Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/08/13
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
235 PM MST SAT JUL 6 2013
.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS.
&&
.SYNOPSIS...
HIGH PRESSURE WILL SLIGHTLY SHIFT TO THE SOUTHEAST THROUGH THIS
WEEKEND...BUT REMAIN SPRAWLED ACROSS THE ENTIRE REGION. MONSOON
ACTIVITY WILL LIKELY REMAIN CONFINED TO THE HIGHER TERRAIN EAST OF
PHOENIX THROUGH EARLY NEXT WEEK...WITH LITTLE CHANCE OF RAIN ACROSS
THE LOWER DESERTS. A GRADUAL RETURN TO A MORE FAVORABLE MONSOON
PATTERN IS POSSIBLE BY LATE NEXT WEEK.
&&
.DISCUSSION...
LATEST WV IMAGERY SHOWS A RELATIVELY TIGHT MOISTURE GRADIENT FROM
SOUTHERN CA TO CENTRAL AZ. STREAMLINE ANALYSIS ALSO SUGGESTS THE
PRESENCE OF A DIFFUSE MID-TROPOSPHERIC TROUGH ACROSS SW AZ AND
PERHAPS A WEAK VORT MAX NEAR THE MEXICAN BORDER. WEAK DIFFLUENCE IS
ALSO APPARENT WITH THE UPPER LEVEL ANTICYCLONE DISPLACED TO THE
EAST. ACROSS THE PHOENIX AREA...LATEST GPS-IPW AT TEMPE REGISTERED
NEAR 1.7 INCHES WHICH IS AROUND 150% OF NORMAL AND JUST ABOUT THE
HIGHEST IT HAS BEEN ALL SUMMER.
ISOLATED CONVECTION HAS INITIATED ACROSS THE MOUNTAINS OF PIMA
COUNTY...BUT VERTICAL DEVELOPMENT HAS BEEN HINDERED SO FAR THIS
AFTERNOON. WITH A DEEP LAYER SOUTHWESTERLY FLOW...ALBEIT AROUND 5
KT...CELLS WILL LIKELY PROPAGATE NORTHWARD THIS AFTERNOON INTO PINAL
AND SOUTHERN MARICOPA COUNTIES. LATEST KPHX AIRCRAFT SOUNDINGS ALSO
SHOW DEEP MOISTURE AND A LACK OF A CAPPING INVERSION WITH SBCAPE >
800 J/KG. SPC RAP CONTINUES TO SUGGEST THAT MLCAPE > 1000 J/KG WILL
BECOME WIDESPREAD ACROSS SOUTHERN AND EASTERN AZ THIS AFTERNOON.
POPS WERE INCREASED EARLIER TODAY FOR THIS AFTERNOON AND THIS
EVENING TO AROUND 20-30 PERCENT SOUTH OF A LINE FROM GILA BEND TO
GLOBE. THUNDERSTORM IMPACTS INCLUDING DOWNBURST WINDS AND BLOWING
DUST WILL ALSO BE HIGHER THAN NORMAL IN THESE AREAS.
&&
.PREVIOUS DISCUSSION...
UPPER FLOW CONTINUES WITH A WESTERLY COMPONENT SUNDAY THROUGH
TUESDAY...CONSEQUENTLY ANY STORMS THAT DEVELOP WILL LIKELY BE
TERRAIN FORCED AND WILL MOVE AWAY FROM THE DESERTS. POPS WERE
ALREADY IN THE SINGLE DIGITS THROUGH EARLY NEXT WEEK AND TODAYS 00Z
MODEL DATA SUPPORTS THIS THINKING. WITH WESTERLY FLOW WILL ALSO COME
SLIGHTLY DRIER AIR AND SLIGHTLY WARMER TEMPERATURES. I THINK ITS
CONCEIVABLE MOST DESERT LOCATIONS COULD BE BACK ABOVE THE 110 DEGREE
MARK FOR A FEW DAYS NEXT WEEK...ALTHOUGH NOT LOOKING AT EXCESSIVE
HEAT LEVELS. TEMPS WERE INCREASED SLIGHTLY FOR MONDAY AND TUESDAY
BASED ON BLENDED BIAS CORRECTED GUIDANCE.
