY. GFS AND ECWMF IN FAIR AGREEMENT BRINGING A COLD FRONT THROUGH
THE NORTHWEST HALF OF THE AREA DURING THE DAY WITH INCREASING
INSTABILITY ALONG IT. PRECIPITABLE WATER AROUND/JUST OVER 1.5 INCHES
SO SOME LOCALLY HEAVY RAINFALL POSSIBLE. CURRENT PRECIPITATION
FORECAST LOOKS PRETTY GOOD. FRONT APPEARS TO GET HUNG UP OVER THE
AREA SUNDAY NIGHT WITH PLENTIFUL MOISTURE AVAILABLE. WILL CONTINUE
TO MID CHANCE POPS FOR NOW. LOW TEMPERATURES IN THE LOW TO UPPER
60S. HIGH TEMPERATURES IN THE MID 80S TO LOW 90S WEST...LOW 90S EAST
OF THE CO/KS BORDER.
MONDAY-MONDAY NIGHT...DRIER AIR ALOFT SLOWLY MOVES IN FROM THE
NORTHWEST DURING THE DAY SUGGESTING A DECREASE IN PRECIPITATION
POTENTIAL FROM NORTHWEST TO SOUTHEAST. SHOULD BE GENERALLY PRECIP
FREE MONDAY NIGHT AS DRIER AIR ALOFT CONTINUES TO MOVE IN FROM THE
NORTHWEST. HIGH TEMPERATURES RANGE FROM THE LOW TO MID 80S IN
COLORADO WITH MID 80S TO AROUND 90 ELSEWHERE. LOWS IN THE LOW TO MID
60S.
TUESDAY-TUESDAY NIGHT...MAY SEE A SLIGHT CHANCE FOR THUNDERSTORMS IN
THE AFTERNOON ALONG AND WEST OF THE CO/KS BORDER WHERE GFS/ECMWF
BRING AN INCREASE IN MID LEVEL MOISTURE FROM THE NORTHWEST AHEAD OF
AN APPROACHING UPPER TROUGH. BETTER MID LEVEL MOISTURE SCOOTS ACROSS
THE NORTHERN 1/3 OR SO OF THE AREA EARLY TUESDAY NIGHT BEFORE
EXITING THE AREA BY 12Z WEDNESDAY AS COLD FRONT MOVES THROUGH THE
WESTERN 1/2 OF THE AREA. HIGH TEMPERATURES IN THE MID 80S TO AROUND
90 WITH LOWS IN THE UPPER 50S TO MID 60S.
WEDNESDAY...UPPER TROUGH AXIS MOVES ACROSS THE AREA DURING THE DAY
BRINGING PERHAPS SOME GUSTY NORTHWEST WINDS TO SOME. MODELS VARY ON
MOISTURE AVAILABILITY AND THUS PRECIPITATION CHANCES. HIGHS IN THE
LOW TO UPPER 80S (WEST TO EAST) WITH LOWS IN THE MID 50S TO LOW 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1121 PM MDT WED AUG 12 2015
VFR CONDITIONS WILL CONTINUE TONIGHT AND THURSDAY AT KGLD AND
KMCK. NAM BOUNDARY LAYER RH INCREASES OVER EASTERN COLORADO LATER
TONIGHT AND COULD POSSIBLY DRIFT EAST ENOUGH TO AFFECT KGLD WITH
MVFR CIGS. THE HRRR KEEPS IT OUTSIDE OF THE AREA SO WILL NOT
MENTION IN THE KGLD TAF BUT WILL NEED TO MONITOR. LATER THURSDAY
EVENING THERE IS A SLIGHT CHANCE OF THUNDERSTORMS AS A SHORTWAVE
COMES OVER THE RIDGE SO WILL INTRODUCE VICINITY STORMS AT BOTH SITES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...LOCKHART
LONG TERM...99
AVIATION...FS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1202 AM CDT THU AUG 13 2015
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 948 PM CDT WED AUG 12 2015
WV Imagery and 00Z upper air analysis indicate an upper level area
of high pressure centered across the South Plains of west Texas
and eastern New Mexico. Near the surface, a lee side trough of low
pressure remains anchored across extreme eastern Colorado.
&&
.SHORT TERM...(THIS EVENING THROUGH Thursday)
ISSUED AT 250 PM CDT WED AUG 12 2015
Temperatures for later this afternoon were necessarily trimmed again
by the HRRR due to widespread cloudiness, rain and cooled air near
the moist upslope convergence zone region between roughly highway 183
and 83. Although the areal coverage has been dramatically reduced
this afternoon, isolated showers could occur easily still occur
through tonight. The convective allowing models as a whole are far
less supportive of additional shower and thunderstorms development
heading into Thursday, perhaps partially owing to less of a
convergence zone with as surface winds turn southerly. With a lack
of widespread precipitation and/or cloudiness, the opportunity for
much warmer raw model forecast temperatures reaching into the 90s
is likely, which will be the case over the next several days.
.LONG TERM...(Thursday NIGHT THROUGH Wednesday)
ISSUED AT 250 PM CDT WED AUG 12 2015
The best chances for precipitation will be a very slight chance for
most of the area, with a best chance in west central Kansas around
Sunday night, when models forecast shortwave energy across the
northern high plains. It is possible the entire area remains dry
during this time. A better opportunity arrives by mid week ,and
could last several days as a baroclinic zone impacts the region
with a breakdown of the upper ridge.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Thursday NIGHT)
ISSUED AT 1200 AM CDT THU AUG 13 2015
A corridor of increased low level moisture combined with light
southeasterly upslope winds may result in the development of low
level stratus across southwest Kansas in the vicinity of KGCK
generally after 09Z this morning. As a result, MVFR cigs/vsbys will
be possible in the vicinity of KGCK with the potential for MVFR
conditions spreading eastward toward KDDC and possibly KHYS around
sunrise. Light southeasterly winds will persist through daybreak
this morning as a lee side trough of low pressure remains anchored
across eastern Colorado. South to southeasterly winds are expected
to increase to around 10 to 20kt late this morning into Thursday
afternoon as the lee side trough strengthens somewhat.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 91 67 91 / 20 20 10 10
GCK 66 91 66 91 / 20 20 0 0
EHA 66 91 67 91 / 10 10 10 10
LBL 67 92 68 91 / 10 10 10 0
HYS 67 92 68 92 / 20 20 10 0
P28 69 91 68 91 / 10 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...JJohnson
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
501 AM EDT THU AUG 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 212 AM EDT THU AUG 13 2015
HEALTHY SHORTWAVE DIGGING SE WITH 850MB THETA-E ADVECTION EARLY WILL
HELP SUPPORT ONGOING CONVECTION MOVING IN FROM THE ARROWHEAD OF MN
AND CANADA EARLY THIS MORNING. LOOK FOR SHOWERS/THUNDERSTORMS TO
CLIP THE W CWA BEFORE DIMINISHING THROUGH THE DAY TODAY. THE 21/00Z
NAM AND 21/03Z HRRR SEEM TO HAVE A PRETTY GOOD HANDLE ON WHAT WOULD
BE A MORE LIKELY SCENARIO...WITH THE GFS AND CANADIAN BRINGING THE
BULK OF PRECIP OVER THE KEWEENAW AND LAKE SUPERIOR THROUGH THE
MORNING HOURS. WILL NEED TO MONITOR THE TRENDS EARLY THIS MORNING.
EXPECT SHOWERS AND A FEW THUNDERSTORMS TO REMAIN POSSIBLE SE THIS
AFTERNOON...AWAY FROM THE LAKE SUPERIOR STABILIZATION. DESPITE THE
ONSHORE FLOW N CENTRAL AND E...THERE WILL BE LITTLE RELIEF FROM THE
HEAT. EXPECT A VERY WARM DAY TODAY...CLOSE TO THE RECORD AT NWS MQT
WHICH IS 89 SET BACK IN 1970. MID TO UPPER 80S WILL BE COMMON FOR
ALL BUT THE TIP OF THE KEWEENAW PENINSULA...AND E OF A LINE FROM
MUNISING TO RAPID RIVER...EVEN WITH THE POTENTIAL FOR SHOWERS IN THE
AREA. PW VALUES MAXING OUT AROUND 1.6IN W TO E TODAY WILL FALL TO
AROUND 1-1.2IN CWA WIDE BY 06Z. WITH THE MAIN SFC TROUGH SET UP OVER
THE W HALF OF LAKE SUPERIOR AND WARM AIR FULLY ENTRENCHED OVER THE
CWA...LOWS IN THE 60S LOOK TO BE A GOOD BET...WITH ADDITIONAL
SHOWERS AND THUNDERSTORMS NEARING FROM THE NW.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 501 AM EDT THU AUG 13 2015
OVER THE NEXT 7 DAYS...RIDGE OVER THE ROCKIES WILL FADE AWAY AS TWO
FAIRLY ENERGETIC SHORTWAVES SWING THRU WRN NAMERICA. THE FIRST
MOVING ACROSS SW CANADA/PACIFIC NW/NRN ROCKIES FRI/SAT WILL AFFECT
THE UPPER LAKES SUN/MON. THE SECOND WILL DIVE FARTHER S INTO THE
ROCKIES TUE/WED AND THEN LIFT NE TO THE UPPER LAKES/NRN
ONTARIO/HUDSON BAY VCNTY BY FRI. WITH THE WEAKENING OF THE WRN
RIDGE...THE CURRENT ERN CONUS TROF WILL FILL AND BE REPLACED BY
ABOVE NORMAL HEIGHTS. THESE LARGE SCALE CHANGES WILL RESULT IN
WARM/HUMID CONDITIONS PREVAILING THRU THE WEEKEND...THEN A FALL BACK
TO SLIGHTLY BLO NORMAL CONDITIONS EARLY NEXT WEEK BEHIND THE FIRST
SHORTWAVE MENTIONED ABOVE. THE PEAK OF THE HEAT/HUMIDITY SHOULD
OCCUR SUN AHEAD OF THAT WAVE. AFTER THE COOL DOWN EARLY IN THE
WEEK...TEMPS SHOULD RETURN TO AROUND NORMAL. AS FOR PCPN...SCT
SHRA/TSTM POTENTIAL WILL CONTINUE THRU FRI...THEN DRY WEATHER WILL
RETURN SAT AS THE NRN PORTION OF THE WRN RIDGE IS FORCED EASTWARD BY
THE SHORTWAVE TROF SWINGING THRU THE NRN ROCKIES. THAT SHORTWAVE
WILL BRING A RISK OF PCPN SUN/MON...THOUGH WITH THE MAIN ENERGY
LIFTING ENE...PCPN COVERAGE WILL PROBABLY BE LIMITED. MODEL
AGREEMENT HAS IMPROVED SOME FOR THE MIDDLE AND END OF NEXT WEEK. IT
APPEARS THERE WILL BE THE POTENTIAL FOR HVY RAINFALL AND PERHAPS
STRONG TO SVR STORMS AT SOME POINT WED/THU IN ASSOCIATION WITH THE
SECOND WAVE LIFTING OUT OF THE W AND ITS ASSOCIATED FAIRLY VIGOROUS
SFC LOW FOR AUG.
BEGINNING FRI...COLD FRONT WILL DROP S ACROSS UPPER MI IN
ASSOCIATION WITH SHORTWAVE MOVING ACROSS THE UPPER LAKES. MAY SEE A
FEW SHRA/TSTMS IN THE MORNING WITH THE FRONT...BUT ACROSS THE
S...FRONTAL PASSAGE WILL BEGIN TO BETTER COINCIDE WITH THE DIURNAL
HEATING CYCLE/INSTABILITY BUILD UP. WITH MLCAPES REACHING AT LEAST
1000-1500J/KG...AND ENHANCED CONVERGENCE DUE TO LAKE BREEZE...TSTMS
SHOULD INCREASE EARLY IN THE AFTN. TIMING OF THE FRONT WILL BE
CRITICAL. IF FRONT PASSES EARLY IN THE AFTN OVER THE S...TSTM
POTENTIAL WILL BE LESS THAN IF THE FRONT PASSES IN THE LATE AFTN.
WITH DEEP LAYER SHEAR AROUND 25KT...SOME STRONG STORMS WILL BE
POSSIBLE AND PERHAPS AN ISOLD SVR STORM IF FROPA IS LATER IN THE
AFTN. IT WILL BE A WARM/HUMID DAY WITH HIGHS MOSTLY IN THE 80S.
LIGHT WINDS OFF LAKE SUPERIOR WILL LEAD TO COOLER CONDITIONS N...BUT
ONLY SLIGHTLY.
DRY WEATHER WILL SET IN FOR FRI NIGHT/SAT UNDER RISING HEIGHTS WITH
MID/UPPER RIDGE BUILDING NE INTO THE UPPER LAKES. SAT WILL BE A
WARM/HUMID DAY WITH HIGH TEMPS IN THE 80S UNDER MOSTLY SUNNY SKIES.
SHORTWAVE TROF MOVING ACROSS THE NRN ROCKIES SAT WILL LIFT ENE INTO
NRN ONTARIO SUN. ASSOCIATED COLD FRONT WILL LIKELY REACH WRN UPPER
MI LATE IN THE AFTN AS GFS WHICH HAD BEEN FASTEST WITH THE FRONT HAS
SLOWED TO BE MORE INLINE WITH THE GEM/ECMWF. WITH BEST HEIGHT
FALLS/DEEP LAYER FORCING PASSING TO THE N...CONVECTION ALONG/AHEAD
OF FRONT AS IT PASSES PROBABLY WON`T BE MORE THAN ISOLD TO SCT.
HOWEVER...AS UPPER JET TRANSLATES E AND BETTER POSITIONS RIGHT
ENTRANCE UPPER DIVERGENCE OVERTOP FRONT SUN NIGHT...EXPECT CHC OF
SHRA/TSTMS TO INCREASE SUN NIGHT. WITH FRONT NOT ARRIVING UNTIL LATE
IN THE DAY...SUN WILL BE A VERY WARM...HUMID DAY AS 850MB THERMAL
RIDGE WITH 850MB TEMPS OF AT LEAST 20C SHIFTS ACROSS THE AREA IN
ADVANCE OF COLD FRONT. EXPECT MAX TEMPS INTO THE UPPER 80S OVER MUCH
OF THE AREA...AND LIKELY REACHING 90F AT SOME LOCATIONS. FAIRLY
TIGHT PRES GRADIENT WILL ALSO LEAD TO GUSTIER WINDS...PROBABLY 20-
25MPH TO PERHAPS 30MPH AT TIMES.
HEALTHY COOLING (AND LOWERING OF DWPTS) WILL FOLLOW THE FRONT FOR
MON AS 850MB TEMPS FALL BACK TO 6 TO 10C. MAX TEMPS SHOULD BE IN THE
UPPER 60S W AND N NEAR LAKE SUPERIOR TO MID 70S SCTNRL/SE. UPPER
DIVERGENCE UNDER RIGHT ENTRANCE OF UPPER JET EXTENDING FROM THE
UPPER LAKES TO NRN/CNTRL QUEBEC MAY HELP SHRA/TSTMS LINGER INTO MON
MORNING OVER THE SCNTRL AND E EVEN THOUGH SFC FRONT SHOULD BE JUST S
AND E OF THAT AREA AT 12Z MON.
DRY WEATHER WILL THEN BE THE RULE MON AFTN INTO TUE AS SFC HIGH PRES
MOVES ACROSS THE UPPER LAKES. WITH SFC HIGH PRES OVER THE AREA AND
PRECIPITABLE WATER UNDER 0.5 INCHES...TEMPS MON NIGHT WILL LIKELY
FALL INTO THE 40S IN THE INTERIOR WITH TRADITIONAL COLD SPOTS
POSSIBLY DOWN INTO THE LWR 40S.
VIGOROUS SHORTWAVE MOVING FROM THE CNTRL ROCKIES AND ACROSS THE
UPPER GREAT LAKES DURING THE MID AND LATE WEEK WILL BRING THE
POTENTIAL FOR ROUNDS OF SHRA/TSTMS AND POSSIBLE HVY RAINFALL.
INITIALLY...STRENGTHENING WAA/MOISTURE ADVECTION IN ADVANCE OF WAVE
WILL SUPPORT SHRA/TSTMS SPREADING INTO UPPER MI WED/WED NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 101 AM EDT THU AUG 13 2015
STEADY SW WINDS ABOVE THE SFC JUST UNDER LLWS CRITERIA WL DRAW MORE
HUMID AIR INTO THE UPR LKS AHEAD OF A SLOWLY APRCHG COLD FNT AND
SUPPORT SOME SHOWERS/PERHAPS A TS AT THE TAF SITES BY 09Z THRU THIS
AFTN...WHEN THE STABILIZING INFLUENCE OF LK SUP WL DIMINISH THE PCPN
CHCS. CONFIDENCE IN THE OCCURRENCE OF THESE SHOWERS AT THE SITES IS
NOT HI ENUF TO VARY FM THE VCSH SHOWN IN THE PREVIOUS TAFS EXCEPT AT
IWD...WHERE RECENT RADAR TRENDS WARRANT AN EXPLICIT MENTION OF TS IN
THE 09-11Z TIME. ALTHOUGH A HEAVIER SHRA COULD BRING AT LEAST TEMPO
MVFR CONDITIONS...THE WARMTH/RELATIVE DRYNESS OF THE LLVLS WL
SUPPORT PREDOMINANT VFR CONDITIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 212 AM EDT THU AUG 13 2015
FOG WILL BE POSSIBLE TODAY THROUGH FRIDAY MORNING OVER MAINLY NE AND
E LAKE SUPERIOR...CLOSER TO THE COLDEST WATER AS WARM HUMID AIR
SHIFTS OVERHEAD. WINDS SHOULD BE LESS THAN 30KTS THROUGH THE
PERIOD...WITH GUSTS NEARING 30KTS OVER A FEW OF THE HIGHER PLATFORMS
OVER W LAKE SUPERIOR INITIALLY THIS MORNING OUT OF THE SW...AND
AGAIN SATURDAY NIGHT INTO SUNDAY.
EXPECT THE HIGH OVER THE OH RIVER VALLEY TO DRIFT OFF THE EAST COAST
THROUGH FRIDAY. A TROUGH MOVING THROUGH NW ONTARIO AND MN THIS
MORNING WILL SWEEP SE ACROSS LAKE SUPERIOR THIS AFTERNOON. IN ITS
WAKE...HIGH PRESSURE WILL BUILD INTO THE UPPER GREAT LAKES ON
FRIDAY. AS THIS HIGH DRIFTS SE INTO THE MID ATLANTIC STATES OVER THE
WEEKEND...A LOW WILL MOVE E FROM S SASKATCHEWAN ACROSS NW ONTARIO
AND TO NEAR JAMES BAY LATE ON SUNDAY. THIS LOW WILL CONTINUE E INTO
QUEBEC ON MONDAY...AND DRAG A COLD FRONT ACROSS THE UPPER LAKES ON
SUNDAY NIGHT. BEHIND THIS FRONT...LOOK FOR A HIGH TO MOVE INTO
MINNESOTA ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...ROLFSON
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
212 AM EDT THU AUG 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 212 AM EDT THU AUG 13 2015
HEALTHY SHORTWAVE DIGGING SE WITH 850MB THETA-E ADVECTION EARLY WILL
HELP SUPPORT ONGOING CONVECTION MOVING IN FROM THE ARROWHEAD OF MN
AND CANADA EARLY THIS MORNING. LOOK FOR SHOWERS/THUNDERSTORMS TO
CLIP THE W CWA BEFORE DIMINISHING THROUGH THE DAY TODAY. THE 21/00Z
NAM AND 21/03Z HRRR SEEM TO HAVE A PRETTY GOOD HANDLE ON WHAT WOULD
BE A MORE LIKELY SCENARIO...WITH THE GFS AND CANADIAN BRINGING THE
BULK OF PRECIP OVER THE KEWEENAW AND LAKE SUPERIOR THROUGH THE
MORNING HOURS. WILL NEED TO MONITOR THE TRENDS EARLY THIS MORNING.
EXPECT SHOWERS AND A FEW THUNDERSTORMS TO REMAIN POSSIBLE SE THIS
AFTERNOON...AWAY FROM THE LAKE SUPERIOR STABILIZATION. DESPITE THE
ONSHORE FLOW N CENTRAL AND E...THERE WILL BE LITTLE RELIEF FROM THE
HEAT. EXPECT A VERY WARM DAY TODAY...CLOSE TO THE RECORD AT NWS MQT
WHICH IS 89 SET BACK IN 1970. MID TO UPPER 80S WILL BE COMMON FOR
ALL BUT THE TIP OF THE KEWEENAW PENINSULA...AND E OF A LINE FROM
MUNISING TO RAPID RIVER...EVEN WITH THE POTENTIAL FOR SHOWERS IN THE
AREA. PW VALUES MAXING OUT AROUND 1.6IN W TO E TODAY WILL FALL TO
AROUND 1-1.2IN CWA WIDE BY 06Z. WITH THE MAIN SFC TROUGH SET UP OVER
THE W HALF OF LAKE SUPERIOR AND WARM AIR FULLY ENTRENCHED OVER THE
CWA...LOWS IN THE 60S LOOK TO BE A GOOD BET...WITH ADDITIONAL
SHOWERS AND THUNDERSTORMS NEARING FROM THE NW.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 248 PM EDT WED AUG 12 2015
A COUPLE OF TROUGHS/COLD FRONTS WILL MOVE THROUGH THE CWA IN NW FLOW
ALOFT...ONE WILL BE MOVING OUT EARLY THU NIGHT AND THE OTHER WILL
MOVE THROUGH LATE THU NIGHT INTO FRI. CONVECTION WITH THE FIRST
TROUGH/FRONT WILL BE DIMINISHING EARLY THU NIGHT. COVERAGE LATE THU
NIGHT INTO FRI WILL DEPEND ON TIMING/INSTABILITY...BUT ISOLATED-
SCATTERED COVERAGE SEEMS REASONABLE. WHILE THU SHOULD SEE HIGHS IN
THE 80S TO AROUND 90...FRI WILL BE A BIT COOLER WITH HIGHS IN THE
80S.
HIGHS TEMPS SAT WILL BE SIMILAR TO SUN OVERALL. AN UPPER RIDGE WILL
BUILD OVER THE AREA SAT...MAKING FOR DRY CONDITIONS SAT AND SAT
NIGHT.
SUN INTO MON WILL SEE INCREASED PRECIP CHANCES AS A SFC LOW MOVES
ACROSS ONTARIO...DRAGGING A COLD FRONT ACROSS THE AREA. TIMING IS
FAIRLY WELL AGREED ON BY CURRENT MODEL RUNS...BUT RUN TO RUN
VARIATIONS ARE REDUCING CONFIDENCE IN TIMING. TIMING WILL DETERMINE
SFC TEMPS AND PRECIP COVERAGE/INSTABILITY. IF THE FRONT IS
SLOWER...ANOTHER VERY WARM AND MUGGY DAY WILL RESULT ON SUN AS 850MB
TEMPS LOOK TO BE AOA 20C. SHOWER AND THUNDERSTORM COVERAGE DOES LOOK
BEST OVER THE CENTRAL AND ERN CWA.
LATE MON INTO TUE LOOKS DRY AND COOLER /EVEN BELOW NORMAL TEMPS/ AS
A SFC HIGH MOVES OVER THE AREA. LOTS OF UNCERTAINTY LOOKING AT THE
MIDDLE TO END OF NEXT WEEK AS MODEL SUGGEST A STRONGER TROUGH/SFC
LOW MOVING INTO REGION AT SOME POINT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 101 AM EDT THU AUG 13 2015
STEADY SW WINDS ABOVE THE SFC JUST UNDER LLWS CRITERIA WL DRAW MORE
HUMID AIR INTO THE UPR LKS AHEAD OF A SLOWLY APRCHG COLD FNT AND
SUPPORT SOME SHOWERS/PERHAPS A TS AT THE TAF SITES BY 09Z THRU THIS
AFTN...WHEN THE STABILIZING INFLUENCE OF LK SUP WL DIMINISH THE PCPN
CHCS. CONFIDENCE IN THE OCCURRENCE OF THESE SHOWERS AT THE SITES IS
NOT HI ENUF TO VARY FM THE VCSH SHOWN IN THE PREVIOUS TAFS EXCEPT AT
IWD...WHERE RECENT RADAR TRENDS WARRANT AN EXPLICIT MENTION OF TS IN
THE 09-11Z TIME. ALTHOUGH A HEAVIER SHRA COULD BRING AT LEAST TEMPO
MVFR CONDITIONS...THE WARMTH/RELATIVE DRYNESS OF THE LLVLS WL
SUPPORT PREDOMINANT VFR CONDITIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 212 AM EDT THU AUG 13 2015
FOG WILL BE POSSIBLE TODAY THROUGH FRIDAY MORNING OVER MAINLY NE AND
E LAKE SUPERIOR...CLOSER TO THE COLDEST WATER AS WARM HUMID AIR
SHIFTS OVERHEAD. WINDS SHOULD BE LESS THAN 30KTS THROUGH THE
PERIOD...WITH GUSTS NEARING 30KTS OVER A FEW OF THE HIGHER PLATFORMS
OVER W LAKE SUPERIOR INITIALLY THIS MORNING OUT OF THE SW...AND
AGAIN SATURDAY NIGHT INTO SUNDAY.
EXPECT THE HIGH OVER THE OH RIVER VALLEY TO DRIFT OFF THE EAST COAST
THROUGH FRIDAY. A TROUGH MOVING THROUGH NW ONTARIO AND MN THIS
MORNING WILL SWEEP SE ACROSS LAKE SUPERIOR THIS AFTERNOON. IN ITS
WAKE...HIGH PRESSURE WILL BUILD INTO THE UPPER GREAT LAKES ON
FRIDAY. AS THIS HIGH DRIFTS SE INTO THE MID ATLANTIC STATES OVER THE
WEEKEND...A LOW WILL MOVE E FROM S SASKATCHEWAN ACROSS NW ONTARIO
AND TO NEAR JAMES BAY LATE ON SUNDAY. THIS LOW WILL CONTINUE E INTO
QUEBEC ON MONDAY...AND DRAG A COLD FRONT ACROSS THE UPPER LAKES ON
SUNDAY NIGHT. BEHIND THIS FRONT...LOOK FOR A HIGH TO MOVE INTO
MINNESOTA ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...TITUS
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
153 AM EDT THU AUG 13 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 315 PM EDT WED AUG 12 2015
FAIR WEATHER WILL CONTINUE THIS EVENING. A WARM FRONT WILL BRING
POTENTIAL FOR A FEW SHOWERS AND THUNDERSTORMS OVER CENTRAL LOWER
MICHIGAN NORTH OF INTERSTATE 96 VERY LATE TONIGHT. FAIR WEATHER
WILL BRIEFLY RETURN THURSDAY BUT A FRONTAL BOUNDARY WILL MOVE
INTO OUR REGION AND THEN STALL OUT THURSDAY NIGHT THROUGH FRIDAY
AND BRING A CHANCE OF SHOWERS AND STORMS THROUGH THAT TIME PERIOD.
FAIR AND HOT WEATHER IS ANTICIPATED THIS WEEKEND WITH HIGH
TEMPERATURES REACHING THE UPPER 80S TO LOWER 90S.
&&
.UPDATE...
ISSUED AT 1103 PM EDT WED AUG 12 2015
UPDATED THE FORECAST AROUND 1030PM TO INCREASE THE 30 PCT CHANCE
AREA FOR SHOWERS AND STORMS ACROSS CENTRAL LOWER MI.
SPECIFICALLY...NOW WE HAVE 30 POPS THROUGH THE NORTHERN 3 TIERS OF
COUNTIES. ALSO ADDED A 20 PCT CHANCE FOR SHOWERS ACROSS THE BULK
OF THE REST OF THE CWA. THE HRRR FOR SEVERAL RUNS NOW HAS BEEN
INDICATING SHOWERS AND A FEW THUNDERSTORMS WORKING SOUTH THROUGH
THE NIGHT ACROSS SOUTHWEST LOWER MICHIGAN. THE EXCEPTION MAY BE
ACROSS THE FAR SOUTHWEST TOWARD SOUTH HAVEN WHERE CONDITIONS
LIKELY WILL REMAIN DRY.
THE SHOWERS AND STORMS ARE FORMING ON THE LEADING EDGE OF MOISTURE
RETURN AS RIDGING IS BEING SHUNTED OFF TO THE SOUTH AND EAST. THE
MOISTURE RETURN IS ALOFT...AND IS BEST SEEN AROUND 850MB/S. 850MB
MOISTURE TRANSPORT...THE LLJ AND MOST UNSTABLE CAPE FIELDS ALL
SHOW A PUSH OF MOISTURE AND INSTABILITY WORKING SOUTHWARD ACROSS
OUR AREA TONIGHT. EXPECTING SCATTERED SHOWERS WITH SOME ISOLATED
EMBEDDED THUNDERSTORMS. NOT EXPECTING STRONG CONVECTION...BUT
THERE MAY BE SOME LOCALLY HEAVY RAIN AND LIGHTNING.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 315 PM EDT WED AUG 12 2015
PRIMARY SHORT TERM FCST CONCERNS INVOLVE DETERMINING POTENTIAL FOR
ANY CONVECTION VERY LATE TONIGHT AND THEN FROM LATE THURSDAY
THROUGH FRIDAY NIGHT.
FAIR WX WILL CONTINUE THIS AFTN/EVE AND WE REMOVED POPS FOR THIS
EVENING BASED ON A CONSENSUS OF LATEST SHORT RANGE GUIDANCE AND
RGNL RADAR TRENDS. A FEW SHOWERS AND STORMS ARE EXPECTED TO
DEVELOP OVER THE U.P. AND FAR NORTHERN LWR MI THIS EVENING. THOSE
WILL MOVE SSE AND COULD AFFECT AREAS WELL TO THE NORTH TO NE OF
KGRR BETWEEN 06Z AND 12Z THUR DUE TO ISENTROPIC UPGLIDE FROM A
A WARM FRONT IN THE AREA.
SW WINDS WILL RAMP UP SOMEWHAT THURSDAY IN ADVANCE OF THE
APPROACHING FRONTAL BOUNDARY. MOST OF THURSDAY SHOULD BE DRY
BEFORE SCATTERED SHOWERS AND STORMS DEVELOP FROM NW TO SE ACROSS
OUR FCST AREA LATE THURSDAY THROUGH THURSDAY NIGHT. THIS AS A
RESULT OF INCREASING ELEVATED INSTABILITY AS H8 LI/S FALL TO -2
TO -4 AND IN AN INCREASINGLY HUMID AND UNSTABLE AIRMASS AS DEW
POINT VALUES RISE THROUGH THE 60S. CONVECTIVE DEVELOPMENT WILL
ALSO BE AIDED BY A 35 TO 40 KT LLJ AND RATHER STRONG 1000-850 MB
MOISTURE TRANSPORT PARTICULARLY BETWEEN 00Z AND 06Z FRI.
THERE WILL BE A CONTINUED CHC OF SCATTERED CONVECTION FRIDAY WITH
A SLOW MOVING FRONTAL BOUNDARY IN THE AREA AND WITH A VERY HUMID
AND INCREASINGLY HUMID AIRMASS IN PLACE. POTENTIAL FOR SOME
STRONGER CONVECTION FRIDAY WILL BE LARGELY CONTINGENT ON HOW MUCH
DAYTIME HEATING AND INSTABILITY DEVELOPS. HOWEVER THE SEVERE
WEATHER THREAT LOOKS LOW DUE TO WEAK WIND FIELDS WITH HEIGHT/WEAK
DEEP LAYER SHEAR AND LACK OF STRONGER FORCING. ANY LINGERING SHOWERS
OR STORMS INTO FRIDAY EVENING WILL GRADUALLY TAPER OFF AND END
OVERNIGHT.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM EDT WED AUG 12 2015
NORTHWEST FLOW WILL DOMINATE THE EXTENDED PERIOD AS UPPER TROUGHING
PERSISTS OVER EASTERN CANADA AND UPPER RIDGING ACROSS THE WESTERN
CONUS...WHICH TEMPORARILY FOLDS OVER THE GREAT LAKES REGION THIS
WEEKEND.
THAT UPPER RIDGING SHOULD BRING FAIR AND WARM WEATHER FOR SATURDAY
AND SUNDAY. DECIDED TO DROP POPS FOR SATURDAY MORNING ALTHOUGH THERE
COULD BE ISOLATED SHOWERS LINGERING ACROSS THE EXTREME SOUTHEAST
FORECAST AREA EARLY IN THE DAY.
HEIGHT FALLS OCCUR SUNDAY NIGHT AND MONDAY AS A SHORTWAVE TROUGH
MOVING ACROSS CANADA BRINGS A TRAILING COLD FRONT INTO MICHIGAN BY
TUESDAY. LATEST MODEL TRENDS ARE THAT THE FRONT CLEARS CLEARS THE
FORECAST AREA BY TUESDAY NIGHT WITH A LULL IN THE PRECIP CHANCES
TUESDAY NIGHT AND WEDNESDAY AS SFC RIDGING IS IN CONTROL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 153 AM EDT THU AUG 13 2015
OUR MAIN FOCUS WITH THE 06Z FCSTS IS ON TWO CHCS OF RAIN...ONE
EARLY THIS MORNING AND ANOTHER MID-LATE EVENING TONIGHT. A FEW
SHOWERS AND EMBEDDED STORMS FORMED TOWARD KCAD EARLIER AND ARE NOW
MOVING SSE. SOME OF THESE ARE EXPECTED TO SURVIVE AND MAKE A RUN
AT KLAN AND KJXN AROUND 08-10Z.
ONCE THE SHOWERS AND STORMS MOVE OUT BY 12Z...WE SHOULD SEE FAIRLY
QUIET WEATHER MOST OF THE DAY TODAY. SKIES WILL CLEAR OUT A
BIT...AND WINDS WILL PICK UP WITH GUSTS OVER 20 KNOTS.
A COLD FRONT WILL START TO APPROACH THE AREA THEN LATER THIS
EVENING AND OVERNIGHT TONIGHT. THIS WILL BRING THE CHC FOR SOME
SHOWERS AND STORMS TO KMKG AND KGRR BEFORE THE END OF THE FCST
PERIOD. SOME LOWER CONDITIONS WILL BE LIKELY IF THE TERMINALS ARE
DIRECTLY AFFECTED BY THE SHOWERS/STORMS.
&&
.MARINE...
ISSUED AT 315 PM EDT WED AUG 12 2015
FAIRLY MINIMAL WIND AND WAVE ACTION IS ANTICIPATED FOR THE REST OF
THIS AFTERNOON THROUGH TONIGHT. SOUTHWEST WINDS WILL RAMP UP ON
THURSDAY CAUSING WAVE HEIGHTS TO BUILD TO 2 TO 4 FEET. HOWEVER
WINDS AND WAVES SHOULD STAY JUST BELOW SMALL CRAFT CRITERIA
THURSDAY IN THE SW FLOW WARM AIR ADVECTION REGIME.
&&
.HYDROLOGY...
ISSUED AT 315 PM EDT WED AUG 12 2015
SCATTERED SHOWERS/STORMS LATE TONIGHT INTO THU COULD PRODUCE SOME
RAINFALL ACROSS THE NORTHERN FORECAST AREA...BUT NO SIGNIFICANT
RAINFALL AMOUNTS/FLOODING ISSUES ARE EXPECTED. BETTER CHANCES FOR
RAIN WILL ARRIVE THU NIGHT INTO FRIDAY AND THEN LATE SUNDAY NIGHT
THROUGH MONDAY NIGHT. PRECIPITABLE WATER VALUES INCREASE OVER 1.50
INCHES THU NIGHT INTO FRIDAY...SUPPORTING A BETTER CHANCE FOR DECENT
RAINFALL TOTALS. 0.25 TO 0.50 INCHES SEEMS POSSIBLE WITH SOME
LOCALLY HIGHER TOTALS IN STORMS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...DUKE
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...NJJ
HYDROLOGY...EBW
MARINE...LAURENS
AREA FORECAST DISCUSSION...CORRECTED
NWS NORTH PLATTE NE
358 AM CDT THU AUG 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT THU AUG 13 2015
THE MODELS ARE IN RATHER UNANIMOUS AGREEMENT THAT THE DISTURBANCE
MOVING THROUGH SHERIDAN COUNTY AT 08Z WOULD BE THE CATALYST FOR
SCATTERED TSTMS ACROSS NCNTL AND SWRN NEB FROM ROUGHLY 22Z
THROUGH 03Z. WINDS ALOFT ARE WEAK...JUST 30 TO 40 KTS AT H300MB
AND BULK SHEAR TO 400MB IS 30 KTS OR LESS SUGGESTING A MARGINAL
SEVERE WEATHER SITUATION. MUCH OF THE INTENSITY OF THE STORMS
WOULD THEN BE DERIVED FROM CAPE WHICH COULD VARY SIGNIFICANT AS
SOME MODELS MIX VERY DEEPLY AND OTHER DO NOT. THE ECM HAS THE
RIGHT IDEA KEEPING DEW POINTS IN THE UPPER 60S TO NEAR 70 WHICH
WOULD PRODUCE MUCAPE AROUND 3500 J/KG. NOTE THE BUNKERS RIGHT MOVER
STORM MOTION IN THE RAP AND THE NAM VARIES FROM 345/10 TO 020/10 KT
WHICH SUGGESTS THERE COULD BACK BUILDING AND LOCALLY HEAVY RAINFALL
AS THE STORMS DEVELOP FROM NORTHEAST TO SOUTHWEST LATE THIS
AFTERNOON.
GIVEN THE WEAK WINDS ALOFT THE STORM ACTIVITY SHOULD WEAKEN AND
SLOWLY DISSIPATE WITH THE LOSS OF HEATING IN THE MID TO LATE
EVENING. THE MODELS SHOW A WEAK FRONT DROPPING STATIONARY ACROSS
THE FCST AREA. NONE OF THE MODELS SHOW STRATUS FORMING BUT THE
SREF SUGGESTS SOME PATCHY FOG COULD DEVELOP AHEAD OF THE FRONT
TONIGHT.
HIGHS TODAY FOLLOW THE GUIDANCE CONSENSUS. MID 90S ARE POSSIBLE
NEAR VALENTINE...CLOSER TO THE SFC LOW ACROSS SD WITH LOWER 90S
ELSEWHERE. LOWS TONIGHT IN THE 60S FOLLOWS A BLEND OF BIAS
CORRECTED DETERMINISTIC MODELS. FORECAST TEMPERATURES TONIGHT
ALONG AND AHEAD OF THE FRONT COULD BE TOO COOL. MIXING MAY
INHIBIT RADIATIONAL COOLING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 358 AM CDT THU AUG 13 2015
FRIDAY THE RIDGE HOLDS STRONG ACROSS THE CENTRAL ROCKIES AHEAD OF
AN APPROACHING TROUGH/COLD FRONT. TEMPS FRIDAY SEASONALLY WARM
WITH MOST AREAS AROUND 90. MODELS KEEP THE AREA INBETWEEN RIDGE
RIDING WAVES SO EXPECT A DRY DAY. CHANGES START SATURDAY AS A
TROUGH DIGS ACROSS THE PACIFIC NW AND NORTHERN ROCKIES. A LOW
PRESSURE SYSTEM WILL CROSS THE NORTHERN ROCKIES WITH A TRAILING
COLD FRONT TO PUSH TOWARDS THE AREA. COMPRESSIONAL HEATING AHEAD
OF THE COLD FRONT SHOULD PUSH ALL AREAS INTO THE 90S. FORECAST
FOLLOWS A MODEL BLEND FOR HIGHS...WHICH MAY BE UNDERDONE. THE KEY
WILL BE THE PLACEMENT/STRENGTH OF THE DRY LINE. MODELS GENERALLY
KEEP THE DRY LINE ACROSS THE WESTERN SANDHILLS...HOWEVER IF THE
DRY LINE CAN PUSH FURTHER EAST...THE MAV MOS GUIDANCE OF NEAR
TRIPLE DIGITS CAN NOT BE RULED OUT FOR PARTS OF WESTERN NEB.
THE COLD FRONT WILL PUSH INTO THE NW CWA BY LATE SATURDAY AND
SHOULD BE THE FOCUS FOR THUNDERSTORMS. THE CHANCE WILL FOLLOW
NEAR THE FRONT AS IT SLOWLY PUSHES SOUTHEAST SATURDAY NIGHT INTO
SUNDAY. SHEAR ALONG THE FRONT AND GOOD INSTABILITY AHEAD OF THE
FRONT SHOULD AID IN SOME STRONG TO POSSIBLY SEVERE STORMS. THE
CLOUDS AND STORMS WILL HELP KEEP TEMPS DOWN FOR SUNDAY.
POST FRONTAL CONDITIONS ARE FAIRLY SIMILAR. THE RIDGE IS
FLATTENED AND FLOW WILL BE MORE ZONAL. A TRAIN OF DISTURBANCES
WILL RESULT IN NUMEROUS CHANCES FOR ISOLATED TO SCATTERED STORMS.
TEMPS FALL INTO THE 80S...AND COULD HOLD IN THE UPPER 70S WITH
MORE CLOUDS OR PUSH TO AROUND 90 WITH MORE AFTERNOON SUN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1148 PM CDT WED AUG 12 2015
FOR BOTH THE KLBF AND KVTN TERMINALS...EXPECT SCATTERED HIGH
CLOUDS OVERNIGHT WITH CIGS AROUND 25000 FT AGL. BY THURSDAY
AFTERNOON...THERE WILL BE AN INCREASED THREAT FOR THUNDERSTORMS
AS A SURFACE TROUGH OF LOW PRESSURE PASSES THROUGH WESTERN AND
NORTH CENTRAL NEBRASKA. THE THREAT FOR STORMS WILL BE GREATEST AT
THE KVTN TERMINAL FROM 21Z THURSDAY THROUGH 03Z FRIDAY...AND AT
THE KLBF TERMINAL FROM 22Z THURSDAY THROUGH 04Z FRIDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
352 AM EDT THU AUG 13 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE BEGINS TO BUILD INTO THE REGION BRINGING A
RETURN OF MOSTLY QUIET WEATHER WITH A FEW POSSIBLE SHOWERS ACROSS
THE NORTH COUNTRY AS A SHORTWAVE CROSSES THE REGION. A WEAK COLD
FRONT WILL BRING THE CHANCE FOR MORE SHOWERS AND A FEW THUNDERSTORMS
FRIDAY INTO SATURDAY. TEMPERATURES WILL SEE A WARMING TREND OVER
THE WEEKEND WITH DAYTIME TEMPERATURES REACHING THE UPPER 80S OVER
THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 348 AM EDT THURSDAY...SURFACE RIDGING WILL BUILD INTO THE
REGION TODAY AS A 500 MB TROUGH SLIDES TOWARDS THE EAST THIS
AFTERNOON. AS A PIECE OF SHORTWAVE ENERGY RIDES THE SOUTHERN
EXTENT OF THE UPPER LEVEL TROUGH THERE COULD BE ENOUGH LIFT TO
GENERATE A FEW ISOLATED TO SCATTERED SHOWERS THIS AFTERNOON. WITH
INCREASING 500MB HEIGHTS AND INCREASED 1000-500MB THICKNESS I DONT
EXPECT ANY WIDESPREAD COVERAGE OF SHOWERS SO I CONTINUED JUST THE
MENTION OF SLIGHT CHANCE WORDING IN THE FORECAST FOR THIS
AFTERNOON.
AS THE TROUGH MOVES OUT OF THE AREA DRY AIR WILL ENTRAIN INTO THE
MID AND UPPER LEVELS SO I EXPECT THE CLOUDS SHOULD BEGIN TO ERODE
MOVING INTO THE LATE AFTERNOON/ EARLY EVENING. LIGHT TO MODERATE
WESTERLY TO SOUTHWESTERLY WINDS WILL PREVAIL AND TEMPS TODAY WILL
WARM INTO THE MID 70S.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/...
AS OF 348 AM EDT THURSDAY...EXPECT A QUIET EVENING ON THURSDAY
NIGHT WITH INCREASING SOUTHERLY FLOW AHEAD OF A COLD FRONT. FRIDAY
MORNING THE SOUTHERLY FLOW QUICKLY INCREASES LOW LEVEL MOISTURE
AND SURFACE TEMPERATURES ACROSS THE NORTH COUNTRY. AS THE MOISTURE
INCREASES SO DOES THE INSTABILITY BUT ONLY MARGINALLY. GIVEN THE
WEAK LAPSE RATES AND MINIMAL SHEAR I DONT EXPECT MORE THAN A FEW
ISOLATED THUNDERSTORMS AS THE UPPER LEVEL VORT MAX`S GENERATE
RAIN SHOWERS ACROSS THE AREA FRIDAY EVENING INTO SATURDAY MORNING.
GIVEN THE RAPID INCREASE OF PRECIPITABLE WATER AND WEAK CORFIDI
VECTORS EXPECT SOME OF THE SHOWERS TO PRODUCE HEAVY RAINFALL RATES
HOWEVER WITH THE ANTECEDENT CONDITIONS STILL BELOW NORMAL FOR THE
AUGUST I`M NOT EXPECTING A SIGNIFICANT FLOODING EVENT. NONETHELESS
HEAVIER SHOWERS COULD LIKELY PRODUCE SOME PONDING OF WATER IN LOW
LYING AREAS AND IN AREAS OF POOR DRAINAGE.
AS THE FRONT CLEARS THE AREA LATE SATURDAY AFTERNOON WE WILL SEE
A NEW AIRMASS MOVE IN BEHIND THE FRONT AS AN UPPER LEVEL RIDGE AND
SURFACE HIGH BUILD IN OVER THE NORTH COUNTRY. EXPECT DAYTIME
TEMPERATURES FRIDAY WILL BE IN THE MID 70S TO LOW 80S WITH THE
OVERNIGHT LOWS ON FRIDAY NIGHT IN THE LOW TO MID 60S. AS THE FRONT
IS MOVING THROUGH THE REGION ON SATURDAY TEMPS WILL NEARLY BE A
REPEAT OF FRIDAY IN THE MID 70S TO LOW 80S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 333 AM EDT THURSDAY...MAIN HEADLINE FOR THE EXTENDED WILL
BE POTENTIAL UPPER 80S/LOWER 90S FOR DAYTIME HIGHS SUNDAY AND
MONDAY. BOTH THE 00Z ECMWF AND 00Z GFS INDICATE BROAD MID-LEVEL
RIDGE AND BUILDING 500MB HEIGHTS INTO THE REGION FROM THE WEST AND
SOUTHWEST...WITH 850MB TEMPS OF +18C TO +19C SUN/MON. RAINFALL
CHANCES APPEAR MINIMUM AND ANTICIPATE FULL HEATING WITH GENERAL
MID-LEVEL SUBSIDENCE IN PLACE. EXPECTATION IS FOR MID 60S
DEWPOINTS...THUS MODERATELY HUMID CONDITIONS. THIS SHOULD ALSO
KEEP LOW TEMPERATURES IN THE MID-UPR 60S FOR MOST SECTIONS FOR
SUNDAY NIGHT.
MID-LEVEL RIDGE BEGINS TO BREAK DOWN MONDAY NIGHT INTO TUESDAY. MAY
SEE SOME SHOWER/ISOLD THUNDER ACTIVITY DEVELOP LATER MONDAY
NIGHT...WITH POTENTIAL ROUND OF WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH SURFACE FRONTAL PASSAGE ON TUESDAY. HAVE INDICATED 30-40 POPS
ACROSS NRN NY 06-12Z TUESDAY...INCREASING TO 45-60 POPS AREAWIDE
DURING THE DAYLIGHT HOURS ON TUESDAY. COULD SEE A FEW STRONGER
THUNDERSTORMS...BUT DIFFICULT TO ASSESS AT THIS TIME GIVEN TIMING
UNCERTAINTY OF FRONTAL PASSAGE WITH RESPECT TO DAYTIME HEATING MAX.