YESTERDAY THE GFS AND EUROPEAN ADVERTISED AN EASTERLY WAVE MOVING
THROUGH NORTHERN MEXICO AND INTO ARIZONA WEDNESDAY/THURSDAY. TODAYS
MODELS ARE STILL HINTING AT A SIMILAR SOLUTION...PERHAPS MORE
THURSDAY/FRIDAY INSTEAD. GFS STILL LOOKS DRIER THAN THE
EUROPEAN...BUT THE OVERALL PATTERN LOOKS FAVORABLE FROM BOTH MODELS
AND GFS ENSEMBLE MEAN. POPS WERE RAISED SLIGHTLY FOR THURSDAY AND
FRIDAY BUT STILL TOO FAR IN ADVANCE TO BE CONCERNED ABOUT SEVERE
WEATHER POTENTIAL.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
ANTICIPATE THE BULK OF ANY SHOWER/THUNDERSTORM ACTIVITY TO BE NORTH
OF THE TERMINALS THIS AFTERNOON/EVENING...WITH LESSER ACTIVITY TO
THE SOUTH AND EAST. GIVEN THE WEAK SOUTH-SOUTHWESTERLY STEERING
FLOWS...STORMS COULD FORM/DRIFT OVER THE LOWER DESERTS NEAR KPHX
KIWA AND KSDL. EXPECT SCT-BKN CLOUD DECKS AT OR ABOVE 10KFT...LOCAL
CIGS DOWN TO 9KFT IN HEAVIER SHOWERS/THUNDERSTORMS. STRONGER STORMS
HAVE THE POTENTIAL TO PRODUCE GUSTY OUTFLOW WINDS UP TO 40KT AND MAY
REDUCE VISIBILITY DOWN TO LESS THAN 1SM FOR A PERIOD OF TIME IN
DENSE BLOWING DUST. AFTER 08Z...ANTICIPATE THAT WINDS WILL BECOME
LIGHT AND VARIABLE...FAVORING EAST-SOUTHEAST DIRECTIONS INTO SUNDAY
MORNING.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCT-BKN HIGH CLOUDS WILL AFFECT REGIONAL TERMINALS THROUGH THE TAF
PERIOD. SFC WINDS WILL GENERALLY FAVOR A SOUTHEASTERLY DIRECTION AT
KIPL...AND A SOUTHERLY DIRECTION AT KBLH...PERSISTING THROUGH THE
EVENING AND OVERNIGHT INTO SUNDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
THUNDERSTORM ACTIVITY WILL BE CONFINED TO THE HIGHER TERRAIN TO THE
NORTH AND EAST OF PHOENIX TUESDAY...WITH TEMPERATURES WARMING TO
110F ACROSS THE LOWER DESERTS. THUNDERSTORM ACTIVITY WILL THEN
GRADUALLY INCREASE ON WEDNESDAY THROUGH FRIDAY AS MOISTURE RAPIDLY
RETURNS TO THE REGION AND THE UPPER HIGH CENTER SHIFTS EASTWARD INTO
NEW MEXICO/COLORADO...WITH TEMPERATURES COOLING DOWN TO NEAR-NORMAL
VALUES BY FRIDAY. MINIMUM HUMIDITIES WILL HOVER IN THE LOW TO MID
TEENS THROUGH WEDNESDAY...RISING TO THE MID 20S BY FRIDAY. WINDS
WILL BE LOCALLY BREEZY DURING THE AFTERNOON AND EVENING HOURS
THROUGH THE FORECAST PERIOD...WITH DIRECTIONS FAVORING THE WEST.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...MEYERS
FIRE WEATHER...MEYERS/PERCHA
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
135 PM MST SAT JUL 6 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLIGHTLY SHIFT TO THE SOUTHEAST THROUGH THIS
WEEKEND...BUT REMAIN SPRAWLED ACROSS THE ENTIRE REGION. MONSOON
ACTIVITY WILL LIKELY REMAIN CONFINED TO THE HIGHER TERRAIN EAST OF
PHOENIX THROUGH EARLY NEXT WEEK...WITH LITTLE CHANCE OF RAIN ACROSS
THE LOWER DESERTS. A GRADUAL RETURN TO A MORE FAVORABLE MONSOON
PATTERN IS POSSIBLE BY LATE NEXT WEEK.
&&
.DISCUSSION...
LATEST WV IMAGERY SHOWS A RELATIVELY TIGHT MOISTURE GRADIENT FROM
SOUTHERN CA TO CENTRAL AZ. STREAMLINE ANALYSIS ALSO SUGGESTS THE
PRESENCE OF A DIFFUSE MID-TROPOSPHERIC TROUGH ACROSS SW AZ AND
PERHAPS A WEAK VORT MAX NEAR THE MEXICAN BORDER. WEAK DIFFLUENCE IS
ALSO APPARENT WITH THE UPPER LEVEL ANTICYCLONE DISPLACED TO THE EAST.
ACROSS THE PHOENIX AREA...LATEST GPS-IPW AT TEMPE REGISTERED NEAR
1.7 INCHES WHICH IS AROUND 150% OF NORMAL AND JUST ABOUT THE HIGHEST
IT HAS BEEN ALL SUMMER.
ISOLATED CONVECTION HAS INITIATED ACROSS THE MOUNTAINS OF PIMA
COUNTY...BUT VERTICAL DEVELOPMENT HAS BEEN HINDERED SO FAR THIS
AFTERNOON. WITH A DEEP LAYER SOUTHWESTERLY FLOW...ALBEIT AROUND 5
KT...CELLS WILL LIKELY PROPAGATE NORTHWARD THIS AFTERNOON INTO PINAL
AND SOUTHERN MARICOPA COUNTIES. LATEST KPHX AIRCRAFT SOUNDINGS ALSO
SHOW DEEP MOISTURE AND A LACK OF A CAPPING INVERSION WITH SBCAPE >
800 J/KG. SPC RAP CONTINUES TO SUGGEST THAT MLCAPE > 1000 J/KG WILL
BECOME WIDESPREAD ACROSS SOUTHERN AND EASTERN AZ THIS AFTERNOON.
POPS WERE INCREASED EARLIER TODAY FOR THIS AFTERNOON AND THIS
EVENING TO AROUND 20-30 PERCENT SOUTH OF A LINE FROM GILA BEND TO
GLOBE. THUNDERSTORM IMPACTS INCLUDING DOWNBURST WINDS AND BLOWING
DUST WILL ALSO BE HIGHER THAN NORMAL IN THESE AREAS.
&&
.PREVIOUS DISCUSSION...
UPPER FLOW CONTINUES WITH A WESTERLY COMPONENT SUNDAY THROUGH
TUESDAY...CONSEQUENTLY ANY STORMS THAT DEVELOP WILL LIKELY BE
TERRAIN FORCED AND WILL MOVE AWAY FROM THE DESERTS. POPS WERE
ALREADY IN THE SINGLE DIGITS THROUGH EARLY NEXT WEEK AND TODAYS 00Z
MODEL DATA SUPPORTS THIS THINKING. WITH WESTERLY FLOW WILL ALSO COME
SLIGHTLY DRIER AIR AND SLIGHTLY WARMER TEMPERATURES. I THINK ITS
CONCEIVABLE MOST DESERT LOCATIONS COULD BE BACK ABOVE THE 110 DEGREE
MARK FOR A FEW DAYS NEXT WEEK...ALTHOUGH NOT LOOKING AT EXCESSIVE
HEAT LEVELS. TEMPS WERE INCREASED SLIGHTLY FOR MONDAY AND TUESDAY
BASED ON BLENDED BIAS CORRECTED GUIDANCE.
YESTERDAY THE GFS AND EUROPEAN ADVERTISED AN EASTERLY WAVE MOVING
THROUGH NORTHERN MEXICO AND INTO ARIZONA WEDNESDAY/THURSDAY. TODAYS
MODELS ARE STILL HINTING AT A SIMILAR SOLUTION...PERHAPS MORE
THURSDAY/FRIDAY INSTEAD. GFS STILL LOOKS DRIER THAN THE
EUROPEAN...BUT THE OVERALL PATTERN LOOKS FAVORABLE FROM BOTH MODELS
AND GFS ENSEMBLE MEAN. POPS WERE RAISED SLIGHTLY FOR THURSDAY AND
FRIDAY BUT STILL TOO FAR IN ADVANCE TO BE CONCERNED ABOUT SEVERE
WEATHER POTENTIAL.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
SCT-BKN MID/HIGH CLOUDS WILL AFFECT CENTRAL ARIZONA SITES THROUGH
THE TAF PERIOD. EASTERLY WINDS WILL CONTINUE TO BLOW UNTIL MIDDAY OR
EARLY AFTERNOON SATURDAY...THEN SHIFT TO A WESTERLY DIRECTION BY MID
OR LATE AFTERNOON. THERE IS AN OUTSIDE CHANCE OF BLOWING DUST AT THE
TERMINALS AS OUTFLOWS FROM DISTANT THUNDERSTORMS MOVE INTO THE
PHOENIX AREA DURING THE LATE AFTERNOON OR EVENING HOURS ON
SATURDAY...BUT CONFIDENCE IS TOO LOW TO INCLUDE IN THE TAFS AT THIS
TIME.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
ONLY SCT-BKN HIGH CLOUDS WILL AFFECT SOUTHEAST CALIFORNIA TERMINALS
THROUGH THE TAF PERIOD. SFC WINDS WILL GENERALLY FAVOR A
SOUTHEASTERLY DIRECTION AT KIPL...AND A SOUTHERLY DIRECTION AT KBLH.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
THUNDERSTORM ACTIVITY WILL BE CONFINED TO THE HIGHER TERRAIN TO THE
NORTH AND EAST OF PHOENIX FROM MONDAY ONWARD INTO WEDNESDAY AS
SOMEWHAT DRIER AIR FILTERS IN FROM THE WEST...WITH TEMPERATURES
WARMING TO 110F...OR WARMER EACH DAY AT MOST LOWER DESERT LOCATIONS.