SHOULD STILL SEE HIGH TEMPS IN THE LOW-MID 80S ACROSS THE VT VALLEYS
ON TUESDAY BEFORE RAINFALL...THOUGH COOLER WITH EARLIER FRONTAL
PASSAGE ACROSS NRN NY BASED ON CURRENT INDICATIONS. WILL CONTINUE TO
MONITOR.
SHOULD SEE CLEARING CONDITIONS TUESDAY NIGHT WITH COOLER/MORE
SEASONABLE CONDITIONS AND LOWER HUMIDITY LEVELS ON WEDNESDAY. HIGH
TEMPERATURES ON WEDNESDAY EXPECTED IN THE UPR 70S TO LOWER
80S...WITH DEWPOINTS BACK INTO THE MID TO UPPER 50S.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...UPPER TROUGH ROTATING SEWD FROM
QUEBEC/ONTARIO WILL MAINTAIN BKN-OVC SKIES THROUGH 14-15Z THIS
MORNING. GENERALLY VFR CEILINGS...BUT LOCALLY MVFR CEILINGS AT SLK
AND POSSIBLY AT MSS/RUT FROM TIME TO TIME THROUGH 12Z. GENERAL
TREND IN RAP MODEL SOUNDINGS IS TO SHOW IMPROVING CEILINGS AND
PARTIAL CLEARING BY 15Z. WITH DAYTIME HEATING AND UPPER TROUGH
PASSAGE...MAY SEE AN ISOLATED AFTERNOON SHOWER...BUT LOW
PROBABILITY DOESN/T WARRANT INCLUSION IN AREA TAFS ATTM. SURFACE
WINDS GENERALLY LESS THAN 10 KTS THROUGH THE PERIOD...LIGHT W-NW
EARLY THIS MORNING...AND GENERALLY W-SW DURING THE BALANCE OF THE
DAYLIGHT PERIOD.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
12Z FRIDAY THROUGH 12Z SATURDAY...MAINLY VFR CONDITIONS...BUT
SCATTERED SHOWER/TSTM DEVELOPMENT WILL BRING INTERVALS OF MVFR OR
BRIEF IFR WITH RAINFALL (MAINLY FRIDAY AFTN INTO EARLY FRIDAY EVE).
LOCALIZED FOG POSSIBLE LATE FRIDAY NIGHT...ESPECIALLY IN VALLEY
AREAS SEEING RAINFALL.
12Z SATURDAY THROUGH MONDAY...ISOLD SHOWER OR TSTM POSSIBLE
SATURDAY AFTERNOON. OTHERWISE MAINLY VFR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...DEAL
SHORT TERM...DEAL
LONG TERM...BANACOS
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
334 AM EDT THU AUG 13 2015
.SYNOPSIS...
LINGERING ISOLATED RAIN SHOWERS WILL DIMINISH OVERNIGHT AS
SURFACE HIGH PRESSURE BEGINS TO BUILD INTO THE REGION. A FEW
SHOWERS ARE POSSIBLE ON THURSDAY AS A MID-LEVEL SHORTWAVE MOVES
ACROSS THE NORTH COUNTRY, BUT MOST OF THE AREA WILL REMAIN DRY AND
SEE SOME SUN. A WEAK COLD FRONT WILL BRING THE CHANCE FOR A FEW
MORE SHOWERS AND THUNDERSTORMS FRIDAY INTO SATURDAY. TEMPERATURES
WILL SEE A WARMING TREND WITH DAYTIME TEMPERATURES REACHING THE
80S OVER THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 134 AM EDT THURSDAY...THE 850 MB TROUGH IS SLOWLY MOVING
TOWARDS THE EAST AND DRIER AIR IS MOVING IN ALOFT. THE LOW LEVEL
MOISTURE IS CAUSING SOME STRATUS TO DEVELOP AND SO I WENT AHEAD
AND INCREASED CLOUD COVER THROUGH THE EARLY MORNING. GIVEN THE
CLOUD COVER I DONT EXPECT MUCH IN THE WAY OF FOG TO DEVELOP
OVERNIGHT SO I REMOVED FOG FROM THE GRIDS. THE REST OF THE
FORECAST REMAINS UNCHANGED.
PREVIOUS DISCUSSION AS OF 1055 PM EDT WEDNESDAY...COMPOSITE RADAR
LOOP SHOWING MOST SHOWER ACTIVITY HAS DIMINISHED ACROSS THE
REGION...EXCEPT FOR SOME SHOWER ACTIVITY ACROSS SOUTHERN ADDISON
AND NORTHERN RUTLAND COUNTIES AT THIS TIME. EXPECTING THIS
CATIVITY TO COME TO AN END OVERNIGHT...WITH SOME PATCHY DENSE FOG
EXPECTED AFTER MIDNIGHT IN THE USUAL FOG PRONE VALLEYS OF VERMONT
AND THE VALLEYS OF THE ADIRONDACKS. DUE TO CLOUD COVER AND THE
LATEST GFS LAMP GUIDANCE HAVE RAISED MIN TEMPERATURES UP OVERNIGHT
IN THE ADIRONDACKS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SATURDAY/...
AS OF 342 PM EDT WEDNESDAY...SURFACE RIDGING WILL BE BUILDING
INTO THE NORTH COUNTRY ON THURSDAY, WHILE A SHORTWAVE WILL
TRAVERSE ACROSS THE REGION, POSSIBLY PROVIDING ENOUGH LIFT FOR A
FEW SHOWERS. 500MB HTS APPEAR TO INCREASE, SO HAVE KEPT POPS AT
SLIGHT CHANCE TO LOW CHANCE ACROSS OUR NORTHERN TIER OF COUNTIES
FROM THE CHAMPLAIN VALLEY EASTWARD. WITH LACK OF DEEP LAYER
MOISTURE AND PWATS OF AN INCH OR LESS OVER THE AREA, EXPECT PARTLY
CLOUDY SKIES, BECOMING MOSTLY CLEAR TOWARDS THURSDAY NIGHT.
DAYTIME TEMPERATURES REACHING THE MID 70S IN THE VALLEYS.
THURSDAY NIGHT WILL BE TRANQUIL FOR MOST OF THE NIGHT, BUT
INCREASING SOUTHERLY FLOW AHEAD OF A WEAK COLD FRONT THAT WILL BE
ON OUR DOORSTEP TO THE WEST FRIDAY MORNING WILL INCREASE MOISTURE
AND WARMING TEMPERATURES. INSTABILITY INCREASES FRIDAY DURING THE
DAY WITH THE GFS INDICATING SBCAPES OVER 1500J/KG POSSIBLE, MAINLY
OVER NRN NY. BEST LIFT/LOW LEVEL DEFORMATION AXIS WILL ARRIVE IN
NWRN NY/ST LAWRENCE VALLEY LATE IN THE DAY, WHEN INSTABILITY
STARTS TO WANE. SHOWERS WITH A RUMBLE OF THUNDER POSSIBLE FRIDAY
NIGHT AS THE WEAK FRONT AND WEAKENING LIFT SLOWLY TRAVERSE ACROSS
THE AREA FROM NW TO SE. PWATS INCREASE TO OVER 1.5 INCHES FRIDAY
NIGHT AND MAY SEE SOME HEAVIER SHOWERS. DAYTIME TEMPERATURES
FRIDAY WILL BE IN THE MID 70S TO LOW 80S. FRIDAY NIGHT LOWS WILL
GENERALLY BE IN THE 60S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 333 AM EDT THURSDAY...MAIN HEADLINE FOR THE EXTENDED WILL
BE POTENTIAL UPPER 80S/LOWER 90S FOR DAYTIME HIGHS SUNDAY AND
MONDAY. BOTH THE 00Z ECMWF AND 00Z GFS INDICATE BROAD MID-LEVEL
RIDGE AND BUILDING 500MB HEIGHTS INTO THE REGION FROM THE WEST AND
SOUTHWEST...WITH 850MB TEMPS OF +18C TO +19C SUN/MON. RAINFALL
CHANCES APPEAR MINIMUM AND ANTICIPATE FULL HEATING WITH GENERAL
MID-LEVEL SUBSIDENCE IN PLACE. EXPECTATION IS FOR MID 60S
DEWPOINTS...THUS MODERATELY HUMID CONDITIONS. THIS SHOULD ALSO
KEEP LOW TEMPERATURES IN THE MID-UPR 60S FOR MOST SECTIONS FOR
SUNDAY NIGHT.
MID-LEVEL RIDGE BEGINS TO BREAK DOWN MONDAY NIGHT INTO TUESDAY. MAY
SEE SOME SHOWER/ISOLD THUNDER ACTIVITY DEVELOP LATER MONDAY
NIGHT...WITH POTENTIAL ROUND OF WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH SURFACE FRONTAL PASSAGE ON TUESDAY. HAVE INDICATED 30-40 POPS
ACROSS NRN NY 06-12Z TUESDAY...INCREASING TO 45-60 POPS AREAWIDE
DURING THE DAYLIGHT HOURS ON TUESDAY. COULD SEE A FEW STRONGER
THUNDERSTORMS...BUT DIFFICULT TO ASSESS AT THIS TIME GIVEN TIMING
UNCERTAINTY OF FRONTAL PASSAGE WITH RESPECT TO DAYTIME HEATING MAX.
SHOULD STILL SEE HIGH TEMPS IN THE LOW-MID 80S ACROSS THE VT VALLEYS
ON TUESDAY BEFORE RAINFALL...THOUGH COOLER WITH EARLIER FRONTAL
PASSAGE ACROSS NRN NY BASED ON CURRENT INDICATIONS. WILL CONTINUE TO
MONITOR.
SHOULD SEE CLEARING CONDITIONS TUESDAY NIGHT WITH COOLER/MORE
SEASONABLE CONDITIONS AND LOWER HUMIDITY LEVELS ON WEDNESDAY. HIGH
TEMPERATURES ON WEDNESDAY EXPECTED IN THE UPR 70S TO LOWER
80S...WITH DEWPOINTS BACK INTO THE MID TO UPPER 50S.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...UPPER TROUGH ROTATING SEWD FROM
QUEBEC/ONTARIO WILL MAINTAIN BKN-OVC SKIES THROUGH 14-15Z THIS
MORNING. GENERALLY VFR CEILINGS...BUT LOCALLY MVFR CEILINGS AT SLK
AND POSSIBLY AT MSS/RUT FROM TIME TO TIME THROUGH 12Z. GENERAL
TREND IN RAP MODEL SOUNDINGS IS TO SHOW IMPROVING CEILINGS AND
PARTIAL CLEARING BY 15Z. WITH DAYTIME HEATING AND UPPER TROUGH
PASSAGE...MAY SEE AN ISOLATED AFTERNOON SHOWER...BUT LOW
PROBABILITY DOESN/T WARRANT INCLUSION IN AREA TAFS ATTM. SURFACE
WINDS GENERALLY LESS THAN 10 KTS THROUGH THE PERIOD...LIGHT W-NW
EARLY THIS MORNING...AND GENERALLY W-SW DURING THE BALANCE OF THE
DAYLIGHT PERIOD.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
12Z FRIDAY THROUGH 12Z SATURDAY...MAINLY VFR CONDITIONS...BUT
SCATTERED SHOWER/TSTM DEVELOPMENT WILL BRING INTERVALS OF MVFR OR
BRIEF IFR WITH RAINFALL (MAINLY FRIDAY AFTN INTO EARLY FRIDAY EVE).
LOCALIZED FOG POSSIBLE LATE FRIDAY NIGHT...ESPECIALLY IN VALLEY
AREAS SEEING RAINFALL.
12Z SATURDAY THROUGH MONDAY...ISOLD SHOWER OR TSTM POSSIBLE
SATURDAY AFTERNOON. OTHERWISE MAINLY VFR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KGM
NEAR TERM...WGH/DEAL
SHORT TERM...KGM
LONG TERM...BANACOS
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
143 AM EDT THU AUG 13 2015
.SYNOPSIS...
LINGERING ISOLATED RAIN SHOWERS WILL DIMINISH OVERNIGHT AS
SURFACE HIGH PRESSURE BEGINS TO BUILD INTO THE REGION. A FEW
SHOWERS ARE POSSIBLE ON THURSDAY AS A MID-LEVEL SHORTWAVE MOVES
ACROSS THE NORTH COUNTRY, BUT MOST OF THE AREA WILL REMAIN DRY AND
SEE SOME SUN. A WEAK COLD FRONT WILL BRING THE CHANCE FOR A FEW
MORE SHOWERS AND THUNDERSTORMS FRIDAY INTO SATURDAY. TEMPERATURES
WILL SEE A WARMING TREND WITH DAYTIME TEMPERATURES REACHING THE
80S OVER THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 134 AM EDT THURSDAY...THE 850 MB TROUGH IS SLOWLY MOVING
TOWARDS THE EAST AND DRIER AIR IS MOVING IN ALOFT. THE LOW LEVEL
MOISTURE IS CAUSING SOME STRATUS TO DEVELOP AND SO I WENT AHEAD
AND INCREASED CLOUD COVER THROUGH THE EARLY MORNING. GIVEN THE
CLOUD COVER I DONT EXPECT MUCH IN THE WAY OF FOG TO DEVELOP
OVERNIGHT SO I REMOVED FOG FROM THE GRIDS. THE REST OF THE
FORECAST REMAINS UNCHANGED.
PREVIOUS DISCUSSION AS OF 1055 PM EDT WEDNESDAY...COMPOSITE RADAR
LOOP SHOWING MOST SHOWER ACTIVITY HAS DIMINISHED ACROSS THE
REGION...EXCEPT FOR SOME SHOWER ACTIVITY ACROSS SOUTHERN ADDISON
AND NORTHERN RUTLAND COUNTIES AT THIS TIME. EXPECTING THIS
CATIVITY TO COME TO AN END OVERNIGHT...WITH SOME PATCHY DENSE FOG
EXPECTED AFTER MIDNIGHT IN THE USUAL FOG PRONE VALLEYS OF VERMONT
AND THE VALLEYS OF THE ADIRONDACKS. DUE TO CLOUD COVER AND THE
LATEST GFS LAMP GUIDANCE HAVE RAISED MIN TEMPERATURES UP OVERNIGHT
IN THE ADIRONDACKS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 342 PM EDT WEDNESDAY...SURFACE RIDGING WILL BE BUILDING
INTO THE NORTH COUNTRY ON THURSDAY, WHILE A SHORTWAVE WILL
TRAVERSE ACROSS THE REGION, POSSIBLY PROVIDING ENOUGH LIFT FOR A
FEW SHOWERS. 500MB HTS APPEAR TO INCREASE, SO HAVE KEPT POPS AT
SLIGHT CHANCE TO LOW CHANCE ACROSS OUR NORTHERN TIER OF COUNTIES
FROM THE CHAMPLAIN VALLEY EASTWARD. WITH LACK OF DEEP LAYER
MOISTURE AND PWATS OF AN INCH OR LESS OVER THE AREA, EXPECT PARTLY
CLOUDY SKIES, BECOMING MOSTLY CLEAR TOWARDS THURSDAY NIGHT.
DAYTIME TEMPERATURES REACHING THE MID 70S IN THE VALLEYS.
THURSDAY NIGHT WILL BE TRANQUIL FOR MOST OF THE NIGHT, BUT
INCREASING SOUTHERLY FLOW AHEAD OF A WEAK COLD FRONT THAT WILL BE
ON OUR DOORSTEP TO THE WEST FRIDAY MORNING WILL INCREASE MOISTURE
AND WARMING TEMPERATURES. INSTABILITY INCREASES FRIDAY DURING THE
DAY WITH THE GFS INDICATING SBCAPES OVER 1500J/KG POSSIBLE, MAINLY
OVER NRN NY. BEST LIFT/LOW LEVEL DEFORMATION AXIS WILL ARRIVE IN
NWRN NY/ST LAWRENCE VALLEY LATE IN THE DAY, WHEN INSTABILITY
STARTS TO WANE. SHOWERS WITH A RUMBLE OF THUNDER POSSIBLE FRIDAY
NIGHT AS THE WEAK FRONT AND WEAKENING LIFT SLOWLY TRAVERSE ACROSS
THE AREA FROM NW TO SE. PWATS INCREASE TO OVER 1.5 INCHES FRIDAY
NIGHT AND MAY SEE SOME HEAVIER SHOWERS. DAYTIME TEMPERATURES
FRIDAY WILL BE IN THE MID 70S TO LOW 80S. FRIDAY NIGHT LOWS WILL
GENERALLY BE IN THE 60S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 342 PM EDT TUESDAY...COLD FRONT WILL MOVE ACROSS THE AREA
EARLY SATURDAY BRINGING SOME SCATTERED LIGHT RAIN SHOWERS ALONG
WITH IT...FEEL THAT MOST OF THE SHOWERS WILL BE EARLY IN THE DAY.
SURFACE HIGH PRESSURE WILL THEN RIDGE INTO THE AREA FOR SATURDAY
NIGHT THROUGH MONDAY NIGHT. ANOTHER COLD FRONT MOVES ACROSS THE
FORECAST AREA ON TUESDAY BRINGING NEXT CHANCE FOR SHOWERS TO THE
AREA...THIS FRONT WILL BE SLOWER MOVING AND MAY KEEP SHOWERS
AROUND FROM TUESDAY INTO WEDNESDAY. TEMPERATURES WILL TREND WARMER
THAN SEASONAL NORMALS NEXT WEEK.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...UPPER TROUGH ROTATING SEWD FROM
QUEBEC/ONTARIO WILL MAINTAIN BKN-OVC SKIES THROUGH 14-15Z THIS
MORNING. GENERALLY VFR CEILINGS...BUT LOCALLY MVFR CEILINGS AT SLK
AND POSSIBLY AT MSS/RUT FROM TIME TO TIME THROUGH 12Z. GENERAL
TREND IN RAP MODEL SOUNDINGS IS TO SHOW IMPROVING CEILINGS AND
PARTIAL CLEARING BY 15Z. WITH DAYTIME HEATING AND UPPER TROUGH
PASSAGE...MAY SEE AN ISOLATED AFTERNOON SHOWER...BUT LOW
PROBABILITY DOESN/T WARRANT INCLUSION IN AREA TAFS ATTM. SURFACE
WINDS GENERALLY LESS THAN 10 KTS THROUGH THE PERIOD...LIGHT W-NW
EARLY THIS MORNING...AND GENERALLY W-SW DURING THE BALANCE OF THE
DAYLIGHT PERIOD.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
12Z FRIDAY THROUGH 12Z SATURDAY...MAINLY VFR CONDITIONS...BUT
SCATTERED SHOWER/TSTM DEVELOPMENT WILL BRING INTERVALS OF MVFR OR
BRIEF IFR WITH RAINFALL (MAINLY FRIDAY AFTN INTO EARLY FRIDAY EVE).
LOCALIZED FOG POSSIBLE LATE FRIDAY NIGHT...ESPECIALLY IN VALLEY
AREAS SEEING RAINFALL.
12Z SATURDAY THROUGH MONDAY...ISOLD SHOWER OR TSTM POSSIBLE
SATURDAY AFTERNOON. OTHERWISE MAINLY VFR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KGM
NEAR TERM...WGH/DEAL
SHORT TERM...KGM
LONG TERM...NEILES
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
129 AM EDT THU AUG 13 2015
.SYNOPSIS...
LINGERING ISOLATED RAIN SHOWERS WILL DIMINISH OVERNIGHT AS
SURFACE HIGH PRESSURE BEGINS TO BUILD INTO THE REGION. A FEW
SHOWERS ARE POSSIBLE ON THURSDAY AS A MID-LEVEL SHORTWAVE MOVES
ACROSS THE NORTH COUNTRY, BUT MOST OF THE AREA WILL REMAIN DRY AND
SEE SOME SUN. A WEAK COLD FRONT WILL BRING THE CHANCE FOR A FEW
MORE SHOWERS AND THUNDERSTORMS FRIDAY INTO SATURDAY. TEMPERATURES
WILL SEE A WARMING TREND WITH DAYTIME TEMPERATURES REACHING THE
80S OVER THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1055 PM EDT WEDNESDAY...COMPOSITE RADAR LOOP SHOWING MOST
SHOWER ACTIVITY HAS DIMINISHED ACROSS THE REGION...EXCEPT FOR SOME
SHOWER ACTIVITY ACROSS SOUTHERN ADDISON AND NORTHERN RUTLAND
COUNTIES AT THIS TIME. EXPECTING THIS CATIVITY TO COME TO AN END
OVERNIGHT...WITH SOME PATCHY DENSE FOG EXPECTED AFTER MIDNIGHT IN
THE USUAL FOG PRONE VALLEYS OF VERMONT AND THE VALLEYS OF THE
ADIRONDACKS. DUE TO CLOUD COVER AND THE LATEST GFS LAMP GUIDANCE
HAVE RAISED MIN TEMPERATURES UP OVERNIGHT IN THE ADIRONDACKS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 342 PM EDT WEDNESDAY...SURFACE RIDGING WILL BE BUILDING
INTO THE NORTH COUNTRY ON THURSDAY, WHILE A SHORTWAVE WILL
TRAVERSE ACROSS THE REGION, POSSIBLY PROVIDING ENOUGH LIFT FOR A
FEW SHOWERS. 500MB HTS APPEAR TO INCREASE, SO HAVE KEPT POPS AT
SLIGHT CHANCE TO LOW CHANCE ACROSS OUR NORTHERN TIER OF COUNTIES
FROM THE CHAMPLAIN VALLEY EASTWARD. WITH LACK OF DEEP LAYER
MOISTURE AND PWATS OF AN INCH OR LESS OVER THE AREA, EXPECT PARTLY
CLOUDY SKIES, BECOMING MOSTLY CLEAR TOWARDS THURSDAY NIGHT.
DAYTIME TEMPERATURES REACHING THE MID 70S IN THE VALLEYS.
THURSDAY NIGHT WILL BE TRANQUIL FOR MOST OF THE NIGHT, BUT
INCREASING SOUTHERLY FLOW AHEAD OF A WEAK COLD FRONT THAT WILL BE
ON OUR DOORSTEP TO THE WEST FRIDAY MORNING WILL INCREASE MOISTURE
AND WARMING TEMPERATURES. INSTABILITY INCREASES FRIDAY DURING THE
DAY WITH THE GFS INDICATING SBCAPES OVER 1500J/KG POSSIBLE, MAINLY
OVER NRN NY. BEST LIFT/LOW LEVEL DEFORMATION AXIS WILL ARRIVE IN
NWRN NY/ST LAWRENCE VALLEY LATE IN THE DAY, WHEN INSTABILITY
STARTS TO WANE. SHOWERS WITH A RUMBLE OF THUNDER POSSIBLE FRIDAY
NIGHT AS THE WEAK FRONT AND WEAKENING LIFT SLOWLY TRAVERSE ACROSS
THE AREA FROM NW TO SE. PWATS INCREASE TO OVER 1.5 INCHES FRIDAY
NIGHT AND MAY SEE SOME HEAVIER SHOWERS. DAYTIME TEMPERATURES
FRIDAY WILL BE IN THE MID 70S TO LOW 80S. FRIDAY NIGHT LOWS WILL
GENERALLY BE IN THE 60S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 342 PM EDT TUESDAY...COLD FRONT WILL MOVE ACROSS THE AREA
EARLY SATURDAY BRINGING SOME SCATTERED LIGHT RAIN SHOWERS ALONG
WITH IT...FEEL THAT MOST OF THE SHOWERS WILL BE EARLY IN THE DAY.
SURFACE HIGH PRESSURE WILL THEN RIDGE INTO THE AREA FOR SATURDAY
NIGHT THROUGH MONDAY NIGHT. ANOTHER COLD FRONT MOVES ACROSS THE
FORECAST AREA ON TUESDAY BRINGING NEXT CHANCE FOR SHOWERS TO THE
AREA...THIS FRONT WILL BE SLOWER MOVING AND MAY KEEP SHOWERS
AROUND FROM TUESDAY INTO WEDNESDAY. TEMPERATURES WILL TREND WARMER
THAN SEASONAL NORMALS NEXT WEEK.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...UPPER TROUGH ROTATING SEWD FROM
QUEBEC/ONTARIO WILL MAINTAIN BKN-OVC SKIES THROUGH 14-15Z THIS
MORNING. GENERALLY VFR CEILINGS...BUT LOCALLY MVFR CEILINGS AT SLK
AND POSSIBLY AT MSS/RUT FROM TIME TO TIME THROUGH 12Z. GENERAL
TREND IN RAP MODEL SOUNDINGS IS TO SHOW IMPROVING CEILINGS AND
PARTIAL CLEARING BY 15Z. WITH DAYTIME HEATING AND UPPER TROUGH
PASSAGE...MAY SEE AN ISOLATED AFTERNOON SHOWER...BUT LOW
PROBABILITY DOESN/T WARRANT INCLUSION IN AREA TAFS ATTM. SURFACE
WINDS GENERALLY LESS THAN 10 KTS THROUGH THE PERIOD...LIGHT W-NW
EARLY THIS MORNING...AND GENERALLY W-SW DURING THE BALANCE OF THE
DAYLIGHT PERIOD.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
12Z FRIDAY THROUGH 12Z SATURDAY...MAINLY VFR CONDITIONS...BUT
SCATTERED SHOWER/TSTM DEVELOPMENT WILL BRING INTERVALS OF MVFR OR
BRIEF IFR WITH RAINFALL (MAINLY FRIDAY AFTN INTO EARLY FRIDAY EVE).
LOCALIZED FOG POSSIBLE LATE FRIDAY NIGHT...ESPECIALLY IN VALLEY
AREAS SEEING RAINFALL.
12Z SATURDAY THROUGH MONDAY...ISOLD SHOWER OR TSTM POSSIBLE
SATURDAY AFTERNOON. OTHERWISE MAINLY VFR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KGM
NEAR TERM...WGH
SHORT TERM...KGM
LONG TERM...NEILES
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
208 AM EDT THU AUG 13 2015
.SYNOPSIS...HIGH PRESSURE WILL GRADUALLY BUILD INTO THE REGION FROM
THE NORTHWEST THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1010 PM WEDNESDAY...
DIURNAL CU HAS DIMINISHED AND RESULTED IN A MOSTLY CLEAR SKY ACROSS
CENTRAL NC THIS EVENING...ALTHOUGH SATELLITE IMAGERY REVEALS AN AREA
OF UPSTREAM SCT TO BKN ALTOCUMULUS IN A RELATIVE MAXIMUM OF MID-
LEVEL MOISTURE CENTERED OVER THE CENTRAL APPALACHIANS PER 00Z RAOB
DATA - MOST NOTABLE AT RNK. THIS AREA OF MOISTURE IS EXPECTED TO
DRIFT SOUTHEAST ACROSS VA AND NC IN CYCLONIC FLOW ALOFT OVERNIGHT...
WHICH WILL LIKELY RESULT IN OCCASIONAL PATCHES OF CLOUDS THAT WILL
INTERRUPT OTHERWISE EXCELLENT VIEWING CONDITIONS FOR THE PEAK OF THE
PERSEID METEOR SHOWER.
INTERESTINGLY...THE HRRR HAS INSISTED FOR SEVERAL RUNS NOW THAT
SHOWERS WILL DEVELOP IN THE LEE OF THE APPALACHIANS AS THE
AFOREMENTIONED POCKET OF MID LEVEL MOISTURE PIVOTS EAST.
HOWEVER...SUCH DEVELOPMENT WOULD BE SURPRISING OWING TO UNSEASONABLY
LOW OBSERVED PRECIPITABLE WATER VALUES OF EIGHT TO NINE TENTHS OF AN
INCH; A LACK OF ANY NOTABLE FORCING FOR ASCENT ASIDE FROM WEAK
PERTURBATIONS IN CYCLONIC FLOW ALOFT; AND THE PRESENCE OF A STOUT
CAPPING INVERSION CENTERED NEAR 700 MB. WILL CONSEQUENTLY KEEP THE
FORECAST DRY...AT LEAST UNTIL OBSERVATIONAL TRENDS SUGGEST
OTHERWISE.
THE COMBINATION OF AN UNSEASONABLY DRY AIR MASS...AND CALM
CONDITIONS...SHOULD SUPPORT COOL TEMPERATURES MOSTLY IN THE LOWER TO
MIDDLE 60S BY MORNING.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 245 PM WEDNESDAY...
THE OVERALL SYNOPTIC PATTERN WILL REMAIN LARGELY UNCHANGED ON
THURSDAY...WITH AN UPPER LEVEL TROUGH OVER THE EAST COAST AND HIGH
PRESSURE AT THE SURFACE. HOWEVER...MODELS DO INDICATE A WEAK
INVERTED TROUGH DRIFTING OVER THE REGION BY THURSDAY AFTERNOON.
REGARDLESS...GIVEN THE VERY DRY AIR AND LACK OF INSTABILITY...STILL
AM EXPECTING A MOSTLY DRY DAY. TEMPS WILL ALSO BE SIMILAR TO WHAT IS
FORECAST FOR TODAY (WEDNESDAY)...WITH HIGHS IN THE MID/UPPER
80S...MAYBE RIGHT AROUND 90 DEGREES ACROSS THE SOUTH AND OVERNIGHT
LOWS GENERALLY IN THE MID 60S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 207 AM THURSDAY...
SUNDAY THROUGH MONDAY NIGHT: SURFACE HIGH PRESSURE WILL RESIDE OVER
THE CAROLINAS ON SUNDAY AND MONDAY AS FLOW ALOFT BECOMES ALMOST NON-
EXISTENT. AS A RESULT ANY KIND OF CONVECTIVE ACTIVITY WOULD HAVE TO
BE INSTABILITY DRIVEN. THE PROBLEM WITH THAT THOUGH IS THAT THE
AIRMASS IS VERY DRY AND SO INSTABILITY WILL BE HARD TO COME BY AS
WELL AT LEAST DURING THE FIRST HALF OF THE LONG TERM.
THEREFORE...WITH VERY LITTLE SHEAR...INSTABILITY...AND
MOISTURE...CONDITIONS SHOULD REMAIN DRY THROUGH MONDAY NIGHT.
TEMPERATURES DURING THIS TIME PERIOD WILL BE IN THE UPPER 80S TO LOW
90S WITH LOWS IN THE UPPER 60S TO NEAR 70 DEGREES.
TUESDAY THROUGH WEDNESDAY: STRONG AND DEEP LOW PRESSURE MOVING
ACROSS NORTHERN QUEBEC WILL HELP THE UPPER LEVEL EASTERN CONUS
TROUGH TO RE-EMERGE AND ALSO GUIDE A SURFACE COLD FRONT
SOUTHEASTWARD TOWARDS THE CAROLINAS ON TUESDAY. AHEAD OF THE
FRONT...MOISTURE WILL BEGIN TO PICK UP AS PW VALUES INCREASE TO OVER
AN INCH AND A HALF. THAT BEING SAID...INSTABILITY AND SHEAR ARE
STILL VERY LOW SO WILL ONLY INTRODUCE SLIGHT CHANCE POPS AT THIS
TIME UNTIL THE VERY END OF THE PERIOD WHEN THE LIKELIHOOD OF SEEING
AT LEAST SOME SHOWER AND THUNDERSTORM ACTIVITY WILL PICK UP.
CONSISTENCY IN MODEL SOLUTION TIMING OF THE FRONT CROSSING THE AREA
IS LACKING WITH THE GFS SHOWING A FASTER SOLUTION THAN THE ECMWF BUT
GENERAL CONSENSUS IS THAT THE FRONT WILL CROSS THE AREA SOMETIME ON
WEDNESDAY. TEMPERATURES AND HUMIDITY WILL CREEP UP AS OPPOSED TO
EARLIER IN THE WEEK WITH HIGHS SOLIDLY IN THE LOWER 90S AND LOWS IN
THE UPPER 60S TO LOW 70S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 125 AM THURSDAY...
AN AREA OF HIGH PRESSURE WILL PROVIDE CENTRAL NC WITH VFR CONDITIONS
INTO THE FIRST HALF OF THE WEEKEND. TODAY...THERE WILL BE A DECK OF
STRATOCUMULUS WITH BASES 6000-8000FT SKIRTING ACROSS THE REGION WITH
A PERIOD OF BROKEN CEILINGS POSSIBLE. IN ADDITION...THERE MAY BE A
SHORT PERIOD OF MVFR VISIBILITY DUE TO FOG AT KRWI BETWEEN
08Z-12Z. OTHERWISE SURFACE WINDS WILL BE LIGHT AND VARIABLE.
WHILE VFR CONDITIONS WILL LIKELY PERSIST LATE IN THE WEEKEND INTO
EARLY NEXT WEEK...CHANCES FOR EARLY MORNING MVFR/IFR CONDITIONS DUE
TO FOG AND LOW CLOUDS WILL BE ON THE INCREASE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...RAH
SHORT TERM...KRD
LONG TERM...ELLIS
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
125 AM EDT THU AUG 13 2015
.SYNOPSIS...HIGH PRESSURE WILL GRADUALLY BUILD INTO THE REGION FROM
THE NORTHWEST THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1010 PM WEDNESDAY...
DIURNAL CU HAS DIMINISHED AND RESULTED IN A MOSTLY CLEAR SKY ACROSS
CENTRAL NC THIS EVENING...ALTHOUGH SATELLITE IMAGERY REVEALS AN AREA
OF UPSTREAM SCT TO BKN ALTOCUMULUS IN A RELATIVE MAXIMUM OF MID-
LEVEL MOISTURE CENTERED OVER THE CENTRAL APPALACHIANS PER 00Z RAOB
DATA - MOST NOTABLE AT RNK. THIS AREA OF MOISTURE IS EXPECTED TO
DRIFT SOUTHEAST ACROSS VA AND NC IN CYCLONIC FLOW ALOFT OVERNIGHT...
WHICH WILL LIKELY RESULT IN OCCASIONAL PATCHES OF CLOUDS THAT WILL
INTERRUPT OTHERWISE EXCELLENT VIEWING CONDITIONS FOR THE PEAK OF THE
PERSEID METEOR SHOWER.
INTERESTINGLY...THE HRRR HAS INSISTED FOR SEVERAL RUNS NOW THAT
SHOWERS WILL DEVELOP IN THE LEE OF THE APPALACHIANS AS THE
AFOREMENTIONED POCKET OF MID LEVEL MOISTURE PIVOTS EAST.
HOWEVER...SUCH DEVELOPMENT WOULD BE SURPRISING OWING TO UNSEASONABLY
LOW OBSERVED PRECIPITABLE WATER VALUES OF EIGHT TO NINE TENTHS OF AN
INCH; A LACK OF ANY NOTABLE FORCING FOR ASCENT ASIDE FROM WEAK
PERTURBATIONS IN CYCLONIC FLOW ALOFT; AND THE PRESENCE OF A STOUT
CAPPING INVERSION CENTERED NEAR 700 MB. WILL CONSEQUENTLY KEEP THE
FORECAST DRY...AT LEAST UNTIL OBSERVATIONAL TRENDS SUGGEST
OTHERWISE.
THE COMBINATION OF AN UNSEASONABLY DRY AIR MASS...AND CALM
CONDITIONS...SHOULD SUPPORT COOL TEMPERATURES MOSTLY IN THE LOWER TO
MIDDLE 60S BY MORNING.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 245 PM WEDNESDAY...
THE OVERALL SYNOPTIC PATTERN WILL REMAIN LARGELY UNCHANGED ON
THURSDAY...WITH AN UPPER LEVEL TROUGH OVER THE EAST COAST AND HIGH
PRESSURE AT THE SURFACE. HOWEVER...MODELS DO INDICATE A WEAK
INVERTED TROUGH DRIFTING OVER THE REGION BY THURSDAY AFTERNOON.
REGARDLESS...GIVEN THE VERY DRY AIR AND LACK OF INSTABILITY...STILL
AM EXPECTING A MOSTLY DRY DAY. TEMPS WILL ALSO BE SIMILAR TO WHAT IS
FORECAST FOR TODAY (WEDNESDAY)...WITH HIGHS IN THE MID/UPPER
80S...MAYBE RIGHT AROUND 90 DEGREES ACROSS THE SOUTH AND OVERNIGHT
LOWS GENERALLY IN THE MID 60S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 205 PM WEDNESDAY...
THROUGH THE WEEKEND: AN UPPER LEVEL TROUGH WILL LINGER OVER THE
ATLANTIC COAST THROUGH THE WEEKEND...WITH GENERALLY SW FLOW ALOFT.
AT THE SURFACE...HIGH PRESSURE WILL DOMINATE...WITH GENERALLY
NORTHEASTERLY OR EASTERLY LIGHT WINDS. DURING THIS TIME...EXPECT DRY
WEATHER...WITH THE BEST CHANCES OF RAIN ALONG THE COAST (IN THE
VICINITY OF THE SURFACE BOUNDARY LINGERING OFF THE COAST) OR IN THE
MOUNTAINS. HIGHS WILL BE IN THE MID 80S TO AROUND 90 DEGREES...WITH
OVERNIGHT LOWS IN THE LOW TO MID 60S.
EARLY NEXT WEEK: RETURN FLOW AROUND THE HIGH WILL BECOME MORE
SOUTHERLY...ADVECTING RELATIVELY WARMER AND MORE MOIST AIR INTO
CENTRAL NC. MEANWHILE...THE AFOREMENTIONED TROUGH WEAKENS AS ANOTHER
APPROACHES FROM THE WEST. CLOUD COVER...ALONG WITH CHANCES FOR
SHOWERS AND STORMS WILL INCREASE THROUGH WEDNESDAY...ALTHOUGH THERE
IS A CHANCE MUCH OF THE AREA COULD REMAIN DRY OR SEE VERY LITTLE
PRECIPITATION. REGARDLESS...WILL CONTINUE TO FORECAST AT LEAST A
SLIGHT CHANCE FOR AFT/EVE SHOWERS/STORMS DURING THIS PERIOD. HIGHS
IN THE UPPER 80S TO LOW 90S EXPECTED...WITH GRADUALLY INCREASING
OVERNIGHT LOWS IN THE UPPER 60S TO LOW 70S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 125 AM THURSDAY...
AN AREA OF HIGH PRESSURE WILL PROVIDE CENTRAL NC WITH VFR CONDITIONS
INTO THE FIRST HALF OF THE WEEKEND. TODAY...THERE WILL BE A DECK OF
STRATOCUMULUS WITH BASES 6000-8000FT SKIRTING ACROSS THE REGION WITH
A PERIOD OF BROKEN CEILINGS POSSIBLE. IN ADDITION...THERE MAY BE A
SHORT PERIOD OF MVFR VISIBILITY DUE TO FOG AT KRWI BETWEEN
08Z-12Z. OTHERWISE SURFACE WINDS WILL BE LIGHT AND VARIABLE.
WHILE VFR CONDITIONS WILL LIKELY PERSIST LATE IN THE WEEKEND INTO
EARLY NEXT WEEK...CHANCES FOR EARLY MORNING MVFR/IFR CONDITIONS DUE
TO FOG AND LOW CLOUDS WILL BE ON THE INCREASE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...RAH
SHORT TERM...KRD
LONG TERM...RAH
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
125 AM CDT THU AUG 13 2015
.UPDATE...
ISSUED AT 110 AM CDT THU AUG 13 2015
THUNDERSTORMS WERE MOVING INTO A LESS UNSTABLE ENVIRONMENT OVER
CENTRAL NORTH DAKOTA AND WERE DIMINISHING TO RAIN SHOWERS. THE
AREA OF SHOWERS WILL PUSH EAST AS THE NIGHT WEARS ON.
UPDATE ISSUED AT 950 PM CDT WED AUG 12 2015
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE AS HIGH BASED
CONVECTION CONTINUES ACROSS SOUTHWEST NORTH DAKOTA IN ASSOCIATION
WITH AN EMBEDDED SHORTWAVE IN THE UPPER LEVEL RIDGE ACROSS FAR
SOUTHEAST MONTANA. OVERALL...THE MARGINAL SEVERE THREAT IS RAPIDLY
ENDING WITH SUNSET AS STORMS HAVE BECOME OUTFLOW DOMINATED. THE 02
UTC HRRR DOES HAVE A GOOD DEPICTION OF THE ONGOING CONVECTION AND
WILL FOLLOW ITS SOLUTION THROUGH THE REMAINDER OF THE NIGHT.
UPDATE ISSUED AT 604 PM CDT WED AUG 12 2015
AS OF 604 PM CDT...THE LONE SUPERCELL THAT WAS NEAR LAKE TSCHIDA
HAS NOW TRANSITIONED INTO A WEAKENING MULTI-CELL CLUSTER AFTER A
STORM MERGER OVER CENTRAL GRANT COUNTY. CERTAINLY CANNOT RULE OUT
ANOTHER LONE SUPERCELL THROUGH SUNSET AHEAD OF THE WEAK SURFACE
TROUGH ACROSS SOUTHWEST THROUGH NORTHEAST NORTH DAKOTA.
HOWEVER...GIVEN THE WARM TEMPERATURES...STORM COVERAGE WILL BE
VERY LOW. ALTHOUGH...ANY CELL THAT CAN BREAK THE CAP WOULD BE
CAPABLE OF DAMAGING WINDS WITH DCAPE VALUES IN EXCESS OF 1800
J/KG.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 228 PM CDT WED AUG 12 2015
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE EXCESSIVE
HEAT AND THUNDERSTORM CHANCES.
CURRENT SURFACE ANALYSIS INDICATES A SURFACE TROUGH EXTENDING FROM
MANITOBA SOUTHWEST INTO NORTHWEST NORTH DAKOTA. MUCH DRIER AIR
WITH DEWPOINTS IN THE UPPER 40S OVER FAR NORTHWEST NORTH DAKOTA
AND NORTHEAST MONTANA. AHEAD OF THE TROUGH MOISTURE POOLING HAS
RESULTED IN A BAND OF LOWER 70 DEWPOINTS FROM SOUTH CENTRAL INTO
NORTHEAST NORTH DAKOTA. SURFACE TEMPERATURES ARE IN THE 90S OVER
MOST OF THE FORECAST AREA...WITH A LARGE AREA OF UPPER 90S ALONG
AND WEST OF THE HIGHWAY 83 CORRIDOR.
APPARENT TEMPERATURES HAVE CLIMBED INTO THE LOWER 100S ACROSS
THE SOUTH CENTRAL INTO THE JAMES RIVER VALLEY. WILL ADD A MENTION
OF HEAT INDEX VALUES ABOVE 100 DEGREES THIS AFTERNOON. IT LOOKS
LIKE MAYBE A 3 HOUR PERIOD OR SO...THUS NO HEAT ADVISORY WILL BE
ISSUED.
UPPER LEVEL RIDGE REMAINS SITUATED OVER THE MONDAY AREA WITH A
SHORTWAVE IMPULSE RIDING DOWN THE RIDGE THROUGH SOUTHERN MANITOBA.
WE REMAIN VERY UNSTABLE ACROSS CENTRAL NORTH DAKOTA WITH ML CAPES
OVER 3000 J/KG AND DECENT BULK LAYER SHEAR. HOWEVER WE REMAIN
CAPPED UNDER THE WARM THERMAL RIDGE. LATEST ITERATIONS OF THE
RAP/HRRR HAVE INDICATED CONVECTION OVER THE FAR SOUTH CENTRAL AND
JAMES RIVER VALLEY FROM AROUND 5 TO 7 PM...BUT KEEP THE STRONGEST
CONVECTION ASSOCIATED WITH THE MANITOBA SHORTWAVE EAST OF THE
FORECAST AREA LATE THIS AFTERNOON AND THIS EVENING. WILL CERTAINLY
NEED TO MONITOR AS ANY THUNDERSTORM DEVELOPMENT COULD QUICKLY
BECOME STRONG TO SEVERE GIVEN THE VERY STRONG INSTABILITY. AS FAR
AS THE FORECAST...HAVE KEPT A SLIGHT CHANCE OVER THIS AREA THROUGH
MID EVENING.
TO THE WEST IT LOOKS LIKE THE RAP/HRRR ARE BRINGING IN CONVECTION
TOO EARLY AND ARE TOO WIDESPREAD WITH THIS CONVECTION. FORECAST
MODELS ARE FAIRLY CONSISTENT IN BRINGING AN AREA OF SHOWERS AND
ISOLATED THUNDERSTORMS INTO WESTERN NORTH DAKOTA TONIGHT AND
TRACKING SOUTHEAST...EXITING THE FAR SOUTH CENTRAL BY LATE
THURSDAY MORNING. THIS WAVE TRACKS BEHIND THE AFOREMENTIONED
SURFACE TROUGH SO THE LACK OF DEEP MOISTURE...COMBINED WITH THE
LACK OF SURFACE HEATING DUE TO THE TIMING...THE THREAT OF STRONGER
STORMS IS EXPECTED TO BE MINIMAL. THE ADDED CLOUD COVER SHOULD
KEEP TEMPERATURES A BIT LOWER MOST AREAS...BUT WE ARE STILL
LOOKING AT LOW TO MID 90S MOST AREAS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 228 PM CDT WED AUG 12 2015
THE LARGE AND PERSISTENT H500 RIDGE OVER THE CENTRAL US IS
FORECAST TO BREAK DOWN BY THE WEEKEND BY AN UPPER LEVEL LOW
CURRENTLY ACROSS THE EASTERN PACIFIC. THE LOW WILL RIDE UP AND
EVENTUALLY BEAT DOWN THE RIDGE BRINGING AN END TO OUR VERY WARM
WEATHER BY SUNDAY.
FOR THURSDAY NIGHT AND FRIDAY CONDITIONS WILL CONTINUE TO BE VERY
WARM WITH LOWS THURSDAY NIGHT IN THE MID TO UPPER 60S...AND HIGHS
FRIDAY FROM THE LOWER 90S FRONT THE TURTLE MOUNTAINS THROUGH THE
JAMES VALLEY...TO THE UPPER 90S IN THE WEST. SURFACE MOISTURE WILL
BE LIMITED BY THE RECENT LACK OF RAIN AND CURING VEGETATION AND AS A
RESULT SURFACE DEWPOINTS WILL NOT BE HIGH ENOUGH TO CREATE CRITICAL
HEAT INDEX VALUES.
AHEAD OF THE FRONT ON FRIDAY...GUSTY SOUTHERLY WINDS OF AROUND 20
MPH ARE EXPECTED. MINIMUM RELATIVE HUMIDITY OF AROUND 20 PERCENT
EXPECTED IN NORTHWESTERN NORTH DAKOTA. HOWEVER...FIRE MANAGERS HAVE
SAID THAT GRASSES ARE NOT CURED ENOUGH IN THE NORTHWEST FOR FIRE
WEATHER CONCERNS AS OF YET.
SOME FIRE WEATHER CONCERNS MAY POP UP IN THE SOUTHWEST ON SATURDAY
WITH GUSTY WEST WINDS OF 15 TO 20 MPH AND RELATIVE HUMIDITY OF 20 TO
25 PERCENT BEHIND THE COLD FRONT ON SATURDAY. THOSE CONDITIONS WOULD
STILL BE JUST BELOW RED FLAG CRITERIA FOR THE SOUTHWEST...WHERE FIRE
MANAGERS SAY THE GRASSES ARE CURING QUICKLY.
A CHANCE OF THUNDERSTORMS CAN BE EXPECTED AHEAD OF THE FRONT FRIDAY
NIGHT IN THE WEST...AND OVER WESTERN AND CENTRAL NORTH DAKOTA
SATURDAY INTO SATURDAY NIGHT ON EITHER SIDE OF THE FRONT AS IT
PASSES THROUGH THE STATE.
BY SUNDAY MUCH COOLER AIR WILL FLOW IN WITH HIGH TEMPERATURES IN THE
70S TO AROUND 80. COOLER AND MORE PLEASANT WEATHER WILL REMAIN IN
PLACE MONDAY TROUGH WEDNESDAY WITH HIGHS MAINLY IN THE MID TO UPPER
70S. SCATTERED THUNDERSTORMS WILL REMAIN IN THE FORECAST WITH
CYCLONIC FLOW AND SHORTWAVE ENERGY MOVING THROUGH SOUTHERN CANADA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 110 AM CDT THU AUG 13 2015
SHOWERS WILL BE MOVING ACROSS THE AREA OVERNIGHT. MOST AREAS DRY
FOR THURSDAY DAYTIME WITH VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JPM
SHORT TERM...TWH
LONG TERM...JV
AVIATION...JPM
AREA FORECAST DISCUSSION
NWS NORMAN OK
1157 PM CDT WED AUG 12 2015
.DISCUSSION...
THE AVIATION DISCUSSION FOR THE 06Z TAFS IS BELOW.
&&
.AVIATION...
GENERALLY EXPECT VFR CONDITIONS THROUGH THE TAF PERIOD.
SHOWERS AND ISOLATED THUNDERSTORMS MAY DEVELOP ACROSS WESTERN
OKLAHOMA AFTER 09Z TONIGHT. IF THE CONVECTION DEVELOPS....IT WILL
INITIALLY AFFECT KGAG AND KWWR. AS THE STORMS SHIFT
SOUTHWARD...THEY WOULD AFFECT KCSM/KHBR/KLAW LATER IN THE
MORNING. KOKC AND KOUN WOULD BE ON THE EASTERN FRINGE FOR ANY
POTENTIAL IMPACTS. IF A HEAVIER SHOWER OR THUNDERSTORM OCCURS OVER
A TAF SITE...MAY SEE A BRIEF PERIOD OF MVFR FLIGHT CONDITIONS.
HOWEVER...CONFIDENCE AND EXPECTED COVERAGE IS TOO LOW TO INCLUDE
MENTION OF TSRA IN TAFS.
MAHALE
&&
.PREV DISCUSSION... /ISSUED 938 PM CDT WED AUG 12 2015/
UPDATE...
ADDED/INCREASED POPS FOR OVERNIGHT AND THURSDAY MORNING.
DISCUSSION...
WITH DEEP MID-LEVEL MOIST LAYER NOT GOING ANYWHERE...OTHER THAN
SHIFTING SLIGHTLY EAST FROM WHERE IT WAS LAST NIGHT AND
TODAY...WEAK MID-LEVEL /H7/ WAA MAY RESULT IN SCATTERED SHOWER
DEVELOPMENT LATE TONIGHT. CANNOT RULE OUT A THUNDERSTORM OR TWO
BUT THEY WILL BE BRIEF AND WEAK. WE WILL INCREASE THE POPS A BIT
FOR TONIGHT ACROSS WESTERN PARTS OF CWA AND SPREAD INTO CENTRAL
OKLAHOMA AFTER DAYBREAK WITH EASTWARD PROG OF MOIST AXIS. WRF AND
RAP FAIRLY CONSISTENT ON WEAK SIGNAL BUT OTHER MODELS HAVE
NOTHING. WRF AND RAP HAVE HANDLED THE WEAKLY FORCED ACTIVITY
BETTER THE PAST FEW DAYS SO WE WILL STICK CLOSER TO THOSE
SOLUTIONS IN THIS UPDATE.
PREV DISCUSSION... /ISSUED 643 PM CDT WED AUG 12 2015/
DISCUSSION...
THE AVIATION DISCUSSION FOR THE 00Z TAFS IS BELOW.
AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD.
ISOLATED SHOWERS AND THUNDERSTORMS MAY DEVELOP ACROSS WESTERN
OKLAHOMA AFTER 09Z TONIGHT. IF THE STORMS DEVELOP....THEY WILL
INITIALLY AFFECT KGAG AND KWWR. AS THE STORMS SHIFT
SOUTHWARD...THEY MAY AFFECT KCSM/KHBR/KLAW LATER IN THE MORNING.
HOWEVER...CONFIDENCE IN STORM DEVELOPMENT IS TOO LOW TO MENTION
IN TAFS FOR NOW.
MAHALE
PREV DISCUSSION... /ISSUED 340 PM CDT WED AUG 12 2015/
DISCUSSION...
THE PERSISTENT LIGHT TO MODERATE RAIN IN WESTERN OKLAHOMA IS
EXPECTED TO LAST SEVERAL MORE HOURS BEFORE DISSIPATING THIS
EVENING. ADDITIONAL RAIN MAY DEVELOP ALONG THE ELEVATED FRONTAL
ZONE LATE TONIGHT INTO THURSDAY MORNING...BUT INDICATIONS SUGGEST
WEAKER FORCING...SO LOWER CHANCES FOR RAIN THEN.
VARIOUS WEAK FEATURES WILL RESULT IN A FEW PERIODS OF LOW RAIN
CHANCES OVER RELATIVELY SMALL GEOGRAPHIC AREAS THROUGH EARLY NEXT
WEEK. IN GENERAL...LITTLE CHANGE TO THE WEATHER IS EXPECTED
THROUGH THE PERIOD.
MEDIUM-RANGE MODELS SUGGEST A MORE POWERFUL STORM SYSTEM IN THE
NORTHERN PLAINS ABOUT MIDWEEK...AND IF THIS ACTUALLY HAPPENS...IT
COULD PUSH A RELATIVELY STRONG COLD FRONT INTO THE SOUTHERN
PLAINS WEDNESDAY OR THURSDAY OF NEXT WEEK. THIS WOULD GREATLY
INCREASE RAIN CHANCES...AND BRING RELATIVELY MILD WEATHER INTO THE
REGION...IF...IT HAPPENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 65 90 68 89 / 10 30 10 0
HOBART OK 68 94 71 92 / 20 30 0 10
WICHITA FALLS TX 70 95 72 94 / 10 40 0 10
GAGE OK 65 91 70 92 / 20 20 0 0
PONCA CITY OK 64 90 69 90 / 0 10 0 10
DURANT OK 69 94 67 94 / 0 10 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
11/10/10
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
603 AM EDT THU AUG 13 2015
.SYNOPSIS...
THE UPPER LEVEL TROUGH THAT BROUGHT US A CHANGE TO COOLER WEATHER
WITH LOW DAYTIME HUMIDITY...WILL BE GRADUALLY WEAKENING OVER THE
NEXT FEW DAYS. WARMER TEMPERATURES WILL MOVE INTO THE REGION OVER
THE UPCOMING WEEKEND. ANOTHER TROUGH AND SURFACE COLD FRONT SHOULD
BRING COOLER AND DRIER AIR BACK INTO THE REGION AROUND MIDWEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLEAR SKIES OVER THE ENTIRE REGION EARLY THIS MORNING...AND THE
FINAL DAY OF THE WANING CRESCENT MOON...WAS BRINGING FANTASTIC
CONDITIONS TO VIEW THE PEAK OF THE PERSEID METEOR SHOWER. TONIGHT
COULD FEATURE SIMILAR CONDITIONS WITH A NEW MOON...BUT AREAS OF
MID AND CLOUD CLOUDS COULD DRIFT SOUTHEAST ACROSS THE REGION AT
TIMES.
TEMPS WERE QUITE CHILLY FOR MID AUGUST...WITH BRADFORD TAKING THE
PRIZE FOR THE LOW TEMP OF 44F AT 09Z.
ELSEWHERE...TEMPS WERE IN THE 50S...TO NEAR 60F IN THE LARGER
METRO AREAS THROUGHOUT THE SUSQ VALLEY.
SOME HIGH CLOUDS WILL DRIFT SE INTO THE COMMONWEALTH TODAY...BUT
THEY WILL BE QUITE THIN AND SHOULD HAVE LITTLE OR NO IMPACT ON
THE OTHERWISE SUNNY...AND SPLENDID CONDITIONS FOR THE MIDDLE OF
AUGUST.
AFTERNOON HIGHS WILL BE IN THE L-M 70S ACROSS THE NRN AND WRN
MTNS...AND AROUND 80F IN THE LOWER SUSQ VALLEY.
THERE COULD BE SOME PATCHY AM...FOG ESPECIALLY NEAR WATER BODIES
AND STREAMS THROUGHOUT THE NORTHERN MOUNTAINS WHERE THE AIR/WATER
DELTA T IS 20 DEG F OR MORE.
00Z WRFARW AND THE LATEST...03Z SREF BOTH SHOW A LOW PROB FOR
SHOWERS ACROSS THE NW PENN MTNS BETWEEN ABOUT 20Z TODAY AND 00Z
FRIDAY...WHILE THE HRRR IS BONE DRY. OUR 10-20 POPS THERE CONTINUE
TO LOOK IN GOOD SHAPE. POPS ELSEWHERE WILL BE ESSENTIALLY ZERO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WARMER TEMPS ARE ON THE WAY FOR FRIDAY. THE ONLY WEATHER FACTORS
ALOFT TO SPEAK OF WILL BE THE PERIODS OF ALTOCU AND CIRRUS THAT
WILL BE MOVING QUICKLY SE ACROSS THE STATE.
HIGH TEMPS FRIDAY WILL VARY FROM THE U70S TO AROUND 80F ACROSS THE
HIGHER TERRAIN OF THE NORTH AND WEST...WHILE THE LOW SUSQ VALLEY
SEES TEMPS RECH ATLEAT 85F.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE SFC HIGH PRESSURE WILL BREAK DOWN AS A SHALLOW TROUGH WILL
DEEPEN AND ALLOW A COLD FRONT TO TRAVERSE THE REGION FRIDAY
AFTERNOON INTO SATURDAY. THE MOISTURE WILL BE FOCUSED ALONG THE
NEW YORK BORDER AND NORTH. THOUGH AS THE TROUGH CONTINUES TO TILT
POSITIVE AND DEEPENS...THERE WILL BE A GREATER CHANCE FOR SHOWERS
AND THUNDERSTORMS ALONG THE CENTRAL MTNS AND THROUGH THE NORTHERN
HALF OF PA. TEMPERATURES WILL BEGIN TO REBOUND UNDER THIS MORE
WESTERLY FLOW OUT AHEAD OF THE FRONT WHICH WILL AID IN ANY
CONVECTION. THE FRONT SHOULD STALL ON SATURDAY...WHICH COULD ALLOW
FOR DAYTIME SUMMER CONVECTION BEFORE THE COLD FRONT PUSHES EAST OF
PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL RETURN FOR THE
BEGINNING OF NEXT WEEK. GIVEN THE PATTERN HAVE ADJUSTED POPS
UPWARD AND SHIFTED THE TIMING ACCORDINGLY. HAVE ADJUSTED
TEMPERATURES UPWARD AS WELL. THE ACTIVE WEATHER PATTERN WILL
CONTINUE THROUGH THE MIDDLE OF NEXT WEEK AS SUCCESSIVE TROUGHS
WILL MOVE THROUGH THE REGION WITH THE NEXT BEST CHANCE TUESDAY
INTO WEDNESDAY.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
09Z TAFS SENT.
EARLIER DISCUSSION BELOW.
MAINLY CLEAR OUT. SOME FOG AROUND...MAINLY AT BFD.
06Z TAFS SENT.
EARLIER DISCUSSION BELOW.
SHOWERS ARE DECREASING IN COVERAGE AS WE MOVE TOWARD SUNSET. A FEW
ISOLATED SHOWERS ARE CREEPING THROUGH THE SOUTH CENTRAL MOUNTAINS
AND JUST OT THE NORTH OF KIPT. WITH THE LOSS OF DAYTIME
HEATING...EXPECT SKIES TO CLEAR AFTER SUNSET WITH PATCHY MVFR FOG
LATER TONIGHT.
THE UPPER TROUGH AXIS BEGINS TO PULL AWAY TO THE NORTHEAST
TOMORROW WHICH WILL ALLOW FOR GOOD VFR CONDITIONS THROUGH THE DAY.
OUTLOOK...
FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
SUN...NO SIG WX.
MON...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...GRUMM/LAMBERT
LONG TERM...CERU/HAGNER
AVIATION...DANGELO/MARTIN/TYBURSKI
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
524 AM EDT THU AUG 13 2015
.SYNOPSIS...
THE UPPER LEVEL TROUGH OVER THE REGION WILL GRADUALLY WEAKEN OVER
THE NEXT FEW DAYS. WARMER TEMPERATURES WILL MOVE INTO THE REGION
OVER THE UPCOMING WEEKEND. ANOTHER TROUGH AND SURFACE COLD FRONT
SHOULD BRING COOLER AND DRIER AIR BACK INTO THE REGION AROUND
MIDWEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
CLEAR SKIES OVER MOST OF THE REGION EARLY THIS MORNING...WITH A
FEW AREAS OF ALTO CU CLOUDS OVER OUR FAR EASTERN COUNTIES...SOON
TO BE EXITING TO THE EAST OF THE CWA. OVERALL GREAT CONDITIONS TO
VIEW THE PEAK OF THE PERSEID METEOR SHOWER.
LIGHT WIND TO CALM AIR ACROSS THE CWA WILL COMBINE WITH SFC
DEWPOINTS IN THE L-M 50S ACROSS CENTRAL AND WRN PENN /AND LOWER
60S OVER THE SUSQ VALLEY/ TO ALLOW ANOTHER SEVERAL DEG F OF
COOLING THROUGH 11Z.
THERE COULD BE SOME PATCHY AM...FOG ESPECIALLY NEAR WATER BODIES
AND STREAMS THROUGHOUT THE NORTHERN MOUNTAINS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/...
MOST GUIDANCE SHOWS A REALLY NICE DAY LIGHT WINDS AND MOSTLY SUNNY
SKIES. THE HRRR ONLY GOES TO 15Z AND IT SHOWS A PRETTY CLEAR RADAR
SCOPE SO TO SPEAK.
THE OPERATIONAL 21Z SREF SHOWS SOME MODEST SHOWER POTENTIAL IN
NORTHWEST PA WITH ABOUT A 15 PERCENT CHANCE OF SHOWERS. THE NEWER
26 MEMBER PARALLEL SREF HAS 5 PERCENT CHANCE OVER A SMALLER
AREA...BASICALLY PARTS OF WARREN COUNTY BETWEEN 21 AND 00 UTC.
THE OVERALL CONSENSUS IS QUITE LOW FOR POPS OVER MOST OF THE
REGION PROBABLY NOT WORTH MENTIONING. PERHAPS A SLIGHT CHANCE OVER
EXTREME NORTHWESTERN PA. BUT VERY LOW PROBABILITY.
SHOULD BE A GOOD DAY TO BE OUTDOORS OVER THE ENTIRE REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE SFC HIGH PRESSURE WILL BREAK DOWN AS A SHALLOW TROUGH WILL
DEEPEN AND ALLOW A COLD FRONT TO TRAVERSE THE REGION FRIDAY
AFTERNOON INTO SATURDAY. THE MOISTURE WILL BE FOCUSED ALONG THE
NEW YORK BORDER AND NORTH. THOUGH AS THE TROUGH CONTINUES TO TILT
POSITIVE AND DEEPENS...THERE WILL BE A GREATER CHANCE FOR SHOWERS
AND THUNDERSTORMS ALONG THE CENTRAL MTNS AND THROUGH THE NORTHERN
HALF OF PA. TEMPERATURES WILL BEGIN TO REBOUND UNDER THIS MORE
WESTERLY FLOW OUT AHEAD OF THE FRONT WHICH WILL AID IN ANY
CONVECTION. THE FRONT SHOULD STALL ON SATURDAY...WHICH COULD ALLOW
FOR DAYTIME SUMMER CONVECTION BEFORE THE COLD FRONT PUSHES EAST OF
PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL RETURN FOR THE
BEGINNING OF NEXT WEEK. GIVEN THE PATTERN HAVE ADJUSTED POPS
UPWARD AND SHIFTED THE TIMING ACCORDINGLY. HAVE ADJUSTED
TEMPERATURES UPWARD AS WELL. THE ACTIVE WEATHER PATTERN WILL
CONTINUE THROUGH THE MIDDLE OF NEXT WEEK AS SUCCESSIVE TROUGHS
WILL MOVE THROUGH THE REGION WITH THE NEXT BEST CHANCE TUESDAY
INTO WEDNESDAY.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
09Z TAFS SENT.
EARLIER DISCUSSION BELOW.
MAINLY CLEAR OUT. SOME FOG AROUND...MAINLY AT BFD.
06Z TAFS SENT.
EARLIER DISCUSSION BELOW.
SHOWERS ARE DECREASING IN COVERAGE AS WE MOVE TOWARD SUNSET. A FEW
ISOLATED SHOWERS ARE CREEPING THROUGH THE SOUTH CENTRAL MOUNTAINS
AND JUST OT THE NORTH OF KIPT. WITH THE LOSS OF DAYTIME
HEATING...EXPECT SKIES TO CLEAR AFTER SUNSET WITH PATCHY MVFR FOG
LATER TONIGHT.
THE UPPER TROUGH AXIS BEGINS TO PULL AWAY TO THE NORTHEAST
TOMORROW WHICH WILL ALLOW FOR GOOD VFR CONDITIONS THROUGH THE DAY.
OUTLOOK...
FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
SUN...NO SIG WX.
MON...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/LAMBERT
NEAR TERM...GRUMM/LAMBERT
SHORT TERM...GRUMM
LONG TERM...CERU/HAGNER
AVIATION...DANGELO/MARTIN/TYBURSKI
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
248 AM EDT THU AUG 13 2015
.SYNOPSIS...
THE UPPER LEVEL TROUGH OVER THE REGION WILL GRADUALLY WEAKEN OVER
THE NEXT FEW DAYS. WARMER TEMPERATURES WILL MOVE INTO THE REGION
OVER THE UPCOMING WEEKEND. ANOTHER TROUGH AND SURFACE COLD FRONT
SHOULD BRING COOLER AND DRIER AIR BACK INTO THE REGION AROUND
MIDWEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
CLEAR SKIES OVER MOST OF THE REGION EARLY THIS MORNING...WITH A
FEW AREAS OF ALTO CU CLOUDS OVER OUR FAR EASTERN COUNTIES...SOON
TO BE EXITING TO THE EAST OF THE CWA. OVERALL GREAT CONDITIONS TO
VIEW THE PEAK OF THE PERSEID METEOR SHOWER.
LIGHT WIND TO CALM AIR ACROSS THE CWA WILL COMBINE WITH SFC
DEWPOINTS IN THE L-M 50S ACROSS CENTRAL AND WRN PENN /AND LOWER
60S OVER THE SUSQ VALLEY/ TO ALLOW ANOTHER SEVERAL DEG F OF
COOLING THROUGH 11Z.
THERE COULD BE SOME PATCHY AM...FOG ESPECIALLY NEAR WATER BODIES
AND STREAMS THROUGHOUT THE NORTHERN MOUNTAINS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/...
MOST GUIDANCE SHOWS A REALLY NICE DAY LIGHT WINDS AND MOSTLY SUNNY
SKIES. THE HRRR ONLY GOES TO 15Z AND IT SHOWS A PRETTY CLEAR RADAR
SCOPE SO TO SPEAK.
THE OPERATIONAL 21Z SREF SHOWS SOME MODEST SHOWER POTENTIAL IN
NORTHWEST PA WITH ABOUT A 15 PERCENT CHANCE OF SHOWERS. THE NEWER
26 MEMBER PARALLEL SREF HAS 5 PERCENT CHANCE OVER A SMALLER
AREA...BASICALLY PARTS OF WARREN COUNTY BETWEEN 21 AND 00 UTC.
THE OVERALL CONSENSUS IS QUITE LOW FOR POPS OVER MOST OF THE
REGION PROBABLY NOT WORTH MENTIONING. PERHAPS A SLIGHT CHANCE OVER
EXTREME NORTHWESTERN PA. BUT VERY LOW PROBABILITY.
SHOULD BE A GOOD DAY TO BE OUTDOORS OVER THE ENTIRE REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE SFC HIGH PRESSURE WILL BREAK DOWN AS A SHALLOW TROUGH WILL
DEEPEN AND ALLOW A COLD FRONT TO TRAVERSE THE REGION FRIDAY
AFTERNOON INTO SATURDAY. THE MOISTURE WILL BE FOCUSED ALONG THE
NEW YORK BORDER AND NORTH. THOUGH AS THE TROUGH CONTINUES TO TILT
POSITIVE AND DEEPENS...THERE WILL BE A GREATER CHANCE FOR SHOWERS
AND THUNDERSTORMS ALONG THE CENTRAL MTNS AND THROUGH THE NORTHERN
HALF OF PA. TEMPERATURES WILL BEGIN TO REBOUND UNDER THIS MORE
WESTERLY FLOW OUT AHEAD OF THE FRONT WHICH WILL AID IN ANY
CONVECTION. THE FRONT SHOULD STALL ON SATURDAY...WHICH COULD ALLOW
FOR DAYTIME SUMMER CONVECTION BEFORE THE COLD FRONT PUSHES EAST OF
PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL RETURN FOR THE
BEGINNING OF NEXT WEEK. GIVEN THE PATTERN HAVE ADJUSTED POPS
UPWARD AND SHIFTED THE TIMING ACCORDINGLY. HAVE ADJUSTED
TEMPERATURES UPWARD AS WELL. THE ACTIVE WEATHER PATTERN WILL
CONTINUE THROUGH THE MIDDLE OF NEXT WEEK AS SUCCESSIVE TROUGHS
WILL MOVE THROUGH THE REGION WITH THE NEXT BEST CHANCE TUESDAY
INTO WEDNESDAY.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
MAINLY CLEAR OUT. SOME FOG AROUND...MAINLY AT BFD.
06Z TAFS SENT.
EARLIER DISCUSSION BELOW.
SHOWERS ARE DECREASING IN COVERAGE AS WE MOVE TOWARD SUNSET. A FEW
ISOLATED SHOWERS ARE CREEPING THROUGH THE SOUTH CENTRAL MOUNTAINS
AND JUST OT THE NORTH OF KIPT. WITH THE LOSS OF DAYTIME
HEATING...EXPECT SKIES TO CLEAR AFTER SUNSET WITH PATCHY MVFR FOG
LATER TONIGHT.
THE UPPER TROUGH AXIS BEGINS TO PULL AWAY TO THE NORTHEAST
TOMORROW WHICH WILL ALLOW FOR GOOD VFR CONDITIONS THROUGH THE DAY.
OUTLOOK...
FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
SUN...NO SIG WX.
MON...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/LAMBERT
NEAR TERM...GRUMM/LAMBERT
SHORT TERM...GRUMM
LONG TERM...CERU/HAGNER
AVIATION...DANGELO/MARTIN/TYBURSKI
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
146 AM EDT THU AUG 13 2015
.SYNOPSIS...
THE UPPER LEVEL TROUGH OVER THE REGION WILL WEAKEN OVER THE NEXT
FEW DAYS. HIGHER HEIGHTS SHOULD MOVE INTO THE REGION OVER THE
WEEKEND ALONG WITH WARMER TEMPERATURES. ANOTHER TROUGH AND SURFACE
COLD FRONT SHOULD BRING COOLER AND DRIER AIR BACK INTO THE REGION
AROUND MIDWEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
MINOR ADJUSTMENTS TO TEMPERATURES AND WEATHER. LAST OF THE PESKY
SHOWERS FINALLY FADING OUT OVER COLUMBIA COUNTY AND SOME CLOUDS AT
LEAST WITH THE REMNANTS OF THE SHOWERS THAT AFFECTED A FEW
LOCATIONS IN THE SOUTHEAST.
MOST AREAS ARE MOSTLY CLEAR EXCEPT THE ABOVE MENTIONED AREAS.
SHOULD BECOME MOSTLY CLEAR AND COOL EVERYWHERE OVERNIGHT. PLEASANT
DRY MORNING. COULD BE SOME PATCHY AM FOG ESPECIALLY NEAR WATER
BODIES AND STREAMS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/...
MOST GUIDANCE SHOWS A REALLY NICE DAY LIGHT WINDS AND MOSTLY SUNNY
SKIES. THE HRRR ONLY GOES TO 15Z AND IT SHOWS A PRETTY CLEAR RADAR
SCOPE SO TO SPEAK.
THE OPERATIONAL 21Z SREF SHOWS SOME MODEST SHOWER POTENTIAL IN
NORTHWEST PA WITH ABOUT A 15 PERCENT CHANCE OF SHOWERS. THE NEWER
26 MEMBER PARALLEL SREF HAS 5 PERCENT CHANCE OVER A SMALLER
AREA...BASICALLY PARTS OF WARREN COUNTY BETWEEN 21 AND 00 UTC.
THE OVERALL CONSENSUS IS QUITE LOW FOR POPS OVER MOST OF THE
REGION PROBABLY NOT WORTH MENTIONING. PERHAPS A SLIGHT CHANCE OVER
EXTREME NORTHWESTERN PA. BUT VERY LOW PROBABILITY.
SHOULD BE A GOOD DAY TO BE OUTDOORS OVER THE ENTIRE REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE SFC HIGH PRESSURE WILL BREAK DOWN AS A SHALLOW TROUGH WILL
DEEPEN AND ALLOW A COLD FRONT TO TRAVERSE THE REGION FRIDAY
AFTERNOON INTO SATURDAY. THE MOISTURE WILL BE FOCUSED ALONG THE
NEW YORK BORDER AND NORTH. THOUGH AS THE TROUGH CONTINUES TO TILT
POSITIVE AND DEEPENS...THERE WILL BE A GREATER CHANCE FOR SHOWERS
AND THUNDERSTORMS ALONG THE CENTRAL MTNS AND THROUGH THE NORTHERN
HALF OF PA. TEMPERATURES WILL BEGIN TO REBOUND UNDER THIS MORE
WESTERLY FLOW OUT AHEAD OF THE FRONT WHICH WILL AID IN ANY
CONVECTION. THE FRONT SHOULD STALL ON SATURDAY...WHICH COULD ALLOW
FOR DAYTIME SUMMER CONVECTION BEFORE THE COLD FRONT PUSHES EAST OF
PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL RETURN FOR THE
BEGINNING OF NEXT WEEK. GIVEN THE PATTERN HAVE ADJUSTED POPS
UPWARD AND SHIFTED THE TIMING ACCORDINGLY. HAVE ADJUSTED
TEMPERATURES UPWARD AS WELL. THE ACTIVE WEATHER PATTERN WILL
CONTINUE THROUGH THE MIDDLE OF NEXT WEEK AS SUCCESSIVE TROUGHS
WILL MOVE THROUGH THE REGION WITH THE NEXT BEST CHANCE TUESDAY
INTO WEDNESDAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
MAINLY CLEAR OUT. SOME FOG AROUND...MAINLY AT BFD.
06Z TAFS SENT.
EARLIER DISCUSSION BELOW.
SHOWERS ARE DECREASING IN COVERAGE AS WE MOVE TOWARD SUNSET. A FEW
ISOLATED SHOWERS ARE CREEPING THROUGH THE SOUTH CENTRAL MOUNTAINS
AND JUST OT THE NORTH OF KIPT. WITH THE LOSS OF DAYTIME
HEATING...EXPECT SKIES TO CLEAR AFTER SUNSET WITH PATCHY MVFR FOG
LATER TONIGHT.
THE UPPER TROUGH AXIS BEGINS TO PULL AWAY TO THE NORTHEAST
TOMORROW WHICH WILL ALLOW FOR GOOD VFR CONDITIONS THROUGH THE DAY.
OUTLOOK...
FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
SUN...NO SIG WX.
MON...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...CERU/HAGNER
AVIATION...DANGELO/MARTIN/TYBURSKI
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1138 PM CDT WED AUG 12 2015
.AVIATION...
VFR WITH LIGHT SE WINDS VEERING S-SW BY THUR AFTN.
.PREV DISCUSSION... /ISSUED 339 PM CDT WED AUG 12 2015/
SHORT TERM...
MID-LEVEL MOISTURE EVIDENT ON WATER VAPOR STREAMING WESTWARD
ACROSS TRANS-PECOS AND BIG BEND THIS AFTERNOON HAS EXPANDED ITS
NORTHERN PERIPHERY INTO THE SOUTH PLAINS. MID-LEVEL MOISTURE
COUPLED WITH WEAK UPSLOPE HAS RESULTED IN CU FIELD SIMILAR TO
YESTERDAY AFTERNOON BUT WITH SOMEWHAT LESS COVERAGE AND FOR NOW
LESS VERTICAL EXTENT.
STEEP LOW LEVEL LAPSE RATES OF -10/KM OR MORE ARE RUNNING INTO
ALMOST AS IMPRESSIVE CAPPING INVERSIONS ACROSS OUR AREA THAT SHOULD
KEEP ANY SHOWERS OR TSTORMS FROM INITIATING. SHORT TERM GUIDANCE
HAS CONTINUED TO STRUGGLE WITH VERTICAL WIND PROFILES AS HIGH
PRESSURE SLOWLY MIGRATES OUT OF WEST TEXAS TOWARD THE FOUR
CORNERS. STREAMLINE SURFACE CONVERGENCE EXTENDING SOUTHWARD DOWN
THE I27 CORRIDOR AND ITS SUBSEQUENT CI CONSISTENTLY ADVERTISED BY
THE HRRR ALL MORNING HAS NOT MATERIALIZED...WHILE THE RAP HAS
STRUGGLED WITH SIMILAR ISSUES. HAVE BEEN WATCHING THE TX/NM BORDER
NEAR THE SW TEXAS PANHANDLE CLOSELY OVER THE LAST COUPLE OF HOURS
GIVEN PERSISTENT SHOWERS AND TSTORMS THE LAST COUPLE OF WEEKS BUT
HAVE DECIDED TO KEEP OUT ANY MENTIONABLE POPS ATTM. ADJUSTED
TEMPS UP A COUPLE OF DEGREES ACROSS OUR SE COUNTIES IN THE ROLLING
PLAINS GIVEN CURRENT TRENDS...OTHERWISE GUIDANCE FOR TEMPS
TODAY...TONIGHT AND TOMORROW SEEM GOOD.
CLOUDS SHOULD CLEAR AFTER SUNSET PROVIDING GOOD VIEWING OF
TONIGHT/S PERSEID METEOR SHOWER PEAKING AFTER MIDNIGHT. HAVE NO
MENTIONABLE POPS IN PLACE OVERNIGHT INTO TOMORROW BUT THERE IS A
NONZERO CHANCE OF LIGHT SHOWERS BRUSHING OUR EASTERN ZONES OFF THE
CAPROCK IF OVERNIGHT CONVECTION SIMILAR TO WHAT WE SAW LAST NIGHT
IS ABLE TO WORK ITS WAY FAR ENOUGH SOUTH OUT OF THE NORTHERN TEXAS
PANHANDLE AND WESTERN OKLAHOMA.
LONG TERM...
THE UA RIDGE IS STILL PROJECTED TO DRIFT WRD TO ACROSS THE FOUR-
CORNERS BY THIS WEEKEND...AND WILL BE PARKED THERE FOR THE MAJORITY
OF THE EXTENDED PERIOD. A FEW MODEL SOLUTIONS CONTINUE TO HINT AT
CHANCES FOR PRECIP MORE SO OFF THE CAPROCK ON FRIDAY...APPEARING TO
BE COURTESY OF A BIT OF MID-UPPER LEVEL MOISTENING AND WEAK
ISENTROPIC UPGLIDE. ALTHOUGH 1000-2000 J/KG OF SFC-BASED CAPE WILL
BE AVAILABLE...A WEAK CAP IS NOTICEABLE PER MODEL SOUNDINGS
AROUND 700 MB...THEREBY INSINUATING THE POTENTIAL FOR SHOWERY/WEAK
THUNDERSTORM ACTIVITY. BY THE WEEKEND INTO EARLY NEXT WEEK
HOWEVER...FOCUS FOR PRECIP WILL SWITCH TO LOCALES ON THE
CAPROCK...NEAREST TO A SFC TROUGH. ALTHOUGH...FLOW ALOFT WILL BE
FROM A NORTHERLY TO NORTHEASTERLY FLOW WHICH IS NOT VERY CONDUCIVE
FOR STORMS ACROSS THE HIGHER TERRAIN OF NM AND CO TO MAKE IT TO
THE SOUTH PLAINS. IT WILL BE HIGHLY DEPENDENT ON THE LOCATION OF
THE AFOREMENTIONED SFC TROUGH...WHETHER IT WILL BE CONFINED TO NM
/AS SUGGESTED BY MODEL SOLUTIONS/ OR CLOSER TO THE TX/NM BORDER.
NONETHELESS...SLIGHT CHANCE POPS PER THE SUPER-BLENDED SOLUTION
APPEARS REASONABLE ATTM. BY MID-WEEK...AN UA SHORTWAVE POISED TO
MOVE FROM THE NW PACIFIC TO THE CENTRAL/NORTHERN PLAINS WILL
RESULT IN THE DE-AMPLIFICATION OF THE UA RIDGE TO OUR WEST AND
HEIGHT FALLS ACROSS THE SOUTHERN PLAINS AS A COLD FRONT
POTENTIALLY APPROACHES THE CWA. WE WILL SEE IF THIS CHANGE IN THE
SYNOPTIC PATTERN DOES INDEED COME INTO FRUITION...AS THAT COLD
FRONT COULD BE OUR NEXT SHOT AT PRECIP.
GIVEN THE UA RIDGE WILL BE NOT BE DIRECTLY OVERHEAD...TEMPS WILL
WARM TO SEASONAL NORMS THROUGHOUT THE EXTENDED PERIOD /LOWER 90S ON
THE CAPROCK TO MIDDLE TO UPPER 90S OFF THE CAPROCK/.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CDT WED AUG 12 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 308 PM CDT WED AUG 12 2015
MAIN FORECAST CONCERNS ARE SMALL PRECIPITATION CHANCES TONIGHT INTO
THURSDAY.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL RIDGE
AMPLIFYING OVER THE ROCKY MOUNTAINS AND UPPER LEVEL TROUGH OVER
EASTERN UNITED STATES. SHORTWAVE TROUGHS ROTATING AROUND THE UPPER
LEVEL RIDGE INTO THE NORTHERN PLAINS AND SOUTHERN CANADA...AS
EVIDENT PER WATER VAPOR SATELLITE IMAGERY. LATEST 19Z SURFACE
ANALYSIS INDICATES HIGH PRESSURE OVER IOWA INTO THE SOUTHERN PLAINS
STATES. THIS IS PROVIDING MOSTLY SUNNY SKIES ACROSS THE FORECAST
AREA PER VISIBLE SATELLITE IMAGERY.
THE 12.12Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT BUILDING SURFACE
RIDGE SOUTH OF THE FORECAST AREA INTO THE OHIO RIVER VALLEY TONIGHT
THURSDAY. FIRST IMPULSE OVER-TOPPING THE UPPER LEVEL RIDGE OVER
SOUTHERN MANITOBA WILL PUSH SOUTHEAST INTO CENTRAL WISCONSIN BY 18Z
THURSDAY. LATEST HI-RESOLUTION ARW/NMM/12.17Z HRRR SUGGEST
CONVECTION IN ASSOCIATION WITH IMPULSE WILL WEAKEN AS IT
APPROACHES THE NORTHERN SECTIONS OF THE FORECAST AREA...THIS IS
EVIDENT...WITH THE 12.12Z GFS/NAM INDICATE WEAKENING ELEVATED
INSTABILITY ALONG AND AHEAD OF THE IMPULSE. HAVE CONTINUED THE
TREND OF SMALL PRECIPITATION CHANCES AFTER 09Z THURSDAY AND INTO
THE DAYTIME HOURS THURSDAY...AS THE 12.12Z MODELS SUGGEST WEAK
MOISTURE CONVERGENCE ALONG LINGERING SURFACE FRONT WITH IMPULSE
COULD PRODUCE AN ISOLATED SHOWER OR THUNDERSTORM.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 308 PM CDT WED AUG 12 2015
FOCUS TURNS TO THE NEXT SHORTWAVE TROUGH OVER-TOPPING THE UPPER
LEVEL RIDGE THURSDAY EVENING INTO FRIDAY. THE LATEST 12.12Z
GFS/NAM/ECMWF ARE WEAKER WITH 925-850MB MOISTURE CONVERGENCE/LIFT
WITH THIS IMPULSE. WITH THE WEAK LOW LEVEL CONVERGENCE AND
INSTABILITY AXIS ALONG THE SURFACE FRONT/OVER THE FORECAST
AREA...POSSIBILITY OF A SMALL CHANCE OF SHOWERS/THUNDERSTORMS
EXIST THURSDAY NIGHT INTO FRIDAY ACROSS MUCH OF THE FORECAST AREA.
UPPER LEVEL RIDGE AXIS BUILDS INTO THE UPPER GREAT LAKES REGION
FRIDAY AFTERNOON INTO SATURDAY. THE 12.12Z GFS/NAM/ECMWF INDICATE
925MB TEMPERATURES RISING TO PLUS 25 TO PLUS 27 DEGREES CELSIUS
ACROSS THE FORECAST AREA BY 00Z SUNDAY. THE COMBINATION OF
SUBSIDENCE AND 925MB TEMPERATURES...HIGH TEMPERATURES WILL BE IN THE
MIDDLE 80S TO AROUND 90...WITH SOME LOCATIONS POSSIBLY RISING INTO
THE LOWER 90S.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES THROUGH THE PERIOD.
THE 12.12Z GFS/ECMWF/GEM ARE IN GOOD AGREEMENT IN FLATTENING UPPER
LEVEL RIDGE AND DEVELOP WEST TO EAST ZONAL FLOW ACROSS THE NORTHERN
TIER STATES. SIGNIFICANT DIFFERENCES OCCUR BETWEEN THE MODELS ON
TIMING/PLACEMENT OF THE TWO SHORTWAVE TROUGHS/SURFACE FEATURES INTO
THE UPPER GREAT LAKES REGION THROUGH THE PERIOD. FIRST IMPULSE
FLATTENS UPPER LEVEL RIDGE AND PUSHES INTO THE GREAT LAKES REGION
SUNDAY INTO MONDAY. MAIN ENERGY WITH SHORTWAVE TROUGH REMAINS
NORTH OF THE FORECAST AREA. LOW LEVEL MOISTURE CONVERGENCE WITH
SURFACE COLD FRONT WILL PROVIDE A CHANCE OF PRECIPITATION ACROSS
MUCH OF THE FORECAST MAINLY SUNDAY NIGHT INTO MONDAY MORNING. NEXT
FEATURE TO IMPACT THE FORECAST AREA TUESDAY NIGHT INTO WEDNESDAY.
DIFFERENCES OCCUR BETWEEN THE 12.12Z GFS/ECMWF ON
STRENGTH/TIMING/PLACEMENT WITH THIS FEATURE. THE MODELS SUGGEST
DECENT MOISTURE CONVERGENCE/TRANSPORT AND LIFT WITH THE SHORTWAVE
TROUGH/SURFACE FEATURE. BASED ON TIMING/PLACEMENT DIFFERENCES WITH
THE MODELS...WILL CONTINUE THE TREND OF A CHANCE OF PRECIPITATION
ACROSS THE FORECAST AREA TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1140 PM CDT WED AUG 12 2015
EXPECT VFR CONDITIONS AT KRST/KLSE THROUGH 14.06Z. THERE STILL IS
A 20 TO 30 PERCENT CHANCE FOR SHOWERS AND THUNDERSTORMS MAINLY
LATE IN THE PERIOD AS A SURFACE TROUGH SWINGS ACROSS THE REGION...
BUT LIMITED SPATIAL COVERAGE PRECLUDES MENTION IN 13.06Z TAFS.
ANY CEILINGS THROUGH THE PERIOD SHOULD BE 10000 FT AGL OR HIGHER.
LIGHT SOUTH-SOUTHWEST WIND OVERNIGHT WILL INCREASE THURSDAY
MORNING AND CONTINUE THROUGH MUCH OF THE AFTERNOON WITH GUSTS
INTO THE LOW 20 KT RANGE AT BOTH KRST/KLSE. WHEREAS WINDS WILL
SHIFT BACK TO THE SOUTH LATE IN THE PERIOD AT KLSE...EXPECT A MORE
WESTERLY WIND AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...ROGERS
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
920 AM MDT THU AUG 13 2015
.UPDATE...
ISSUED AT 920 AM MDT THU AUG 13 2015
LOWERED CLOUD COVER ACROSS MUCH OF THE REGION THROUGH THE MORNING
HOURS AS THE WEAK SHORTWAVE IS ONLY PRODUCING A FEW CLOUDS ACROSS
AREAS NORTH OF I-70 THIS MORNING WITH NO SHOWERS AND MOSTLY SUNNY
SKIES. REST OF FORECAST ON TRACK FOR STORMS TO DEVELOP OVER HIGHER
TERRAIN THIS AFTERNOON WITH SOME DRIFT INTO VALLEYS THIS EVENING.
INCREASED POPS THIS EVENING ALONG THE NORTHERN AND CENTRAL DIVIDE
MOUNTAINS AS THE RAP IS SHOWING ACTIVITY LINGERING HERE THROUGH
SUNSET AS THE WEAK SHORTWAVE EXITS THE REGION. MOST ACTIVITY
SHOULD DIE DOWN AFTER SUNSET AS NO DISTINCT FORCING PRESENT TO
KEEP SHOWERS GOING OVERNIGHT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM MDT THU AUG 13 2015
A WEAK SHORTWAVE TROUGH WILL MOVE THROUGH THE RIDGE POSITIONED
OVER THE REGION THROUGH MIDDAY BEFORE PASSING EAST OF THE DIVIDE
AROUND MIDDAY. EXPECT THIS FEATURE WILL BE CAPABLE OF GENERATING A
FEW LIGHT SHOWERS PRIOR TO NOON...ESPECIALLY ACROSS THE NORTH...
WITH EMBEDDED THUNDERSTORMS POSSIBLE. SHOWER AND THUNDERSTORM
ACTIVITY WILL INCREASE DURING THE AFTERNOON WITH DAYTIME HEATING
WORKING ON LINGERING MONSOON MOISTURE. SOME STORMS WILL BE CAPABLE
OF GENERATING LOCALIZED HEAVY RAIN. IN THE ABSENCE OF FORCING...
EXPECT MOIST CONVECTION WILL DISSIPATE IN THE LATE EVENING. NO
APPRECIABLE CHANGE IN CONDITIONS IS EXPECTED FRIDAY AS THE HIGH
PRESSURE CENTER SHIFTS SLIGHTLY WEST. DAYTIME HEATING WILL RESULT
IN A RECYCLING OF LINGERING MOISTURE FOR ANOTHER ROUND OF
AFTERNOON SHOWERS AND THUNDERSTORMS. MODELS INDICATED A RISING 7H
TEMPERATURES WHICH SHOULD BRING AFTERNOON HIGHS BACK TO NEAR
NORMAL BY FRIDAY AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 400 AM MDT THU AUG 13 2015
THE MIDRANGE MODELS REMAIN IN GOOD AGREEMENT THROUGH THE EXTENDED
PERIOD. FRI NGT THROUGH SAT...MOISTURE WILL REMAIN TRAPPED
BENEATH STRONG HIGH PRESSURE OVER MUCH OF THE WESTERN U.S...
PRODUCING ISOLD TO SCTD AFTERNOON AND EARLY EVENING SHOWERS AND
THUNDERSTORMS. THE MAIN MONSOONAL PLUME WILL BE MUCH LESS
DISTINCT AND FLOWING OVER SRN CA...NV AND ID. AS A STRONG LOW
PRESSURE SYSTEM MOVES ALONG THE U.S. AND CANADIAN BORDER SAT AND
SUN...THE RIDGE WILL BE FLATTENED AND PUSHED SOUTH WHILE THE WEAK
MONSOONAL PLUME IS DRAGGED ACROSS THE AREA. THIS SHOULD RESULT IN
A SMALL UPTICK IN SHOWERS AND THUNDERSTORMS OVER THE WEEKEND.
MONDAY SHOULD SEE THE RIDGE RETROGRADE OVER AZ WITH DRIER AIR
OVER THE FORECAST AREA. THEN TUE AND WED THE GFS SHOWS A SHARP
TROUGH DIGGING INTO IDAHO AND REACHING SW WYOMING WED MORNING. THE
GFS THEN MOVES IT ACROSS SRN WY DURING THE DAY. THE ECMWF
STRENGTHENS THE LOW EARLIER AND DIGS IT SOUTH OREGON TUE
AFTERNOON...THEN MOVES IT INTO WESTERN WY WED AFTERNOON. BOTH
MODELS SHOW WINDS SHOULD INCREASE WED...WITH THE FORECAST AREA
GENERALLY REMAINING IN THE DRY SLOT OF THE SYSTEM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 400 AM MDT THU AUG 13 2015
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THIS
MORNING...WITH NORMAL DRAINAGE WINDS EXPECTED. FROM 18Z-03Z
THURSDAY...ISOLD SHOWERS AND THUNDERSTORMS AREA EXPECTED OVER ALL
OF EASTERN UT AND THE LOWER ELEVATIONS OF WESTERN CO. SCATTERED
THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS OF CENTRAL AND SW
CO...WITH LOCAL HEAVY RAIN AND SMALL HAIL POSSIBLE. TSTMS WILL BE
IN THE VCNTY OF KEGE...KASE AND KTEX WITH 25 PERCENT CHANCE OF A
STORM AFFECTING THOSE AIRPORTS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...MDA
SHORT TERM...NL
LONG TERM...CC
AVIATION...CC
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
617 AM EDT THU AUG 13 2015
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND FROM THE OHIO VALLEY EASTWARD INTO THE
DELMARVA REGION THROUGH FRIDAY. A FRONTAL SYSTEM WILL BE NEAR THE
SOUTHEAST COAST. ASSOCIATED FRONTAL MOISTURE WILL REMAIN MAINLY
EAST OF THE FORECAST AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE RIDGE WILL CONTINUE NORTH OF THE FORECAST AREA THROUGH
TONIGHT. THE MODELS KEEP DEEP MOISTURE ASSOCIATED WITH THE FRONT
NEAR THE SOUTHEAST COAST EAST OF THE FORECAST AREA. HEATING AND
SOME LOW-LEVEL CONVERGENCE ASSOCIATED WITH THE SEA-BREEZE FRONT
AND WEAK TROUGH IN THE FORECAST AREA SHOWN BY THE NAM AND ECMWF COULD
HELP SUPPORT THUNDERSTORMS. BASED ON THE DRY WATER VAPOR IMAGERY
AND MODEL FORECAST SOUNDINGS BELIEVE MID-LEVEL CAPPING WILL
DOMINATE. EXPECT LITTLE OR NO THUNDERSTORM COVERAGE. THE HRRR AND
SPC WRF DISPLAYED JUST ISOLATED COVERAGE. WE MAINTAINED THE VERY
LOW POPS WITH HIGHER VALUES IN THE EAST PART BECAUSE OF
CONVERGENCE NEAR THE SEA-BREEZE FRONT...AND SOUTHWEST SECTION
CLOSE TO WHERE A FEW SHOWERS OCCURRED DURING THE EARLY MORNING
HOURS AND HRRR DISPLAYED GREATER COVERAGE THIS AFTERNOON. LEANED
TOWARD THE HIGHER HIGH TEMPERATURE GUIDANCE BASED ON THE RECENT
BIAS. USED THE GUIDANCE CONSENSUS FOR THE LOW TEMPERATURE
FORECAST.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
THE MODELS KEEP MOISTURE SHALLOW IN THE FORECAST AREA FRIDAY AND
FRIDAY NIGHT. DEEPER MOISTURE AND CONVERGENCE REMAIN OFF THE
COAST ALONG THE FRONT WITH HIGH PRESSURE RIDGING INTO THE FORECAST
AREA FROM THE NORTH. THERE SHOULD BE LITTLE LOW-LEVEL CONVERGENCE
EXCEPT POSSIBLY ALONG THE SEA-BREEZE FRONT WHICH MAY MOVE WELL
INLAND. WE KEPT THE POPS LOW WHICH WAS SUPPORTED BY BOTH THE NAM
AND GFS MOS. THE TEMPERATURE GUIDANCE WAS CLOSE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF DISPLAY SOME WEAK SURFACE TROUGHING IN THE
FORECAST AREA DURING MUCH OF THE MEDIUM-RANGE PERIOD. SOME UPPER
TROUGHING APPEARS TO SHIFT FARTHER WEST EARLY IN THE PERIOD...BUT
GETS REESTABLISHED LATE IN THE PERIOD. THE PATTERN SUPPORTS A
CHANCE OF THUNDERSTORMS. THE GFS...ECMWF...AND EKD MOS HAVE POPS
OF 10 TO 30 PERCENT WITH MORE CONSISTENCY FOR HIGHER POPS MONDAY
THROUGH WEDNESDAY. THE MOS HAS TEMPERATURES NEAR CLIMATOLOGY
THROUGH THE PERIOD.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS EXPECTED FOR A MAJORITY OF THE TAF PERIOD.