THUNDERSTORM ACTIVITY WILL THEN GRADUALLY INCREASE ON THURSDAY AND
FRIDAY AS MOISTURE WORKS ITS WAY BACK INTO THE REGION FROM THE SOUTH
AND SOUTHEAST AS THE UPPER HIGH CENTER SHIFTS EASTWARD INTO NEW
MEXICO/COLORADO...WITH TEMPERATURES COOLING DOWN TO NEAR-NORMAL
VALUES BY FRIDAY. MINIMUM HUMIDITIES IN THE LOW TO MID TEENS FROM
MONDAY THROUGH WEDNESDAY WILL RISE INTO THE UPPER TEENS TO MID 20S
BY FRIDAY. WINDS WILL BE LOCALLY BREEZY DURING THE AFTERNOON AND
EVENING HOURS THROUGH THE FORECAST PERIOD...WITH DIRECTIONS
FAVORING THE WEST.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...PERCHA
FIRE WEATHER...PERCHA
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
930 AM MDT SAT JUL 6 2013
.UPDATE...
&&
.SHORT TERM...THE WEAK WAVE WHICH CAME THROUGH THE FRONT RANGE
BEFORE DAWN HAS LEFT THE AREA WITH SOME SLIGHT DRYING AND
DOWNSLOPE FLOW. RESULTANT INTEGRATED PW VALUES FROM GPS HAS SHOWN
A DECREASE OF .20" IN THE PAST 3 HOURS. PLATTEVILLE PROFILER ALSO
SHOWING THIS SHIFT WITH NORTHWEST FLOW FROM NEAR SURFACE UP TO
550 MB. SURFACE DEWPOINTS ARE DOWN A BIT OVER THE FRONT RANGE BUT
REMAIN IN THE 50S OVER THE EASTERN PLAINS.
AS WITH THE PAST FEW DAYS OVERALL AIRMASS REMAINS MOIST BUT
STABILITY IS MARGINAL WITH SURFACE BASED CAPES UP TO 500J/KG OVER
PLAINS AND MAYBE UP TO 1000JKG OVER THE HIGHER TERRAIN OF
FOOTHILLS AND PALMER DIVIDE. AGAIN...BRIEF HEAVY RAIN AND GUSTY
WINDS LOOK TO BE THE MAIN OUTPUT FROM STORMS TODAY. GIVEN HIGH PW
VALUES CERTAINLY A FEW STORMS MAY PUT OUT A HALF INCH OF RAIN IN A
SHORT PERIOD OF TIME. SEVERE WEATHER THREAT QUITE LOW AGAIN WITH
RATHER WEAK SPEED/DIRECTIONAL SHEAR PROFILE AND LOW CAPE VALUES.
.AVIATION...SURFACE WINDS RATHER LIGHT/VARIABLE THIS AM BUT LIKELY
SHIFTING TO SOME SORT OF EAST/NORTHEAST DIRECTION BEFORE
CONVECTION BEGINS. EXPECT MORE ERRATIC WIND DIRECTIONS BY LATER
THIS AFTERNOON PENDING OUTFLOW FROM SHOWER DEVELOPMENT. LATEST
NAM/RUC ARE NOT TOO EXCITED ABOUT STORMS OVER THE TERMINALS AND
KEEP MOST OF THE PRECIP ANCHORED OVER TERRAIN WEST AND SOUTH OF
DENVER WHILE HRRR SEEMS OVER ZEALOUS IN STORMS OVER DENVER AREA.