SHALLOW LOW-LEVEL MOISTURE MAY PROMOTE MVFR RESTRICTIONS AT FOG
PRONE AGS/OGB EARLY THIS MORNING...ALTHOUGH WINDS HAVE STAYED UP
AROUND 3 KNOTS WHICH SHOULD CONTINUE TO LIMIT POTENTIAL. ANY
FOG/STRATUS SHOULD DISSIPATE BY 13Z. HIGH PRESSURE AND A
RELATIVELY DRY AIRMASS WILL PROMOTE MOSTLY SUNNY SKIES TODAY.
CUMULUS EXPECTED TO DEVELOP BY THIS AFTERNOON ALTHOUGH NOT
EXPECTING ANY SHOWERS OR STORMS AT CAE/CUB/OGB. ONLY A SLIGHT
CHANCE AT AGS/DNL WHERE MOISTURE IS SLIGHTLY MORE
FAVORABLE...ALTHOUGH STILL LIMITED. LIGHT AND VARIABLE WINDS EARLY
THIS MORNING WILL PICK UP OUT OF THE NORTHEAST AT AROUND 5 TO 10
KNOTS AFTER SUNRISE.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT RESTRICTIONS TO AVIATION
ARE EXPECTED AT THIS TIME.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1034 AM CDT THU AUG 13 2015
.UPDATE...
ISSUED AT 1028 AM CDT THU AUG 13 2015
HIGH PRESSURE DOMINATES MUCH OF THE MIDWEST AND OHIO RIVER VALLEY
THIS MORNING. WEAK WINDS ANTICIPATED AT THE SURFACE, AND
TEMPERATURES STEADILY CLIMBING THIS MORNING INTO THE MID TO UPPER
70S, ON THE WAY TO THE MID 80S. LITTLE MORE THAN SCT CU
EXPECTED IN THE WAY OF CLOUD COVER. NO UPDATES ARE ANTICIPATED AT
THIS TIME.
&&
.SHORT TERM...(TODAY)
ISSUED AT 311 AM CDT THU AUG 13 2015
RIDGE OF HIGH PRESSURE EXTENDING FROM THE MID-ATLANTIC STATES TO THE
CENTRAL PLAINS IS PROVIDING CLEAR SKIES AND NEARLY CALM WINDS TO
CENTRAL ILLINOIS TONIGHT. 07Z/2AM SURFACE OBS ARE SHOWING DEWPOINT
DEPRESSIONS OF 0-3F IN MANY LOCATIONS...WHICH IS BEGINNING TO LEAD
TO PATCHY FOG. LATEST HRRR EVEN SUGGESTS A FEW SPOTS MAY SEE
VISIBILITIES REDUCED TO AROUND 1/4 MILE AT TIMES...HOWEVER IT DOES
NOT APPEAR THERE WILL BE WIDESPREAD DENSE FOG. GIVEN CURRENT TRENDS
AND CONSISTENT HRRR FORECAST...WILL INCLUDE PATCHY FOG DURING THE
EARLY MORNING HOURS. ONCE ANY FOG DISSIPATES...MOSTLY SUNNY
CONDITIONS WILL PREVAIL FOR THE BALANCE OF THE DAY. HIGH/THIN
CIRRUS BLOW OFF FROM CONVECTION ACROSS THE UPPER MIDWEST WILL STREAM
ACROSS THE SKY AND SCT DIURNAL CLOUDS WILL DEVELOP AS WELL...HOWEVER
OVERALL CONDITIONS WILL REMAIN MOSTLY SUNNY. AFTERNOON HIGH
TEMPERATURES WILL TOP OUT IN THE MIDDLE 80S.
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 311 AM CDT THU AUG 13 2015
WEAK COLD FRONT CURRENTLY OVER NORTH DAKOTA/MINNESOTA WILL TRY TO
SETTLE SOUTHWARD INTO ILLINOIS OVER THE NEXT 24-48 HOURS...HOWEVER
IT WILL BE PUSHING DIRECTLY INTO A PERSISTENT RIDGE OF HIGH PRESSURE
AND WILL NEVER PASS THROUGH THE KILX CWA. MODELS HAVE BEEN SHOWING
THE BOUNDARY SAGGING INTO NORTHERN SECTIONS OF ILLINOIS AND INDIANA
FRIDAY NIGHT INTO SATURDAY THEN DISSIPATING COMPLETELY OVER THE
WEEKEND. DUE TO SYNOPTIC SUBSIDENCE AND A LACK OF DEEP-LAYER
MOISTURE...AREAL COVERAGE OF CONVECTION ALONG THE FRONT WILL BE
MINIMAL. WHILE MOST OF THIS ACTIVITY WILL REMAIN NORTH AND EAST OF
THE KILX CWA...ISOLATED THUNDERSTORMS COULD POTENTIALLY DEVELOP
ALONG/NORTH OF A BLOOMINGTON TO PARIS LINE FRIDAY NIGHT INTO
SATURDAY. DUE TO UNCERTAINTIES ABOUT THE EXACT SOUTHWARD POSITION
OF THE FRONT AND LACK OF MOISTURE...WILL MAINTAIN A DRY FORECAST
ACROSS THE BOARD AT THIS TIME.
MAIN WEATHER STORY THIS WEEKEND WILL BE THE INCREASING HEAT AND
HUMIDITY AS THE CENTRAL PLAINS UPPER RIDGE SHIFTS SOUTHEASTWARD.
AMPLE SUNSHINE AND RISING UPPER HEIGHTS WILL ALLOW HIGH TEMPERATURES
TO RISE INTO THE LOWER 90S BY SUNDAY. WHILE CONDITIONS APPEAR TO
REMAIN HOT AND DRY THIS WEEKEND...A POTENTIAL FLY-IN-THE-OINTMENT
WILL BE A WEAKNESS IN THE RIDGE AXIS SEEN PROMINENTLY ON THE ECMWF
AND TO A LESSER EXTENT ON THE GFS. THE ECMWF SHOWS THIS WEAKNESS
DEVELOPING OVER THE OHIO RIVER VALLEY ON SUNDAY...WHICH COULD
POTENTIALLY TRIGGER ISOLATED CONVECTION ACROSS THE E/SE CWA. GFS
KEEPS THE WEAKNESS FURTHER EAST AND MAINTAINS DRY WEATHER. WILL
STICK WITH A COMPLETELY DRY FORECAST FOR NOW...BUT WILL KEEP AN EYE
ON FUTURE MODEL RUNS TO SEE HOW THEY HANDLE THIS FEATURE.
THE NEXT SIGNIFICANT FRONTAL BOUNDARY IS STILL PROGGED TO ARRIVE BY
MONDAY AFTERNOON...WITH THE LATEST GFS NOW BRINGING THE BOUNDARY
FURTHER SOUTH INTO CENTRAL ILLINOIS...MUCH LIKE PREVIOUS RUNS OF THE
ECMWF/GEM HAD DONE. GIVEN GOOD MODEL CONSENSUS...CONFIDENCE IS
GROWING THAT SCATTERED THUNDERSTORMS WILL DEVELOP NORTH OF THE I-70
CORRIDOR MONDAY AFTERNOON...THEN CONTINUE EVERYWHERE MONDAY NIGHT
INTO TUESDAY AS THE FRONT STALLS. AFTER THAT...CONSIDERABLE
DISCREPANCIES DEVELOP AMONG THE 00Z AUG 13 MODELS CONCERNING THE
ARRIVAL OF A STRONGER SHORT-WAVE FOR THE MIDDLE OF NEXT WEEK.
ECMWF HAS SLOWED THE WAVE AND HAS THUS MAINTAINED THE EARLY WEEK
BAROCLINIC ZONE ACROSS THE AREA THROUGH WEDNESDAY. MEANWHILE...THE
GFS/GEM HAVE BOTH KEPT THEIR PREVIOUS SOLUTION OF BRINGING THE
WAVE IN QUICKER...THUS ALLOWING THE EARLY WEEK FRONT TO LIFT NORTH
OF THE AREA. WILL FOLLOW THE MORE CONSISTENT GFS/GEM
HERE...RESULTING IN WARM/DRY CONDITIONS TUESDAY NIGHT AND
WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 646 AM CDT THU AUG 13 2015
HIGHLY VARIABLE GROUND FOG HAS CAUSED THE TAF SITES TO QUICKLY
CHANGE FROM VFR TO IFR/LIFR FOR SHORT PERIODS OF TIME THIS
MORNING. VISIBILITY SEEMS TO HAVE IMPROVED OVER THE LAST
HOUR...BUT WILL CONTINUE WITH A TEMPO FOR MVFR FOG THROUGH 13Z.
FORECAST SOUNDINGS AND EXPECTED AIRMASS CONDITIONS INDICATE WE
COULD SEE SIMILAR CONDITIONS AGAIN LATE TONIGHT. SOME INCREASE IN
CIRRUS CLOUDS COULD HELP ALLEVIATE THAT SOMEWHAT. GENERALLY LIGHT
WINDS ARE EXPECTED THROUGH THE PERIOD, WITH WIND DIRECTION MAINLY
SOUTH TO SOUTHWEST.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
646 AM CDT THU AUG 13 2015
.SHORT TERM...(TODAY)
ISSUED AT 311 AM CDT THU AUG 13 2015
RIDGE OF HIGH PRESSURE EXTENDING FROM THE MID-ATLANTIC STATES TO THE
CENTRAL PLAINS IS PROVIDING CLEAR SKIES AND NEARLY CALM WINDS TO
CENTRAL ILLINOIS TONIGHT. 07Z/2AM SURFACE OBS ARE SHOWING DEWPOINT
DEPRESSIONS OF 0-3F IN MANY LOCATIONS...WHICH IS BEGINNING TO LEAD
TO PATCHY FOG. LATEST HRRR EVEN SUGGESTS A FEW SPOTS MAY SEE
VISIBILITIES REDUCED TO AROUND 1/4 MILE AT TIMES...HOWEVER IT DOES
NOT APPEAR THERE WILL BE WIDESPREAD DENSE FOG. GIVEN CURRENT TRENDS
AND CONSISTENT HRRR FORECAST...WILL INCLUDE PATCHY FOG DURING THE
EARLY MORNING HOURS. ONCE ANY FOG DISSIPATES...MOSTLY SUNNY
CONDITIONS WILL PREVAIL FOR THE BALANCE OF THE DAY. HIGH/THIN
CIRRUS BLOW OFF FROM CONVECTION ACROSS THE UPPER MIDWEST WILL STREAM
ACROSS THE SKY AND SCT DIURNAL CLOUDS WILL DEVELOP AS WELL...HOWEVER
OVERALL CONDITIONS WILL REMAIN MOSTLY SUNNY. AFTERNOON HIGH
TEMPERATURES WILL TOP OUT IN THE MIDDLE 80S.
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 311 AM CDT THU AUG 13 2015
WEAK COLD FRONT CURRENTLY OVER NORTH DAKOTA/MINNESOTA WILL TRY TO
SETTLE SOUTHWARD INTO ILLINOIS OVER THE NEXT 24-48 HOURS...HOWEVER
IT WILL BE PUSHING DIRECTLY INTO A PERSISTENT RIDGE OF HIGH PRESSURE
AND WILL NEVER PASS THROUGH THE KILX CWA. MODELS HAVE BEEN SHOWING
THE BOUNDARY SAGGING INTO NORTHERN SECTIONS OF ILLINOIS AND INDIANA
FRIDAY NIGHT INTO SATURDAY THEN DISSIPATING COMPLETELY OVER THE
WEEKEND. DUE TO SYNOPTIC SUBSIDENCE AND A LACK OF DEEP-LAYER
MOISTURE...AREAL COVERAGE OF CONVECTION ALONG THE FRONT WILL BE
MINIMAL. WHILE MOST OF THIS ACTIVITY WILL REMAIN NORTH AND EAST OF
THE KILX CWA...ISOLATED THUNDERSTORMS COULD POTENTIALLY DEVELOP
ALONG/NORTH OF A BLOOMINGTON TO PARIS LINE FRIDAY NIGHT INTO
SATURDAY. DUE TO UNCERTAINTIES ABOUT THE EXACT SOUTHWARD POSITION
OF THE FRONT AND LACK OF MOISTURE...WILL MAINTAIN A DRY FORECAST
ACROSS THE BOARD AT THIS TIME.
MAIN WEATHER STORY THIS WEEKEND WILL BE THE INCREASING HEAT AND
HUMIDITY AS THE CENTRAL PLAINS UPPER RIDGE SHIFTS SOUTHEASTWARD.
AMPLE SUNSHINE AND RISING UPPER HEIGHTS WILL ALLOW HIGH TEMPERATURES
TO RISE INTO THE LOWER 90S BY SUNDAY. WHILE CONDITIONS APPEAR TO
REMAIN HOT AND DRY THIS WEEKEND...A POTENTIAL FLY-IN-THE-OINTMENT
WILL BE A WEAKNESS IN THE RIDGE AXIS SEEN PROMINENTLY ON THE ECMWF
AND TO A LESSER EXTENT ON THE GFS. THE ECMWF SHOWS THIS WEAKNESS
DEVELOPING OVER THE OHIO RIVER VALLEY ON SUNDAY...WHICH COULD
POTENTIALLY TRIGGER ISOLATED CONVECTION ACROSS THE E/SE CWA. GFS
KEEPS THE WEAKNESS FURTHER EAST AND MAINTAINS DRY WEATHER. WILL
STICK WITH A COMPLETELY DRY FORECAST FOR NOW...BUT WILL KEEP AN EYE
ON FUTURE MODEL RUNS TO SEE HOW THEY HANDLE THIS FEATURE.
THE NEXT SIGNIFICANT FRONTAL BOUNDARY IS STILL PROGGED TO ARRIVE BY
MONDAY AFTERNOON...WITH THE LATEST GFS NOW BRINGING THE BOUNDARY
FURTHER SOUTH INTO CENTRAL ILLINOIS...MUCH LIKE PREVIOUS RUNS OF THE
ECMWF/GEM HAD DONE. GIVEN GOOD MODEL CONSENSUS...CONFIDENCE IS
GROWING THAT SCATTERED THUNDERSTORMS WILL DEVELOP NORTH OF THE I-70
CORRIDOR MONDAY AFTERNOON...THEN CONTINUE EVERYWHERE MONDAY NIGHT
INTO TUESDAY AS THE FRONT STALLS. AFTER THAT...CONSIDERABLE
DISCREPANCIES DEVELOP AMONG THE 00Z AUG 13 MODELS CONCERNING THE
ARRIVAL OF A STRONGER SHORT-WAVE FOR THE MIDDLE OF NEXT WEEK.
ECMWF HAS SLOWED THE WAVE AND HAS THUS MAINTAINED THE EARLY WEEK
BAROCLINIC ZONE ACROSS THE AREA THROUGH WEDNESDAY. MEANWHILE...THE
GFS/GEM HAVE BOTH KEPT THEIR PREVIOUS SOLUTION OF BRINGING THE
WAVE IN QUICKER...THUS ALLOWING THE EARLY WEEK FRONT TO LIFT NORTH
OF THE AREA. WILL FOLLOW THE MORE CONSISTENT GFS/GEM
HERE...RESULTING IN WARM/DRY CONDITIONS TUESDAY NIGHT AND
WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 646 AM CDT THU AUG 13 2015
HIGHLY VARIABLE GROUND FOG HAS CAUSED THE TAF SITES TO QUICKLY
CHANGE FROM VFR TO IFR/LIFR FOR SHORT PERIODS OF TIME THIS
MORNING. VISIBILITY SEEMS TO HAVE IMPROVED OVER THE LAST
HOUR...BUT WILL CONTINUE WITH A TEMPO FOR MVFR FOG THROUGH 13Z.
FORECAST SOUNDINGS AND EXPECTED AIRMASS CONDITIONS INDICATE WE
COULD SEE SIMILAR CONDITIONS AGAIN LATE TONIGHT. SOME INCREASE IN
CIRRUS CLOUDS COULD HELP ALLEVIATE THAT SOMEWHAT. GENERALLY LIGHT
WINDS ARE EXPECTED THROUGH THE PERIOD, WITH WIND DIRECTION MAINLY
SOUTH TO SOUTHWEST.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
739 AM EDT THU AUG 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 212 AM EDT THU AUG 13 2015
HEALTHY SHORTWAVE DIGGING SE WITH 850MB THETA-E ADVECTION EARLY WILL
HELP SUPPORT ONGOING CONVECTION MOVING IN FROM THE ARROWHEAD OF MN
AND CANADA EARLY THIS MORNING. LOOK FOR SHOWERS/THUNDERSTORMS TO
CLIP THE W CWA BEFORE DIMINISHING THROUGH THE DAY TODAY. THE 21/00Z
NAM AND 21/03Z HRRR SEEM TO HAVE A PRETTY GOOD HANDLE ON WHAT WOULD
BE A MORE LIKELY SCENARIO...WITH THE GFS AND CANADIAN BRINGING THE
BULK OF PRECIP OVER THE KEWEENAW AND LAKE SUPERIOR THROUGH THE
MORNING HOURS. WILL NEED TO MONITOR THE TRENDS EARLY THIS MORNING.
EXPECT SHOWERS AND A FEW THUNDERSTORMS TO REMAIN POSSIBLE SE THIS
AFTERNOON...AWAY FROM THE LAKE SUPERIOR STABILIZATION. DESPITE THE
ONSHORE FLOW N CENTRAL AND E...THERE WILL BE LITTLE RELIEF FROM THE
HEAT. EXPECT A VERY WARM DAY TODAY...CLOSE TO THE RECORD AT NWS MQT
WHICH IS 89 SET BACK IN 1970. MID TO UPPER 80S WILL BE COMMON FOR
ALL BUT THE TIP OF THE KEWEENAW PENINSULA...AND E OF A LINE FROM
MUNISING TO RAPID RIVER...EVEN WITH THE POTENTIAL FOR SHOWERS IN THE
AREA. PW VALUES MAXING OUT AROUND 1.6IN W TO E TODAY WILL FALL TO
AROUND 1-1.2IN CWA WIDE BY 06Z. WITH THE MAIN SFC TROUGH SET UP OVER
THE W HALF OF LAKE SUPERIOR AND WARM AIR FULLY ENTRENCHED OVER THE
CWA...LOWS IN THE 60S LOOK TO BE A GOOD BET...WITH ADDITIONAL
SHOWERS AND THUNDERSTORMS NEARING FROM THE NW.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 501 AM EDT THU AUG 13 2015
OVER THE NEXT 7 DAYS...RIDGE OVER THE ROCKIES WILL FADE AWAY AS TWO
FAIRLY ENERGETIC SHORTWAVES SWING THRU WRN NAMERICA. THE FIRST
MOVING ACROSS SW CANADA/PACIFIC NW/NRN ROCKIES FRI/SAT WILL AFFECT
THE UPPER LAKES SUN/MON. THE SECOND WILL DIVE FARTHER S INTO THE
ROCKIES TUE/WED AND THEN LIFT NE TO THE UPPER LAKES/NRN
ONTARIO/HUDSON BAY VCNTY BY FRI. WITH THE WEAKENING OF THE WRN
RIDGE...THE CURRENT ERN CONUS TROF WILL FILL AND BE REPLACED BY
ABOVE NORMAL HEIGHTS. THESE LARGE SCALE CHANGES WILL RESULT IN
WARM/HUMID CONDITIONS PREVAILING THRU THE WEEKEND...THEN A FALL BACK
TO SLIGHTLY BLO NORMAL CONDITIONS EARLY NEXT WEEK BEHIND THE FIRST
SHORTWAVE MENTIONED ABOVE. THE PEAK OF THE HEAT/HUMIDITY SHOULD
OCCUR SUN AHEAD OF THAT WAVE. AFTER THE COOL DOWN EARLY IN THE
WEEK...TEMPS SHOULD RETURN TO AROUND NORMAL. AS FOR PCPN...SCT
SHRA/TSTM POTENTIAL WILL CONTINUE THRU FRI...THEN DRY WEATHER WILL
RETURN SAT AS THE NRN PORTION OF THE WRN RIDGE IS FORCED EASTWARD BY
THE SHORTWAVE TROF SWINGING THRU THE NRN ROCKIES. THAT SHORTWAVE
WILL BRING A RISK OF PCPN SUN/MON...THOUGH WITH THE MAIN ENERGY
LIFTING ENE...PCPN COVERAGE WILL PROBABLY BE LIMITED. MODEL
AGREEMENT HAS IMPROVED SOME FOR THE MIDDLE AND END OF NEXT WEEK. IT
APPEARS THERE WILL BE THE POTENTIAL FOR HVY RAINFALL AND PERHAPS
STRONG TO SVR STORMS AT SOME POINT WED/THU IN ASSOCIATION WITH THE
SECOND WAVE LIFTING OUT OF THE W AND ITS ASSOCIATED FAIRLY VIGOROUS
SFC LOW FOR AUG.
BEGINNING FRI...COLD FRONT WILL DROP S ACROSS UPPER MI IN
ASSOCIATION WITH SHORTWAVE MOVING ACROSS THE UPPER LAKES. MAY SEE A
FEW SHRA/TSTMS IN THE MORNING WITH THE FRONT...BUT ACROSS THE
S...FRONTAL PASSAGE WILL BEGIN TO BETTER COINCIDE WITH THE DIURNAL
HEATING CYCLE/INSTABILITY BUILD UP. WITH MLCAPES REACHING AT LEAST
1000-1500J/KG...AND ENHANCED CONVERGENCE DUE TO LAKE BREEZE...TSTMS
SHOULD INCREASE EARLY IN THE AFTN. TIMING OF THE FRONT WILL BE
CRITICAL. IF FRONT PASSES EARLY IN THE AFTN OVER THE S...TSTM
POTENTIAL WILL BE LESS THAN IF THE FRONT PASSES IN THE LATE AFTN.
WITH DEEP LAYER SHEAR AROUND 25KT...SOME STRONG STORMS WILL BE
POSSIBLE AND PERHAPS AN ISOLD SVR STORM IF FROPA IS LATER IN THE
AFTN. IT WILL BE A WARM/HUMID DAY WITH HIGHS MOSTLY IN THE 80S.
LIGHT WINDS OFF LAKE SUPERIOR WILL LEAD TO COOLER CONDITIONS N...BUT
ONLY SLIGHTLY.
DRY WEATHER WILL SET IN FOR FRI NIGHT/SAT UNDER RISING HEIGHTS WITH
MID/UPPER RIDGE BUILDING NE INTO THE UPPER LAKES. SAT WILL BE A
WARM/HUMID DAY WITH HIGH TEMPS IN THE 80S UNDER MOSTLY SUNNY SKIES.
SHORTWAVE TROF MOVING ACROSS THE NRN ROCKIES SAT WILL LIFT ENE INTO
NRN ONTARIO SUN. ASSOCIATED COLD FRONT WILL LIKELY REACH WRN UPPER
MI LATE IN THE AFTN AS GFS WHICH HAD BEEN FASTEST WITH THE FRONT HAS
SLOWED TO BE MORE INLINE WITH THE GEM/ECMWF. WITH BEST HEIGHT
FALLS/DEEP LAYER FORCING PASSING TO THE N...CONVECTION ALONG/AHEAD
OF FRONT AS IT PASSES PROBABLY WON`T BE MORE THAN ISOLD TO SCT.
HOWEVER...AS UPPER JET TRANSLATES E AND BETTER POSITIONS RIGHT
ENTRANCE UPPER DIVERGENCE OVERTOP FRONT SUN NIGHT...EXPECT CHC OF
SHRA/TSTMS TO INCREASE SUN NIGHT. WITH FRONT NOT ARRIVING UNTIL LATE
IN THE DAY...SUN WILL BE A VERY WARM...HUMID DAY AS 850MB THERMAL
RIDGE WITH 850MB TEMPS OF AT LEAST 20C SHIFTS ACROSS THE AREA IN
ADVANCE OF COLD FRONT. EXPECT MAX TEMPS INTO THE UPPER 80S OVER MUCH
OF THE AREA...AND LIKELY REACHING 90F AT SOME LOCATIONS. FAIRLY
TIGHT PRES GRADIENT WILL ALSO LEAD TO GUSTIER WINDS...PROBABLY 20-
25MPH TO PERHAPS 30MPH AT TIMES.
HEALTHY COOLING (AND LOWERING OF DWPTS) WILL FOLLOW THE FRONT FOR
MON AS 850MB TEMPS FALL BACK TO 6 TO 10C. MAX TEMPS SHOULD BE IN THE
UPPER 60S W AND N NEAR LAKE SUPERIOR TO MID 70S SCTNRL/SE. UPPER
DIVERGENCE UNDER RIGHT ENTRANCE OF UPPER JET EXTENDING FROM THE
UPPER LAKES TO NRN/CNTRL QUEBEC MAY HELP SHRA/TSTMS LINGER INTO MON
MORNING OVER THE SCNTRL AND E EVEN THOUGH SFC FRONT SHOULD BE JUST S
AND E OF THAT AREA AT 12Z MON.
DRY WEATHER WILL THEN BE THE RULE MON AFTN INTO TUE AS SFC HIGH PRES
MOVES ACROSS THE UPPER LAKES. WITH SFC HIGH PRES OVER THE AREA AND
PRECIPITABLE WATER UNDER 0.5 INCHES...TEMPS MON NIGHT WILL LIKELY
FALL INTO THE 40S IN THE INTERIOR WITH TRADITIONAL COLD SPOTS
POSSIBLY DOWN INTO THE LWR 40S.
VIGOROUS SHORTWAVE MOVING FROM THE CNTRL ROCKIES AND ACROSS THE
UPPER GREAT LAKES DURING THE MID AND LATE WEEK WILL BRING THE
POTENTIAL FOR ROUNDS OF SHRA/TSTMS AND POSSIBLE HVY RAINFALL.
INITIALLY...STRENGTHENING WAA/MOISTURE ADVECTION IN ADVANCE OF WAVE
WILL SUPPORT SHRA/TSTMS SPREADING INTO UPPER MI WED/WED NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 735 AM EDT THU AUG 13 2015
UPSTREAM SHOWERS AND THUNDERSTORMS DIMINISHED QUICKLY FROM CANADA
AND NW MN EARLY THIS MORNING. STILL SOME RAIN SHOWERS...BUT
THUNDERSTORM POTENTIAL HAS DIMINISHED THROUGH AT LEAST MID MORNING.
FOR THIS AFTERNOON...EXPECTING CONVECTION TO STAY MAINLY TO THE E OF
IWD AND CMX...IN PART DUE TO THE STABILIZING INFLUENCE OF LAKE
SUPERIOR. THUNDERSTORM COVERAGE IS UNCERTAIN SO WILL NOT MENTION
THUNDERSTORMS IN THE SAW TAFS AT THIS POINT. DEPENDING ON PRECIP AND
OVERALL LOW LEVEL MOISTURE...BR COULD COME BACK TO SAW AFTER 06Z
TONIGHT BUT EXPECTING VIS TO STAY MAINLY MVFR OR HIGHER.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 212 AM EDT THU AUG 13 2015
FOG WILL BE POSSIBLE TODAY THROUGH FRIDAY MORNING OVER MAINLY NE AND
E LAKE SUPERIOR...CLOSER TO THE COLDEST WATER AS WARM HUMID AIR
SHIFTS OVERHEAD. WINDS SHOULD BE LESS THAN 30KTS THROUGH THE
PERIOD...WITH GUSTS NEARING 30KTS OVER A FEW OF THE HIGHER PLATFORMS
OVER W LAKE SUPERIOR INITIALLY THIS MORNING OUT OF THE SW...AND
AGAIN SATURDAY NIGHT INTO SUNDAY.
EXPECT THE HIGH OVER THE OH RIVER VALLEY TO DRIFT OFF THE EAST COAST
THROUGH FRIDAY. A TROUGH MOVING THROUGH NW ONTARIO AND MN THIS
MORNING WILL SWEEP SE ACROSS LAKE SUPERIOR THIS AFTERNOON. IN ITS
WAKE...HIGH PRESSURE WILL BUILD INTO THE UPPER GREAT LAKES ON
FRIDAY. AS THIS HIGH DRIFTS SE INTO THE MID ATLANTIC STATES OVER THE
WEEKEND...A LOW WILL MOVE E FROM S SASKATCHEWAN ACROSS NW ONTARIO
AND TO NEAR JAMES BAY LATE ON SUNDAY. THIS LOW WILL CONTINUE E INTO
QUEBEC ON MONDAY...AND DRAG A COLD FRONT ACROSS THE UPPER LAKES ON
SUNDAY NIGHT. BEHIND THIS FRONT...LOOK FOR A HIGH TO MOVE INTO
MINNESOTA ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...ROLFSON
AVIATION...KF
MARINE...KF
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
627 AM CDT THU AUG 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT THU AUG 13 2015
THE MODELS ARE IN RATHER UNANIMOUS AGREEMENT THAT THE DISTURBANCE
MOVING THROUGH SHERIDAN COUNTY AT 08Z WOULD BE THE CATALYST FOR
SCATTERED TSTMS ACROSS NCNTL AND SWRN NEB FROM ROUGHLY 22Z
THROUGH 03Z. WINDS ALOFT ARE WEAK...JUST 30 TO 40 KTS AT H300MB
AND BULK SHEAR TO 400MB IS 30 KTS OR LESS SUGGESTING A MARGINAL
SEVERE WEATHER SITUATION. MUCH OF THE INTENSITY OF THE STORMS
WOULD THEN BE DERIVED FROM CAPE WHICH COULD VARY SIGNIFICANT AS
SOME MODELS MIX VERY DEEPLY AND OTHER DO NOT. THE ECM HAS THE
RIGHT IDEA KEEPING DEW POINTS IN THE UPPER 60S TO NEAR 70 WHICH
WOULD PRODUCE MUCAPE AROUND 3500 J/KG. NOTE THE BUNKERS RIGHT MOVER
STORM MOTION IN THE RAP AND THE NAM VARIES FROM 345/10 TO 020/10 KT
WHICH SUGGESTS THERE COULD BACK BUILDING AND LOCALLY HEAVY RAINFALL
AS THE STORMS DEVELOP FROM NORTHEAST TO SOUTHWEST LATE THIS
AFTERNOON.
GIVEN THE WEAK WINDS ALOFT THE STORM ACTIVITY SHOULD WEAKEN AND
SLOWLY DISSIPATE WITH THE LOSS OF HEATING IN THE MID TO LATE
EVENING. THE MODELS SHOW A WEAK FRONT DROPPING STATIONARY ACROSS
THE FCST AREA. NONE OF THE MODELS SHOW STRATUS FORMING BUT THE
SREF SUGGESTS SOME PATCHY FOG COULD DEVELOP AHEAD OF THE FRONT
TONIGHT.
HIGHS TODAY FOLLOW THE GUIDANCE CONSENSUS. MID 90S ARE POSSIBLE
NEAR VALENTINE...CLOSER TO THE SFC LOW ACROSS SD WITH LOWER 90S
ELSEWHERE. LOWS TONIGHT IN THE 60S FOLLOWS A BLEND OF BIAS
CORRECTED DETERMINISTIC MODELS. FORECAST TEMPERATURES TONIGHT
ALONG AND AHEAD OF THE FRONT COULD BE TOO COOL. MIXING MAY
INHIBIT RADIATIONAL COOLING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 358 AM CDT THU AUG 13 2015
FRIDAY THE RIDGE HOLDS STRONG ACROSS THE CENTRAL ROCKIES AHEAD OF
AN APPROACHING TROUGH/COLD FRONT. TEMPS FRIDAY SEASONALLY WARM
WITH MOST AREAS AROUND 90. MODELS KEEP THE AREA INBETWEEN RIDGE
RIDING WAVES SO EXPECT A DRY DAY. CHANGES START SATURDAY AS A
TROUGH DIGS ACROSS THE PACIFIC NW AND NORTHERN ROCKIES. A LOW
PRESSURE SYSTEM WILL CROSS THE NORTHERN ROCKIES WITH A TRAILING
COLD FRONT TO PUSH TOWARDS THE AREA. COMPRESSIONAL HEATING AHEAD
OF THE COLD FRONT SHOULD PUSH ALL AREAS INTO THE 90S. FORECAST
FOLLOWS A MODEL BLEND FOR HIGHS...WHICH MAY BE UNDERDONE. THE KEY
WILL BE THE PLACEMENT/STRENGTH OF THE DRY LINE. MODELS GENERALLY
KEEP THE DRY LINE ACROSS THE WESTERN SANDHILLS...HOWEVER IF THE
DRY LINE CAN PUSH FURTHER EAST...THE MAV MOS GUIDANCE OF NEAR
TRIPLE DIGITS CAN NOT BE RULED OUT FOR PARTS OF WESTERN NEB.
THE COLD FRONT WILL PUSH INTO THE NW CWA BY LATE SATURDAY AND
SHOULD BE THE FOCUS FOR THUNDERSTORMS. THE CHANCE WILL FOLLOW
NEAR THE FRONT AS IT SLOWLY PUSHES SOUTHEAST SATURDAY NIGHT INTO
SUNDAY. SHEAR ALONG THE FRONT AND GOOD INSTABILITY AHEAD OF THE
FRONT SHOULD AID IN SOME STRONG TO POSSIBLY SEVERE STORMS. THE
CLOUDS AND STORMS WILL HELP KEEP TEMPS DOWN FOR SUNDAY.
POST FRONTAL CONDITIONS ARE FAIRLY SIMILAR. THE RIDGE IS
FLATTENED AND FLOW WILL BE MORE ZONAL. A TRAIN OF DISTURBANCES
WILL RESULT IN NUMEROUS CHANCES FOR ISOLATED TO SCATTERED STORMS.
TEMPS FALL INTO THE 80S...AND COULD HOLD IN THE UPPER 70S WITH
MORE CLOUDS OR PUSH TO AROUND 90 WITH MORE AFTERNOON SUN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 627 AM CDT THU AUG 13 2015
THE DISTURBANCE MOVING THROUGH SWRN SD THIS MORNING WILL BE THE
CATALYST FOR SCATTERED TSTMS ACROSS NCNTL AND SWRN NEB FROM
ROUGHLY 22Z THROUGH 03Z. OTHERWISE...VFR IS EXPECTED. THE SREF AND
SUGGEST SOME POTENTIAL FOR PATCHY FOG EARLY FRIDAY
MORNING...GENERALLY FROM KLBF TO KANW AND EAST. THE FORECAST IS
FOR VFR GIVEN THE FORECAST COVERAGE BY THE NAM AND THE LOW
PROBABILITY SHOWN BY THE SREF.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
947 AM EDT THU AUG 13 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE BEGINS TO BUILD INTO THE REGION TODAY BRINGING
A RETURN OF MOSTLY QUIET WEATHER WITH A FEW POSSIBLE SHOWERS
ACROSS THE NORTH COUNTRY AS A SHORTWAVE CROSSES THE REGION. A WEAK
COLD FRONT WILL BRING THE CHANCE FOR MORE SHOWERS AND A FEW
THUNDERSTORMS FRIDAY INTO SATURDAY. TEMPERATURES WILL SEE A
WARMING TREND OVER THE WEEKEND WITH DAYTIME TEMPERATURES REACHING
THE UPPER 80S OVER THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 947 AM EDT THURSDAY...OVERALL FORECAST IN GOOD SHAPE WITH
THE ONLY TWEAKS BEING THE ADDITION OF A BIT MORE CLOUD COVER THIS
MORNING...WHICH WILL ALSO LIMIT THE CONVECTIVE POTENTIAL DURING
THE MORNING HOURS. HAVE MOVED THE SHOWER POTENTIAL TO THE
AFTERNOON HOURS.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/...
AS OF 348 AM EDT THURSDAY...EXPECT A QUIET EVENING ON THURSDAY
NIGHT WITH INCREASING SOUTHERLY FLOW AHEAD OF A COLD FRONT. FRIDAY
MORNING THE SOUTHERLY FLOW QUICKLY INCREASES LOW LEVEL MOISTURE
AND SURFACE TEMPERATURES ACROSS THE NORTH COUNTRY. AS THE MOISTURE
INCREASES SO DOES THE INSTABILITY BUT ONLY MARGINALLY. GIVEN THE
WEAK LAPSE RATES AND MINIMAL SHEAR I DONT EXPECT MORE THAN A FEW
ISOLATED THUNDERSTORMS AS THE UPPER LEVEL VORT MAX`S GENERATE
RAIN SHOWERS ACROSS THE AREA FRIDAY EVENING INTO SATURDAY MORNING.
GIVEN THE RAPID INCREASE OF PRECIPITABLE WATER AND WEAK CORFIDI
VECTORS EXPECT SOME OF THE SHOWERS TO PRODUCE HEAVY RAINFALL RATES
HOWEVER WITH THE ANTECEDENT CONDITIONS STILL BELOW NORMAL FOR THE
AUGUST I`M NOT EXPECTING A SIGNIFICANT FLOODING EVENT. NONETHELESS
HEAVIER SHOWERS COULD LIKELY PRODUCE SOME PONDING OF WATER IN LOW
LYING AREAS AND IN AREAS OF POOR DRAINAGE.
AS THE FRONT CLEARS THE AREA LATE SATURDAY AFTERNOON WE WILL SEE
A NEW AIR MASS MOVE IN BEHIND THE FRONT AS AN UPPER LEVEL RIDGE
AND SURFACE HIGH BUILD IN OVER THE NORTH COUNTRY. EXPECT DAYTIME
TEMPERATURES FRIDAY WILL BE IN THE MID 70S TO LOW 80S WITH THE
OVERNIGHT LOWS ON FRIDAY NIGHT IN THE LOW TO MID 60S. AS THE FRONT
IS MOVING THROUGH THE REGION ON SATURDAY TEMPS WILL NEARLY BE A
REPEAT OF FRIDAY IN THE MID 70S TO LOW 80S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 333 AM EDT THURSDAY...MAIN HEADLINE FOR THE EXTENDED WILL
BE POTENTIAL UPPER 80S/LOWER 90S FOR DAYTIME HIGHS SUNDAY AND
MONDAY. BOTH THE 00Z ECMWF AND 00Z GFS INDICATE BROAD MID-LEVEL
RIDGE AND BUILDING 500MB HEIGHTS INTO THE REGION FROM THE WEST AND
SOUTHWEST...WITH 850MB TEMPS OF +18C TO +19C SUN/MON. RAINFALL
CHANCES APPEAR MINIMUM AND ANTICIPATE FULL HEATING WITH GENERAL
MID-LEVEL SUBSIDENCE IN PLACE. EXPECTATION IS FOR MID 60S
DEW POINTS...THUS MODERATELY HUMID CONDITIONS. THIS SHOULD ALSO
KEEP LOW TEMPERATURES IN THE MID-UPR 60S FOR MOST SECTIONS FOR
SUNDAY NIGHT.
MID-LEVEL RIDGE BEGINS TO BREAK DOWN MONDAY NIGHT INTO TUESDAY. MAY
SEE SOME SHOWER/ISOLD THUNDER ACTIVITY DEVELOP LATER MONDAY
NIGHT...WITH POTENTIAL ROUND OF WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH SURFACE FRONTAL PASSAGE ON TUESDAY. HAVE INDICATED 30-40 POPS
ACROSS NRN NY 06-12Z TUESDAY...INCREASING TO 45-60 POPS AREAWIDE
DURING THE DAYLIGHT HOURS ON TUESDAY. COULD SEE A FEW STRONGER
THUNDERSTORMS...BUT DIFFICULT TO ASSESS AT THIS TIME GIVEN TIMING
UNCERTAINTY OF FRONTAL PASSAGE WITH RESPECT TO DAYTIME HEATING MAX.
SHOULD STILL SEE HIGH TEMPS IN THE LOW-MID 80S ACROSS THE VT VALLEYS
ON TUESDAY BEFORE RAINFALL...THOUGH COOLER WITH EARLIER FRONTAL
PASSAGE ACROSS NRN NY BASED ON CURRENT INDICATIONS. WILL CONTINUE TO
MONITOR.
SHOULD SEE CLEARING CONDITIONS TUESDAY NIGHT WITH COOLER/MORE
SEASONABLE CONDITIONS AND LOWER HUMIDITY LEVELS ON WEDNESDAY. HIGH
TEMPERATURES ON WEDNESDAY EXPECTED IN THE UPR 70S TO LOWER
80S...WITH DEW POINTS BACK INTO THE MID TO UPPER 50S.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...UPPER TROUGH ROTATING SEWD FROM
SERN ONTARIO WILL MAINTAIN BKN-OVC SKIES THROUGH 14-16Z...WITH
LOCALIZED MVFR CEILINGS PERSISTING AT SLK/MSS/MPV. GENERAL TREND
IN RAP MODEL SOUNDINGS IS TO SHOW IMPROVING CEILINGS AFTER
16Z...BUT MAY SEE LOCALIZED MVFR CONDITIONS PERSIST NEAR THE MTNS
WITH VCSH INCLUDED IN SLK TAF DURING THE AFTERNOON HOURS. SURFACE
WINDS GENERALLY LESS THAN 10 KTS THROUGH THE PERIOD...LIGHT W-NW
EARLY THIS MORNING...AND GENERALLY W-SW DURING THE BALANCE OF THE
DAYLIGHT PERIOD. CLEARING TONIGHT WILL LEAD TO LOCALIZED NOCTURNAL
FOG WITH LIFR EXPECTED SLK/MPV AFTER 08Z.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
12Z FRIDAY THROUGH 12Z SATURDAY...MAINLY VFR CONDITIONS...BUT
SCATTERED SHOWER/TSTM DEVELOPMENT WILL BRING INTERVALS OF MVFR OR
BRIEF IFR WITH RAINFALL (MAINLY FRIDAY AFTN INTO EARLY FRIDAY EVE).
LOCALIZED FOG POSSIBLE LATE FRIDAY NIGHT...ESPECIALLY IN VALLEY
AREAS SEEING RAINFALL.
12Z SATURDAY THROUGH MONDAY...ISOLD SHOWER OR TSTM POSSIBLE
SATURDAY AFTERNOON. OTHERWISE MAINLY VFR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...EVENSON
SHORT TERM...DEAL
LONG TERM...BANACOS
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
740 AM EDT THU AUG 13 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE BEGINS TO BUILD INTO THE REGION BRINGING A
RETURN OF MOSTLY QUIET WEATHER WITH A FEW POSSIBLE SHOWERS ACROSS
THE NORTH COUNTRY AS A SHORTWAVE CROSSES THE REGION. A WEAK COLD
FRONT WILL BRING THE CHANCE FOR MORE SHOWERS AND A FEW THUNDERSTORMS
FRIDAY INTO SATURDAY. TEMPERATURES WILL SEE A WARMING TREND OVER
THE WEEKEND WITH DAYTIME TEMPERATURES REACHING THE UPPER 80S OVER
THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 712 AM EDT THURSDAY...NOT MUCH CHANGE WITH THIS FORECAST
UPDATE AS THERE ARE A FEW WEAK ISOLATED RAIN SHOWERS DEVELOPING
ACROSS THE AREA. TEMPS AND DEW POINTS ARE IN LINE WITH CURRENT
OBSERVATIONS SO NO CHANGES WERE NEEDED. STILL EXPECT ISOLATED/
SCATTERED SHOWERS TO DEVELOP THIS AFTERNOON AS THE SHORTWAVE
ENERGY PROVIDES ENOUGH SUPPORT FOR SOME RAIN SHOWERS TO POP UP
GENERALLY ALONG NORTHERN NEW YORK AND IN NORTHERN VERMONT.
PREVIOUS DISCUSSION AS OF 348 AM EDT THURSDAY...SURFACE RIDGING
WILL BUILD INTO THE REGION TODAY AS A 500 MB TROUGH SLIDES TOWARDS
THE EAST THIS AFTERNOON. AS A PIECE OF SHORTWAVE ENERGY RIDES THE
SOUTHERN EXTENT OF THE UPPER LEVEL TROUGH THERE COULD BE ENOUGH
LIFT TO GENERATE A FEW ISOLATED TO SCATTERED SHOWERS THIS
AFTERNOON. WITH INCREASING 500MB HEIGHTS AND INCREASED 1000-500MB
THICKNESS I DONT EXPECT ANY WIDESPREAD COVERAGE OF SHOWERS SO I
CONTINUED JUST THE MENTION OF SLIGHT CHANCE WORDING IN THE
FORECAST FOR THIS AFTERNOON.
AS THE TROUGH MOVES OUT OF THE AREA DRY AIR WILL ENTRAIN INTO THE
MID AND UPPER LEVELS SO I EXPECT THE CLOUDS SHOULD BEGIN TO ERODE
MOVING INTO THE LATE AFTERNOON/ EARLY EVENING. LIGHT TO MODERATE
WESTERLY TO SOUTHWESTERLY WINDS WILL PREVAIL AND TEMPS TODAY WILL
WARM INTO THE MID 70S.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/...
AS OF 348 AM EDT THURSDAY...EXPECT A QUIET EVENING ON THURSDAY
NIGHT WITH INCREASING SOUTHERLY FLOW AHEAD OF A COLD FRONT. FRIDAY
MORNING THE SOUTHERLY FLOW QUICKLY INCREASES LOW LEVEL MOISTURE
AND SURFACE TEMPERATURES ACROSS THE NORTH COUNTRY. AS THE MOISTURE
INCREASES SO DOES THE INSTABILITY BUT ONLY MARGINALLY. GIVEN THE
WEAK LAPSE RATES AND MINIMAL SHEAR I DONT EXPECT MORE THAN A FEW
ISOLATED THUNDERSTORMS AS THE UPPER LEVEL VORT MAX`S GENERATE
RAIN SHOWERS ACROSS THE AREA FRIDAY EVENING INTO SATURDAY MORNING.
GIVEN THE RAPID INCREASE OF PRECIPITABLE WATER AND WEAK CORFIDI
VECTORS EXPECT SOME OF THE SHOWERS TO PRODUCE HEAVY RAINFALL RATES
HOWEVER WITH THE ANTECEDENT CONDITIONS STILL BELOW NORMAL FOR THE
AUGUST I`M NOT EXPECTING A SIGNIFICANT FLOODING EVENT. NONETHELESS
HEAVIER SHOWERS COULD LIKELY PRODUCE SOME PONDING OF WATER IN LOW
LYING AREAS AND IN AREAS OF POOR DRAINAGE.
AS THE FRONT CLEARS THE AREA LATE SATURDAY AFTERNOON WE WILL SEE
A NEW AIRMASS MOVE IN BEHIND THE FRONT AS AN UPPER LEVEL RIDGE AND
SURFACE HIGH BUILD IN OVER THE NORTH COUNTRY. EXPECT DAYTIME
TEMPERATURES FRIDAY WILL BE IN THE MID 70S TO LOW 80S WITH THE
OVERNIGHT LOWS ON FRIDAY NIGHT IN THE LOW TO MID 60S. AS THE FRONT
IS MOVING THROUGH THE REGION ON SATURDAY TEMPS WILL NEARLY BE A
REPEAT OF FRIDAY IN THE MID 70S TO LOW 80S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 333 AM EDT THURSDAY...MAIN HEADLINE FOR THE EXTENDED WILL
BE POTENTIAL UPPER 80S/LOWER 90S FOR DAYTIME HIGHS SUNDAY AND
MONDAY. BOTH THE 00Z ECMWF AND 00Z GFS INDICATE BROAD MID-LEVEL
RIDGE AND BUILDING 500MB HEIGHTS INTO THE REGION FROM THE WEST AND
SOUTHWEST...WITH 850MB TEMPS OF +18C TO +19C SUN/MON. RAINFALL
CHANCES APPEAR MINIMUM AND ANTICIPATE FULL HEATING WITH GENERAL
MID-LEVEL SUBSIDENCE IN PLACE. EXPECTATION IS FOR MID 60S
DEWPOINTS...THUS MODERATELY HUMID CONDITIONS. THIS SHOULD ALSO
KEEP LOW TEMPERATURES IN THE MID-UPR 60S FOR MOST SECTIONS FOR
SUNDAY NIGHT.
MID-LEVEL RIDGE BEGINS TO BREAK DOWN MONDAY NIGHT INTO TUESDAY. MAY
SEE SOME SHOWER/ISOLD THUNDER ACTIVITY DEVELOP LATER MONDAY
NIGHT...WITH POTENTIAL ROUND OF WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH SURFACE FRONTAL PASSAGE ON TUESDAY. HAVE INDICATED 30-40 POPS
ACROSS NRN NY 06-12Z TUESDAY...INCREASING TO 45-60 POPS AREAWIDE
DURING THE DAYLIGHT HOURS ON TUESDAY. COULD SEE A FEW STRONGER
THUNDERSTORMS...BUT DIFFICULT TO ASSESS AT THIS TIME GIVEN TIMING
UNCERTAINTY OF FRONTAL PASSAGE WITH RESPECT TO DAYTIME HEATING MAX.
SHOULD STILL SEE HIGH TEMPS IN THE LOW-MID 80S ACROSS THE VT VALLEYS
ON TUESDAY BEFORE RAINFALL...THOUGH COOLER WITH EARLIER FRONTAL
PASSAGE ACROSS NRN NY BASED ON CURRENT INDICATIONS. WILL CONTINUE TO
MONITOR.
SHOULD SEE CLEARING CONDITIONS TUESDAY NIGHT WITH COOLER/MORE
SEASONABLE CONDITIONS AND LOWER HUMIDITY LEVELS ON WEDNESDAY. HIGH
TEMPERATURES ON WEDNESDAY EXPECTED IN THE UPR 70S TO LOWER
80S...WITH DEWPOINTS BACK INTO THE MID TO UPPER 50S.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...UPPER TROUGH ROTATING SEWD FROM
SERN ONTARIO WILL MAINTAIN BKN-OVC SKIES THROUGH 14-16Z...WITH
LOCALIZED MVFR CEILINGS PERSISTING AT SLK/MSS/MPV. GENERAL TREND
IN RAP MODEL SOUNDINGS IS TO SHOW IMPROVING CEILINGS AFTER
16Z...BUT MAY SEE LOCALIZED MVFR CONDITIONS PERSIST NEAR THE MTNS
WITH VCSH INCLUDED IN SLK TAF DURING THE AFTERNOON HOURS. SURFACE
WINDS GENERALLY LESS THAN 10 KTS THROUGH THE PERIOD...LIGHT W-NW
EARLY THIS MORNING...AND GENERALLY W-SW DURING THE BALANCE OF THE
DAYLIGHT PERIOD. CLEARING TONIGHT WILL LEAD TO LOCALIZED NOCTURNAL
FOG WITH LIFR EXPECTED SLK/MPV AFTER 08Z.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
12Z FRIDAY THROUGH 12Z SATURDAY...MAINLY VFR CONDITIONS...BUT
SCATTERED SHOWER/TSTM DEVELOPMENT WILL BRING INTERVALS OF MVFR OR
BRIEF IFR WITH RAINFALL (MAINLY FRIDAY AFTN INTO EARLY FRIDAY EVE).
LOCALIZED FOG POSSIBLE LATE FRIDAY NIGHT...ESPECIALLY IN VALLEY
AREAS SEEING RAINFALL.
12Z SATURDAY THROUGH MONDAY...ISOLD SHOWER OR TSTM POSSIBLE
SATURDAY AFTERNOON. OTHERWISE MAINLY VFR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...DEAL
SHORT TERM...DEAL
LONG TERM...BANACOS
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
719 AM EDT THU AUG 13 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE BEGINS TO BUILD INTO THE REGION BRINGING A
RETURN OF MOSTLY QUIET WEATHER WITH A FEW POSSIBLE SHOWERS ACROSS
THE NORTH COUNTRY AS A SHORTWAVE CROSSES THE REGION. A WEAK COLD
FRONT WILL BRING THE CHANCE FOR MORE SHOWERS AND A FEW THUNDERSTORMS
FRIDAY INTO SATURDAY. TEMPERATURES WILL SEE A WARMING TREND OVER
THE WEEKEND WITH DAYTIME TEMPERATURES REACHING THE UPPER 80S OVER
THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 712 AM EDT THURSDAY...NOT MUCH CHANGE WITH THIS FORECAST
UPDATE AS THERE ARE A FEW WEAK ISOLATED RAIN SHOWERS DEVELOPING
ACROSS THE AREA. TEMPS AND DEW POINTS ARE IN LINE WITH CURRENT
OBSERVATIONS SO NO CHANGES WERE NEEDED. STILL EXPECT ISOLATED/
SCATTERED SHOWERS TO DEVELOP THIS AFTERNOON AS THE SHORTWAVE
ENERGY PROVIDES ENOUGH SUPPORT FOR SOME RAIN SHOWERS TO POP UP
GENERALLY ALONG NORTHERN NEW YORK AND IN NORTHERN VERMONT.
PREVIOUS DISCUSSION AS OF 348 AM EDT THURSDAY...SURFACE RIDGING
WILL BUILD INTO THE REGION TODAY AS A 500 MB TROUGH SLIDES TOWARDS
THE EAST THIS AFTERNOON. AS A PIECE OF SHORTWAVE ENERGY RIDES THE
SOUTHERN EXTENT OF THE UPPER LEVEL TROUGH THERE COULD BE ENOUGH
LIFT TO GENERATE A FEW ISOLATED TO SCATTERED SHOWERS THIS
AFTERNOON. WITH INCREASING 500MB HEIGHTS AND INCREASED 1000-500MB
THICKNESS I DONT EXPECT ANY WIDESPREAD COVERAGE OF SHOWERS SO I
CONTINUED JUST THE MENTION OF SLIGHT CHANCE WORDING IN THE
FORECAST FOR THIS AFTERNOON.
AS THE TROUGH MOVES OUT OF THE AREA DRY AIR WILL ENTRAIN INTO THE
MID AND UPPER LEVELS SO I EXPECT THE CLOUDS SHOULD BEGIN TO ERODE
MOVING INTO THE LATE AFTERNOON/ EARLY EVENING. LIGHT TO MODERATE
WESTERLY TO SOUTHWESTERLY WINDS WILL PREVAIL AND TEMPS TODAY WILL
WARM INTO THE MID 70S.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/...
AS OF 348 AM EDT THURSDAY...EXPECT A QUIET EVENING ON THURSDAY
NIGHT WITH INCREASING SOUTHERLY FLOW AHEAD OF A COLD FRONT. FRIDAY
MORNING THE SOUTHERLY FLOW QUICKLY INCREASES LOW LEVEL MOISTURE
AND SURFACE TEMPERATURES ACROSS THE NORTH COUNTRY. AS THE MOISTURE
INCREASES SO DOES THE INSTABILITY BUT ONLY MARGINALLY. GIVEN THE
WEAK LAPSE RATES AND MINIMAL SHEAR I DONT EXPECT MORE THAN A FEW
ISOLATED THUNDERSTORMS AS THE UPPER LEVEL VORT MAX`S GENERATE
RAIN SHOWERS ACROSS THE AREA FRIDAY EVENING INTO SATURDAY MORNING.
GIVEN THE RAPID INCREASE OF PRECIPITABLE WATER AND WEAK CORFIDI
VECTORS EXPECT SOME OF THE SHOWERS TO PRODUCE HEAVY RAINFALL RATES
HOWEVER WITH THE ANTECEDENT CONDITIONS STILL BELOW NORMAL FOR THE
AUGUST I`M NOT EXPECTING A SIGNIFICANT FLOODING EVENT. NONETHELESS
HEAVIER SHOWERS COULD LIKELY PRODUCE SOME PONDING OF WATER IN LOW
LYING AREAS AND IN AREAS OF POOR DRAINAGE.
AS THE FRONT CLEARS THE AREA LATE SATURDAY AFTERNOON WE WILL SEE
A NEW AIRMASS MOVE IN BEHIND THE FRONT AS AN UPPER LEVEL RIDGE AND
SURFACE HIGH BUILD IN OVER THE NORTH COUNTRY. EXPECT DAYTIME
TEMPERATURES FRIDAY WILL BE IN THE MID 70S TO LOW 80S WITH THE
OVERNIGHT LOWS ON FRIDAY NIGHT IN THE LOW TO MID 60S. AS THE FRONT
IS MOVING THROUGH THE REGION ON SATURDAY TEMPS WILL NEARLY BE A
REPEAT OF FRIDAY IN THE MID 70S TO LOW 80S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 333 AM EDT THURSDAY...MAIN HEADLINE FOR THE EXTENDED WILL
BE POTENTIAL UPPER 80S/LOWER 90S FOR DAYTIME HIGHS SUNDAY AND
MONDAY. BOTH THE 00Z ECMWF AND 00Z GFS INDICATE BROAD MID-LEVEL
RIDGE AND BUILDING 500MB HEIGHTS INTO THE REGION FROM THE WEST AND
SOUTHWEST...WITH 850MB TEMPS OF +18C TO +19C SUN/MON. RAINFALL
CHANCES APPEAR MINIMUM AND ANTICIPATE FULL HEATING WITH GENERAL
MID-LEVEL SUBSIDENCE IN PLACE. EXPECTATION IS FOR MID 60S
DEWPOINTS...THUS MODERATELY HUMID CONDITIONS. THIS SHOULD ALSO
KEEP LOW TEMPERATURES IN THE MID-UPR 60S FOR MOST SECTIONS FOR
SUNDAY NIGHT.
MID-LEVEL RIDGE BEGINS TO BREAK DOWN MONDAY NIGHT INTO TUESDAY. MAY
SEE SOME SHOWER/ISOLD THUNDER ACTIVITY DEVELOP LATER MONDAY
NIGHT...WITH POTENTIAL ROUND OF WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH SURFACE FRONTAL PASSAGE ON TUESDAY. HAVE INDICATED 30-40 POPS
ACROSS NRN NY 06-12Z TUESDAY...INCREASING TO 45-60 POPS AREAWIDE
DURING THE DAYLIGHT HOURS ON TUESDAY. COULD SEE A FEW STRONGER
THUNDERSTORMS...BUT DIFFICULT TO ASSESS AT THIS TIME GIVEN TIMING
UNCERTAINTY OF FRONTAL PASSAGE WITH RESPECT TO DAYTIME HEATING MAX.
SHOULD STILL SEE HIGH TEMPS IN THE LOW-MID 80S ACROSS THE VT VALLEYS
ON TUESDAY BEFORE RAINFALL...THOUGH COOLER WITH EARLIER FRONTAL
PASSAGE ACROSS NRN NY BASED ON CURRENT INDICATIONS. WILL CONTINUE TO
MONITOR.
SHOULD SEE CLEARING CONDITIONS TUESDAY NIGHT WITH COOLER/MORE
SEASONABLE CONDITIONS AND LOWER HUMIDITY LEVELS ON WEDNESDAY. HIGH
TEMPERATURES ON WEDNESDAY EXPECTED IN THE UPR 70S TO LOWER
80S...WITH DEWPOINTS BACK INTO THE MID TO UPPER 50S.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...UPPER TROUGH ROTATING SEWD FROM
QUEBEC/ONTARIO WILL MAINTAIN BKN-OVC SKIES THROUGH 14-15Z THIS
MORNING. GENERALLY VFR CEILINGS...BUT LOCALLY MVFR CEILINGS AT SLK
AND POSSIBLY AT MSS/RUT FROM TIME TO TIME THROUGH 12Z. GENERAL
TREND IN RAP MODEL SOUNDINGS IS TO SHOW IMPROVING CEILINGS AND
PARTIAL CLEARING BY 15Z. WITH DAYTIME HEATING AND UPPER TROUGH
PASSAGE...MAY SEE AN ISOLATED AFTERNOON SHOWER...BUT LOW
PROBABILITY DOESN/T WARRANT INCLUSION IN AREA TAFS ATTM. SURFACE
WINDS GENERALLY LESS THAN 10 KTS THROUGH THE PERIOD...LIGHT W-NW
EARLY THIS MORNING...AND GENERALLY W-SW DURING THE BALANCE OF THE
DAYLIGHT PERIOD.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
12Z FRIDAY THROUGH 12Z SATURDAY...MAINLY VFR CONDITIONS...BUT
SCATTERED SHOWER/TSTM DEVELOPMENT WILL BRING INTERVALS OF MVFR OR
BRIEF IFR WITH RAINFALL (MAINLY FRIDAY AFTN INTO EARLY FRIDAY EVE).
LOCALIZED FOG POSSIBLE LATE FRIDAY NIGHT...ESPECIALLY IN VALLEY
AREAS SEEING RAINFALL.
12Z SATURDAY THROUGH MONDAY...ISOLD SHOWER OR TSTM POSSIBLE
SATURDAY AFTERNOON. OTHERWISE MAINLY VFR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...DEAL
SHORT TERM...DEAL
LONG TERM...BANACOS
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
958 AM CDT THU AUG 13 2015
.UPDATE...
ISSUED AT 958 AM CDT THU AUG 13 2015
MAINLY SHOWERS ACROSS A SMALL PORTION OF THE REGION APPEAR TO BE
DISSIPATING. THIS ACTIVITY IS LIKELY ASSOCIATED WITH THE RIGHT
ENTRANCE REGION OF AN UPPER JET AND LOW-MID LEVEL FORCING AS A
COUPLE SUBTLE UPPER WAVES APPROACH FROM THE WEST. A WEAK 850MB
TROUGH PROPAGATES THROUGH THE REGION WITH 850MB TEMPS COOLING FROM
NORTH TO SOUTH THROUGH THE AFTERNOON HOURS. SHOWER/THUNDER CHANCES
WOULD SEEM POSSIBLE ALONG AND SOUTH OF THIS WEAK COLD
FRONT (MUCH LIKE THE 11Z EXPERIMENTAL HRRR DEPICTS). ADJUSTED
POPS TOWARD THIS SCENARIO. STRONGER STORMS APPEAR UNLIKELY GIVEN
WEAK FORCING AND WEAK DEEP LAYER SHEAR. WILL NEED TO WATCH
INSTABILITY...BUT CURRENT INDICATIONS SUGGEST MLCAPE POSSIBLY UP
TO 1000 J/KG BY PEAK HEATING...WHICH COMBINED WITH EXPECTED DEEP
LAYER SHEAR AND WEAK FORCING PROBABLY NOT SUFFICIENT FOR SEVERE
STORMS.
CLOUD COVER AND POSSIBLE SHOWERS MAY HOLD MAX TEMPS DOWN A
BIT...BUT STILL UPPER 80S NEAR 90F APPEAR A GOOD BET.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 316 AM CDT THU AUG 13 2015
PRECIP CHANCES TODAY AND TEMPERATURES WILL BE THE MAIN FORECAST
ISSUE FOR THE SHORT TERM.
UPPER RIDGING CONTINUES OVER THE ROCKIES AND WESTERN PLAINS...BUT
THE WV LOOP SHOWS A FAIRLY SIGNIFICANT SHORTWAVE COMING OVER THE
TOP OF IT IN SOUTHERN SASKATCHEWAN...AND ANOTHER WEAKER SHORTWAVE
JUST ENTERING THE FAR WESTERN DAKOTAS NEAR THE ND/SD BORDER. THE
MAIN COMPLEX OF THUNDERSTORMS FROM THE SOUTHERN SHORTWAVE IS
MOSTLY IN SOUTH DAKOTA...BUT SOME ACTIVITY HAS BEEN LINGERING ON
THE ND SIDE WITH A FEW SPOTS IN SOUTHWEST ND REPORTING SOME RAIN.
THIS SHORTWAVE WILL MOVE EASTWARD THROUGH THE MORNING...AND SOME
SPOTTY SHOWERS GETTING INTO OUR SOUTHERN COUNTIES LATER THIS
MORNING IS NOT OUT OF THE QUESTION. INCLUDED SOME LOW POPS IN THE
SOUTH AFTER 12Z.
OF GREATER QUESTION IS WHAT WILL HAPPEN WHEN THE NORTHERN
SHORTWAVE COMES DOWN INTO THE REGION LATER TODAY. NONE OF THE
MODELS HAVE BEEN DOING VERY WELL LATELY...SO HARD TO TRUST ANY ONE
SOLUTION. THERE IS A FAIR AMOUNT OF SHOWERS ENTERING NORTHWESTERN
ND WITH THE CURRENT SYSTEM...SO WILL THEY HOLD TOGETHER AND WILL
THERE BE ENOUGH INSTABILITY BY THE TIME THE SHORTWAVE ARRIVES FOR
STRONGER STORMS TO DEVELOP? MOST MODEL SOLUTIONS CONCENTRATE
ACTIVITY IN THE SOUTHERN CWA...WHICH MAKES SENSE AS THE SHORTWAVE
STARTS TO COME SOUTH ON THE FRONT SIDE OF THE UPPER TROUGH. AFTER
MORNING ACTIVITY...DO THINK THERE WILL BE SOME TIME TO DESTABILIZE
NEAR THE SOUTH DAKOTA BORDER. BEST SHEAR IS FURTHER SOUTH SO THINK
THAT MOST OF THE STORMS IN OUR AREA WILL BE SUB SEVERE. FOR NOW
HAVE SOME ISOLATED THUNDERSTORM CHANCES THIS AFTERNOON MAINLY
SOUTH OF I-94...BUT WILL MONITOR THE SITUATION CLOSELY AS THE
SHORTWAVE APPROACHES.
THE OTHER ISSUE WILL BE TEMPERATURES THROUGHOUT THE PERIOD. CLOUDS
AND SOME PRECIP ALONG WITH SLIGHTLY LOWER 850MB TEMPS TODAY WILL
KEEP TEMPS A BIT LOWER THAN YESTERDAY...BUT AT LEAST THE WESTERN
CWA WILL STILL GET NEAR 90 DEGREES. A WEAK SFC HIGH OVER THE
EASTERN CWA TONIGHT SHOULD ALLOW TEMPS TO FALL NICELY...BUT HIGHER
DEW POINTS WILL KEEP LOWS IN THE 60S. FRIDAY WILL BE EVEN WARMER
THAN TODAY WITH CLEAR SKIES AND SFC WINDS SHIFTING BACK TO THE
SOUTH AS THE HIGH MOVES EAST AND A TROUGH DEVELOPS OVER MT. HIGHS
SHOULD GET INTO THE 90S WITH SOME 80S HANGING ON OVER THE EASTERN
CWA.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 AM CDT THU AUG 13 2015
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE UPPER RIDGE WILL START
TO FLATTEN A BIT AS AN UPPER LEVEL TROUGH BEGINS TO MOVE INTO
SASKATCHEWAN INTO MANITOBA. A FAIRLY VIGOROUS SFC LOW PRESSURE
CENTER WILL MOVE ACROSS SOUTHERN CANADA THROUGH THE START OF THE
WEEKEND...AND SOUTHERLY WINDS WILL PICK UP AHEAD OF IT. THE WINDS
WILL KEEP THE BOUNDARY LAYER FRIDAY NIGHT MIXED SO LOWS WILL
STAY IN THE UPPER 60S AND EVEN LOW 70S. THE BREEZY SOUTH WINDS
WILL CONTINUE TO BRING GOOD MIXING SATURDAY AND MODELS ARE IN GOOD
AGREEMENT WITH THE THERMAL RIDGE BEING OVER THE AREA AT THIS TIME.
BUMPED UP HIGHS A BIT FOR SOME MID 90S IN SOME PARTS OF THE
CWA...AND SOME HIGHER READINGS ARE NOT OUT OF THE QUESTION. A COLD
FRONT WILL COME DOWN SATURDAY NIGHT AND SHOULD PROVIDE ENOUGH LOW
LEVEL CONVERGENCE FOR SOME THUNDERSTORMS TO FORM ALONG IT. KEPT
FAIRLY HIGH POPS GOING SATURDAY NIGHT WITH TEMPS STARTING TO COME
DOWN A BIT.
SUNDAY-WEDNESDAY...COOLER AIR WILL MOVE INTO THE REGION BEHIND THE
FRONT ON SUNDAY WITH HIGH PRESSURE EXPECTED TO PROVIDE QUIET WEATHER
INTO THE START OF THE WORK WEEK. A FLATTER UPPER AIR PATTERN WILL
PERSIST THROUGH MID-WEEK...WITH AVERAGE TO SLIGHTLY BELOW AVERAGE
TEMPS. PRECIP CHANCES ARE MORE UNCERTAIN BY LATE IN THE PERIOD AS
THE GLOBAL MODELS DIFFER ON TIMING/AMPLITUDE OF AN UPPER WAVE
LIFTING FROM THE ROCKIES INTO THE PLAINS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 710 AM CDT THU AUG 13 2015
PATCHY FOG HAS REDUCED VIS AT KTVF TO 1/4 MILE THIS MORNING. THERE
COULD BE SOME BOUNCING AROUND FOR THE NEXT HOUR OR SO BEFORE THE
VIS IMPROVES BACK TO VFR. THE REST OF THE CWA WILL SEE MAINLY HIGH
CLOUDS ABOVE 15000 FT...WITH WINDS SETTLING DOWN OUT OF THE SOUTH
AT AROUND 10 KTS. SHOWERS AND THUNDERSTORMS WILL BE MOVING IN BUT
NOT CONFIDENT ENOUGH TO INCLUDE IT AT TAF SITES AT THIS POINT.
WINDS WILL BECOME LIGHT AND VARIABLE TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...JR
AREA FORECAST DISCUSSION
NWS NORMAN OK
1058 AM CDT THU AUG 13 2015
.UPDATE...
MADE ONLY MINOR UPDATES AS FORECAST SEEMS TO BE MOSTLY ON TRACK.
&&
.DISCUSSION...
A FEW SHOWERS CONTINUE OVER NORTH CENTRAL OKLAHOMA THIS MORNING.
THIS ACTIVITY TO BE RATHER SHORT LIVED. OTHERWISE...EXPECT
ANOTHER WARM AND PARTLY CLOUDY DAY.
&&
.PREV DISCUSSION... /ISSUED 726 AM CDT THU AUG 13 2015/
UPDATE...
TRIMMED BACK PRECIP/WX CHANCES THIS MORNING...
DISCUSSION...
PULLED BACK PRECIP/WX CHANCES THIS MORNING GIVEN CURRENT RADAR
TRENDS. SATELLITE SUGGEST CONTINUED ACCAS DEVELOPMENT... BUT
OVERALL LACK OF PRECIP THIS MORNING. HRRR RUNS HAVE PULLED BACK
CONSIDERABLY... ADDING SOME CONFIDENCE TO THE DECISION. WILL
CONTINUE WITH SLIGHT CHANCE FOR MUCH OF WESTERN OK THROUGH THIS
MORNING GIVEN ISOLATED SHOWERS AND THUNDER WILL REMAIN POSSIBLE...
BUT MORE THAN LIKELY MANY WILL STAY DRY.
JTK
PREV DISCUSSION... /ISSUED 606 AM CDT THU AUG 13 2015/
AVIATION...13/12Z TAF ISSUANCE...
BKN TO OVC MID-LEVEL STRATO CU AND CU CONTINUE TO BUILD ACROSS WRN
PORTIONS OF OK. A FEW SCATTERED SHOWERS HAVE ALSO DEVELOPED AND
THIS ACTIVITY IS EXPECTED TO CONTINUE THROUGH THE MORNING HOURS...
PRIMARILY IMPACTING KGAG/KWWR AND POTENTIALLY KCSM/KHBR. NOT AS
DEVELOPED AS YESTERDAY MORNING... IMPACTS LOOK TO BE RELATIVELY
MINOR... WITH VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE
PERIOD. WINDS WILL REMAIN LIGHT TO MODERATE AND OUT OF THE E/SE
THROUGH FRIDAY MORNING.
JTK
PREV DISCUSSION... /ISSUED 334 AM CDT THU AUG 13 2015/
DISCUSSION...
THIS MORNING... CONTINUING TO WATCH EXPANDING AREA OF ACCAS ACROSS
NWRN AND WRN OK THROUGH 0830Z (330AM). FARTHER NORTH IN KS... A FEW
UPDRAFTS HAVE STARTED TO GO UP. SHORT RANGE GUIDANCE FROM THE
HRRR/WRFS/RUC HAVE BEEN CONSISTENT IN GENERATING CONVECTION ACROSS
THE WRN OK. SIMILAR THE PAST FEW NIGHTS... MINUS AN AREA OF ONGOING
CONVECTION IN SWRN KS... MODEST MID-LEVEL MOISTURE AND ASCENT ARE
PREVALENT... AND EVIDENT BY THE DEVELOPING MID-LEVEL CU ON IR. ALSO
OF NOTE THIS MORNING... SPC MESOANALYSIS SHOWS A GOOD 1000-1500 J/KG
AXIS OF MUCAPE CENTERED OVER WRN OK. OVERALL... EXPECT SCATTERED
SHOWERS AND ISOLATE THUNDER TO INITIATE BETWEEN 09 AND 10Z THIS
MORNING IN WRN OK... LIKELY PERSISTING THROUGH NOON. MEANWHILE...
TEMPS TODAY WILL SLOWLY CLIMB INTO THE UPPER 80S ACROSS NRN AND
CENTRAL OK TO THE MID 90S ACROSS SRN OK/WRN N TX.
INTO FRIDAY... SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS WILL
DEVELOP ONCE AGAIN ACROSS FAR SWRN OK AND WRN N TX IN RESPONSE TO
DEVELOPING MID-LEVEL CONVERGENCE. CHANCES WILL REMAIN LOW... BUT
WORTHY OF A MENTION INTO THE AFTN. TEMPS WILL REMAIN NEAR NORMAL...
WITH HIGHS IN THE 90S ACROSS THE REGION.
FOR THE WEEKEND INTO EARLY NEXT WEEK... AFTN HIGHS WILL REMAIN
STEADY EACH DAY... IN THE 90S ACROSS THE SRN PLAINS. LATE MON INTO
TUE... A WEAK FRONT WILL APPROACH NWRN OK... WITH A SLIGHT CHANCES OF
SOME SCATTERED PRECIP POSSIBLY NUDGING INTO FAR NWRN OK EARLY TUE
MORNING... BUT OVERALL... CONDITIONS SHOULD BE DRY AND PLEASANT.
LATE IN THE WEEK... THU-FRI... BOTH THE GFS AND ECMWF SUGGEST A
DECENT COLD FRONT WILL MOVE INTO THE REGION BRINGING A GOOD CHANCE
AT ANOTHER ROUND OF PRECIP. AT THE MOMENT... THE GFS IS THE MORE
BULLISH SOLUTION... WITH THE ECMWF LESS AGGRESSIVE AND A STEP
SLOWER.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 90 69 90 67 / 10 10 10 0
HOBART OK 92 71 94 69 / 10 10 10 10
WICHITA FALLS TX 94 73 95 71 / 10 10 20 10
GAGE OK 91 69 92 67 / 10 10 10 0
PONCA CITY OK 90 69 90 67 / 10 0 10 0
DURANT OK 93 68 95 69 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
14/23
AREA FORECAST DISCUSSION
NWS NORMAN OK
726 AM CDT THU AUG 13 2015
.UPDATE...
TRIMMED BACK PRECIP/WX CHANCES THIS MORNING...
&&
.DISCUSSION...
PULLED BACK PRECIP/WX CHANCES THIS MORNING GIVEN CURRENT RADAR
TRENDS. SATELLITE SUGGEST CONTINUED ACCAS DEVELOPMENT... BUT
OVERALL LACK OF PRECIP THIS MORNING. HRRR RUNS HAVE PULLED BACK
CONSIDERABLY... ADDING SOME CONFIDENCE TO THE DECISION. WILL
CONTINUE WITH SLIGHT CHANCE FOR MUCH OF WESTERN OK THROUGH THIS
MORNING GIVEN ISOLATED SHOWERS AND THUNDER WILL REMAIN POSSIBLE...
BUT MORE THAN LIKELY MANY WILL STAY DRY.
JTK
&&
.PREV DISCUSSION... /ISSUED 606 AM CDT THU AUG 13 2015/
AVIATION...13/12Z TAF ISSUANCE...
BKN TO OVC MID-LEVEL STRATO CU AND CU CONTINUE TO BUILD ACROSS WRN
PORTIONS OF OK. A FEW SCATTERED SHOWERS HAVE ALSO DEVELOPED AND
THIS ACTIVITY IS EXPECTED TO CONTINUE THROUGH THE MORNING HOURS...
PRIMARILY IMPACTING KGAG/KWWR AND POTENTIALLY KCSM/KHBR. NOT AS
DEVELOPED AS YESTERDAY MORNING... IMPACTS LOOK TO BE RELATIVELY
MINOR... WITH VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE
PERIOD. WINDS WILL REMAIN LIGHT TO MODERATE AND OUT OF THE E/SE
THROUGH FRIDAY MORNING.
JTK
PREV DISCUSSION... /ISSUED 334 AM CDT THU AUG 13 2015/
DISCUSSION...
THIS MORNING... CONTINUING TO WATCH EXPANDING AREA OF ACCAS ACROSS
NWRN AND WRN OK THROUGH 0830Z (330AM). FARTHER NORTH IN KS... A FEW
UPDRAFTS HAVE STARTED TO GO UP. SHORT RANGE GUIDANCE FROM THE
HRRR/WRFS/RUC HAVE BEEN CONSISTENT IN GENERATING CONVECTION ACROSS
THE WRN OK. SIMILAR THE PAST FEW NIGHTS... MINUS AN AREA OF ONGOING
CONVECTION IN SWRN KS... MODEST MID-LEVEL MOISTURE AND ASCENT ARE
PREVALENT... AND EVIDENT BY THE DEVELOPING MID-LEVEL CU ON IR. ALSO
OF NOTE THIS MORNING... SPC MESOANALYSIS SHOWS A GOOD 1000-1500 J/KG
AXIS OF MUCAPE CENTERED OVER WRN OK. OVERALL... EXPECT SCATTERED
SHOWERS AND ISOLATE THUNDER TO INITIATE BETWEEN 09 AND 10Z THIS
MORNING IN WRN OK... LIKELY PERSISTING THROUGH NOON. MEANWHILE...
TEMPS TODAY WILL SLOWLY CLIMB INTO THE UPPER 80S ACROSS NRN AND
CENTRAL OK TO THE MID 90S ACROSS SRN OK/WRN N TX.
INTO FRIDAY... SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS WILL
DEVELOP ONCE AGAIN ACROSS FAR SWRN OK AND WRN N TX IN RESPONSE TO
DEVELOPING MID-LEVEL CONVERGENCE. CHANCES WILL REMAIN LOW... BUT
WORTHY OF A MENTION INTO THE AFTN. TEMPS WILL REMAIN NEAR NORMAL...
WITH HIGHS IN THE 90S ACROSS THE REGION.
FOR THE WEEKEND INTO EARLY NEXT WEEK... AFTN HIGHS WILL REMAIN
STEADY EACH DAY... IN THE 90S ACROSS THE SRN PLAINS. LATE MON INTO
TUE... A WEAK FRONT WILL APPROACH NWRN OK... WITH A SLIGHT CHANCES OF
SOME SCATTERED PRECIP POSSIBLY NUDGING INTO FAR NWRN OK EARLY TUE
MORNING... BUT OVERALL... CONDITIONS SHOULD BE DRY AND PLEASANT.
LATE IN THE WEEK... THU-FRI... BOTH THE GFS AND ECMWF SUGGEST A
DECENT COLD FRONT WILL MOVE INTO THE REGION BRINGING A GOOD CHANCE
AT ANOTHER ROUND OF PRECIP. AT THE MOMENT... THE GFS IS THE MORE
BULLISH SOLUTION... WITH THE ECMWF LESS AGGRESSIVE AND A STEP
SLOWER.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 90 69 90 67 / 10 10 10 0
HOBART OK 92 71 94 69 / 20 10 10 10
WICHITA FALLS TX 93 73 95 71 / 10 10 20 10
GAGE OK 90 69 92 67 / 20 10 10 0
PONCA CITY OK 89 69 90 67 / 0 0 10 0
DURANT OK 93 68 95 69 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
645 AM EDT THU AUG 13 2015
.SYNOPSIS...
THE UPPER LEVEL TROUGH THAT BROUGHT US A CHANGE TO COOLER WEATHER
WITH LOW DAYTIME HUMIDITY...WILL BE GRADUALLY WEAKENING OVER THE
NEXT FEW DAYS. WARMER TEMPERATURES WILL MOVE INTO THE REGION OVER
THE UPCOMING WEEKEND. ANOTHER TROUGH AND SURFACE COLD FRONT SHOULD
BRING COOLER AND DRIER AIR BACK INTO THE REGION AROUND MIDWEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLEAR SKIES OVER THE ENTIRE REGION EARLY THIS MORNING...AND THE
FINAL DAY OF THE WANING CRESCENT MOON...WAS BRINGING FANTASTIC
CONDITIONS TO VIEW THE PEAK OF THE PERSEID METEOR SHOWER. TONIGHT
COULD FEATURE SIMILAR CONDITIONS WITH A NEW MOON...BUT AREAS OF
MID AND CLOUD CLOUDS COULD DRIFT SOUTHEAST ACROSS THE REGION AT
TIMES.
TEMPS WERE QUITE CHILLY FOR MID AUGUST...WITH BRADFORD TAKING THE
PRIZE FOR THE LOW TEMP OF 42F AT 10Z.
ELSEWHERE...TEMPS WERE IN THE 50S...TO NEAR 60F IN THE LARGER
METRO AREAS THROUGHOUT THE SUSQ VALLEY.
SOME HIGH CLOUDS WILL DRIFT SE INTO THE COMMONWEALTH TODAY...BUT
THEY WILL BE QUITE THIN AND SHOULD HAVE LITTLE OR NO IMPACT ON
THE OTHERWISE SUNNY...AND SPLENDID CONDITIONS FOR THE MIDDLE OF
AUGUST.
AFTERNOON HIGHS WILL BE IN THE L-M 70S ACROSS THE NRN AND WRN
MTNS...AND AROUND 80F IN THE LOWER SUSQ VALLEY.
THERE COULD BE SOME PATCHY AM...FOG ESPECIALLY NEAR WATER BODIES
AND STREAMS THROUGHOUT THE NORTHERN MOUNTAINS WHERE THE AIR/WATER
DELTA T IS 20 DEG F OR MORE.
00Z WRFARW AND THE LATEST...03Z SREF BOTH SHOW A LOW PROB FOR
SHOWERS ACROSS THE NW PENN MTNS BETWEEN ABOUT 20Z TODAY AND 00Z
FRIDAY...WHILE THE 09Z HRRR IS BONE DRY. OUR 10-20 POPS THERE
CONTINUE TO LOOK IN GOOD SHAPE. POPS ELSEWHERE WILL BE ESSENTIALLY
ZERO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WARMER TEMPS ARE ON THE WAY FOR FRIDAY. THE ONLY WEATHER FACTORS
ALOFT TO SPEAK OF WILL BE THE PERIODS OF ALTOCU AND CIRRUS THAT
WILL BE MOVING QUICKLY SE ACROSS THE STATE.
HIGH TEMPS FRIDAY WILL VARY FROM THE U70S TO AROUND 80F ACROSS THE
HIGHER TERRAIN OF THE NORTH AND WEST...WHILE THE LOW SUSQ VALLEY
SEES TEMPS RECH ATLEAT 85F.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE SFC HIGH PRESSURE WILL BREAK DOWN AS A SHALLOW TROUGH WILL
DEEPEN AND ALLOW A COLD FRONT TO TRAVERSE THE REGION FRIDAY
AFTERNOON INTO SATURDAY. THE MOISTURE WILL BE FOCUSED ALONG THE
NEW YORK BORDER AND NORTH. THOUGH AS THE TROUGH CONTINUES TO TILT
POSITIVE AND DEEPENS...THERE WILL BE A GREATER CHANCE FOR SHOWERS
AND THUNDERSTORMS ALONG THE CENTRAL MTNS AND THROUGH THE NORTHERN
HALF OF PA. TEMPERATURES WILL BEGIN TO REBOUND UNDER THIS MORE
WESTERLY FLOW OUT AHEAD OF THE FRONT WHICH WILL AID IN ANY
CONVECTION. THE FRONT SHOULD STALL ON SATURDAY...WHICH COULD ALLOW
FOR DAYTIME SUMMER CONVECTION BEFORE THE COLD FRONT PUSHES EAST OF
PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL RETURN FOR THE
BEGINNING OF NEXT WEEK. GIVEN THE PATTERN HAVE ADJUSTED POPS
UPWARD AND SHIFTED THE TIMING ACCORDINGLY. HAVE ADJUSTED
TEMPERATURES UPWARD AS WELL. THE ACTIVE WEATHER PATTERN WILL
CONTINUE THROUGH THE MIDDLE OF NEXT WEEK AS SUCCESSIVE TROUGHS
WILL MOVE THROUGH THE REGION WITH THE NEXT BEST CHANCE TUESDAY
INTO WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
NO LARGE CHANGES TO 12Z TAF PACKAGE.
NICE SUNRISE HERE...CLEAR SKIES NOW. BFD ABOUT THE ONLY
SPOT THAT HAD FOG OVERNIGHT. COULD SEE THE PERSEID METEOR
SHOWER EARLIER.
SOME HIGHER CLOUDS LATE TODAY...MAINLY NW.
WEEKEND NOT LOOKING TO BAD AT THIS POINT.
OUTLOOK...
FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
SUN...NO SIG WX.
MON...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...GRUMM/LAMBERT
LONG TERM...CERU/HAGNER
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
642 AM EDT THU AUG 13 2015
.SYNOPSIS...
THE UPPER LEVEL TROUGH THAT BROUGHT US A CHANGE TO COOLER WEATHER
WITH LOW DAYTIME HUMIDITY...WILL BE GRADUALLY WEAKENING OVER THE
NEXT FEW DAYS. WARMER TEMPERATURES WILL MOVE INTO THE REGION OVER
THE UPCOMING WEEKEND. ANOTHER TROUGH AND SURFACE COLD FRONT SHOULD
BRING COOLER AND DRIER AIR BACK INTO THE REGION AROUND MIDWEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLEAR SKIES OVER THE ENTIRE REGION EARLY THIS MORNING...AND THE
FINAL DAY OF THE WANING CRESCENT MOON...WAS BRINGING FANTASTIC
CONDITIONS TO VIEW THE PEAK OF THE PERSEID METEOR SHOWER. TONIGHT
COULD FEATURE SIMILAR CONDITIONS WITH A NEW MOON...BUT AREAS OF
MID AND CLOUD CLOUDS COULD DRIFT SOUTHEAST ACROSS THE REGION AT
TIMES.
TEMPS WERE QUITE CHILLY FOR MID AUGUST...WITH BRADFORD TAKING THE
PRIZE FOR THE LOW TEMP OF 44F AT 09Z.
ELSEWHERE...TEMPS WERE IN THE 50S...TO NEAR 60F IN THE LARGER
METRO AREAS THROUGHOUT THE SUSQ VALLEY.
SOME HIGH CLOUDS WILL DRIFT SE INTO THE COMMONWEALTH TODAY...BUT
THEY WILL BE QUITE THIN AND SHOULD HAVE LITTLE OR NO IMPACT ON
THE OTHERWISE SUNNY...AND SPLENDID CONDITIONS FOR THE MIDDLE OF
AUGUST.
AFTERNOON HIGHS WILL BE IN THE L-M 70S ACROSS THE NRN AND WRN
MTNS...AND AROUND 80F IN THE LOWER SUSQ VALLEY.
THERE COULD BE SOME PATCHY AM...FOG ESPECIALLY NEAR WATER BODIES
AND STREAMS THROUGHOUT THE NORTHERN MOUNTAINS WHERE THE AIR/WATER
DELTA T IS 20 DEG F OR MORE.
00Z WRFARW AND THE LATEST...03Z SREF BOTH SHOW A LOW PROB FOR
SHOWERS ACROSS THE NW PENN MTNS BETWEEN ABOUT 20Z TODAY AND 00Z
FRIDAY...WHILE THE HRRR IS BONE DRY. OUR 10-20 POPS THERE CONTINUE
TO LOOK IN GOOD SHAPE. POPS ELSEWHERE WILL BE ESSENTIALLY ZERO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WARMER TEMPS ARE ON THE WAY FOR FRIDAY. THE ONLY WEATHER FACTORS
ALOFT TO SPEAK OF WILL BE THE PERIODS OF ALTOCU AND CIRRUS THAT
WILL BE MOVING QUICKLY SE ACROSS THE STATE.
HIGH TEMPS FRIDAY WILL VARY FROM THE U70S TO AROUND 80F ACROSS THE
HIGHER TERRAIN OF THE NORTH AND WEST...WHILE THE LOW SUSQ VALLEY
SEES TEMPS RECH ATLEAT 85F.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE SFC HIGH PRESSURE WILL BREAK DOWN AS A SHALLOW TROUGH WILL
DEEPEN AND ALLOW A COLD FRONT TO TRAVERSE THE REGION FRIDAY
AFTERNOON INTO SATURDAY. THE MOISTURE WILL BE FOCUSED ALONG THE
NEW YORK BORDER AND NORTH. THOUGH AS THE TROUGH CONTINUES TO TILT
POSITIVE AND DEEPENS...THERE WILL BE A GREATER CHANCE FOR SHOWERS
AND THUNDERSTORMS ALONG THE CENTRAL MTNS AND THROUGH THE NORTHERN
HALF OF PA. TEMPERATURES WILL BEGIN TO REBOUND UNDER THIS MORE
WESTERLY FLOW OUT AHEAD OF THE FRONT WHICH WILL AID IN ANY
CONVECTION. THE FRONT SHOULD STALL ON SATURDAY...WHICH COULD ALLOW
FOR DAYTIME SUMMER CONVECTION BEFORE THE COLD FRONT PUSHES EAST OF
PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL RETURN FOR THE
BEGINNING OF NEXT WEEK. GIVEN THE PATTERN HAVE ADJUSTED POPS
UPWARD AND SHIFTED THE TIMING ACCORDINGLY. HAVE ADJUSTED
TEMPERATURES UPWARD AS WELL. THE ACTIVE WEATHER PATTERN WILL
CONTINUE THROUGH THE MIDDLE OF NEXT WEEK AS SUCCESSIVE TROUGHS
WILL MOVE THROUGH THE REGION WITH THE NEXT BEST CHANCE TUESDAY
INTO WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
NO LARGE CHANGES TO 12Z TAF PACKAGE.
NICE SUNRISE HERE...CLEAR SKIES NOW. BFD ABOUT THE ONLY
SPOT THAT HAD FOG OVERNIGHT. COULD SEE THE PERSEID METEOR
SHOWER EARLIER.
SOME HIGHER CLOUDS LATE TODAY...MAINLY NW.
WEEKEND NOT LOOKING TO BAD AT THIS POINT.
OUTLOOK...
FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
SUN...NO SIG WX.
MON...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...GRUMM/LAMBERT
LONG TERM...CERU/HAGNER
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1041 AM CDT THU AUG 13 2015
.UPDATE...
ISSUED AT 1040 AM CDT THU AUG 13 2015
QUITE A BIT TO DEAL WITH THIS MORNING. CONVECTION WITH WEAK UPPER
WAVE MOVING THROUGH THE MEAN RIDGE THIS MORNING HAS MAINTAINED AND
EVEN BECOME MORE WIDESPREAD...ALTHOUGH THE EXTENT OF THUNDER
REMAINS QUIET SPOTTY. WAVE CONTINUES TO DRIFT EAST AND
SOUTHEAST...WITH STRONGEST OF THE UPPER FORCING THIS MORNING
GLANCING ACROSS NORTHEAST SOUTH DAKOTA...HEADING TOWARD SOUTHERN
MINNESOTA. TOUGH CALL ON THE PRECIPITATION TRENDS TODAY WITH
ALMOST ALL GUIDANCE LACKING AN ADEQUATE SIMULATION OF CURRENT
CONDITIONS. HRRR MARGINALLY USEFUL...BUT APPEARS TO NOT BE
HANDLING THE STRONGER FORCED AREA TO THE NORTHEAST WELL AT ALL.
HAVE PUSHED POPS CONSIDERABLY HIGHER IN THE SHORT TERM IN THE MID
JAMES VALLEY THROUGH HIGHWAY 14 CORRIDOR...AND EXPANDED SOME
SLIGHTS/SPRINKLES DOWN TOWARD I 90 BY VERY LATE MORNING AND EARLY
AFTERNOON IN ADVANCE OF TAIL OF WAVE...BUT DRY AIR BELOW MID CLOUD
DECK WILL MAKE THIS SOMEWHAT A STRUGGLE TO REACH THE GROUND.
GIVEN THE DRY LAYER IN THE KABR 12Z RAOB...NO SURPRISE THAT
SHOWERS AND THUNDERSTORMS HAVE CREATED A DECENT COLD AIR POOL AND
DISRUPTED THE LOCAL LOW LEVEL CONVERGENCE FIELDS. HAD A FEW WIND
GUSTS CLOSE TO 40 MPH WITH LEADING EDGE OF SHOWERS IN EAST CENTRAL
SD...AND WILL CONTINUE TO BE A THREAT AS AREA EXPANDS INTO SW MN
AT MID MORNING. OTHERWISE...EXTENT OF CLOUDS AND THE PRECIPITATION
THIS MORNING TAKING A GOOD BITE OUT OF DIURNAL HEATING CYCLE...AS
WILL ANY LINGERING PRECIPITATION THIS BY EARLY AFTERNOON. HAVE
LOWERED HIGHS SEVERAL DEGREES ACROSS NORTHERN AREAS...AND IN FACT
HAVE RAISED HIGHS A BIT IN THE FAR SOUTH.
INITIAL THOUGHTS ARE THAT CURRENT CLOUDS/PRECIP WILL CREATE A
CHALLENGE TOWARD DEVELOPMENT OF SEVERE STORMS LATER TODAY. STILL
HAVE DECENT MID LEVEL LAPSE RATES...SO THOSE AREAS WHICH POTENTIALLY
HEAT OUT THE BEST TOWARD THE WEST SHOULD HAVE THE MOST FAVORABLE
INSTABILITY PROFILE...AND THE GREATER CHANCE WOULD REMAIN TOWARD
LOWER BRULE LOCATIONS. HOWEVER...WEAK WIND SHEAR WILL KEEP ORGANIZATION
POTENTIAL LIMITED...WITH MARGINALLY SEVERE WIND GUSTS AND LARGE
HAIL WOULD THE PRIMARY THREAT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT THU AUG 13 2015
ANOTHER WARM DAY ACROSS THE AREA...BUT MAIN FOCUS FOR TODAY IS ON
CONVECTIVE CHANCES AS WEAK RIDGE-TOPPING SHORTWAVE SLIDES THROUGH
THE NORTHERN PLAINS. WAVE CURRENTLY MOVING THROUGH THE WESTERN
DAKOTAS AND TRIGGERING SPOTTY ELEVATED CONVECTION INTO CENTRAL SD AS
OF 08Z. FEW IF ANY OF THE HI-RES MODELS SEEM TO BE CAPTURING THE
SOUTHERN EXTENT OF THE CURRENT ACTIVITY WELL...THOUGH ADMITTEDLY
WITH CLOUD BASES LARGELY REGISTERING AT OR ABOVE 11KFT...MUCH OF THE
PRECIP SEEN ON RADAR IMAGERY MAY NOT BE REACHING THE GROUND.