CONSIDERING THE CURRENT DRYING WOULD FAVOR LATER DEVELOPMENT AND
MAYBE MORE ISOLATED. NOT SURE IF TEMP FOR TS TODAY IS TOO MUCH AND
WILL REEVALUATE FOR 18Z ISSUANCE.
&&
.PREV DISCUSSION... /ISSUED 416 AM MDT SAT JUL 6 2013/
SHORT TERM...A BAND OF THUNDERSTORMS MOVED ACROSS THE MOUNTAINS
EARLY THIS MORNING...ASSOCIATED WITH A WIND SHIFT THAT CAME OUT OF
YESTERDAYS UTAH CONVECTION. THE LAST BATCH OF SHOWERS ASSOCIATED
WITH THIS WILL LIKELY FADE OVER THE NEXT HOUR OR TWO AS IT MOVES
ONTO THE PLAINS...BUT WILL BRING A LITTLE RAIN JUST NORTH OF
DENVER AND SOME WIND OVER A LARGER AREA THROUGH SUNRISE.
PRECIPITABLE WATER AROUND 0.90 INCH IS ABOUT THE SAME AS THIS
TIME YESTERDAY...PERHAPS EVEN DOWN A LITTLE...BUT SURFACE DEW
POINTS ARE UP A COUPLE OF DEGREES. THIS MAY MAKE THE ENVIRONMENT A
LITTLE MORE FAVORABLE FOR THUNDERSTORM DEVELOPMENT TODAY. STILL
NOT A LOT OF INSTABILITY...AROUND 500 J/KG ACROSS MOST OF THE AREA
BUT POSSIBLY UP TO 1000 J/KG IF THE PLAINS WARM UP TO THE MID 90S
IN THE MIDDAY SUNSHINE...WHICH WILL PROBABLY HAPPEN.
WITHOUT MUCH SHEAR AND HIGH FREEZING LEVEL...SEVERE THREAT IS
PRETTY LOW. ONCE AGAIN CLOUDS WILL LINGER OVERNIGHT...BEST POPS
ON THE PLAINS IN THE EVENING THEN LOW POPS LATE. IT HAS BEEN HARD
TO KEEP TEMPERATURES BELOW 90 IN DENVER...I DID LOWER HIGHS
SLIGHTLY FOR THE CLOUD COVER...BUT STILL 90S MOST PLACES.
LONG TERM...SUNDAY AND MONDAY...THE MDLS KEEP THE UPPER RIDGE
STRETCHING FROM ARIZONA TO OKLAHOMA WITH A MODERATE WEST TO
SOUTHWESTERLY FLOW OVER THE CWFA. INTERACTIVE SOUNDINGS GENERALLY
KEEP PW VALUES IN THE 0.8-0.9 RANGE BOTH DAYS...CAPES DIFFER SOME
FM MODEL TO MODEL BUT GENERALLY IN THE 400-1400 J/KG RANGE...WITH
THE GREATEST INSTBY OVER THE NERN CORNER OF THE STATE. THE GFS IS
MUCH MORE GENEROUS WITH THE MOISTURE VS THE NAM...SO A MEAN OF THE
TWO (800-1000 J/KG) SEEMS LIKE THE BEST GUESS IN TERMS OF THE
INSTBY. BEST CHANCE COVERAGE WISE WILL BE OVER THE HIGHER TERRAIN
WITH GENERALLY CHC POPS OVER THE NORTHEASTERN PLAINS DURING THE
LATE AFTERNOON AND EVENING. STILL CANNOT RULE OUT THE POSSIBILITY
OF ONE OR TWO NOCTURNAL STORMS. THE RIDGE ITSELF IS PROGGED TO
BUILD NORTHWARD AND CENTER ITSELF OVER THE STATE TUESDAY THROUGH
FRIDAY. AS A RESULT...IT SHOULD BE A BIT HOTTER AND
DRIER...ESPECIALLY OVER THE WESTERN PORTION OF THE CWFA FOR THE
REMAINDER OF THE PERIOD. SOME SUBTROPICAL MOISTURE HOWEVER STILL
REMAINS UNDER THE RIDGE SO WL GENERALLY GO WITH SLGT CHC POPS AT
THAT TIME. THE GFS KEEPS BOUNDARY LAYER MOISTURE LINGERING OVER
THE NORTHEASTERN PLAINS WEDNESDAY BUT INCREASING SUBSIDENCE ALOFT
ASSOCIATED WITH THE RIDGE MAY HELP TO LIMIT DEEP CONVECTION BY
THAT TIME. STORM MOTION STILL AOA 15 KTS ON SUNDAY AND MONDAY...