NEVERTHELESS...HAVE ADDED SOME LOW POPS TO OUR NORTHWEST CORNER FOR
THE EARLY MORNING HOURS. WILL ALSO WATCH FOR SPOTTY DEVELOPMENT
FARTHER EAST THROUGH THE HIGHWAY 14 CORRIDOR...AS MODELS IN GOOD
AGREEMENT SHOWING A CONVERGENCE ZONE AMID WEAK 850MB WARM ADVECTION
IN THIS AREA AROUND 12Z. AGAIN THINK MOISTURE...OR LACK THEREOF...
MAY BE A LIMITING FACTOR THOUGH...AND OPTED TO NOT INCLUDE EARLY
MORNING POPS THERE AS A RESULT.
THINK MAIN EFFECT OF THE CURRENT ACTIVITY WILL BE TO FORCE A WEAK
SURFACE LOW AND ASSOCIATED LOW LEVEL BOUNDARIES A BIT FARTHER SOUTH
THAN PREVIOUSLY FORECAST...WHICH SHOULD BRING THE CHANCE FOR MID-
LATE AFTERNOON DEVELOPMENT FARTHER SOUTH AS WELL. THUS HAVE SHIFTED
POPS CLOSER TO I-90 CORRIDOR FOR THE LATE AFTERNOON EVENING...WITH
BETTER CHANCE STILL EXPECTED NEAR/NORTH OF THE BOUNDARY FROM SOUTH
CENTRAL SD...NORTHEASTWARD TOWARD EAST CENTRAL SD AND NORTHERN
PORTIONS OF OUR SOUTHWEST MN COUNTIES. AT THIS POINT THINK ACTIVITY
IN OUR AREA WILL BE MORE SPARSE GIVEN BETTER UPPER SUPPORT IS TO OUR
NORTHEAST...BUT DECENT HEATING INTO THE UPPER 80S-LOWER 90S...ALONG
WITH WEAK UPPER LEVEL FORCING WARRANTS LOW POPS THROUGH THE WESTERN
AND NORTHERN PARTS OF THE FORECAST AREA. WITH MID-UPPER LEVEL TEMPS
COOLING SLIGHTLY WITH PASSAGE OF THE WAVE...MID LEVEL LAPSE RATES
ARE FAVORABLE FOR SOME HAIL FROM PULSE STORMS. DRY MID LEVELS COULD
SUPPORT GUSTY WINDS AS WELL...WITH FORECAST SOUNDINGS INDICATING
DOWNDRAFT CAPE NEAR 1000J/KG IN THE LATE AFTERNOON/EARLY EVENING.
WILL HAVE A MENTION OF THIS IN THE HWO...BUT THINK THREAT OF STRONG
TO SEVERE STORMS IS RATHER ISOLATED. CONVECTION EXPECTED TO WIND
DOWN THROUGH THE EARLY-MID EVENING AS TEMPERATURES COOL AND ANY
UPPER SUPPORT SLIDES EAST...LEAVING DRY CONDITIONS OVERNIGHT INTO
EARLY FRIDAY WITH LOWS IN THE MID-UPPER 60S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 400 AM CDT THU AUG 13 2015
ON FRIDAY...THE LARGE UPPER RIDGE OF HIGH PRESSURE REMAINS CENTERED
ACROSS THE SOUTHERN AND CENTRAL ROCKIES...BECOMING ELONGATED IN A
POSITIVE TILT FROM NEAR THE FOUR CORNERS AREA TO MINNESOTA FRIDAY
NIGHT. AS A SHORT WAVE MOVES EASTWARD OVER THE RIDGE ON SATURDAY...
THE RIDGE FLATTENS SOMEWHAT BUT REMAINS BASICALLY IN THE SAME
LOCATION ON SATURDAY. THE RIDGE LOOKS TOO MUCH TO OVERCOME FOR TSRA
TO FORM FRIDAY...FRIDAY NIGHT AND SATURDAY SO LEFT CONDITIONS DRY.
IT WILL ALSO BE VERY WARM...WITH TEMPERATURES WELL ABOVE NORMAL. BUT
MODERATE HUMIDITY LEVELS WILL KEEP HEAT INDEX VALUES GENERALLY IN
THE 90S AND AWAY FROM READINGS OVER 100 DEGREES.
THE VARIOUS MODELS ARE IN GOOD AGREEMENT IN HOW THEY HANDLE THE
AFOREMENTIONED SHORT WAVE`S MOVEMENT EASTWARD SATURDAY NIGHT AND
SUNDAY...AND A SECOND SHORT WAVE ON ITS HEELS WHICH MOVES INTO OUR
AREA ON SUNDAY. AHEAD OF THE FIRST SHORT WAVE AND ASSOCIATED SURFACE
COLD FRONT...SOUTHERLY WINDS WILL BE QUITE BREEZY ON SATURDAY. THEN
BY 12Z SUNDAY...THE MODELS HAVE THE FIRST SHORT WAVE EXTENDING FROM
NEAR WINNIPEG SOUTHWARD ALONG THE I 29 CORRIDOR IN EASTERN ND...
FOLLOWED BY THE SECOND WAVE MOVING INTO CENTRAL ND TO NORTHWEST SD
BY 00Z MONDAY. THE MODELS HAVE ALSO FINALLY COALESCED AROUND THE
SURFACE FRONTAL TIMING ON SUNDAY...MOVING IT SLOWLY EASTWARD THROUGH
THE DAY...EXITING THE ZONES AROUND SIOUX CITY AND STORM LAKE BY
ABOUT 03Z TO 06Z MONDAY. WITH THE SURFACE FRONT ACTING AS A
FOCUS...SCATTERED THUNDERSTORMS SHOULD DEVELOP SATURDAY NIGHT AND
SUNDAY. BUT WITH A BULK OF THE SHORT WAVE DYNAMICS WITH THE FIRST
WAVE TO OUR NORTH...AND THE SECOND WAVE WELL TO OUR WEST...THERE IS
NOT ENOUGH EVIDENCE TO GO LIKELY POPS WITH NUMEROUS STORM COVERAGE.
THE CHANCES FOR SEVERE WEATHER WITH THESE STORMS SATURDAY NIGHT
AND/OR SUNDAY ARE PROBABLY FAIRLY REMOTE IN OUR FORECAST AREA. DEEP
LAYER WIND SHEAR IS NOT VERY STRONG AT ALL AHEAD OF THE FRONTAL
BOUNDARY...AND BOTH THE NAM AND GFS SHOW 0-6KM BULK WIND VECTORS ONLY
ON THE ORDER OF 15 TO 25 KNOTS AT 12Z SUNDAY. 1KM ML CAPE ALSO
RAPIDLY WANES IN OUR WESTERN ZONES AFTER 06Z SUNDAY...AND BECOMES
NEARLY NON EXISTENT BY 12Z SUNDAY. THAT SAID ELEVATED CAPE AROUND
850-800MB REMAINS IN PLACE THROUGH 12Z SUNDAY ALONG WITH DECENT
NEGATIVE LIFTED INDEX VALUES OF AROUND -4C AT 850MB ON A
YANKTON...TO SIOUX FALLS TO MARSHALL MN LINE. WIND SHEAR REMAINS
SUBDUED ON SUNDAY.
ANOTHER UPPER TROUGH IS FORECAST TO MOVE EASTWARD ACROSS THE WESTERN
U.S. STATES ON TUESDAY AND WEDNESDAY WITH THE GEM GLOBAL BEING A
FAST OUTLIER THIS TIME AROUND. THEREFORE A BLEND OF THE SLOWER ECMWF
AND THE 6-9 HOUR QUICKER GFS WAS PREFERRED. THEREFORE WITH THIS
UPPER TROUGH...TSRA CHANCES WILL BEGIN TO RAMP UP AGAIN IN THE
TUESDAY NIGHT AND WEDNESDAY PERIODS...WITH LITTLE TO NO CHANCES ON
MONDAY AND MONDAY NIGHT. CONCERNING TEMPERATURES...IT WILL BE
COOLER. AFTER SATURDAYS WARM READINGS...SUNDAYS HIGHS WILL BE A
MORE SEASONAL 80 TO 85...AND GENERALLY IN THE UPPER 70S TO MID 80S
REMAINING MONDAY THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 634 AM CDT THU AUG 13 2015
SCATTERED HIGH-BASED SHOWERS/STORMS IN FAR WESTERN PORTIONS OF
THE FORECAST AREA TO START THE PERIOD COULD BRUSH KHON THROUGH
FIRST 2-3 HOURS OF THIS TAF PERIOD. THUNDER HAS BEEN SPOTTY...AND
MORE LIKELY TO PASS SOUTH OF KHON SO HAVE NOT INCLUDED TSRA FOR
THE EARLY MORNING AT THIS TIME. THIS ACTIVITY EXPECTED TO REMAIN
NORTH OF I-90 AND GRADUALLY WEAKEN AS IT MOVES EAST THROUGH THE
MORNING...WITH ISOLATED TO SCATTERED REDEVELOPMENT EXPECTED BY
LATE AFTERNOON/EVENING ACROSS WESTERN AND NORTHERN PORTIONS OF THE
REGION. KHON COULD BE AFFECTED BY THE SPOTTY STORMS WITH THIS
REDEVELOPMENT...BUT EXPECTED TO REMAIN NORTH/WEST OF KFSD/KSUX AT
THIS TIME. ANY STORMS ACROSS THE AREA THIS EVENING ARE EXPECTED TO
DIMINISH BY 04Z-05Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHAPMAN
SHORT TERM...JH
LONG TERM...MJ
AVIATION...JH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
322 PM MDT THU AUG 13 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 315 PM MDT THU AUG 13 2015
CURRENTLY...
AS PER WATER VAPOR IMGY...MONSOON PLUME IS OVER THE REGION. AT 2
PM...ISOLD TSRA ALREADY HAVE DEVELOPED OVER THE PLAINS WHILE ISOLD
TSRA WERE NOTED OVER THE MTNS AND UPPER SAN LUIS VALLEY. CONVECTION
ON THE PLAINS IS ASSOCIATED WITH A WEAK BOUNDARY MOVING SOUTH DOWN
THE PLAINS. TEMPS AT 2 PM WERE GENERALLY IN THE L/M90S ACROSS THE
PLAINS WITH 80S EL PASO COUNTY AND 70S AND 80S MTNS/VALLEYS. CAPES
WERE QUITE HIGH OVER THE FAR E PLAINS WITH VALUES 2500-3000 J/KG.
REST OF TODAY...
HRRR HAS BEEN PRETTY ACCURATE TODAY IN THAT IT WAS FCSTING
CONVECTION TO INITIATE EARLY OVER THE PLAINS AND IT DID. THIS
CONVECTION WILL LIKELY CONTINUE THROUGH THE REST OF THE AFTERNOON
ALTHOUGH IT MAY NOT BE AS HEAVY AND EXTENSIVE AS HRRR INDICATES.
MAIN CONCERN OVER THE PLAINS WILL BE CG LTG...BUT SOME LOCALLY HEAVY
RAIN AND GUSTY WINDS CANT BE RULED OUT OVER THE FAR E
PLAINS...ESPECIALLY LATE THIS AFTERNOON....AS CAPE VALUES ARE HIGH
AND DWPTS ARE IN THE 60S.
CONVECTION OVER THE MTNS WILL ALSO GRADUALLY INCREASE. INSTABILITY
AS NOTED BY THE SPC MESO PAGE...IS CONSIDERABLY LESS OVER THE I-25
CORRIDOR AND MTNS/VALLEYS.
THIS EVENING INTO TONIGHT...
2ND ROUND OF CONVECTION WILL BE POSSIBLE AS PER
GUIDANCE....DEVELOPING OVER THE GREATER PIKES PEAK REGION LATE
THIS AFTERNOON AND THEN DROPPING SOUTHEAST ACROSS THE PLAINS. THIS
CONVECTION WILL LIKELY LAST INTO THE MID TO LATE EVENING HOURS
BEFORE DECREASING LATE TONIGHT. ONE OR TWO STORMS MAY LAST INTO
THE EARLY MORNING HOURS.
WILL HAVE TO KEEP AN EYE ON THE BURN SCARS FROM LATE THIS AFTERNOON
INTO EARLY EVENING DUE TO THE LOCAL HEAVY RAIN THREAT.
TOMORROW...
500 MB HIGH WILL BE LOCATED OVER NW NEW MEXICO. THIS WILL PLACE THE
REGION UNDER WEAK N-NW FLOW ALOFT. PWAT VALUES ARE EXPECTED TO
REMAIN RELATIVELY HIGH OVER THE REGION WITH 1.0 - 1.2" THROUGHOUT
THE COLUMN. INSTABILITY WILL BE LIMITED ON THE PLAINS TOMORROW SO
EXPECT ONLY ISOLD CONVECTION OVER THE FAR E PLAINS TOMORROW. BEST
CHANCE OF STORMS WILL BE OVER ALL OF THE MTNS ACROSS THE FCST
AREA. GIVEN WEAK FLOW ALOFT SOME OF THE STORMS WILL BE CAPABLE OF
DROPPING LOCALLY HEAVY RAIN. MAX TEMPS TOMORROW WILL BE A BIT
COOLER THAN TODAY...WITH HIGHS MAINLY IN THE L/M90S PLAINS...80S
EL PASO COUNTY AND 70S/80S MTNS. /HODANISH
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 315 PM MDT THU AUG 13 2015
FRIDAY NIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE WILL SLOWLY MOVE INTO THE DESERT SOUTHWEST AS
AN UPPER LEVEL TROF MOVES ACROSS THE PNW INTO SRN CANADA OVER THE
WEEKEND. A FEW STORMS MAY LINGER ACROSS THE FAR SE PLAINS FRIDAY
EVENING BUT COVERAGE AND INTENSITY WILL QUICKLY DIMINISH AS
NOCTURNAL PROCESSES BECOME DOMINANT. SATURDAY LOOKS TO BE A QUITE
DAY ACROSS THE PLAINS WITH UPPER LEVEL HIGH STILL IN PLACE...WITH
SUBSIDENCE AND WEAK STEERING WINDS ALOFT LIMITING ACTIVITY ACROSS
THE PLAINS. EXPECT TO SEE ONLY ISOLATED TO SCATTERED AFTERNOON
SHOWERS AND THUNDERSTORMS LIMITED TO THE HIGHER ELEVATIONS SATURDAY.
SUNDAY THROUGH MONDAY...
UPPER LEVEL TROF MOVING THROUGH SRN CANADA WILL DROP A COLD FRONT
DOWN THROUGH THE CWA EARLY SUNDAY MORNING...WITH SE UPSLOPE FLOW
EXPECTED TO DEVELOP IN THE AFTERNOON. STORMS WILL FIRE OVER THE
HIGHER TERRAIN IN THE LATE MORNING TO EARLY AFTERNOON HOURS BEFORE
MOVING ACROSS THE PLAINS IN THE LATE AFTERNOON AS UPPER LEVEL
STEERING WINDS INCREASE OUT OF THE NW. HEADING INTO MONDAY...THE GFS
STALLS THE COLD FRONTAL BOUNDARY IN SRN CO AND NRN NM WHILE THE
ECMWF IS MUCH MORE PROGRESSIVE PUSHING THE BOUNDARY INTO TX AND
OKLAHOMA...WITH THE GFS SHOWING HIGHER MID LEVEL AND UPPER LEVEL
MOISTURE FIELDS. EXPECT ANOTHER ROUND OF ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS THE AREA.
TUESDAY THROUGH THURSDAY...
A SHIFT IN THE PATTERN IS EXPECTED TUESDAY AS WESTERLY WINDS
INCREASE ALOFT AND MIX DOWN TO THE SFC...LOWERING DEW POINTS
ACROSS THE PLAINS INTO THE UPPER 30S AND LOW 40S. A DRY LINE WILL
LIKELY DEVELOP ACROSS THE FAR SE PLAINS AND COULD POTENTIALLY
SERVE AS A FOCUS FOR STRONGER STORMS TUESDAY AND WEDNESDAY. MODEL
ENSEMBLE MEMBERS DIVERGE SIGNIFICANTLY BY WEDNESDAY WITH THE
TIMING AND STRENGTH OF THE NEXT UPPER LEVEL TROF MOVING ACROSS THE
NRN TIER...BUT OVERALL SHOWER AND THUNDERSTORM ACTIVITY LOOKS TO
BE LIMITED TUESDAY THROUGH THURSDAY NEXT WEEK. LUKINBEAL
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 315 PM MDT THU AUG 13 2015
KCOS AND KPUB WILL PROBABLY SEE SOME TSRA/OUTFLOW BOUNDARIES LATER
THIS AFTERNOON AND POSSIBLY EARLY EVENING...WITH SKIES THEN
CLEARING. OVERALL ANTICIPATE VFR CONDITIONS NEXT 24H AT ALL 3 TAF
SITES...KPUB...KALS AND KCOS. CONVECTION TOMORROW SHOULD BE CONFINED
TO THE HIGHER TRRN.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HODANISH
LONG TERM...AL/HODANISH
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1128 AM MDT THU AUG 13 2015
.UPDATE...
ISSUED AT 920 AM MDT THU AUG 13 2015
LOWERED CLOUD COVER ACROSS MUCH OF THE REGION THROUGH THE MORNING
HOURS AS THE WEAK SHORTWAVE IS ONLY PRODUCING A FEW CLOUDS ACROSS
AREAS NORTH OF I-70 THIS MORNING WITH NO SHOWERS AND MOSTLY SUNNY
SKIES. REST OF FORECAST ON TRACK FOR STORMS TO DEVELOP OVER HIGHER
TERRAIN THIS AFTERNOON WITH SOME DRIFT INTO VALLEYS THIS EVENING.
INCREASED POPS THIS EVENING ALONG THE NORTHERN AND CENTRAL DIVIDE
MOUNTAINS AS THE RAP IS SHOWING ACTIVITY LINGERING HERE THROUGH
SUNSET AS THE WEAK SHORTWAVE EXITS THE REGION. MOST ACTIVITY
SHOULD DIE DOWN AFTER SUNSET AS NO DISTINCT FORCING PRESENT TO
KEEP SHOWERS GOING OVERNIGHT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM MDT THU AUG 13 2015
A WEAK SHORTWAVE TROUGH WILL MOVE THROUGH THE RIDGE POSITIONED
OVER THE REGION THROUGH MIDDAY BEFORE PASSING EAST OF THE DIVIDE
AROUND MIDDAY. EXPECT THIS FEATURE WILL BE CAPABLE OF GENERATING A
FEW LIGHT SHOWERS PRIOR TO NOON...ESPECIALLY ACROSS THE NORTH...
WITH EMBEDDED THUNDERSTORMS POSSIBLE. SHOWER AND THUNDERSTORM
ACTIVITY WILL INCREASE DURING THE AFTERNOON WITH DAYTIME HEATING
WORKING ON LINGERING MONSOON MOISTURE. SOME STORMS WILL BE CAPABLE
OF GENERATING LOCALIZED HEAVY RAIN. IN THE ABSENCE OF FORCING...
EXPECT MOIST CONVECTION WILL DISSIPATE IN THE LATE EVENING. NO
APPRECIABLE CHANGE IN CONDITIONS IS EXPECTED FRIDAY AS THE HIGH
PRESSURE CENTER SHIFTS SLIGHTLY WEST. DAYTIME HEATING WILL RESULT
IN A RECYCLING OF LINGERING MOISTURE FOR ANOTHER ROUND OF
AFTERNOON SHOWERS AND THUNDERSTORMS. MODELS INDICATED A RISING 7H
TEMPERATURES WHICH SHOULD BRING AFTERNOON HIGHS BACK TO NEAR
NORMAL BY FRIDAY AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 400 AM MDT THU AUG 13 2015
THE MIDRANGE MODELS REMAIN IN GOOD AGREEMENT THROUGH THE EXTENDED
PERIOD. FRI NGT THROUGH SAT...MOISTURE WILL REMAIN TRAPPED
BENEATH STRONG HIGH PRESSURE OVER MUCH OF THE WESTERN U.S...
PRODUCING ISOLD TO SCTD AFTERNOON AND EARLY EVENING SHOWERS AND
THUNDERSTORMS. THE MAIN MONSOONAL PLUME WILL BE MUCH LESS
DISTINCT AND FLOWING OVER SRN CA...NV AND ID. AS A STRONG LOW
PRESSURE SYSTEM MOVES ALONG THE U.S. AND CANADIAN BORDER SAT AND
SUN...THE RIDGE WILL BE FLATTENED AND PUSHED SOUTH WHILE THE WEAK
MONSOONAL PLUME IS DRAGGED ACROSS THE AREA. THIS SHOULD RESULT IN
A SMALL UPTICK IN SHOWERS AND THUNDERSTORMS OVER THE WEEKEND.
MONDAY SHOULD SEE THE RIDGE RETROGRADE OVER AZ WITH DRIER AIR
OVER THE FORECAST AREA. THEN TUE AND WED THE GFS SHOWS A SHARP
TROUGH DIGGING INTO IDAHO AND REACHING SW WYOMING WED MORNING. THE
GFS THEN MOVES IT ACROSS SRN WY DURING THE DAY. THE ECMWF
STRENGTHENS THE LOW EARLIER AND DIGS IT SOUTH OREGON TUE
AFTERNOON...THEN MOVES IT INTO WESTERN WY WED AFTERNOON. BOTH
MODELS SHOW WINDS SHOULD INCREASE WED...WITH THE FORECAST AREA
GENERALLY REMAINING IN THE DRY SLOT OF THE SYSTEM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1125 AM MDT THU AUG 13 2015
CONVECTION WILL FIRE AGAIN THIS AFTERNOON AND CONTINUE INTO THE
EVENING HOURS BEFORE SUBSIDING AROUND 02Z. SOME TAF SITES MAY SEE
VCTS INCLUDING ALL MTN SITES AND RIFLE AND MONTROSE. BIGGEST
CONCERN WILL BE HEAVY DOWNPOURS AND SOME GUSTY WINDS. ILS
BREAKPOINTS WILL LIKELY BE MET AT ASPEN...EAGLE...AND RIFLE IF
SHOWERS/STORMS MOVE NEAR TAF SITES. REMAINING SITES SHOULD REMAIN
ABOVE BREAKPOINTS. QUIET OVERNIGHT WITH A REPEAT TOMORROW
AFTERNOON AND EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...MDA
SHORT TERM...NL
LONG TERM...CC
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS KEY WEST FL
257 PM EDT THU AUG 13 2015
.DISCUSSION...IN THE MID AND UPPER LEVELS...(700-200 MB)...LATEST
AVAILABLE IR IMAGERY OVERLAID WITH MODEL STREAMLINE ANALYSIS AS OF
200 PM DEPICTS THE CENTER OF A DEEP AND WARM ANTICYCLONE OVER EASTERN
NEW MEXICO. LIKE EACH DAY FOR THE PAST WEEK...AND ATTENDANT UPPER
RIDGE AXIS SNAKES EAST SOUTHEASTWARD TO ACROSS THE FLORIDA PENINSULA.
TO THE NORTH OF THAT...AN ABNORMALLY FULL LATITUDE TROUGH AXIS FOR
THE MID AUGUST IS EVIDENT FROM WESTERN QUEBEC SOUTH TO THE FLORIDA
PANHANDLE.
AT THE SURFACE AND IN THE LOWER TO MID LEVELS...SURFACE TO 700
MB...LATEST IR IMAGERY OVERLAID WITH MARINE AND LAND SURFACE
OBSERVATIONS AND ANALYSIS AS OF 200 PM DETAILS A SURFACE COLD FRONT
ACROSS NORTHERN FLORIDA. A WEAKNESS OR SURFACE TROUGH IS IN PLACE
ACROSS THE NORTHERN BAHAMAS TO ANDROS ISLAND. THIS COMBINATION IS
RESULTING IN LIGHT SOUTHEAST TO SOUTH WINDS ACROSS THE ISLANDS.
EARLIER TODAY...A LIGHT SOUTH WIND INVIGORATED AN EPISODIC YET BRIEF
UPPER KEYS CUMULUS LINE.
.CURRENTLY...AS OF 200 PM...SKIES ARE PARTLY CLOUDY ACROSS THE
ISLANDS AND ADJOINING WATERS. TEMPERATURES ARE CURRENTLY IN THE UPPER
80S TO LOWER 90S. RADAR DETCTS ONLY A FEW SHOWERS WELL WEST OF THE
FLORIDA KEYS. C-MAN STATIONS ALONG THE FLORIDA KEYS ARE PRESENTLY IN
SOUTHEAST TO SOUTH AT AROUND 5 KNOTS.
.SHORT TERM...TONIGHT THRU SATURDAY NIGHT. THE BASE OF THE DEEP MID
AND UPPER TROUGH WILL MOVE SOUTHWARDS A BIT OVERNIGHT...ALLOWING THE
COOL SURFACE FRONTAL BOUNDARY OVER NORTHERN FLORIDA TO MOVE SLIGHTLY
SOUTHWARD A BIT TOMORROW. WEAK RIDGING ACROSS SOUTH FLORIDA WILL KEEP
A LIGHT TO GENTLE SOUTHEAST TO SOUTH FLOW FROM THE SURFACE TO 500 MB
OVERNIGHT. NEVERTHELESS...THE LATEST HRRR DISPLAYS DEVELOPMENT OF AN
MCS OVER THE EVERGLADES THIS EVENING...PUSHING BOUNDARIES TOWARDS THE
UPPER KEYS. GIVEN A CLOUD LINE IN PLACE THERE...ACTIVITY COULD EXTEND
SOUTHWARDS TO THE MIDDLE KEYS. BUT CONFIDENCE IN THIS SCENARIO IS TOO
LOW. SO WILL CONTINUE WITH ISOLATED POPS IN THE GRIDS. THE SAME IS
THE CASE ON FRIDAY.
FOR FRIDAY NIGHT THRU SATURDAY NIGHT...SLIGHTLY ELEVATED LOWER LEVEL
CONFLUENT FLOW...IN ADVANCE OF THE SURFACE TROUGH/FRONT OVER NORTH
FLORIDA...COMBINED WITH DEEPER LOWER TO MIDDLE LEVEL TROPOSPHERIC
MOISTURE AND A GENTLE TO MODERATE FLOW...WILL ALLOW FOR DEVELOPMENT
OF SCATTERED SHOWERS AND THUNDERSTORMS. FOR NOW...COVERAGE WILL BE
WIDELY SCATTERED...SO WILL HOLD WITH THE INHERITED 30 PERCENT POPS WE
ALREADY HAVE IN THE GRIDS.
SUNDAY THRU THURSDAY...THE SURFACE RIDGE WILL REMAIN ACROSS NORTH
FLORIDA AND IN COMBINATION WITH MODEL FORECAST COLUMNAR PWAT BETWEEN
1.75 AND 2.00 INCHES. THIS SHOULD RESULT IN A RETURN TO NEAR NORMAL
RAIN CHANCES...30%...FOR THE PERIODS.
&&
.MARINE...A WEAK PRESSURE PATTERN WILL PERSIST ACROSS THE REGION
TONIGHT. AN AREA OF HIGH PRESSURE WILL REMAIN IN PLACE ACROSS THE
SOUTHEASTERN UNITED STATES FRIDAY THROUGH MONDAY...RESULTING IN
GENTLE TO MODERATE EAST TO SOUTHEAST BREEZES ON ALL KEYS COASTAL
WATERS. HENCE...NO HEADLINES OR ADVISORIES ARE ANTICIPATED ATTM.
&&
.AVIATION...UNTIL 12Z/15TH...VFR CONDITIONS WILL PREVAIL AT THE KEY WEST AND
MARATHON TERMINALS. MOSTLY SOUTHEAST WINDS OF LESS THAN 10 KNOTS ARE
EXPECTED AT THE ISLAND AIRPORTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
KEY WEST 81 90 79 89 / 20 20 30 30
MARATHON 81 93 79 91 / 20 20 30 30
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE.........FUTTERMAN
AVIATION/NOWCASTS.....APA
DATA COLLECTION.......CHESSER
VISIT US ON THE WEB AT WEATHER.GOV/KEY
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1228 PM CDT THU AUG 13 2015
.UPDATE...
ISSUED AT 1028 AM CDT THU AUG 13 2015
HIGH PRESSURE DOMINATES MUCH OF THE MIDWEST AND OHIO RIVER VALLEY
THIS MORNING. WEAK WINDS ANTICIPATED AT THE SURFACE, AND
TEMPERATURES STEADILY CLIMBING THIS MORNING INTO THE MID TO UPPER
70S, ON THE WAY TO THE MID 80S. LITTLE MORE THAN SCT CU
EXPECTED IN THE WAY OF CLOUD COVER. NO UPDATES ARE ANTICIPATED AT
THIS TIME.
&&
.SHORT TERM...(TODAY)
ISSUED AT 311 AM CDT THU AUG 13 2015
RIDGE OF HIGH PRESSURE EXTENDING FROM THE MID-ATLANTIC STATES TO THE
CENTRAL PLAINS IS PROVIDING CLEAR SKIES AND NEARLY CALM WINDS TO
CENTRAL ILLINOIS TONIGHT. 07Z/2AM SURFACE OBS ARE SHOWING DEWPOINT
DEPRESSIONS OF 0-3F IN MANY LOCATIONS...WHICH IS BEGINNING TO LEAD
TO PATCHY FOG. LATEST HRRR EVEN SUGGESTS A FEW SPOTS MAY SEE
VISIBILITIES REDUCED TO AROUND 1/4 MILE AT TIMES...HOWEVER IT DOES
NOT APPEAR THERE WILL BE WIDESPREAD DENSE FOG. GIVEN CURRENT TRENDS
AND CONSISTENT HRRR FORECAST...WILL INCLUDE PATCHY FOG DURING THE
EARLY MORNING HOURS. ONCE ANY FOG DISSIPATES...MOSTLY SUNNY
CONDITIONS WILL PREVAIL FOR THE BALANCE OF THE DAY. HIGH/THIN
CIRRUS BLOW OFF FROM CONVECTION ACROSS THE UPPER MIDWEST WILL STREAM
ACROSS THE SKY AND SCT DIURNAL CLOUDS WILL DEVELOP AS WELL...HOWEVER
OVERALL CONDITIONS WILL REMAIN MOSTLY SUNNY. AFTERNOON HIGH
TEMPERATURES WILL TOP OUT IN THE MIDDLE 80S.
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 311 AM CDT THU AUG 13 2015
WEAK COLD FRONT CURRENTLY OVER NORTH DAKOTA/MINNESOTA WILL TRY TO
SETTLE SOUTHWARD INTO ILLINOIS OVER THE NEXT 24-48 HOURS...HOWEVER
IT WILL BE PUSHING DIRECTLY INTO A PERSISTENT RIDGE OF HIGH PRESSURE
AND WILL NEVER PASS THROUGH THE KILX CWA. MODELS HAVE BEEN SHOWING
THE BOUNDARY SAGGING INTO NORTHERN SECTIONS OF ILLINOIS AND INDIANA
FRIDAY NIGHT INTO SATURDAY THEN DISSIPATING COMPLETELY OVER THE
WEEKEND. DUE TO SYNOPTIC SUBSIDENCE AND A LACK OF DEEP-LAYER
MOISTURE...AREAL COVERAGE OF CONVECTION ALONG THE FRONT WILL BE
MINIMAL. WHILE MOST OF THIS ACTIVITY WILL REMAIN NORTH AND EAST OF
THE KILX CWA...ISOLATED THUNDERSTORMS COULD POTENTIALLY DEVELOP
ALONG/NORTH OF A BLOOMINGTON TO PARIS LINE FRIDAY NIGHT INTO
SATURDAY. DUE TO UNCERTAINTIES ABOUT THE EXACT SOUTHWARD POSITION
OF THE FRONT AND LACK OF MOISTURE...WILL MAINTAIN A DRY FORECAST
ACROSS THE BOARD AT THIS TIME.
MAIN WEATHER STORY THIS WEEKEND WILL BE THE INCREASING HEAT AND
HUMIDITY AS THE CENTRAL PLAINS UPPER RIDGE SHIFTS SOUTHEASTWARD.
AMPLE SUNSHINE AND RISING UPPER HEIGHTS WILL ALLOW HIGH TEMPERATURES
TO RISE INTO THE LOWER 90S BY SUNDAY. WHILE CONDITIONS APPEAR TO
REMAIN HOT AND DRY THIS WEEKEND...A POTENTIAL FLY-IN-THE-OINTMENT
WILL BE A WEAKNESS IN THE RIDGE AXIS SEEN PROMINENTLY ON THE ECMWF
AND TO A LESSER EXTENT ON THE GFS. THE ECMWF SHOWS THIS WEAKNESS
DEVELOPING OVER THE OHIO RIVER VALLEY ON SUNDAY...WHICH COULD
POTENTIALLY TRIGGER ISOLATED CONVECTION ACROSS THE E/SE CWA. GFS
KEEPS THE WEAKNESS FURTHER EAST AND MAINTAINS DRY WEATHER. WILL
STICK WITH A COMPLETELY DRY FORECAST FOR NOW...BUT WILL KEEP AN EYE
ON FUTURE MODEL RUNS TO SEE HOW THEY HANDLE THIS FEATURE.
THE NEXT SIGNIFICANT FRONTAL BOUNDARY IS STILL PROGGED TO ARRIVE BY
MONDAY AFTERNOON...WITH THE LATEST GFS NOW BRINGING THE BOUNDARY
FURTHER SOUTH INTO CENTRAL ILLINOIS...MUCH LIKE PREVIOUS RUNS OF THE
ECMWF/GEM HAD DONE. GIVEN GOOD MODEL CONSENSUS...CONFIDENCE IS
GROWING THAT SCATTERED THUNDERSTORMS WILL DEVELOP NORTH OF THE I-70
CORRIDOR MONDAY AFTERNOON...THEN CONTINUE EVERYWHERE MONDAY NIGHT
INTO TUESDAY AS THE FRONT STALLS. AFTER THAT...CONSIDERABLE
DISCREPANCIES DEVELOP AMONG THE 00Z AUG 13 MODELS CONCERNING THE
ARRIVAL OF A STRONGER SHORT-WAVE FOR THE MIDDLE OF NEXT WEEK.
ECMWF HAS SLOWED THE WAVE AND HAS THUS MAINTAINED THE EARLY WEEK
BAROCLINIC ZONE ACROSS THE AREA THROUGH WEDNESDAY. MEANWHILE...THE
GFS/GEM HAVE BOTH KEPT THEIR PREVIOUS SOLUTION OF BRINGING THE
WAVE IN QUICKER...THUS ALLOWING THE EARLY WEEK FRONT TO LIFT NORTH
OF THE AREA. WILL FOLLOW THE MORE CONSISTENT GFS/GEM
HERE...RESULTING IN WARM/DRY CONDITIONS TUESDAY NIGHT AND
WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1225 PM CDT THU AUG 13 2015
VFR THROUGH THE DAY WITH VERY LITTLE IN THE WAY OF CLOUDS EXCEPT A
FEW CU AND SCT CIRRUS. HIGH PRESSURE REMAINING OVER THE FA WITH
LIGHT WINDS VARYING SOMEWHAT FROM MOSTLY SOUTHWESTERLY. ENOUGH
LLVL MOISTURE REMAINS IN THE BOUNDARY LAYER AND PERSISTENCE
FORECAST WILL KEEP MVFR VIS DROP IN THE EARLY MORNING BEFORE 12Z
AT ALL TERMINALS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
344 PM EDT THU AUG 13 2015
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD SOUTH OF THE AREA THROUGH FRIDAY.
A WEAK COLD FRONT WILL APPROACH FRIDAY NIGHT AND CROSS THE AREA
SATURDAY. A WARM RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE
REGION FROM THE SOUTHWEST SUNDAY INTO MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
HRRR MODEL OUTPUT CONTS TO SUGGEST THE POSSIBILITY OF SHWRS FROM
ENE TO INTERIOR SW DOWNEAST PTNS OF THE FA GOING INTO THIS EVE...
CLOSE TO WHERE SKIES VARIED FROM PTLY TO MSLY CLDY N OF THIS AREA
TO MSLY SUNNY S. THE PROBLEM IS THAT THE HRRR HAS BEEN ADVERTISING
THE PRESENCE OF SHWRS OVR THE N/CNTRL PTNS OF THE FA OVR THE LAST
FEW HRS WHERE RADAR REF IMAGERY HAS HARDLY SHOW ANY. FOR NOW...WILL
KEEP ISOLD TO SCT SHWRS OVR THE AFOREMENTIONED PTNS OF THE FA INTO
THIS EVE...THEN XPCT ANY SHWRS TO DISSIPATE LATE TNGT. WE KEPT
FCST QPF...MSLY IN THE 00-06Z TM FRAME VERY LGT...MSLY LESS THAN
0.05 INCHES...WITH FCST MODEL SOUNDINGS INDICATING NAY CAPE
POTENTIAL BELOW 400 J/KG.
OTHERWISE...WITH CLRG SKIES AND LIGHTENING WINDS OVRNGT...THE
POTENTIAL OF LOW LYING PATCHY FOG WILL INCREASE LATE TNGT TOWARD
SUNRISE FRI MORN FROM N CNTRL TO DOWNEAST AREAS. AFT PATCHY ERLY
MORN FOG DISSIPATES BY MID FRI MORN...SKIES SHOULD BE MSLY SUNNY
AND WITH A SW SFC WIND...HI TEMPS SHOULD RECOVER TO ABV NORMAL
VALUES FOR THIS TM OF SEASON. A WEAKENING COLD FRONT ASSOCIATED
WITH A WEAKENING S/WV FROM CNTRL CAN WILL BRING A CHC OF SHWRS AND
MAYBE ISOLD TSTMS (MAX SBCAPE POTENTIAL ABOUT 400 J/KG) OVR FAR
NW PTNS OF THE FA BY ERLY FRI EVE...THEN SLOWLY SPREADING SE INTO
NERN TO N CNTRL PTNS OF THE FA LATE FRI NGT INTO ERLY SAT MORN.
STREAM BASIN QPF WILL BE FAIRLY MODEST WITH THIS SYSTEM THRU LATE
NGT FRI NGT GIVEN SCT SHWR POTENTIAL...BUT A FEW LCTNS RECEIVING
HEAVIER RN SHWRS COULD RECEIVE A QUARTER INCH OR MORE OF RAINFALL
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
EXPECT WEAK SURFACE AND UPPER LEVEL LOW PRESSURE SYSTEM OVER THE
REGION DURING THE DAY SATURDAY. SOME INSTABILITY OVER CENTRAL
AREAS ALONG WITH INTERIOR SOUTH CENTRAL... SO WILL INCLUDE
SCATTERED THUNDER. EXPECT HIGH PRESSURE TO BUILD IN FROM THE WEST
DURING THE DAY SUNDAY. THE NAM... GFS AND ECMWF HAVE MINOR
DIFFERENCES SO WILL USE MODEL CONSENSUS TECHNIQUE AND BLEND ALL
THREE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE MAIN FORECAST CONCERN FOR THE EXTENDED FORECAST PERIOD IS A
COLD FRONT WHICH IS PROGGED TO TRACK ACROSS THE NORTHEAST EARLY
NEXT WEEK. SCTD SHOWERS AND THUNDERSTORMS WILL BREAK OUT ACROSS
WRN MAINE MONDAY AFTERNOON...AND THEN GRADUALLY SPREAD EWRD ACROSS
THE REST OF THE STATE MONDAY NIGHT AND TUESDAY. BY TUESDAY
NIGHT...THE MAIN FOCUS OF PRECIP WILL BE ACROSS OUR ERN AND SRN
ZONES AS THE FRONT BEGINS TO MOVE OFF SHORE. ONLY THE DOWNEAST
AREA SHOULD SEE RAIN ON WEDNESDAY AS A WEAK RIDGE OF HIGH PRESSURE
BUILDS IN FROM QUEBEC ACROSS NRN MAINE. TEMPERATURES WILL START
OUT ABOVE NORMAL WITH HIGHS WELL INTO THE 80S ON MONDAY. HOWEVER
SOMEWHAT COOLER AIR BEHIND THE FRONT...ALONG WITH THE EXPECTED
RAINFALL AND CLOUD COVER...WILL RESULT IN COOLER TEMPS FOR TUESDAY
AND WEDNESDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
NEAR TERM: MAINLY VFR THRU FRI NGT. PATCHY MVFR/IFR VSBY IS
POSSIBLE AT ANY TAF SITE LATE TNGT IN PATCHY FOG. CLGS/VSBYS MAY
APCH HI MVFR THRESHOLDS LATE FRI NGT ACROSS NRN TAF SITES IN
SHWRS.
SHORT TERM: EXPECT MVFR/VFR CONDITIONS SATURDAY THEN VFR
CONDITIONS SUNDAY AND MONDAY. MVFR CONDITIONS EXPECTED TUESDAY.
&&
.MARINE...
NEAR TERM: NO HDLNS THRU FRI NGT ATTM...WITH HI PD SE SWELL TNGT
INTO FRI MORN TRANSITIONING TO LOWER PD WIND WVS FRI AFTN AND FRI
NGT AS RETURN SW SFC WINDS INCREASE. KEPT CLOSE TO WW3 WV GUIDANCE
THIS UPDATE DUE TO CURRENT SWELL COMPONENT.
SHORT TERM: GFS40 AND NAM12 SIMILAR WITH WINDS SO WILL USE
CONSENSUS METHOD FOR WINDS WITH 50/50 BLEND. FOR WAVES: WITH
SUSTAINED WINDS EXPECTED TO BE RELATIVELY LIGHT... PRIMARY WAVE
SYSTEM WILL BE SOUTHEASTERLY SWELL (3-4 FEET/8 SECONDS)
ORIGINATING FROM OUTSIDE COASTAL WATERS. HAVE USED 1200Z RUN OF
NEAR SHORE WAVE MODEL RUN ON WAVE WATCH III BOUNDARY CONDITIONS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...VJN
SHORT TERM...MIGNONE
LONG TERM...BERDES
AVIATION...VJN/MIGNONE
MARINE...VJN/MIGNONE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
328 PM EDT THU AUG 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 212 AM EDT THU AUG 13 2015
HEALTHY SHORTWAVE DIGGING SE WITH 850MB THETA-E ADVECTION EARLY WILL
HELP SUPPORT ONGOING CONVECTION MOVING IN FROM THE ARROWHEAD OF MN
AND CANADA EARLY THIS MORNING. LOOK FOR SHOWERS/THUNDERSTORMS TO
CLIP THE W CWA BEFORE DIMINISHING THROUGH THE DAY TODAY. THE 21/00Z
NAM AND 21/03Z HRRR SEEM TO HAVE A PRETTY GOOD HANDLE ON WHAT WOULD
BE A MORE LIKELY SCENARIO...WITH THE GFS AND CANADIAN BRINGING THE
BULK OF PRECIP OVER THE KEWEENAW AND LAKE SUPERIOR THROUGH THE
MORNING HOURS. WILL NEED TO MONITOR THE TRENDS EARLY THIS MORNING.
EXPECT SHOWERS AND A FEW THUNDERSTORMS TO REMAIN POSSIBLE SE THIS
AFTERNOON...AWAY FROM THE LAKE SUPERIOR STABILIZATION. DESPITE THE
ONSHORE FLOW N CENTRAL AND E...THERE WILL BE LITTLE RELIEF FROM THE
HEAT. EXPECT A VERY WARM DAY TODAY...CLOSE TO THE RECORD AT NWS MQT
WHICH IS 89 SET BACK IN 1970. MID TO UPPER 80S WILL BE COMMON FOR
ALL BUT THE TIP OF THE KEWEENAW PENINSULA...AND E OF A LINE FROM
MUNISING TO RAPID RIVER...EVEN WITH THE POTENTIAL FOR SHOWERS IN THE
AREA. PW VALUES MAXING OUT AROUND 1.6IN W TO E TODAY WILL FALL TO
AROUND 1-1.2IN CWA WIDE BY 06Z. WITH THE MAIN SFC TROUGH SET UP OVER
THE W HALF OF LAKE SUPERIOR AND WARM AIR FULLY ENTRENCHED OVER THE
CWA...LOWS IN THE 60S LOOK TO BE A GOOD BET...WITH ADDITIONAL
SHOWERS AND THUNDERSTORMS NEARING FROM THE NW.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 327 PM EDT THU AUG 13 2015
BEGINNING FRI NIGHT AND SAT NIGHT...EXPECT DRY WEATHER UNDER RISING
HEIGHTS WITH MID/UPPER RIDGE BUILDING NE FROM THE NORTHERN PLAINS
INTO THE UPPER LAKES. SAT WILL BE A WARM/HUMID DAY WITH HIGH TEMPS
WELL INTO THE 80S PERHAPS EVEN LOWER 90S IN A FEW SPOTS AS NEAR 20C
8H TEMPS MIX DRY ADIABATICALLY TOWARD SFC UNDER MOSTLY SUNNY SKIES.
SUN INTO MON...SHORTWAVE TROF MOVING ACROSS THE NRN ROCKIES SAT WILL
LIFT ENE INTO NRN ONTARIO SUN. MODEL CONSENSUS SHOWS ASSOCIATED COLD
FRONT WILL LIKELY REACH WRN UPPER MI LATE SUNDAY AFTN/EARLY EVENING
AND THEN EXITING THE ERN U.P. MON MORNING WITH THE NAM SLIGHTLY
FASTER WITH THAN THE GFS/GEM/ECMWF. WITH BEST HEIGHT FALLS/DEEP
LAYER FORCING PASSING TO THE N...CONVECTION ALONG/AHEAD OF FRONTAL
PASSAGE PROBABLY WON`T BE MORE THAN ISOLD TO SCT. HOWEVER...AS UPPER
JET TRANSLATES E INTO ONTARIO RIGHT ENTRANCE UPPER DIVERGENCE MAY
SEE SOME INCREASE IN COVERAGE OF CONVECTION ALONG FRONT INTO CENTRAL
AND ERN UPR MI SUN NIGHT INTO EARLY MON.
WITH FRONT NOT ARRIVING UNTIL LATE IN THE DAY...SUN WILL BE ANOTHER
VERY WARM...HUMID DAY AS 8H THERMAL RIDGE WITH 8H TEMPS OF AT LEAST
20C SHIFTS ACROSS THE AREA IN ADVANCE OF COLD FRONT. EXPECT MAX
TEMPS INTO THE UPPER 80S TO LOWER 90S ACROSS MUCH OF THE AREA.
FAIRLY TIGHT PRES GRADIENT WILL ALSO LEAD TO GUSTIER SOUTHWEST
WINDS...PROBABLY 20-25MPH TO PERHAPS 30MPH AT TIMES AS NOTED OFF
MIXED BUFR FCST SNDGS.
ABRUPT COOLING (AND LOWERING OF DWPTS) WILL FOLLOW THE FRONT FOR MON
AS 850MB TEMPS FALL BACK TO 6 TO 10C. EXPECT MAX TEMPS TO RANGE FROM
THE UPPER 60S W AND N NEAR LAKE SUPERIOR TO MID 70S SCTNRL/SE.
CONTINUED UPPER DIVERGENCE UNDER RIGHT ENTRANCE OF UPPER JET MAY
ALLOW LINGERING SHRA/TSTMS INTO MON MORNING OVER THE SCNTRL AND E
FCST AREA NEAR EXITING FRONT...BUT OTHERWISE EXPECT DRYING
CONDITIONS IN THE WAKE OF THE FRONT.
LOOK FOR DRY WEATHER MON AFTN INTO TUE AS SFC HIGH PRES MOVES ACROSS
AND DOMINATES THE UPPER LAKES. WITH SFC HIGH PRES OVER THE AREA AND
PRECIPITABLE WATER UNDER 0.5 INCHES...EXPECT MIN TEMPS MON NIGHT TO
FALL INTO THE 40S IN THE INTERIOR WITH TRADITIONAL COLD SPOTS
POSSIBLY DOWN INTO THE LWR 40S.
MODELS CONSISTENT SHOWING VIGOROUS SHORTWAVE EMERGING FROM THE CNTRL
ROCKIES AND MOVING ACROSS THE UPPER GREAT LAKES FROM MID TO LATE
NEXT WEEK. THIS SHORTWAVE WILL BRING THE POTENTIAL FOR ROUNDS OF
SHRA/TSTMS AND POSSIBLE HVY RAINFALL. INITIALLY...STRENGTHENING
WAA/MOISTURE ADVECTION IN ADVANCE OF THIS WAVE ALONG WITH THE
PRESENCE OF A WEAKER NW FLOW SHORTWAVE WILL SUPPORT SCT SHRA/TSTMS
SPREADING INTO UPPER MI LATE TUE NIGHT INTO WED. IT LOOKS LIKE THE
BETTER CHANCE FOR WIDESPREAD STORMS AND HEAVY RAIN WILL BE THU INTO
THU NIGHT WITH STRONG WAA/MOISTURE TRANSPORT IN ADVANCE OF
APPROACHING STRONG WAVE AND ASSOC COLD FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 126 PM EDT THU AUG 13 2015
CLOUDS HAVE BUILT UP WITH DAYTIME HEATING...BUT FOR THE AFTN INTO
THE EVENING...EXPECT BEST CHANCE FOR SHRA AND POSSIBLE TSRA TO
AFFECT KSAW. SINCE TSRA COVERAGE IS TOO UNCERTAIN DID NOT INCLUDE IN
THE TAF ATTM. COLD FRONT WILL WORK ACROSS UPR MICHIGAN ON FRIDAY
MORNING...BUT LIMITED MOISTURE SHOULD ONLY RESULT IN SCT-BKN MID
CLOUDS AT THE TAF SITES. DEPENDING ON EXTENT OF RAIN THIS AFTN AT
KSAW COULD SEE PATCHY MVFR FOG BRIEFLY DEVELOP THERE LATE TONIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 212 AM EDT THU AUG 13 2015
FOG WILL BE POSSIBLE TODAY THROUGH FRIDAY MORNING OVER MAINLY NE AND
E LAKE SUPERIOR...CLOSER TO THE COLDEST WATER AS WARM HUMID AIR
SHIFTS OVERHEAD. WINDS SHOULD BE LESS THAN 30KTS THROUGH THE
PERIOD...WITH GUSTS NEARING 30KTS OVER A FEW OF THE HIGHER PLATFORMS
OVER W LAKE SUPERIOR INITIALLY THIS MORNING OUT OF THE SW...AND
AGAIN SATURDAY NIGHT INTO SUNDAY.
EXPECT THE HIGH OVER THE OH RIVER VALLEY TO DRIFT OFF THE EAST COAST
THROUGH FRIDAY. A TROUGH MOVING THROUGH NW ONTARIO AND MN THIS
MORNING WILL SWEEP SE ACROSS LAKE SUPERIOR THIS AFTERNOON. IN ITS
WAKE...HIGH PRESSURE WILL BUILD INTO THE UPPER GREAT LAKES ON
FRIDAY. AS THIS HIGH DRIFTS SE INTO THE MID ATLANTIC STATES OVER THE
WEEKEND...A LOW WILL MOVE E FROM S SASKATCHEWAN ACROSS NW ONTARIO
AND TO NEAR JAMES BAY LATE ON SUNDAY. THIS LOW WILL CONTINUE E INTO
QUEBEC ON MONDAY...AND DRAG A COLD FRONT ACROSS THE UPPER LAKES ON
SUNDAY NIGHT. BEHIND THIS FRONT...LOOK FOR A HIGH TO MOVE INTO
MINNESOTA ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...VOSS
AVIATION...JLA
MARINE...KF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
321 PM EDT THU AUG 13 2015
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 321 PM EDT THU AUG 13 2015
A COLD FRONT WILL SLOWLY SINK SOUTH ACROSS LOWER MICHIGAN TONIGHT
AND FRIDAY BEFORE WASHING OUT NEAR I-96. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TONIGHT MOVING FROM NORTH TO SOUTH. A
WARM TO HOT WEEKEND IS EXPECTED WITH HIGHS IN THE UPPER 80S
SATURDAY AND SUNDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 321 PM EDT THU AUG 13 2015
FORECAST CONCERNS DEAL WITH A WEAK COLD FRONT MOVING SOUTH ACROSS
LOWER MICHIGAN TONIGHT AND FRIDAY.
OVERALL...I`M NOT TOO IMPRESSED WITH THIS SYSTEM. THE LLJ ASSOCIATED
WITH THE SYSTEM IS VERY WEAK AND WON`T PROVIDE MUCH SUPPORT.
THERMODYNAMICALLY...600 J/K SBCAPE IS WHAT THE SYSTEM WILL HAVE TO
WORK WITH. PWATS ARE NOT OVERLY HIGH EITHER. LATEST HRRR DOESN/T
SHOW MUCH PCPN THROUGH THE EARLY OVERNIGHT HOURS. HOWEVER...THERE IS
A WEAK SHORT WAVE THAT MODELS SHOW STRENGTHENING A BIT FRIDAY AS THE
COLD FRONT SETTLES TO NEAR I-96. THE BEST CHANCE OF RAIN LOOKS TO BE
OVER THE EASTERN CWA FRIDAY MID DAY. CHANCES FOR SEVERE STORMS LOOK
LOW TOO WITH ONLY 25-30 KTS OF SHEAR AVAILABLE. PCPN CHANCES WILL
DWINDLE LATE FRIDAY AND FRIDAY NIGHT...BUT WON/T BE QUITE ZERO DUE
TO THE PRESENCE OF THE WASHED OUT FRONTAL BOUNDARY.
SATURDAY LOOKS DRY AND VERY WARM WITH HIGHS IN THE UPPER 80S.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 321 PM EDT THU AUG 13 2015
UPPER RIDGING WILL BRING FAIR AND WARM WEATHER FOR SUNDAY WITH
HEIGHT FALLS OCCURRING SUNDAY NIGHT AND MONDAY AS A SHORTWAVE TROUGH
MOVING ACROSS CANADA BRINGS A TRAILING COLD FRONT INTO MICHIGAN BY
TUESDAY. LATEST MODEL TRENDS ARE THAT THE FRONT CLEARS CLEARS THE
FORECAST AREA BY TUESDAY NIGHT WITH A LULL IN THE PRECIP CHANCES
TUESDAY NIGHT AND POSSIBLY WEDNESDAY AS SFC RIDGING IS IN CONTROL.
DECIDED TO LOWER POPS FROM GUIDANCE A BIT ON WEDNESDAY AS BEST MID
LEVEL MOISTURE CONVERGENCE APPEARS TO BE NORTH OR WEST OF LOWER
MICHIGAN...ALTHOUGH SHOWERS AND THUNDERSTORMS SHOULD BE REACHING
WESTERN ZONES LATE IN THE DAY...CONTINUING INTO THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 202 PM EDT THU AUG 13 2015
VFR CONDITIONS EXPECTED THROUGH 00Z WITH SOUTHWEST WINDS GUSTING
OVER 20 KNOTS AT TIMES. SHOWERS AND THUNDERSTORMS WILL BRING AREAS
OF MVFR CONDITIONS ACROSS CENTRAL LOWER MICHIGAN BY 06Z AND
SOUTHERN LOWER MICHIGAN BY AROUND 10Z. THESE CONDITIONS WILL
PERSIST THROUGH ABOUT 12 TO 15Z THEN VFR IS EXPECTED THROUGH 18Z
FRIDAY.
&&
.MARINE...
ISSUED AT 321 PM EDT THU AUG 13 2015
MARINE HEADLINES WILL REMAIN AS IS...ALTHOUGH SCA CONDITIONS ARE
MARGINAL. WINDS WILL SUBSIDE THIS EVENING AND THE HEADLINE MAY BE BE
CANCELLED EARLY.
&&
.HYDROLOGY...
ISSUED AT 315 PM EDT WED AUG 12 2015
SCATTERED SHOWERS/STORMS LATE TONIGHT INTO THU COULD PRODUCE SOME
RAINFALL ACROSS THE NORTHERN FORECAST AREA...BUT NO SIGNIFICANT
RAINFALL AMOUNTS/FLOODING ISSUES ARE EXPECTED. BETTER CHANCES FOR
RAIN WILL ARRIVE THU NIGHT INTO FRIDAY AND THEN LATE SUNDAY NIGHT
THROUGH MONDAY NIGHT. PRECIPITABLE WATER VALUES INCREASE OVER 1.50
INCHES THU NIGHT INTO FRIDAY...SUPPORTING A BETTER CHANCE FOR DECENT
RAINFALL TOTALS. 0.25 TO 0.50 INCHES SEEMS POSSIBLE WITH SOME
LOCALLY HIGHER TOTALS IN STORMS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 8 PM EDT THIS EVENING FOR MIZ037-
043-050-056-064.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EDT FRIDAY FOR LMZ845>849.
&&
$$
SYNOPSIS...04
SHORT TERM...04
LONG TERM...WDM
AVIATION...OSTUNO
HYDROLOGY...EBW
MARINE...04
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
306 PM EDT THU AUG 13 2015
.SHORT TERM...TONIGHT
A COUPLE OF LOW AMPLITUDE SHORTWAVES EMANATING FROM WESTERLIES OVER
CENTRAL CANADA ARE NOTED ON 1830Z WATER VAPOR IMAGERY PROPAGATING
SOUTHEAST AROUND THE NE PERIPHERY OF THE EXPANSIVE WEST-CENTRAL
CONUS RIDGE. THE FIRST IS NOTED ALONG THE NORTHERN WESTERN EDGE OF
LAKE SUPERIOR; THE SECOND OVER LAKE WINNIPEG. INITIAL WAVE IS
PROGGED TO TRANSIT THE CWA AROUND 03-06Z AND WILL OUTPACE THE SLOWLY
EVOLVING THERMODYNAMIC ENVIRONMENT. COUPLED WITH WEAK WARM ADVECTION
ALOFT, EXPECT SUFFICIENT FORCING TO PRODUCE A JUST A PARTIAL
COVERAGE WEAK CONVECTIVE SHOWERS BUT NOTHING OF NOTE DURING THE
AFOREMENTIONED TIME FRAME. THIS IS HIGHLIGHTED IN THE GRIDS WITH A
BLANKET 30 POP THROUGH 2AM.
STEEPER LAPSE RATE RATE ENVIRONMENT ORIGINATING OVER THE MS VALLEY
WILL THEN STRING INTO THE AREA WITHIN ONGOING SWLY FLOW ON THE HEELS
OF THIS WAVE. WARM 900-800MB LAYER WILL CONTAIN MOST UNSTABLE
PARCELS FEATURING 700 TO 1000 J/KG LOW DENSITY CAPE. THOUGHTS
REGARDING NOCTURNAL COOLING OF UPPER ATMOSPHERE AND ONGOING
DIFFERENTIAL WAA REMAIN FROM PREV DISCUSSION REMAIN IN PLAY AND
OFFER ADDED CONFIDENCE IN SLIGHTLY MORE VIGOROUS CONVECTIVE
DEVELOPMENT UPON THE ARRIVAL OF THE SECOND WAVE LATE TONIGHT INTO
EARLY FRIDAY MORNING. QPF IN MOST GUIDANCE IS UNINSPIRING, LIKELY
OWING TO DRY AIR IN THE LOWEST 5KFT, BUT INTENSITY OF ANY CONVECTION
SHOULD OVERCOME THE DRY AIR FAIRLY EASILY. COVERAGE CONCERNS
PRECLUDE A HIGHER POP MENTION, BUT 08-12Z PERIOD APPEARS WORTH AT
LEAST ANOTHER BLANKET CHC POP...SLIGHTLY HIGHER ACROSS SW AREAS
WHERE THE ELEVATED INSTABILITY GRADIENT IN THE RAP IS MODELED TO BE
STRONGEST. TENDENCY FOR ANY CONVECTION TO REMAIN FOCUSED ALONG THE
INSTABILITY GRADIENT LIMITS PROSPECTS FOR ANYTHING TO REACH DETROIT
METRO BEFORE SUNRISE.
MIXED LOW-LEVEL ENVIRONMENT AND LIGHT WAA THROUGH THE LOWER PORTION
OF THE COLUMN WILL SUPPORT LOWS AROUND 70 DEGREES TONIGHT.
&&
.LONG TERM...
WEAKENING SURFACE TROUGH TO TRACK INTO SOUTHERN LOWER MICHIGAN
DURING FRIDAY AS UPPER LEVEL TROUGH AXIS SLIDES THROUGH THE CENTRAL
GREAT LAKES FRIDAY NIGHT. LOW/MID LEVEL WINDS DROP OFF THROUGH THE
DAY...WITH 0-6 KM BULK SHEAR DROPPING BELOW 20 KNOTS...THUS SEVERE
POTENTIAL WILL BE LIMITED...AND WILL NEED TO RELAY ON HIGH
INSTABILITY...WHICH MAY NEVER MATERIALIZE...AS NAM CONTINUES TO
OVERPLAY LOW LEVEL MOISTURE...WITH MID 70 SURFACE DEW PTS
FORECASTED. MORE REALISTIC DEW PTS IN THE 65 TO 70 DEGREE
RANGE...WHICH SHOULD BE SUFFICIENT TO GENERATE MODERATE INSTABILITY
(BASED ON 500 MB TEMPS OF -12 C WITH TEMPS WELL INTO THE 80S)...0-1
KM CAPES OF AROUND 2000 J/KG...WHICH COULD BE SUFFICIENT FOR A PULSE
STRONG TO MARGINALLY SEVERE STORM...BUT WEAKENING LOW LEVEL JET/LOW
LEVEL CONVERGENCE SHOULD LIMIT OVERALL COVERAGE.
STRONG UPPER LEVEL RIDGE OVER THE ROCKIES (SETTING RECORD HIGHS
ACROSS NORTH DAKOTA YESTERDAY)...EXTENDING NORTH INTO SOUTHERN
ALBERTA/SASKATCHEWAN WILL BE FOLDING OVER...ALLOWING FOR SOME WARMER
AIR/UPPER LEVEL RIDGING TO SPILL OVER INTO SOUTHERN LOWER MICHIGAN
MICHIGAN OVER THE WEEKEND...RESULTING IN TEMPERATURES LIKELY
REACHING 90 DEGREES BY SUNDAY...AS 850 MB TEMPS RISE INTO THE UPPER
TEENS ON SATURDAY...AND APPROACHING 20 C ON SUNDAY...WITH 1000-500
MB THICKNESSES CLIMBING TO NEAR 580 DAM. REMNANT LOW LEVEL BOUNDARY
AROUND ON SATURDAY AND AMPLE INSTABILITY COULD PROVE SUFFICIENT TO
GENERATE SOME CONVECTIVE ACTIVITY (LOW/SLIGHT CHANCE) BEFORE WARM
MID LEVEL AIR/RIDGE AXIS/CAP WORKS INTO THE AREA. WEAK WIND
FIELDS/MID LEVEL LAPSE RATES SHOULD TRANSLATE TO GARDEN VARIETY TYPE
STORMS IF THEY DO IN FACT DEVELOP.
AN ELONGATED SHORTWAVE WILL PROVIDE SYNOPTIC LIFT FOR A
PRECIPITATION SYSTEM THAT WILL MAKE ITS WAY SOUTHEASTWARD THROUGH
MICHIGAN MONDAY AFTERNOON AND THROUGH THE NIGHT. A WARM AND HUMID
AIR MASS AHEAD OF THE ADVANCING COLD FRONT WILL PROVE TO CREATE
MUGGY CONDITIONS ON MONDAY. WHILE ANY EARLY PRECIPITATION WILL
HINDER SIGNIFICANT HEATING DURING THE LATER AFTERNOON...HIGH
TEMPERATURES ARE STILL EXPECTED TO REACH INTO THE MID 80S BY EARLY
AFTERNOON. AFTER MONDAY...THE FORECAST BECOMES A BIT MUDDLED. THE
CHANCE FOR THUNDERSTORMS WILL EXIST THROUGHOUT THE CWA TUESDAY
THROUGH THURSDAY UNTIL WE CAN RESOLVE BETTER TRACKING/TIMING OF
PRECIPITATION.
&&
.MARINE...
SOUTHWEST WINDS 10 TO 15 KNOTS IN PLACE OVER THE CENTRAL GREAT LAKES
AHEAD OF A SURFACE TROUGH...WHICH WILL SLIP THROUGH THE REGION
TOMORROW...TRIGGERING A FEW SHOWERS AND THUNDERSTORMS.
HIGH PRESSURE AND WARM AIR STREAMING IN FOR THE WEEKEND WILL LEAD TO
HIGHER LOW LEVEL STABILITY...TRANSLATING TO WEAK WINDS AND LOW
WAVES.
&&
.AVIATION...ISSUED 1254 PM EDT THU AUG 13 2015
VFR THROUGH TONIGHT WITH SOUTHWEST WINDS OF 10 TO 15KTS FALLING
BELOW 10 KTS OVERNIGHT. INCREASING MID-LEVEL INSTABILITY WILL BRING
A CHANCE OF SHOWERS AND TSTORMS LATE, MAINLY ACROSS THE NORTH. LEFT
MENTION OF TSTORMS IN FOR MBS/FNT BUT WILL OPT TO MONITOR TRENDS
BEFORE INTRODUCING ELSEWHERE.
FOR DTW...EPISODES OF FEW-SCT CLOUDS AOB 5KFT WILL BE POSSIBLE
THROUGH TONIGHT.
//DTW THRESHOLD PROBABILITIES...
* LOW FOR THUNDERSTORM POTENTIAL TONIGHT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...JVC
LONG TERM....SF/PS
MARINE.......SF
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
127 PM EDT THU AUG 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 212 AM EDT THU AUG 13 2015
HEALTHY SHORTWAVE DIGGING SE WITH 850MB THETA-E ADVECTION EARLY WILL
HELP SUPPORT ONGOING CONVECTION MOVING IN FROM THE ARROWHEAD OF MN
AND CANADA EARLY THIS MORNING. LOOK FOR SHOWERS/THUNDERSTORMS TO
CLIP THE W CWA BEFORE DIMINISHING THROUGH THE DAY TODAY. THE 21/00Z
NAM AND 21/03Z HRRR SEEM TO HAVE A PRETTY GOOD HANDLE ON WHAT WOULD
BE A MORE LIKELY SCENARIO...WITH THE GFS AND CANADIAN BRINGING THE
BULK OF PRECIP OVER THE KEWEENAW AND LAKE SUPERIOR THROUGH THE
MORNING HOURS. WILL NEED TO MONITOR THE TRENDS EARLY THIS MORNING.
EXPECT SHOWERS AND A FEW THUNDERSTORMS TO REMAIN POSSIBLE SE THIS
AFTERNOON...AWAY FROM THE LAKE SUPERIOR STABILIZATION. DESPITE THE
ONSHORE FLOW N CENTRAL AND E...THERE WILL BE LITTLE RELIEF FROM THE
HEAT. EXPECT A VERY WARM DAY TODAY...CLOSE TO THE RECORD AT NWS MQT
WHICH IS 89 SET BACK IN 1970. MID TO UPPER 80S WILL BE COMMON FOR
ALL BUT THE TIP OF THE KEWEENAW PENINSULA...AND E OF A LINE FROM
MUNISING TO RAPID RIVER...EVEN WITH THE POTENTIAL FOR SHOWERS IN THE
AREA. PW VALUES MAXING OUT AROUND 1.6IN W TO E TODAY WILL FALL TO
AROUND 1-1.2IN CWA WIDE BY 06Z. WITH THE MAIN SFC TROUGH SET UP OVER
THE W HALF OF LAKE SUPERIOR AND WARM AIR FULLY ENTRENCHED OVER THE
CWA...LOWS IN THE 60S LOOK TO BE A GOOD BET...WITH ADDITIONAL
SHOWERS AND THUNDERSTORMS NEARING FROM THE NW.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 501 AM EDT THU AUG 13 2015
OVER THE NEXT 7 DAYS...RIDGE OVER THE ROCKIES WILL FADE AWAY AS TWO
FAIRLY ENERGETIC SHORTWAVES SWING THRU WRN NAMERICA. THE FIRST
MOVING ACROSS SW CANADA/PACIFIC NW/NRN ROCKIES FRI/SAT WILL AFFECT
THE UPPER LAKES SUN/MON. THE SECOND WILL DIVE FARTHER S INTO THE
ROCKIES TUE/WED AND THEN LIFT NE TO THE UPPER LAKES/NRN
ONTARIO/HUDSON BAY VCNTY BY FRI. WITH THE WEAKENING OF THE WRN
RIDGE...THE CURRENT ERN CONUS TROF WILL FILL AND BE REPLACED BY
ABOVE NORMAL HEIGHTS. THESE LARGE SCALE CHANGES WILL RESULT IN
WARM/HUMID CONDITIONS PREVAILING THRU THE WEEKEND...THEN A FALL BACK
TO SLIGHTLY BLO NORMAL CONDITIONS EARLY NEXT WEEK BEHIND THE FIRST
SHORTWAVE MENTIONED ABOVE. THE PEAK OF THE HEAT/HUMIDITY SHOULD
OCCUR SUN AHEAD OF THAT WAVE. AFTER THE COOL DOWN EARLY IN THE
WEEK...TEMPS SHOULD RETURN TO AROUND NORMAL. AS FOR PCPN...SCT
SHRA/TSTM POTENTIAL WILL CONTINUE THRU FRI...THEN DRY WEATHER WILL
RETURN SAT AS THE NRN PORTION OF THE WRN RIDGE IS FORCED EASTWARD BY
THE SHORTWAVE TROF SWINGING THRU THE NRN ROCKIES. THAT SHORTWAVE
WILL BRING A RISK OF PCPN SUN/MON...THOUGH WITH THE MAIN ENERGY
LIFTING ENE...PCPN COVERAGE WILL PROBABLY BE LIMITED. MODEL
AGREEMENT HAS IMPROVED SOME FOR THE MIDDLE AND END OF NEXT WEEK. IT
APPEARS THERE WILL BE THE POTENTIAL FOR HVY RAINFALL AND PERHAPS
STRONG TO SVR STORMS AT SOME POINT WED/THU IN ASSOCIATION WITH THE
SECOND WAVE LIFTING OUT OF THE W AND ITS ASSOCIATED FAIRLY VIGOROUS
SFC LOW FOR AUG.
BEGINNING FRI...COLD FRONT WILL DROP S ACROSS UPPER MI IN
ASSOCIATION WITH SHORTWAVE MOVING ACROSS THE UPPER LAKES. MAY SEE A
FEW SHRA/TSTMS IN THE MORNING WITH THE FRONT...BUT ACROSS THE
S...FRONTAL PASSAGE WILL BEGIN TO BETTER COINCIDE WITH THE DIURNAL
HEATING CYCLE/INSTABILITY BUILD UP. WITH MLCAPES REACHING AT LEAST
1000-1500J/KG...AND ENHANCED CONVERGENCE DUE TO LAKE BREEZE...TSTMS
SHOULD INCREASE EARLY IN THE AFTN. TIMING OF THE FRONT WILL BE
CRITICAL. IF FRONT PASSES EARLY IN THE AFTN OVER THE S...TSTM
POTENTIAL WILL BE LESS THAN IF THE FRONT PASSES IN THE LATE AFTN.
WITH DEEP LAYER SHEAR AROUND 25KT...SOME STRONG STORMS WILL BE
POSSIBLE AND PERHAPS AN ISOLD SVR STORM IF FROPA IS LATER IN THE
AFTN. IT WILL BE A WARM/HUMID DAY WITH HIGHS MOSTLY IN THE 80S.
LIGHT WINDS OFF LAKE SUPERIOR WILL LEAD TO COOLER CONDITIONS N...BUT
ONLY SLIGHTLY.
DRY WEATHER WILL SET IN FOR FRI NIGHT/SAT UNDER RISING HEIGHTS WITH
MID/UPPER RIDGE BUILDING NE INTO THE UPPER LAKES. SAT WILL BE A
WARM/HUMID DAY WITH HIGH TEMPS IN THE 80S UNDER MOSTLY SUNNY SKIES.
SHORTWAVE TROF MOVING ACROSS THE NRN ROCKIES SAT WILL LIFT ENE INTO
NRN ONTARIO SUN. ASSOCIATED COLD FRONT WILL LIKELY REACH WRN UPPER
MI LATE IN THE AFTN AS GFS WHICH HAD BEEN FASTEST WITH THE FRONT HAS
SLOWED TO BE MORE INLINE WITH THE GEM/ECMWF. WITH BEST HEIGHT
FALLS/DEEP LAYER FORCING PASSING TO THE N...CONVECTION ALONG/AHEAD
OF FRONT AS IT PASSES PROBABLY WON`T BE MORE THAN ISOLD TO SCT.
HOWEVER...AS UPPER JET TRANSLATES E AND BETTER POSITIONS RIGHT
ENTRANCE UPPER DIVERGENCE OVERTOP FRONT SUN NIGHT...EXPECT CHC OF
SHRA/TSTMS TO INCREASE SUN NIGHT. WITH FRONT NOT ARRIVING UNTIL LATE
IN THE DAY...SUN WILL BE A VERY WARM...HUMID DAY AS 850MB THERMAL
RIDGE WITH 850MB TEMPS OF AT LEAST 20C SHIFTS ACROSS THE AREA IN
ADVANCE OF COLD FRONT. EXPECT MAX TEMPS INTO THE UPPER 80S OVER MUCH
OF THE AREA...AND LIKELY REACHING 90F AT SOME LOCATIONS. FAIRLY
TIGHT PRES GRADIENT WILL ALSO LEAD TO GUSTIER WINDS...PROBABLY 20-
25MPH TO PERHAPS 30MPH AT TIMES.
HEALTHY COOLING (AND LOWERING OF DWPTS) WILL FOLLOW THE FRONT FOR
MON AS 850MB TEMPS FALL BACK TO 6 TO 10C. MAX TEMPS SHOULD BE IN THE
UPPER 60S W AND N NEAR LAKE SUPERIOR TO MID 70S SCTNRL/SE. UPPER
DIVERGENCE UNDER RIGHT ENTRANCE OF UPPER JET EXTENDING FROM THE
UPPER LAKES TO NRN/CNTRL QUEBEC MAY HELP SHRA/TSTMS LINGER INTO MON
MORNING OVER THE SCNTRL AND E EVEN THOUGH SFC FRONT SHOULD BE JUST S
AND E OF THAT AREA AT 12Z MON.
DRY WEATHER WILL THEN BE THE RULE MON AFTN INTO TUE AS SFC HIGH PRES
MOVES ACROSS THE UPPER LAKES. WITH SFC HIGH PRES OVER THE AREA AND
PRECIPITABLE WATER UNDER 0.5 INCHES...TEMPS MON NIGHT WILL LIKELY
FALL INTO THE 40S IN THE INTERIOR WITH TRADITIONAL COLD SPOTS
POSSIBLY DOWN INTO THE LWR 40S.
VIGOROUS SHORTWAVE MOVING FROM THE CNTRL ROCKIES AND ACROSS THE
UPPER GREAT LAKES DURING THE MID AND LATE WEEK WILL BRING THE
POTENTIAL FOR ROUNDS OF SHRA/TSTMS AND POSSIBLE HVY RAINFALL.
INITIALLY...STRENGTHENING WAA/MOISTURE ADVECTION IN ADVANCE OF WAVE
WILL SUPPORT SHRA/TSTMS SPREADING INTO UPPER MI WED/WED NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 126 PM EDT THU AUG 13 2015
CLOUDS HAVE BUILT UP WITH DAYTIME HEATING...BUT FOR THE AFTN INTO
THE EVENING...EXPECT BEST CHANCE FOR SHRA AND POSSIBLE TSRA TO
AFFECT KSAW. SINCE TSRA COVERAGE IS TOO UNCERTAIN DID NOT INCLUDE IN
THE TAF ATTM. COLD FRONT WILL WORK ACROSS UPR MICHIGAN ON FRIDAY
MORNING...BUT LIMITED MOISTURE SHOULD ONLY RESULT IN SCT-BKN MID
CLOUDS AT THE TAF SITES. DEPENDING ON EXTENT OF RAIN THIS AFTN AT
KSAW COULD SEE PATCHY MVFR FOG BRIEFLY DEVELOP THERE LATE TONIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 212 AM EDT THU AUG 13 2015
FOG WILL BE POSSIBLE TODAY THROUGH FRIDAY MORNING OVER MAINLY NE AND
E LAKE SUPERIOR...CLOSER TO THE COLDEST WATER AS WARM HUMID AIR
SHIFTS OVERHEAD. WINDS SHOULD BE LESS THAN 30KTS THROUGH THE
PERIOD...WITH GUSTS NEARING 30KTS OVER A FEW OF THE HIGHER PLATFORMS
OVER W LAKE SUPERIOR INITIALLY THIS MORNING OUT OF THE SW...AND
AGAIN SATURDAY NIGHT INTO SUNDAY.
EXPECT THE HIGH OVER THE OH RIVER VALLEY TO DRIFT OFF THE EAST COAST
THROUGH FRIDAY. A TROUGH MOVING THROUGH NW ONTARIO AND MN THIS
MORNING WILL SWEEP SE ACROSS LAKE SUPERIOR THIS AFTERNOON. IN ITS
WAKE...HIGH PRESSURE WILL BUILD INTO THE UPPER GREAT LAKES ON
FRIDAY. AS THIS HIGH DRIFTS SE INTO THE MID ATLANTIC STATES OVER THE
WEEKEND...A LOW WILL MOVE E FROM S SASKATCHEWAN ACROSS NW ONTARIO
AND TO NEAR JAMES BAY LATE ON SUNDAY. THIS LOW WILL CONTINUE E INTO
QUEBEC ON MONDAY...AND DRAG A COLD FRONT ACROSS THE UPPER LAKES ON
SUNDAY NIGHT. BEHIND THIS FRONT...LOOK FOR A HIGH TO MOVE INTO
MINNESOTA ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...ROLFSON
AVIATION...JLA
MARINE...KF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
315 PM CDT THU AUG 13 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 314 PM CDT THU AUG 13 2015
THE MAIN FOCUS IS THUNDERSTORMS THIS EVENING. SHORT TERM MODELS
(HRRR/RAP) HAVE BEEN CONSISTENT WITH TROUGH/WEAK FRONT IN THE
NEBRASKA SANDHILLS BECOMING THE FOCUS FOR THUNDERSTORMS IN THE NEXT
COUPLE HOURS. THIS IS SUPPORTED BY WEAK UPPER DIFFERENTIAL VORTICITY
ADVECTION...INCREASING LOW LEVEL CONVERGENCE AND WEAKENING CAP.
HAVEN/T SEE STRONG CU DEVELOPMENT YET BUT DO BELIEVE IT WILL OCCUR
AND THOSE THUNDERSTORMS WILL SLIDE INTO THE WESTERN HAVE OF THE
FORECAST AREA BY MID EVENING. BELIEVE THE HRRR DEPICTION IS A BIT
QUICK TIMING WISE AND OPTED TO SLOW THINGS DOWN A COUPLE HOURS.
MAJORITY OF THESE STORMS SHOULD BE NON-SEVERE...ALTHOUGH CAPABLE OF
PRODUCING STRONG GUSTY WINDS...BUT A FEW SEVERE STORMS ARE POSSIBLE
INTO THE EARLY EVENING HOURS. MAIN HAZARD SHOULD BE STRONG WINDS.
HAVE INCREASED PRECIPITATION CHANCE A BIT BUT WANE THEM IN THE
WESTERN AREAS BY MIDNIGHT. SOME HINTS OF SOME MORE LATE NIGHT
CONVECTION IN THE COLUMBUS AREA WITH MID LEVEL SYSTEM GRADUALLY
DRIFTING SOUTH. NOT TAKING THAT OFF THE TABLE YET AND HAVE KEPT LATE
NIGHT PRECIPITATION CHANCES IN THE EAST...AND LINGERED THEM INTO
EARLY FRIDAY.
TEMPERATURES WILL BE SEASONALLY WARM THROUGH FRIDAY...AND SUNSHINE
SHOULD BE IN FULL FORCE BY AFTERNOON. A TYPICAL MID AUGUST DAY.
WINDS WILL BE STEADY FROM THE SOUTH BUT NOT QUITE AS STRONG
AS TODAY...A DAY WE HAVE A FEW PLACES GUST TO 25 MPH AT TIMES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 PM CDT THU AUG 13 2015
AN UPPER LEVEL RIDGE IS ACROSS THE AREA FRIDAY NIGHT INTO SATURDAY.
THIS WILL HELP KEEP TEMPERATURES ON THE WARMER SIDE. A SURFACE LOW
DEVELOPS ALONG THE HIGH PLAINS AND THE PRESSURE GRADIENT INCREASES.
WINDS FROM THE SOUTH WILL INCREASE. BY SATURDAY NIGHT AN UPPER LEVEL
WAVE MOVES OVER THE RIDGE AND THE SURFACE LOW AND FRONT APPROACH THE
FORECAST AREA. THERE COULD BE SOME THUNDERSTORMS DURING THE EVENING
HOURS...BUT THE BETTER CHANCE WILL BE AFTER MIDNIGHT AS THE SURFACE
FRONT APPROACHES. THE THUNDERSTORM CHANCES CONTINUE ON SUNDAY AS THE
FRONT MOVES INTO THE FORECAST AREA. THERE ARE A FEW DIFFERENCES IN
THE MODELS WITH HOW FAR THE FRONT MOVES TO THE SOUTHEAST BEFORE
STALLING AND WEAKENING. EITHER WAY THE FRONT SHOULD STILL BE IN THE
FORECAST AREA SUNDAY AFTERNOON AND EVENING AS THE MAIN UPPER WAVE
MOVES INTO THE AREA. THIS WILL PROVIDE THE BEST CHANCE FOR
THUNDERSTORMS THROUGH THE PERIOD. THE WEAK FRONT IS EXPECTED TO
CONTINUE TO SAG TO THE SOUTH ON MONDAY AND THERE IS STILL A CHANCE
FOR SHOWERS AND THUNDERSTORMS DURING THE DAY ON MONDAY. ANOTHER
UPPER LEVEL WAVE MOVES THROUGH MONDAY NIGHT INTO TUESDAY AND AT
LEAST PORTIONS OF THE FORECAST AREA WILL HAVE A CHANCE FOR
THUNDERSTORMS.
FOR THE PERIOD TUESDAY NIGHT THROUGH THURSDAY THE MODELS HAVE SOME
DIFFERENCES. THE ECMWF BRINGS AN UPPER WAVE ACROSS THE AREA DURING
THIS TIME FRAME WHILE THE GFS KEEPS IT TO THE WEST AND HAS A
STRONGER UPPER LOW. IF THE GFS IS RIGHT...EXPECT MAINLY DRY
CONDITIONS FOR TUESDAY NIGHT THROUGH THURSDAY...BUT THE ECMWF WOULD
INDICATE THERE WOULD BE SOME SHOWERS AND THUNDERSTORMS AROUND FOR
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...THEN DRY FOR THURSDAY. HAVE
KEPT SOME POPS IN FOR THIS PERIOD...EXCEPT THURSDAY. WITH THE
UNCERTAINTY OF THE MODELS HAVE TRIED NOT TO MAKE TOO MANY CHANGES.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1232 PM CDT THU AUG 13 2015
BREEZY CONDITIONS WILL START THE FORECAST PERIOD OUT WITH GUSTS TO
20KTS AT TIMES. LOOK FOR VFR CONDITIONS UNTIL EARLY EVENING WHEN
ISOLATED TO SCATTERED THUNDERSTORMS MOVE THROUGH BOTH KEAR AND
KGRI. COVERAGE WILL BE A MIT AND MISS AND HAVE ONLY INCLUDED A
VICINITY MENTION. THAT PRECIPITATION SHOULD MOVE THROUGH BY
ABOUT MIDNIGHT WITH JUST SOME MID CLOUDS REMAINING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...NOAA/NWS/MORITZ
LONG TERM...JCB
AVIATION...NOAA/NWS/MORITZ
AREA FORECAST DISCUSSION
NWS ELKO NV
210 PM PDT THU AUG 13 2015
.SYNOPSIS...GOOD MONSOON PUSH WILL RESULT IN CONVECTION FOR MOST
OF THE CWA BEFORE DRIER AIR ADVECTS EASTWARD OVER THE NEXT COUPLE
OF DAYS. WINDY CONDITIONS TODAY AND TOMORROW BEFORE THEY DECREASE
BY THE WEEKEND.
&&
.SHORT TERM...THIS AFTERNOON THROUGH SATURDAY. A 500MB LOW WITH A
70KT JET MAX NEAR THE NV/CA BORDER IS PULLING A DECENT AMOUNT OF
MONSOONAL MOISTURE ACROSS MOST THE CWA. THIS HAS PUSHED THE NV
"DRY LINE" TO JUST EAST OF WMC. THE HIGHER SFC MOISTURE STILL
EXIST ACROSS EASTERN NV WHERE PW VALUES OF 1+ INCH AND 50+ DEW
POINTS ARE FAIRLY COMMON. WOULD EXPECT SCATTERED THUNDERSTORMS TO
DEVELOP THIS AFTERNOON WITH BEST WETTING RAIN POTENTIAL IN EASTERN
NV; HOWEVER...THIS MAY NOT BE THE CASE AS WEAK UPPER LEVEL
WARMING OCCURRED ACROSS EASTERN NV...INDICATED BY THE LKN MORNING
SOUNDING. THINKING IS FIRST ACTIVITY SHOULD BEGIN FURTHER WEST
ALONG THE BOUNDARY WHERE THIS WARMING IS WEAKER AND CAN BE QUICKLY
OVERCOME. ACTIVITY IN EASTERN NV WILL OCCUR BUT MORE ON THE
ISOLATED SIDE. THE HRRR AND RAP13 AGREE WITH THIS THINKING SO
BUMPED POPS UP IN LANDER...EASTERN HUMDOLDT...WESTERN ELKO...AND
NW NYE COUNTIES. THE OTHER ISSUE IS WHETHER THESE WILL WET OR DRY.
ANY ACTIVITY IN EASTERN NV WILL BE WET...HOWEVER ONCE WEST OF AN
BATTLE MTN TO EUREKA LINE...THEY COULD BE DRY OR MOVING AT A FAIRLY
QUICK RATE TO LIMIT THE WETING POTENTIAL. OVERALL ACTIVITY
DIMINISHES TONIGHT WITH REDEVELOPMENT TOMORROW IN EASTERN ELKO AND
WHITE PINE COUNTIES AS THE 500MB LOW PUSHES NE AND DRIVES THE DRY
LINE FURTHER EAST. ONCE AGAIN...SOME OF THIS CONVECTION COULD BE
DRY ON THE WESTERN EDGES. BY SATURDAY...DRY LINE IS PUSHED WELL
SOUTH AND EAST...WITH ONLY PORTION OF EASTERN WHITE PINE COUNTY
EXPECTED TO SEE CONVECTION.
THE OTHER ISSUE IS WINDS AS THIS UPPER LEVEL WITH ASSOCIATED JET
MAX LIFTS NORTHEAST. ALL THE CWA WILL EXPERIENCE WINDY CONDITIONS
THROUGH FRIDAY WITH HUMBODLT AND NW NYE COUNTIES THE WORST
(30-35KT GUSTS IN HIGHER TERRAIN). WINDS RELAX ON SATURDAY AS HIGH
PRESSURE BUILDS IN.
AS FOR TEMPS...WITH SOUTHERLY WINDS...EXPECT WARM CONDITIONS TODAY
(90S) AND FOR EASTERN HALF OF CWA TOMORROW. A SLIGHT DROP IN HIGH
TEMPS IS EXPECTED IN WESTERN AREAS DUE TO WIND DIRECTION CHANGE
AND SLIGHTLY LOWER 500MB HEIGHTS.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT THURSDAY. WILL KEEP THIS
PERIOD DRY FOR NOW. THE MODELS ARE IN VERY GOOD AGREEMENT ONLY
THROUGH MONDAY MORNING...PORTRAYING A NEARLY STATIONARY BROAD RIDGE
OF HIGH PRESSURE OVER THE SOUTHWEST CONUS. AFTERWARD...THE MODELS
ARE NEGOTIATING STRENGTH AND POSITION OF AN UPPER LOW PROGGED TO
DROP DOWN FROM THE PACIFIC NORTHWEST REGION. IF THE GFS MODEL PANS
OUT...THERE COULD BE A SUBSTANTIAL COOLING AND A SHOT OF
PRECIPITATION AROUND MIDWEEK AS THE UPPER LOW MOVES THROUGH THE LKN
CWFA. HOWEVER IF THE ECMWF MODEL RINGS TRUE...THE UPPER LOW WILL
MOVE FURTHER NORTH AND WITH LESS INTENSITY...THUS ONLY BRUSHING THE
SILVER STATE WITH AN INITIAL IMPULSE AS EARLY AS MONDAY
AFTERNOON...THEN SETTLING ON A GENERAL TROUGH SCENARIO AS THE WEEK
PROGRESSES. EITHER SOLUTION WILL AT LEAST BRING TEMPERATURES BELOW
90 DEGREES IN THE DAYTIME BY TUESDAY.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL FOR KWMC KEKO KELY AND KTPH
THROUGH FRIDAY AFTERNOON. HOWEVER SHOWERS AND THUNDERSTORMS WILL
POSSIBLY AFFECT ALL SITES TODAY...LESS LIKELY FOR KWMC AND KTPH. ON
FRIDAY SHOWERS AND THUNDERSTORMS WILL DEVELOP FURTHER EAST TO ONLY
AFFECT KELY AND KEKO.
&&
.FIRE WEATHER...MAIN CONCERN FOR THE NEAR TERM IS DRY LIGHTNING IN
467...468...WESTERN PORTIONS OF 454 AND 457. STORM MOTION IS
EXPECTED TO REMAIN NEAR 15-20KT IN THESE AREAS SO WETTING RAIN
POTENTIAL IS PRETTY LOW. THE OTHER AREA OF CONCERN IS WIND/RH IN
WESTERN HUMDOBLDT COUNTY. CRITERIA ARE NOT EXPECTED TO HIT IN THIS
AREA BUT WINDS WILL REMAIN BREEZY AND RH SHOULD DROP BELOW 15%
WITH POOR RECOVER OVERNIGHT. TOMORROW...DRY THUNDERSTORM CONCERNS
ARE OVER 469 AND EASTERN 454...WHILE HOLD POTENTIAL EXIST
(DEPENDING ON TODAY`S LIGHTNING COVERAGE) IN 468 AND EASTERN 467
WHERE GUSTY WINDS AND LOW RH VALUES ARE EXPECTED. WILL HAVE TO
MONITOR THIS HOLD OVER THREAT CLOSELY THIS AFTERNOON. ACTIVITY IN
470 AND 455 WILL REMAIN WET WITH INCREASE COVERAGE TOMORROW.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
85/92/92/85
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
135 PM EDT THU AUG 13 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE BEGINS TO BUILD INTO THE REGION TODAY BRINGING
A RETURN OF MOSTLY QUIET WEATHER WITH A FEW POSSIBLE SHOWERS
ACROSS THE NORTH COUNTRY AS A SHORTWAVE CROSSES THE REGION. A WEAK
COLD FRONT WILL BRING THE CHANCE FOR MORE SHOWERS AND A FEW
THUNDERSTORMS FRIDAY INTO SATURDAY. TEMPERATURES WILL SEE A
WARMING TREND OVER THE WEEKEND WITH DAYTIME TEMPERATURES REACHING
THE UPPER 80S OVER THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 135 PM EDT THURSDAY...FINALLY GETTING SOME WEAK CONVECTION
DEVELOPING FROM THE NORTHERN ADIRONDACKS EASTWARD IN RESPONSE TO
SHORTWAVE TROUGH MOVING INTO THE AREA. INSTABILITY IS LIMITED THUS
ONCE SHORTWAVE MOVES EAST OF THE AREA THIS EVENING AND DAYTIME
HEATING COMES TO AN END...THE SHOWERS WILL DIMINISH QUICKLY. GOING
FORECAST HAS THIS COVERED WELL AND ONLY REAL TWEAK WAS TO ADJUST
SKY COVER TO REFLECT CURRENT CONDITIONS.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/...
AS OF 348 AM EDT THURSDAY...EXPECT A QUIET EVENING ON THURSDAY
NIGHT WITH INCREASING SOUTHERLY FLOW AHEAD OF A COLD FRONT. FRIDAY
MORNING THE SOUTHERLY FLOW QUICKLY INCREASES LOW LEVEL MOISTURE
AND SURFACE TEMPERATURES ACROSS THE NORTH COUNTRY. AS THE MOISTURE
INCREASES SO DOES THE INSTABILITY BUT ONLY MARGINALLY. GIVEN THE
WEAK LAPSE RATES AND MINIMAL SHEAR I DO NOT EXPECT MORE THAN A
FEW ISOLATED THUNDERSTORMS AS THE UPPER LEVEL VORT MAX`S GENERATE
RAIN SHOWERS ACROSS THE AREA FRIDAY EVENING INTO SATURDAY MORNING.
GIVEN THE RAPID INCREASE OF PRECIPITABLE WATER AND WEAK CORFIDI
VECTORS EXPECT SOME OF THE SHOWERS TO PRODUCE HEAVY RAINFALL RATES
HOWEVER WITH THE ANTECEDENT CONDITIONS STILL BELOW NORMAL FOR THE
AUGUST I`M NOT EXPECTING A SIGNIFICANT FLOODING EVENT. NONETHELESS
HEAVIER SHOWERS COULD LIKELY PRODUCE SOME PONDING OF WATER IN LOW
LYING AREAS AND IN AREAS OF POOR DRAINAGE.
AS THE FRONT CLEARS THE AREA LATE SATURDAY AFTERNOON WE WILL SEE
A NEW AIR MASS MOVE IN BEHIND THE FRONT AS AN UPPER LEVEL RIDGE
AND SURFACE HIGH BUILD IN OVER THE NORTH COUNTRY. EXPECT DAYTIME
TEMPERATURES FRIDAY WILL BE IN THE MID 70S TO LOW 80S WITH THE
OVERNIGHT LOWS ON FRIDAY NIGHT IN THE LOW TO MID 60S. AS THE FRONT
IS MOVING THROUGH THE REGION ON SATURDAY TEMPS WILL NEARLY BE A
REPEAT OF FRIDAY IN THE MID 70S TO LOW 80S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 333 AM EDT THURSDAY...MAIN HEADLINE FOR THE EXTENDED WILL
BE POTENTIAL UPPER 80S/LOWER 90S FOR DAYTIME HIGHS SUNDAY AND
MONDAY. BOTH THE 00Z ECMWF AND 00Z GFS INDICATE BROAD MID-LEVEL
RIDGE AND BUILDING 500MB HEIGHTS INTO THE REGION FROM THE WEST AND
SOUTHWEST...WITH 850MB TEMPS OF +18C TO +19C SUN/MON. RAINFALL
CHANCES APPEAR MINIMUM AND ANTICIPATE FULL HEATING WITH GENERAL
MID-LEVEL SUBSIDENCE IN PLACE. EXPECTATION IS FOR MID 60S
DEW POINTS...THUS MODERATELY HUMID CONDITIONS. THIS SHOULD ALSO
KEEP LOW TEMPERATURES IN THE MID-UPR 60S FOR MOST SECTIONS FOR
SUNDAY NIGHT.