WITH THE FLOW ALOFT WEAKENING AS THE RIDGE BUILDS OVER NERN CO FOR
THE REST OF THE PERIOD.
AVIATION...VFR CONDITIONS EXPECTED THROUGH TONIGHT. WINDS SHOULD
SHIFT TO THE NORTHEAST BEHIND THE EARLY MORNING SHOWERS AND EAST
TO NORTHEAST WINDS SHOULD PREVAIL TODAY...THOUGH AFTERNOON
THUNDERSTORMS MAY DISRUPT THE PATTERN. SCATTERED STORMS ARE
EXPECTED THIS AFTERNOON...STILL GENERALLY WEAK. THERE IS A SLIGHT
CHANCE OF GUSTY WINDS TO 40 KNOTS AND LOWERED CEILINGS REQUIRING
INSTRUMENT APPROACHES TO KDEN IN THE LATE AFTERNOON AND EARLY
EVENING.
HYDROLOGY...MODEL SOUNDINGS SHOW MEAN WIND DECREASING TO ABOUT 8
KNOTS THIS AFTERNOON. FAIRLY LINEAR WIND STRUCTURE WOULD SUPPORT
FORWARD PROPAGATION HOWEVER...AND THE OVERNIGHT STORMS HAVE BEEN
MOVING FASTER THAN THE MEAN WIND. BETWEEN THE WIND STRUCTURE AND
LIMITED CAPE NOT TOO WORRIED ABOUT A FLOOD THREAT...PERHAPS AN
INCH IN UNDER AN HOUR FROM A SLOW MOVING STORM SOMEWHERE BUT IN
GENERAL STORMS SHOULD BE MOVING AND NOT THAT STRONG. IF THERE WERE
BETTER LOW LEVEL INFLOW IT WOULD BE A DIFFERENT STORY...BUT NOT
TODAY. SO A LOW THREAT OF FLOODING IN THE BURN AREAS THIS
AFTERNOON AND NO THREAT ELSEWHERE.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM....COOPER
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
748 PM EDT SUN JUL 7 2013
.SYNOPSIS...
STRONG SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EVENING
PERIOD. THERE IS ANOTHER POSSIBILITY FOR STRONG STORMS AHEAD OF A
COLD FRONT PUSHING INTO THE REGION MONDAY. DISTURBED WEATHER WILL
CONTINUE THROUGH MOST OF THE WEEK...ALTHOUGH TEMPERATURES WILL
MODERATE BACK TO MORE SEASONABLE LEVELS. THERE IS THE POSSIBILITY
OF HOT AND HUMID CONDITIONS RETURNING NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
730 PM UPDATE...
EARLIER STRONG TO SEVERE THUNDERSTORMS HAVE LEFT A MULTITUDE OF
FINE-LINE OUTFLOW BOUNDARIES LENDING TO A STABLE PROFILE
CONTRADICTING THE LATEST SPC MESOANALYSIS. NEVERTHELESS...THE
APPROACH OF THE LONGWAVE TROUGH AXIS FROM THE OHIO RIVER VALLEY TO
THE EAST IS RESULTING IN INCREASING DIFFLUENCE ALOFT AND
CONSEQUENTIAL LIFT WEST OF THE REGION.
FOLLOWING CLOSELY WITH THE LATEST HRRR OUTPUT AND CONSIDER WHERE
THE BETTER DYNAMICS RESIDE WITHIN THE LONGWAVE FLOW PATTERN...
ANTICIPATE A CONTINUATION OF SHOWER AND THUNDERSTORM ACTIVITY
OVERNIGHT ACROSS NORTHERN AND WESTERN PORTIONS OF THE FORECAST
AREA. HAVE CHANCE TO LIKELY POPS ACCORDINGLY WITH THE BELIEF OF
THE MAIN THREATS BEING HEAVY RAIN AND LIGHTNING. SHOULD ANY STORMS
BECOME SUBSTANTIALLY LOFTED HIGH INTO THE ATMOSPHERE...THEN THERE
IS THE CHANCE THAT THE DROPPING CORE WILL LEAD TO LOCALIZED STRONG
TO DAMAGING WINDS AT THE SURFACE...THOUGH LOW CONFIDENCE ON THIS
OUTCOME PRESENTLY.
THOUGH COOLER AT THE SURFACE DUE TO EARLIER THUNDERSTORMS...THE
CONTINUED CLOUD COVER OVERNIGHT COUPLED WITH MODEST DEWPOINTS
ACROSS THE REGION AROUND THE UPPER 60S SHOULD RESULT IN LOW
TEMPERATURES DOWN INTO THE LOW 70S UNDER WEST-SOUTHWESTERLY FLOW.
FOG WILL BE AN ISSUE ALONG THE SOUTH COAST INTO THE MORNING. HAVE
GREATEST CONFIDENCE OF IMPACTS ACROSS INTERIOR PORTIONS OF CAPE
COD AS WELL AS NANTUCKET. VISIBILITIES AT TIMES COULD BE AS LOW AS
A QUARTER OF A MILE. AN INITIAL HINT OF SUCH AN IMPACT IS SEEN
PRESENTLY AT NANTUCKET AS CLOUDS JUST 200 FEET AGL ARE BEING
OBSERVED.
PREVIOUS DISCUSSION...
STRONG TO SEVERE THUNDERSTORMS CONTINUE ACROSS A MAJORITY OF THE
REGION AS SUBSTANTIAL INSTABILITY HAS OVER-COMPENSATED THE WEAK
SHEAR STILL OBSERVED ACROSS THE REGION.
TWO AREAS OF FOCUS...INSTABILITY AND SHEAR ACROSS THE WESTERN
INTERIOR...AND ALONG SEA-BREEZE BOUNDARIES PRESSING INTO THE
EASTERN AND SOUTHEASTERN COASTAL PLAINS.
IN SIMPLICITY...THESE STORMS HAVE THE POTENTIAL OF PRODUCING VERY
HEAVY RAINFALL POTENTIALLY LEADING TO LOCALIZED FLOODING...STRONG
TO DAMAGING WINDS...LARGE HAIL...AND LIGHTNING.
EXPECT STORMS TO CONTINUE INTO THE EVENING HOURS...GRADUALLY
DISSIPATING...WITH THE BETTER FOCUS OF WEATHER SHIFTING NORTH AND
WEST OF SOUTHERN NEW ENGLAND.
ANTICIPATING THE OVERNIGHT TO BE RELATIVELY QUIET AS INSTABILITY
DIMINISHES ACROSS THE REGION. WINDS BECOMING MORE SOUTHERLY
ALLOWING SEA-BREEZES TO WASH OUT. THERE IS THE POSSIBILITY FOR
DENSE FOG ALONG THE SOUTH-SHORE WITH VISIBILITIES DOWN TO A
QUARTER MILE OR LESS. REMAINING MILD WITH LOWS DOWN AROUND THE
UPPER 60S.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY INTO MONDAY NIGHT...
TROUGH WEAKENING AS IT LIFTS EAST ACROSS NEW ENGLAND THROUGH THE
PERIOD. WILL SEE INCREASING DIFFLUENCE ALOFT ALONG WITH A
FAVORABLE LEFT-EXIT REGION AS A SOUTH-TO-NORTH JET AXIS INCREASES
AT H3. MAIN LEAD IMPULSE THROUGH THE TROUGH PATTERN PUSHING
CYCLONICALLY AROUND THE TROUGH SHOULD ALSO AID IN ENHANCED ASCENT
ACROSS THE REGION. AND FINALLY AN ACCOMPANYING SURFACE COLD FRONT
WILL BE THE EMPHASIS OF LOCALIZED CONVERGENCE...APPROACHING
SOUTHERN NEW ENGLAND DURING THE DAY...SLOWING AS IT PUSHES INTO
SOUTHERN NEW ENGLAND AGAINST THE OFFSHORE RIDGE.
THE SYNOPTIC PATTERN ABOVE SUGGESTS DEEP-LAYER ASCENT ACROSS THE
REGION TO WHICH THE ENVIRONMENT WILL REMAIN PRIMED WITH DEEP-LAYER
MOISTURE AS DEWPOINTS RANGE AROUND THE LOW 70S. COLD POOL BUILDING
FROM THE WEST ALOFT COULD IMPROVE MID-LEVEL LAPSE RATES. THE MAIN
UNCERTAINTY IS WHETHER INSTABILITY WILL BE SIGNIFICANT OR RATHER
OVER-SHADOWED BY MID- TO UPPER-LEVEL CLOUD DEBRIS.