MID-LEVEL RIDGE BEGINS TO BREAK DOWN MONDAY NIGHT INTO TUESDAY. MAY
SEE SOME SHOWER/ISOLD THUNDER ACTIVITY DEVELOP LATER MONDAY
NIGHT...WITH POTENTIAL ROUND OF WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH SURFACE FRONTAL PASSAGE ON TUESDAY. HAVE INDICATED 30-40 POPS
ACROSS NRN NY 06-12Z TUESDAY...INCREASING TO 45-60 POPS AREAWIDE
DURING THE DAYLIGHT HOURS ON TUESDAY. COULD SEE A FEW STRONGER
THUNDERSTORMS...BUT DIFFICULT TO ASSESS AT THIS TIME GIVEN TIMING
UNCERTAINTY OF FRONTAL PASSAGE WITH RESPECT TO DAYTIME HEATING MAX.
SHOULD STILL SEE HIGH TEMPS IN THE LOW-MID 80S ACROSS THE VT VALLEYS
ON TUESDAY BEFORE RAINFALL...THOUGH COOLER WITH EARLIER FRONTAL
PASSAGE ACROSS NRN NY BASED ON CURRENT INDICATIONS. WILL CONTINUE TO
MONITOR.
SHOULD SEE CLEARING CONDITIONS TUESDAY NIGHT WITH COOLER/MORE
SEASONABLE CONDITIONS AND LOWER HUMIDITY LEVELS ON WEDNESDAY. HIGH
TEMPERATURES ON WEDNESDAY EXPECTED IN THE UPR 70S TO LOWER
80S...WITH DEW POINTS BACK INTO THE MID TO UPPER 50S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
THROUGH 12Z FRIDAY...UPPER TROUGH ROTATING SEWD FROM
SERN ONTARIO WILL MAINTAIN BKN-OVC SKIES THROUGH 14-16Z...WITH
LOCALIZED MVFR CEILINGS PERSISTING AT SLK/MSS/MPV. GENERAL TREND
IN RAP MODEL SOUNDINGS IS TO SHOW IMPROVING CEILINGS AFTER
16Z...BUT MAY SEE LOCALIZED MVFR CONDITIONS PERSIST NEAR THE MTNS
WITH VCSH INCLUDED IN SLK TAF DURING THE AFTERNOON HOURS. SURFACE
WINDS GENERALLY LESS THAN 10 KTS THROUGH THE PERIOD...LIGHT W-NW
EARLY THIS MORNING...AND GENERALLY W-SW DURING THE BALANCE OF THE
DAYLIGHT PERIOD. CLEARING TONIGHT WILL LEAD TO LOCALIZED NOCTURNAL
FOG WITH LIFR EXPECTED SLK/MPV AFTER 08Z.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
12Z FRIDAY THROUGH 12Z SATURDAY...MAINLY VFR CONDITIONS...BUT
SCATTERED SHOWER/TSTM DEVELOPMENT WILL BRING INTERVALS OF MVFR OR
BRIEF IFR WITH RAINFALL (MAINLY FRIDAY AFTN INTO EARLY FRIDAY EVE).
LOCALIZED FOG POSSIBLE LATE FRIDAY NIGHT...ESPECIALLY IN VALLEY
AREAS SEEING RAINFALL.
12Z SATURDAY THROUGH MONDAY...ISOLD SHOWER OR TSTM POSSIBLE
SATURDAY AFTERNOON. OTHERWISE MAINLY VFR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...EVENSON
SHORT TERM...DEAL
LONG TERM...BANACOS
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
613 PM EDT THU AUG 13 2015
.SYNOPSIS...
A SURFACE RIDGE COVERING MUCH OF THE EASTERN U.S. WILL BE IN
CONTROL OF THE WEATHER FOR THE WEEKEND. HOWEVER...WEAK TROUGHS OF
LOW PRESSURE WILL TRY TO BREAK DOWN THE RIDGE AS THEY MOVE DOWN
FROM THE UPPER GREAT LAKES. CERTAINLY...WARMER TEMPERATURES ARE
IN STORE. A COLD FRONT SHOULD BRING COOLER AND DRIER AIR BACK
INTO THE REGION EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
WEAK SURFACE HIGH PRESSURE...RISING HEIGHTS AND DRY AIR. SHOULD BE
QUIET THROUGH MIDNIGHT. THE CUMULUS OVER THE WESTERN MOUNTAINS
SHOULD SLOW DISSIPATE AS THE SUN SETS. ANOTHER NICE COOL EVENING
AND OVERNIGHT.
&&
.SHORT TERM /MIDNIGHT THROUGH 6 PM FRIDAY/...
SHOULD REMAIN DRY OVERNIGHT. SOME PATCHY VALLEY FOG IS POSSIBLE.
HRRR TENDS TO KEEP THE CHANCE OF RAIN WELL TO OUR NORTH AND WEST.
THE MOST RECENT HRRR SHOWS SOME SHOWERS IN ONTARIO NORTH OF LAKE
ERIE TOO FAR AWAY TO GET EXCITED. THE SREF WOULD SUGGEST 20
PERCENT CHANCE IN NW BUT 3KM HRRR WAS USED TO DECREASE THIS.
SREF AND GEFS ALONG WITH THE NCEP DETERMINISTIC SUITE SHOW HIGHER
PROBABILITIES OF RAIN ALONG NY BORDER FRIDAY AFTERNOON. EACH
SYSTEM VARIES BUT 30 TO 50 PERCENT CHANCE SHOWERS AND
THUNDERSTORMS SEEMS REASONABLE IN THE TWO ENSEMBLE SYSTEMS. LOWER
AS ONE MOVES SOUTH INTO PENNSYLVANIA.
PREVIOUS DISCUSSION:
THE TROUGH STALLS ALONG OR JUST NORTH OF THE NY BORDER IN THE
MORNING. THERE WILL BE SOME WAA FROM THE WEST AS THE FLAT SFC
RIDGE TO OUR SOUTH SITS STILL. DEWPOINTS WILL PROBABLY DROP A
LITTLE FROM WHAT THEY WILL BE IN THE MORNING...SO INSTABILITY WILL
CLIMB A BIT ON FRIDAY BUT CAPES WON/T GET ALL THAT HIGH. BFD NAM
SOUNDING DRAWS LESS THAN 500 JOULES. HEIGHTS ARE RISING ON THE
WHOLE AS WELL. PLENTY OF MDLS DO CRANK OUT SOME CONVECTION ACROSS
THE NORTH...SO WILL CONTINUE TO CARRY HIGH-END CHC/SCT POPS ALONG
THE NY BORDER FOR THE DAYTIME.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A LARGE UPPER LEVEL HIGH PRESSURE SYSTEM OVER THE INTERMOUNTAIN
WEST WILL DOMINATE THE WEATHER PATTERN OF NORTH AMERICA THROUGH
NEXT WEEK. ANY LOWS/TROUGHS/FRONTS WILL HAVE TO NAVIGATE OVER AND
AROUND THIS HIGH PRESSURE. THE FIRST TROUGH WILL COME THROUGH
LATE FRIDAY THROUGH SATURDAY. AS THE LARGE UPPER LEVEL HIGH
RETROGRADES AND THE ACCOMPANYING RIDGE TILTS POSITIVELY THE CORRESPONDING
TROUGH MOVING INTO THE EAST COAST WILL DEEPEN....BRINGING A FRONT
THROUGH THE REGION LATE SATURDAY. AS THIS BOUNDARY STALL AND MOVES
INTO DRIER AIR...ANY SHOWERS AND THUNDERSTORMS WILL BE MAINLY
THROUGH THE NORTHERN HALF OF PA...AND ALONG THE CENTRAL AND NW
MTNS. THROUGH THIS TIMEFRAME EXPECT THAT TEMPERATURES WILL BEGIN
TO REBOUND UNDER THIS MORE WESTERLY FLOW OUT AHEAD OF THE FRONT
WHICH WILL AID IN ANY CONVECTION.
AS THE FRONT STALLS SATURDAY...ANY CONVECTION THAT DOES FORM
WILL BE AT OR OUT AHEAD OF THE COLD FRONT AS IT PUSHES EAST OF
PENNSYLVANIA LATE SATURDAY INTO SUNDAY. MODELS ARE TRENDING WARMER
AS HIGHS WILL BE AROUND 5 TO 10 DEGREES ABOVE NORMAL THE WEEKEND
THROUGH TUESDAY. AS THE BEFORE MENTIONED HIGH PRESSURE OVER THE
SOUTHWESTERN UNITED STATES CONTINUES TO MOVE WESTWARD...THE
PATTERN ACROSS THE REST OF CONUS WILL BECOME MORE ZONAL. HAVE
ADJUSTED POPS FOR TIMING AND POSITION OF FRONT. THE NEXT BEST
CHANCE FOR PRECIPITATION WILL BE TUESDAY...THOUGH THERE IS SOME
DISPARITY ON TIMING SO HAVE LEFT BROAD CHANCE POPS THROUGH TUESDAY
INTO WEDNESDAY.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
HIGH PRESSURE OVER THE REGION WILL PROVIDE THE AREA WITH A NEAR
CERTAINTY OF VFR CONDS AND LIGHT WIND THROUGH TONIGHT. ANY VALLEY
FOG OVER NORTHERN PA WILL BE ISOLATED AND SHOULD NOT AFFECT THE
CENTRAL PA AIRFIELDS. FRI LOOKS DRY AND VFR AS WELL. THERE IS
ONLY A VERY SLIGHT CHC FOR A SHOWER LATE IN THE DAY FRI AT KBFD AS
THE RETURN FLOW AROUND THE SFC HIGH RUNS INTO THE NW FLOW ALOFT
AND SOME PAC MOISTURE.
OUTLOOK...
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE THUNDER.
SUN...NO SIG WX.
MON...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...GRUMM/DANGELO
SHORT TERM...GRUMM/DANGELO
LONG TERM...CERU/HAGNER
AVIATION...DANGELO/FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
406 PM EDT THU AUG 13 2015
.SYNOPSIS...
A SURFACE RIDGE COVERING MUCH OF THE EASTERN U.S. WILL BE IN
CONTROL OF THE WEATHER FOR THE WEEKEND. HOWEVER...WEAK TROUGHS OF
LOW PRESSURE WILL TRY TO BREAK DOWN THE RIDGE AS THEY MOVE DOWN
FROM THE UPPER GREAT LAKES. CERTAINLY...WARMER TEMPERATURES ARE
IN STORE. A COLD FRONT SHOULD BRING COOLER AND DRIER AIR BACK
INTO THE REGION EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
WEAK SURFACE HIGH PRESSURE...RISING HEIGHTS AND DRY AIR. SHOULD BE
QUIET THROUGH MIDNIGHT. THE CUMULUS OVER THE WESTERN MOUNTAINS
SHOULD SLOW DISSIPATE AS THE SUN SETS. ANOTHER NICE COOL EVENING
AND OVERNIGHT.
&&
.SHORT TERM /MIDNIGHT THROUGH 6 PM FRIDAY/...
SHOULD REMAIN DRY OVERNIGHT. SOME PATCHY VALLEY FOG IS POSSIBLE.
HRRR TENDS TO KEEP THE CHANCE OF RAIN WELL TO OUR NORTH AND WEST.
THE MOST RECENT HRRR SHOWS SOME SHOWERS IN ONTARIO NORTH OF LAKE
ERIE TOO FAR AWAY TO GET EXCITED. THE SREF WOULD SUGGEST 20
PERCENT CHANCE IN NW BUT 3KM HRRR WAS USED TO DECREASE THIS.
SREF AND GEFS ALONG WITH THE NCEP DETERMINISTIC SUITE SHOW HIGHER
PROBABILITIES OF RAIN ALONG NY BORDER FRIDAY AFTERNOON. EACH
SYSTEM VARIES BUT 30 TO 50 PERCENT CHANCE SHOWERS AND
THUNDERSTORMS SEEMS REASONABLE IN THE TWO ENSEMBLE SYSTEMS. LOWER
AS ONE MOVES SOUTH INTO PENNSYLVANIA.
PREVIOUS DISCUSSION:
THE TROUGH STALLS ALONG OR JUST NORTH OF THE NY BORDER IN THE
MORNING. THERE WILL BE SOME WAA FROM THE WEST AS THE FLAT SFC
RIDGE TO OUR SOUTH SITS STILL. DEWPOINTS WILL PROBABLY DROP A
LITTLE FROM WHAT THEY WILL BE IN THE MORNING...SO INSTABILITY WILL
CLIMB A BIT ON FRIDAY BUT CAPES WON/T GET ALL THAT HIGH. BFD NAM
SOUNDING DRAWS LESS THAN 500 JOULES. HEIGHTS ARE RISING ON THE
WHOLE AS WELL. PLENTY OF MDLS DO CRANK OUT SOME CONVECTION ACROSS
THE NORTH...SO WILL CONTINUE TO CARRY HIGH-END CHC/SCT POPS ALONG
THE NY BORDER FOR THE DAYTIME.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A LARGE UPPER LEVEL HIGH PRESSURE SYSTEM OVER THE INTERMOUNTAIN
WEST WILL DOMINATE THE WEATHER PATTERN OF NORTH AMERICA THROUGH
NEXT WEEK. ANY LOWS/TROUGHS/FRONTS WILL HAVE TO NAVIGATE OVER AND
AROUND THIS HIGH PRESSURE. THE FIRST TROUGH WILL COME THROUGH
LATE FRIDAY THROUGH SATURDAY. AS THE LARGE UPPER LEVEL HIGH
RETROGRADES AND THE ACCOMPANYING RIDGE TILTS POSITIVELY THE CORRESPONDING
TROUGH MOVING INTO THE EAST COAST WILL DEEPEN....BRINGING A FRONT
THROUGH THE REGION LATE SATURDAY. AS THIS BOUNDARY STALL AND MOVES
INTO DRIER AIR...ANY SHOWERS AND THUNDERSTORMS WILL BE MAINLY
THROUGH THE NORTHERN HALF OF PA...AND ALONG THE CENTRAL AND NW
MTNS. THROUGH THIS TIMEFRAME EXPECT THAT TEMPERATURES WILL BEGIN
TO REBOUND UNDER THIS MORE WESTERLY FLOW OUT AHEAD OF THE FRONT
WHICH WILL AID IN ANY CONVECTION.
AS THE FRONT STALLS SATURDAY...ANY CONVECTION THAT DOES FORM
WILL BE AT OR OUT AHEAD OF THE COLD FRONT AS IT PUSHES EAST OF
PENNSYLVANIA LATE SATURDAY INTO SUNDAY. MODELS ARE TRENDING WARMER
AS HIGHS WILL BE AROUND 5 TO 10 DEGREES ABOVE NORMAL THE WEEKEND
THROUGH TUESDAY. AS THE BEFORE MENTIONED HIGH PRESSURE OVER THE
SOUTHWESTERN UNITED STATES CONTINUES TO MOVE WESTWARD...THE
PATTERN ACROSS THE REST OF CONUS WILL BECOME MORE ZONAL. HAVE
ADJUSTED POPS FOR TIMING AND POSITION OF FRONT. THE NEXT BEST
CHANCE FOR PRECIPITATION WILL BE TUESDAY...THOUGH THERE IS SOME
DISPARITY ON TIMING SO HAVE LEFT BROAD CHANCE POPS THROUGH TUESDAY
INTO WEDNESDAY.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
HIGH PRESSURE FIRMLY IN CONTROL. OTHER THAN SOME VERY HIGH-BASED
CU...JUST SOME HIGHER CLOUDS LATE TODAY...MAINLY NW. VALLEY FOG
MAY NOT SHOW UP AGAIN TONIGHT...AS TEMPS ONLY FALL INTO THE 50S IN
THE NRN TIER. FRI LOOKS DRY AND VFR AS WELL. THERE IS ONLY A VERY
SLIGHT CHC FOR A SHOWER LATE IN THE DAY FRI AT KBFD AS THE RETURN
FLOW AROUND THE SFC HIGH RUNS INTO THE NW FLOW ALOFT AND SOME PAC
MOISTURE.
OUTLOOK...
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE THUNDER.
SUN...NO SIG WX.
MON...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...GRUMM/DANGELO
SHORT TERM...GRUMM/DANGELO
LONG TERM...CERU/HAGNER
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1245 PM CDT THU AUG 13 2015
.UPDATE...
ISSUED AT 1040 AM CDT THU AUG 13 2015
QUITE A BIT TO DEAL WITH THIS MORNING. CONVECTION WITH WEAK UPPER
WAVE MOVING THROUGH THE MEAN RIDGE THIS MORNING HAS MAINTAINED AND
EVEN BECOME MORE WIDESPREAD...ALTHOUGH THE EXTENT OF THUNDER
REMAINS QUIET SPOTTY. WAVE CONTINUES TO DRIFT EAST AND
SOUTHEAST...WITH STRONGEST OF THE UPPER FORCING THIS MORNING
GLANCING ACROSS NORTHEAST SOUTH DAKOTA...HEADING TOWARD SOUTHERN
MINNESOTA. TOUGH CALL ON THE PRECIPITATION TRENDS TODAY WITH
ALMOST ALL GUIDANCE LACKING AN ADEQUATE SIMULATION OF CURRENT
CONDITIONS. HRRR MARGINALLY USEFUL...BUT APPEARS TO NOT BE
HANDLING THE STRONGER FORCED AREA TO THE NORTHEAST WELL AT ALL.
HAVE PUSHED POPS CONSIDERABLY HIGHER IN THE SHORT TERM IN THE MID
JAMES VALLEY THROUGH HIGHWAY 14 CORRIDOR...AND EXPANDED SOME
SLIGHTS/SPRINKLES DOWN TOWARD I 90 BY VERY LATE MORNING AND EARLY
AFTERNOON IN ADVANCE OF TAIL OF WAVE...BUT DRY AIR BELOW MID CLOUD
DECK WILL MAKE THIS SOMEWHAT A STRUGGLE TO REACH THE GROUND.
GIVEN THE DRY LAYER IN THE KABR 12Z RAOB...NO SURPRISE THAT
SHOWERS AND THUNDERSTORMS HAVE CREATED A DECENT COLD AIR POOL AND
DISRUPTED THE LOCAL LOW LEVEL CONVERGENCE FIELDS. HAD A FEW WIND
GUSTS CLOSE TO 40 MPH WITH LEADING EDGE OF SHOWERS IN EAST CENTRAL
SD...AND WILL CONTINUE TO BE A THREAT AS AREA EXPANDS INTO SW MN
AT MID MORNING. OTHERWISE...EXTENT OF CLOUDS AND THE PRECIPITATION
THIS MORNING TAKING A GOOD BITE OUT OF DIURNAL HEATING CYCLE...AS
WILL ANY LINGERING PRECIPITATION THIS BY EARLY AFTERNOON. HAVE
LOWERED HIGHS SEVERAL DEGREES ACROSS NORTHERN AREAS...AND IN FACT
HAVE RAISED HIGHS A BIT IN THE FAR SOUTH.
INITIAL THOUGHTS ARE THAT CURRENT CLOUDS/PRECIP WILL CREATE A
CHALLENGE TOWARD DEVELOPMENT OF SEVERE STORMS LATER TODAY. STILL
HAVE DECENT MID LEVEL LAPSE RATES...SO THOSE AREAS WHICH POTENTIALLY
HEAT OUT THE BEST TOWARD THE WEST SHOULD HAVE THE MOST FAVORABLE
INSTABILITY PROFILE...AND THE GREATER CHANCE WOULD REMAIN TOWARD
LOWER BRULE LOCATIONS. HOWEVER...WEAK WIND SHEAR WILL KEEP ORGANIZATION
POTENTIAL LIMITED...WITH MARGINALLY SEVERE WIND GUSTS AND LARGE
HAIL WOULD THE PRIMARY THREAT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT THU AUG 13 2015
ANOTHER WARM DAY ACROSS THE AREA...BUT MAIN FOCUS FOR TODAY IS ON
CONVECTIVE CHANCES AS WEAK RIDGE-TOPPING SHORTWAVE SLIDES THROUGH
THE NORTHERN PLAINS. WAVE CURRENTLY MOVING THROUGH THE WESTERN
DAKOTAS AND TRIGGERING SPOTTY ELEVATED CONVECTION INTO CENTRAL SD AS
OF 08Z. FEW IF ANY OF THE HI-RES MODELS SEEM TO BE CAPTURING THE
SOUTHERN EXTENT OF THE CURRENT ACTIVITY WELL...THOUGH ADMITTEDLY
WITH CLOUD BASES LARGELY REGISTERING AT OR ABOVE 11KFT...MUCH OF THE
PRECIP SEEN ON RADAR IMAGERY MAY NOT BE REACHING THE GROUND.
NEVERTHELESS...HAVE ADDED SOME LOW POPS TO OUR NORTHWEST CORNER FOR
THE EARLY MORNING HOURS. WILL ALSO WATCH FOR SPOTTY DEVELOPMENT
FARTHER EAST THROUGH THE HIGHWAY 14 CORRIDOR...AS MODELS IN GOOD
AGREEMENT SHOWING A CONVERGENCE ZONE AMID WEAK 850MB WARM ADVECTION
IN THIS AREA AROUND 12Z. AGAIN THINK MOISTURE...OR LACK THEREOF...
MAY BE A LIMITING FACTOR THOUGH...AND OPTED TO NOT INCLUDE EARLY
MORNING POPS THERE AS A RESULT.
THINK MAIN EFFECT OF THE CURRENT ACTIVITY WILL BE TO FORCE A WEAK
SURFACE LOW AND ASSOCIATED LOW LEVEL BOUNDARIES A BIT FARTHER SOUTH
THAN PREVIOUSLY FORECAST...WHICH SHOULD BRING THE CHANCE FOR MID-
LATE AFTERNOON DEVELOPMENT FARTHER SOUTH AS WELL. THUS HAVE SHIFTED
POPS CLOSER TO I-90 CORRIDOR FOR THE LATE AFTERNOON EVENING...WITH
BETTER CHANCE STILL EXPECTED NEAR/NORTH OF THE BOUNDARY FROM SOUTH
CENTRAL SD...NORTHEASTWARD TOWARD EAST CENTRAL SD AND NORTHERN
PORTIONS OF OUR SOUTHWEST MN COUNTIES. AT THIS POINT THINK ACTIVITY
IN OUR AREA WILL BE MORE SPARSE GIVEN BETTER UPPER SUPPORT IS TO OUR
NORTHEAST...BUT DECENT HEATING INTO THE UPPER 80S-LOWER 90S...ALONG
WITH WEAK UPPER LEVEL FORCING WARRANTS LOW POPS THROUGH THE WESTERN
AND NORTHERN PARTS OF THE FORECAST AREA. WITH MID-UPPER LEVEL TEMPS
COOLING SLIGHTLY WITH PASSAGE OF THE WAVE...MID LEVEL LAPSE RATES
ARE FAVORABLE FOR SOME HAIL FROM PULSE STORMS. DRY MID LEVELS COULD
SUPPORT GUSTY WINDS AS WELL...WITH FORECAST SOUNDINGS INDICATING
DOWNDRAFT CAPE NEAR 1000J/KG IN THE LATE AFTERNOON/EARLY EVENING.
WILL HAVE A MENTION OF THIS IN THE HWO...BUT THINK THREAT OF STRONG
TO SEVERE STORMS IS RATHER ISOLATED. CONVECTION EXPECTED TO WIND
DOWN THROUGH THE EARLY-MID EVENING AS TEMPERATURES COOL AND ANY
UPPER SUPPORT SLIDES EAST...LEAVING DRY CONDITIONS OVERNIGHT INTO
EARLY FRIDAY WITH LOWS IN THE MID-UPPER 60S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 400 AM CDT THU AUG 13 2015
ON FRIDAY...THE LARGE UPPER RIDGE OF HIGH PRESSURE REMAINS CENTERED
ACROSS THE SOUTHERN AND CENTRAL ROCKIES...BECOMING ELONGATED IN A
POSITIVE TILT FROM NEAR THE FOUR CORNERS AREA TO MINNESOTA FRIDAY
NIGHT. AS A SHORT WAVE MOVES EASTWARD OVER THE RIDGE ON SATURDAY...
THE RIDGE FLATTENS SOMEWHAT BUT REMAINS BASICALLY IN THE SAME
LOCATION ON SATURDAY. THE RIDGE LOOKS TOO MUCH TO OVERCOME FOR TSRA
TO FORM FRIDAY...FRIDAY NIGHT AND SATURDAY SO LEFT CONDITIONS DRY.
IT WILL ALSO BE VERY WARM...WITH TEMPERATURES WELL ABOVE NORMAL. BUT
MODERATE HUMIDITY LEVELS WILL KEEP HEAT INDEX VALUES GENERALLY IN
THE 90S AND AWAY FROM READINGS OVER 100 DEGREES.
THE VARIOUS MODELS ARE IN GOOD AGREEMENT IN HOW THEY HANDLE THE
AFOREMENTIONED SHORT WAVE`S MOVEMENT EASTWARD SATURDAY NIGHT AND
SUNDAY...AND A SECOND SHORT WAVE ON ITS HEELS WHICH MOVES INTO OUR
AREA ON SUNDAY. AHEAD OF THE FIRST SHORT WAVE AND ASSOCIATED SURFACE
COLD FRONT...SOUTHERLY WINDS WILL BE QUITE BREEZY ON SATURDAY. THEN
BY 12Z SUNDAY...THE MODELS HAVE THE FIRST SHORT WAVE EXTENDING FROM
NEAR WINNIPEG SOUTHWARD ALONG THE I 29 CORRIDOR IN EASTERN ND...
FOLLOWED BY THE SECOND WAVE MOVING INTO CENTRAL ND TO NORTHWEST SD
BY 00Z MONDAY. THE MODELS HAVE ALSO FINALLY COALESCED AROUND THE
SURFACE FRONTAL TIMING ON SUNDAY...MOVING IT SLOWLY EASTWARD THROUGH
THE DAY...EXITING THE ZONES AROUND SIOUX CITY AND STORM LAKE BY
ABOUT 03Z TO 06Z MONDAY. WITH THE SURFACE FRONT ACTING AS A
FOCUS...SCATTERED THUNDERSTORMS SHOULD DEVELOP SATURDAY NIGHT AND
SUNDAY. BUT WITH A BULK OF THE SHORT WAVE DYNAMICS WITH THE FIRST
WAVE TO OUR NORTH...AND THE SECOND WAVE WELL TO OUR WEST...THERE IS
NOT ENOUGH EVIDENCE TO GO LIKELY POPS WITH NUMEROUS STORM COVERAGE.
THE CHANCES FOR SEVERE WEATHER WITH THESE STORMS SATURDAY NIGHT
AND/OR SUNDAY ARE PROBABLY FAIRLY REMOTE IN OUR FORECAST AREA. DEEP
LAYER WIND SHEAR IS NOT VERY STRONG AT ALL AHEAD OF THE FRONTAL
BOUNDARY...AND BOTH THE NAM AND GFS SHOW 0-6KM BULK WIND VECTORS ONLY
ON THE ORDER OF 15 TO 25 KNOTS AT 12Z SUNDAY. 1KM ML CAPE ALSO
RAPIDLY WANES IN OUR WESTERN ZONES AFTER 06Z SUNDAY...AND BECOMES
NEARLY NON EXISTENT BY 12Z SUNDAY. THAT SAID ELEVATED CAPE AROUND
850-800MB REMAINS IN PLACE THROUGH 12Z SUNDAY ALONG WITH DECENT
NEGATIVE LIFTED INDEX VALUES OF AROUND -4C AT 850MB ON A
YANKTON...TO SIOUX FALLS TO MARSHALL MN LINE. WIND SHEAR REMAINS
SUBDUED ON SUNDAY.
ANOTHER UPPER TROUGH IS FORECAST TO MOVE EASTWARD ACROSS THE WESTERN
U.S. STATES ON TUESDAY AND WEDNESDAY WITH THE GEM GLOBAL BEING A
FAST OUTLIER THIS TIME AROUND. THEREFORE A BLEND OF THE SLOWER ECMWF
AND THE 6-9 HOUR QUICKER GFS WAS PREFERRED. THEREFORE WITH THIS
UPPER TROUGH...TSRA CHANCES WILL BEGIN TO RAMP UP AGAIN IN THE
TUESDAY NIGHT AND WEDNESDAY PERIODS...WITH LITTLE TO NO CHANCES ON
MONDAY AND MONDAY NIGHT. CONCERNING TEMPERATURES...IT WILL BE
COOLER. AFTER SATURDAYS WARM READINGS...SUNDAYS HIGHS WILL BE A
MORE SEASONAL 80 TO 85...AND GENERALLY IN THE UPPER 70S TO MID 80S
REMAINING MONDAY THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1245 PM CDT THU AUG 13 2015
GENERALLY AM EXPECTING VFR FLIGHT CONDITIONS TO CONTINUE THROUGH
THE TAF PERIOD. EXCEPTIONS WOULD BE THE TYPICAL VISIBILITY DROP
DURING ANY CONVECTIVE DEVELOPMENT DURING THE LATER AFTERNOON AND
EARLY EVENING...BUT APPEARS AT THIS TIME AS IF PROSPECT AT THE TAF
SITES REMAINS BELOW A MENTIONABLE THRESHOLD. ALSO...WITH
PRECIPITATION AROUND KHON FROM TODAY MOISTENING UP THE BOUNDARY
LAYER AND THE LIKELIHOOD OF INCREASED STABILIZATION TONIGHT NEAR A
WEAK BOUNDARY...COULD SEE A BIT OF FOG DEVELOP. HAVE KEPT AS MVFR
FOR THE TIME...BUT WOULD NOT SAY THAT A BRIEF DIP TOWARD IFR IS
OUT OF THE QUESTION.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHAPMAN
SHORT TERM...JH
LONG TERM...MJ
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
306 PM CDT THU AUG 13 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 306 PM CDT THU AUG 13 2015
LATEST WATER VAPOR SATELLITE IMAGERY SHOWS WEAK SHORTWAVE TROUGH
OVER THE EASTERN DAKOTAS AND WESTERN MINNESOTA. LATEST MOSAIC
RADAR INDICATES SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS WESTERN/CENTRAL MINNESOTA AND SOUTHWEST/CENTRAL
WISCONSIN...THIS IS IN RESPONSE TO WEAK MOISTURE CONVERGENCE AT
925-850MB AND WEAK 850-700MB QG FORCING PER THE 13.15Z RAP.
MAIN FORECAST CONCERNS ARE SMALL PRECIPITATION CHANCES TONIGHT INTO
FRIDAY.
THE 13.12Z GFS/NAM ARE IN GOOD AGREEMENT MOVING WEAK SHORTWAVE
TROUGH SOUTHEAST ACROSS THE FORECAST AREA TONIGHT. THE 13.12Z
GFS/NAM SUGGEST WEAK MOISTURE CONVERGENCE/QG FORCING IN ASSOCIATION
WITH THE SHORTWAVE TROUGH...WITH THE BETTER FORCING AND MOISTURE
CONVERGENCE CONFINED OVER SOUTHERN WISCONSIN BY 06Z FRIDAY. IN
ADDITION...THE 13.15Z RAP AND 13.12Z NAM SHOW A CAP OVER THE
FORECAST AREA THIS EVENING...THIS WILL INHIBIT WIDESPREAD COVERAGE
OF SHOWER/THUNDERSTORM DEVELOPMENT. HAVE KEPT SMALL PRECIPITATION
CHANCES THROUGH 06Z...AND AFTER 06Z CONFINED PRECIPITATION CHANCES OVER
THE EXTREME SOUTHERN PART OF THE FORECAST AREA.
NEXT WEAK IMPULSE MOVES INTO EASTERN WISCONSIN AFTER 18Z FRIDAY.
THE 13.12Z GFS/NAM INDICATE BETTER MOISTURE CONVERGENCE AND
FORCING WITH THIS FEATURE OVER THE SOUTHERN AND EASTERN PARTS OF
WISCONSIN. CONFINED THE PRECIPITATION CHANCES MAINLY ALONG EAST OF
THE MISSISSIPPI RIVER AFTER 18Z FRIDAY.
WARM AIR FILTERING INTO THE FORECAST AREA WILL ALLOW HIGH
TEMPERATURES TO CLIMB ABOVE NORMAL INTO THE MIDDLE 80S TO
POSSIBLY THE LOWER 90S AT A FEW LOCATIONS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 306 PM CDT THU AUG 13 2015
UPPER LEVEL TROUGH OVER THE PACIFIC NORTHWEST FLATTENS RIDGE OVER
THE NORTHERN PLAINS AND BUILDS RIDGE AXIS INTO THE GREAT LAKES
REGION FRIDAY NIGHT INTO SATURDAY. THE 13.12Z GFS/NAM/ECMWF SUGGEST
925MB TEMPERATURES RISING TO PLUS 25 TO PLUS 28 DEGREES CELSIUS BY
00Z SUNDAY. TEMPERATURES WILL REMAIN ABOVE NORMAL FOR
SATURDAY...WITH TEMPERATURES RISING AGAIN INTO THE MIDDLE 80S TO
LOWER 90S.
FOCUS TURNS TO UPPER LEVEL TROUGH FLATTENING UPPER LEVEL RIDGE AND
DEVELOPING WEST TO EAST ZONAL FLOW ACROSS THE NORTHERN TIER STATES.
SURFACE FRONT WITH THE UPPER LEVEL TROUGH TRACKS INTO NORTHERN
WISCONSIN AND WESTERN IOWA BY 00Z MONDAY. SLIGHT DIFFERENCES IN
TIMING OF SURFACE FRONT WILL IMPACT WHEN THE BETTER MOISTURE
CONVERGENCE/QG FORCING TO MOVE OVER THE WESTERN HALF OF THE
FORECAST AREA AND THE POSSIBILITY OF SHOWER/THUNDERSTORMS. AT
THIS TIME...HAVE CONFINED PRECIPITATION CHANCES OVER THE NORTHWEST
SECTIONS OF THE FORECAST AREA.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES SUNDAY INTO
MONDAY...THEN TUESDAY NIGHT INTO THURSDAY. THE 13.12Z GFS/ECMWF/GEM
ARE IN GOOD AGREEMENT IN DEVELOPING WEST TO EAST ZONAL FLOW ACROSS
THE NORTHERN TIER STATES THROUGH 00Z WEDNESDAY AND AMPLIFY UPPER
LEVEL RIDGE OVER THE NORTHERN PLAINS WEDNESDAY INTO THURSDAY.
SURFACE FRONT/SHORTWAVE TROUGH TRACKS SOUTH AND EAST OF THE FORECAST
AREA MONDAY. DECENT LOW LEVEL MOISTURE CONVERGENCE AND LIFT ALONG
THE FRONT WILL PRODUCE SHOWERS/THUNDERSTORMS ACROSS THE FORECAST
AREA SUNDAY NIGHT INTO MONDAY. SURFACE RIDGE BUILDS INTO THE
FORECAST AREA MONDAY INTO TUESDAY. THEN...SIGNIFICANT DIFFERENCES
ARE INDICATED BETWEEN THE 13.12Z GFS/ECMWF WEDNESDAY INTO
THURSDAY...AS THE MODELS SHOW MAJOR DIFFERENCES IN TIMING OF THE
UPPER LEVEL TROUGH/LOW PUSHING INTO THE GREAT LAKES REGION WEDNESDAY
INTO THURSDAY. THIS HAS MAJOR IMPACTS ON PRECIPITATION CHANCES
TUESDAY NIGHT INTO THURSDAY. BASED ON THIS CONFIDENCE TUESDAY NIGHT
INTO THURSDAY IS LOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1236 PM CDT THU AUG 13 2015
SCATTERED SHOWERS AND STORMS WILL DEVELOP NEAR A BOUNDARY NORTH OF
INTERSTATE 90 THIS AFTERNOON AND SOUTH OF INTERSTATE 90 THIS
EVENING. WITH THE CHANCES 20 TO 30 PERCENT...OPTED NOT TO INCLUDE
THEM IN THE TAFS AT THIS TIME. THERE WILL BE SCATTERED TO BROKEN
DECK AT 5 TO 7K FEET WITH A BROKEN 12 TO 15K DECK ABOVE IT.
VISIBILITIES IN THE SHOWERS AND STORMS WILL BECOME IFR/MVFR.
OTHERWISE WE WILL SEE VFR VISIBILITIES. WITH DIURNAL HEATING...WEST
WINDS WILL GUST TO AROUND 20 KNOTS. THESE GUSTS WILL THEN
DISSIPATE AROUND 14.02Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...BOYNE
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 246 PM CDT THU AUG 13 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A RATHER
ILL-DEFINED SURFACE TROUGH POSITIONED OVER NORTHWEST WISCONSIN.
SHOWERS AND STORMS STARTED FIRING FURTHER EAST THOUGH...ALONG A 1-
2KM MOISTURE DISCONTINUITY...AND IN A REGION OF 800-1200 J/KG OF ML
CAPE. 0-6KM BULK SHEAR VALUES ARE AROUND 30 KTS...WHILE 0-3KM
HELICITY IS APPROX. 250...SO IT IS NOT UNREASONABLE TO THINK WE
COULD HAVE A FEW SEVERE STORMS LATER THIS AFTERNOON WITH FURTHER
DESTABILIZATION. CONDITIONS ARE FAIRLY QUIET UPSTREAM.
THUNDERSTORMS OVER MINNESOTA AND SOUTH DAKOTA WILL CONTINUE TO MOVE
SOUTHEAST WITH THE MEAN FLOW. THERE IS A SHORTWAVE OVER THE LAKE
WINNIPEG REGION THAT WILL ARRIVE TONIGHT...BUT THE ATMOSPHERE IS
MORE DRY IN THAT AREA. WITH A WARM AND MOIST AIRMASS POSITIONED
ACROSS THE REGION...SHOWER AND THUNDERSTORM POTENTIAL IS THE MAIN
FORECAST CONCERN.
TONIGHT...A FEW SHOWERS AND THUNDERSTORMS MAY BE ONGOING OVER
CENTRAL AND NORTHEAST WISCONSIN AT THE START OF THE EVENING...BUT
SHOULD DISSIPATE AS INSTABILITY IS LOST. WILL KEEP A SMALL CHANCE
IN THE FORECAST THROUGH MIDNIGHT. THEREAFTER...NOT MUCH TO HANG
YOUR HAT ON. WILL SEE A SHORTWAVE PUSH INTO THE UPPER PENINSULA
AFTER MIDNIGHT...WHERE A MID-LEVEL DEWPOINT GRADIENT IS PROJECTED TO
STALL OUT. HOWEVER...NOT MUCH IN THE WAY OF CLOUD COVER NEAR THE
SHORTWAVE OVER MANITOBA...AND AN UPSTREAM SOUNDING FROM INL IS VERY
DRY IN THE MID-LEVELS. THEREFORE...IT APPEARS POSSIBLE THAT THE
REST OF THE NIGHT WILL BE A DRY ONE AND WILL REMOVE PRECIP CHANCES.
MUGGY LOWS IN THE 60S.
FRIDAY...THINK THE QUIETER STRETCH OF WEATHER WILL CARRY OVER INTO
FRIDAY MORNING BEFORE CLOUDS BUILD WITH HEATING OF THE DAY...WITH
SOME ENHANCEMENT FROM A SHORTWAVE TROUGH OVERHEAD. PROJECTED ML
CAPES ARE VERY IMPRESSIVE OVER EASTERN WI (AROUND 3000 J/KG) IN THE
AFTERNOON WHERE LOCALIZED CONVERGENCE WILL TAKE PLACE VIA LAKE
BREEZE. WILL CONTINUE TO SHOW THE HIGHEST CHANCE OF PRECIP OVER THE
EAST. MARGINAL SEVERE STORMS WILL AGAIN BE POSSIBLE GIVEN THE
IMPRESSIVE INSTABILITY AND 0-6KM BULK SHEARS OF 25-30KTS. ANOTHER
HOT AND MUGGY DAY WITH HIGHS IN THE MID TO UPPER 80S.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 246 PM CDT THU AUG 13 2015
THE FOUR CORNERS TO GREAT LAKES UPR RDG IS STILL FCST TO WEAKEN
AND RETROGRADE TO THE SW CONUS THIS WEEKEND. THIS WOULD LEAVE THE
MAIN BAND OF WESTERLIES TO RUN ALONG THE NRN TIER OF STATES FOR
THE FIRST HALF OF NEXT WEEK WITH SEVERAL SYSTEMS TO IMPACT OUR
WEATHER. THE MAIN STORY FOR MID-WEEK WL BE THE MOVEMENT OF A
STRONG SHORTWAVE TROF TOWARD THE CNTRL CONUS AND DOWNSTREAM UPR
RIDGING OVER THE E-CNTRL CONUS. A SURGE OF WARMER/MORE MOIST AIR
INTO WI COULD LEAD TO ADDL PCPN CHCS. TEMPS WL BE WELL ABOVE
NORMAL THRU SUNDAY...FALL A TOUCH BELOW NORMAL MON-TUE AND BEGIN
TO WARM ABOVE NORMAL WED/THU.
CANNOT RULE OUT A FEW LINGERING SHWRS OR TSTMS OVER SRN SECTIONS
OF THE FCST AREA FRI EVENING AS THE CDFNT AND MID-LEVEL SHORTWAVE
TO STILL BE IN THE PROCESS OF EXITING THE REGION. OTHERWISE...
WEAK SFC HI PRES TO DRIFT INTO THE GREAT LAKES ALONG WITH BUILDING
UPR HEIGHTS AS THE NE EXTENT OF THE UPR RDG PUSHES INTO WI. SKIES
ARE EXPECTED TO BECOME MOSTLY CLEAR OVRNGT AND WITH WINDS BECOMING
LGT/VRBL...ANTICIPATE SOME LATE NGT FOG TO DEVELOPE AND HAVE ADDED
THIS POTENTIAL TO THE FCST. MIN TEMPS TO RANGE FROM THE MID TO UPR
50S NORTH...TO THE LWR TO MID 60S SOUTH.
THE UPR RDG AXIS REMAINS OVERHEAD THRU SAT...THEREBY INHIBITING
ANY CHC FOR TSTMS AS A SOLID CAP TO BE IN PLACE. 8H TEMPS IN THE
+20-+22C RANGE...COMBINED WITH MOSTLY SUNNY SKIES AND RELATIVELY
LIGHT WINDS...SHOULD BRING A VERY WARM AND HUMID DAY TO THE AREA.
LOOK FOR MAX TEMPS TO RANGE FROM THE LWR TO MID 80S NEAR LAKE MI
(LAKE BREEZE INFLUENCED)...TO THE MID 80S TO LWR 90S INLAND WITH
THE WARMEST TEMPS WEST OF THE FOX VALLEY. HEAT INDICES COULD REACH
THE UPR 80S TO MID 90S SAT AFTERNOON.
THE SFC HI SHIFTS EAST AND THE UPR RDG STARTS TO GET SUPPRESSED
SWD SAT NGT AS A MODEST SHORTWAVE TROF MOVES ALONG THE
U.S.-CANADIAN BORDER. A CDFNT ACCOMPANYING THIS SYSTEM IS FCST TO
REACH THE UPR MS VALLEY BY DAYBREAK...BUT BE TOO FAR AWAY TO BRING
ANY PCPN TO NE WI. ANTICIPATE ANOTHER MOSTLY CLEAR AND MUGGY NGT
WITH A LIGHT SOUTH WIND AND PERHAPS MORE PATCHY FOG. FOR THE MOST
PART...LOOK FOR MIN TEMPS TO END UP IN THE 65-70 DEG RANGE. EVEN
THO THE BETTER MID-LEVEL DYNAMICS ARE PROGGED TO LIFT E-NE INTO
ONTARIO ON SUNDAY...THE CDFNT WL CONT TO PUSH EWD AND IMPINGE ON
N-CNTRL WI BY LATE AFTERNOON. TEMPS ALOFT ARE STILL QUITE WARM ON
SUNDAY (8H TEMPS +18 TO +21C) AND MODELS ARE SHOWING THE MOISTURE
TRANSPORT TO RUN ALONG THE FNT...THUS HAVE CONTINUED THE TREND OF
ONLY MENTIONING A SMALL CHC POP FOR N-CNTRL WI DURING THE
AFTERNOON HOURS. THE REST OF NE WI WL SEE MOSTLY SUNNY TO PARTLY
CLOUDY SKIES AND ANOTHER VERY WARM/HUMID DAY. MAX TEMPS TO RANGE
FROM THE LWR TO MID 80S N-CNTRL WI...TO AROUND 90 DEGS ACROSS
E-CNTRL WI.
THE CDFNT IS FCST TO STRETCH FROM NE TO SW WI BY 12Z MON AND EXIT
E-CNTRL WI AROUND MIDDAY MON. INSTABILITY DOES WEAKEN SUNDAY NGT
AS THE FNT APPROACHES...HOWEVER NE WI TO RESIDE UNDER THE
FAVORABLE RIGHT ENTRANCE REGION OF THE UPR JET WHICH WL ONLY ADD
TO THE LIFT ALONG WITH THE CDFNT. HI CHC OR LIKELY POPS STILL
LOOK GOOD IN THE VCNTY OF THE FRONTAL BOUNDARY WITH THESE POPS
THEN SHIFTED SE ON MON. NRN WI SHOULD BE ABLE TO END THE PCPN CHCS
BY MON AFTERNOON AS THE FNT PULLS AWAY AND HI PRES STARTS TO
SETTLE SE TOWARD NRN SECTIONS OF THE GREAT LAKES. MAX TEMPS ON MON
WL BE VASTLY COOLER THAN PREVIOUS DAYS WITH CLOUDS/PCPN/CDFNT IN
THE AREA. READINGS TO RANGE FROM THE LWR TO MID 70S NORTH...MID TO
UPR 70S SOUTH.
DRIER CONDITIONS ARE THEN EXPECTED FOR MON NGT AND TUE AS THE SFC
HI TO RESIDE FROM ONTARIO TO THE NRN GREAT LAKES. MIN TEMPS MON
NGT COULD DROP INTO THE MID TO UPR 40S OVER PARTS OF N-CNTRL WI...
WHILE THE REST OF AREA WL SEE THE 50S. MAX TEMPS ON TUE WL BE
BELOW NORMAL WITH AROUND 70S DEGS LAKESIDE...LWR TO MID 70S NORTH
AND MID TO UPR 70S SOUTH.
A NEW AND STRONG-LOOKING SHORTWAVE TROF IS FCST TO MOVE FROM THE
PACIFIC NW TUE NGT TO THE NRN/CNTRL PLAINS BY NEXT THU. DOWNSTREAM
UPR RIDGING IS EXPECTED TO BRING AN INCREASING SOUTHERLY FLOW INTO
WI WITH AN UPTICK IN BOTH ISEN LIFT AND MOISTURE. IN ADDITION...
A WRMFNT IS PROGGED TO LIFT NWD TOWARD THE GREAT LAKES. WHILE
TIMING OF ALL THESE WEATHER ELEMENTS ARE STILL FAR FROM CERTAIN...
PCPN CHCS WL BE ON THE INCREASE TUE NGT THRU THU. MAX TEMPS AT
MID-WEEK ARE EXPECTED TO CLIMB TO AT OR ABOVE NORMAL LEVELS.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1210 PM CDT THU AUG 13 2015
MAINLY VFR CONDITIONS THROUGH THE TAF PERIOD BUT WITH A
COUPLE POTENTIAL PITFALLS. A WARM AND HUMID AIRMASS IS EXPECTED TO
CONTRIBUTE TO SCATTERED THUNDERSTORM DEVELOP THIS AFTERNOON.
COVERAGE AND TIMING REMAIN RELATIVELY UNCERTAIN...AND COVERAGE IS
EXPECTED TO BE SPARSE ENOUGH TO PRECLUDE A MENTION IN THE TAF
FORECAST. IF STORMS DO DEVELOP...GUSTY STRAIGHT LINE WINDS AND
SMALL HAIL WILL BE POSSIBLE. STORMS SHOULD DIMINISH FAIRLY QUICKLY
AFTER ABOUT 01-02Z THIS EVENING...LEAVING VFR CONDITIONS FOR THE
REMAINDER OF THE TAF PERIOD. SOME STORMS POSSIBLE AGAIN ON
FRIDAY AFTERNOON...PRIMARILY OVER EASTERN WISCONSIN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......AK
AVIATION.......MPC