EVALUATING THE UPSTREAM PATTERN ACROSS THE MID-ATLANTIC TODAY...
HAVE A GREATER EXPECTATION THAT INSTABILITY WILL LIKELY GENERATE
WITH VALUES AROUND 1000 J/KG. WITH SOUTHWESTERLY UNI-DIRECTIONAL
SHEAR OF 30-35 KTS...ANTICIPATING MULTI-CELLULAR THUNDERSTORM
CLUSTERS WHICH WILL HAVE THE POTENTIAL TO BECOME SEVERE. THREATS
WITH THESE STORMS ARE SIMILAR AS TO TODAY...HEAVY RAIN ALONG WITH
THE POTENTIAL FOR FLASH FLOODING...STRONG TO DAMAGING WINDS...
LARGE HAIL...AND LIGHTNING. THOUGH CONFIDENCE IS LOW...THERE MAY
BE THE POSSIBILITY FOR AN ISOLATED TORNADO.
STILL SOME UNCERTAINTY ON EXACTLY WHERE AND WHEN ACTIVITY WILL
FIRST INITIATE. KEY IS WHEREVER THE SUN IS ABLE TO WARM THE
SURFACE SIGNIFICANTLY AND ALLOW FOR BOUNDARY LAYER DESTABILIZATION.
AGAIN...CLOUD DEBRIS IS LIKELY TO BE AN ISSUE.
SOME DISCREPANCIES WITH THE DETERMINISTIC FORECAST GUIDANCE.
HPC/WPC HAS GREATER CONFIDENCE WITH THE ECMWF OVER THE NAM/GFS
BOTH EXHIBIT A SLIGHTLY STRONGER TROUGH PATTERN AGAINST A DOMINANT
RIDGE ACROSS THE WESTERN ATLANTIC.
INTO THE EVENING PERIOD...THE COLD FRONT PUSHES SLOWLY THROUGH
SOUTHERN NEW ENGLAND. WET WEATHER ACTIVITY IS LIKELY TO LINGER
INTO THE EARLY EVENING PERIOD GRADUALLY DISSIPATING OVERNIGHT.
BEHIND THE FRONT ANTICIPATE A COOLER AND DRIER AIR MASS WITH
WEST-NORTHWESTERLY FLOW.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGHLIGHTS...
* WARM AND HUMID CONDITIONS CONTINUE THROUGH MOST OF THIS WEEK
* ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE TUE
* A BETTER CHANCE FOR MORE WIDESPREAD SHOWERS AND STORMS WED-THU
OVERVIEW AND MODEL PREFERENCES...
07/12Z MODEL GUIDANCE CONTINUES TO SHOW REASONABLY GOOD AGREEMENT
WITH THE LARGER SCALE PATTERNS...ALONG WITH TYPICAL DETAIL
DIFFERENCES TOWARD THE END OF THIS WEEK. MAINLY USED THE WPC
SOLUTION TO TWEAK THE EXTENDED WITH THE CONCERN FOR ISOLATED
SEVERE WEATHER TODAY. THIS SOLUTION RELIED UPON THE ECMWF
ENSEMBLE MEAN.
EXPECTING RIDGING OVER THE ATLANTIC TO BREAK DOWN THIS WEEK. THIS
WILL PERMIT A WEAK MID-LEVEL TROUGH TO MOVE OVER THE GREAT LAKES
LATE THIS WEEK. THERE IS SOME QUESTION AS TO HOW DEEP THIS TROUGH
GETS...AND IF IT MAY EVEN RESULT IN A CUTOFF LOW. THIS IS ONE OF
THE IMPORTANT DETAILS YET TO BE RESOLVED.
WHAT THIS ALL MEANS IS THAT THE ZONAL JET WHICH SETS UP NEAR OUR
REGION INITIALLY WILL GIVE WAY TO MORE DEEP SOUTHERLY FLOW IN
ADVANCE OF THE DEEPENING TROUGH TO THE WEST. THE PERIOD LOOKS TO
BE FAIRLY ACTIVE THROUGHOUT THANKS INITIALLY TO THE JET ITSELF AND
THE WEAKER SHORTWAVES THAT MOVE THROUGH IT. THEN A MUCH MORE
AMPLIFIED LOW PRES AND FRONTAL SYSTEM WILL AFFECT OUR REGION
LATE THIS WEEK...WITH THE POSSIBILITY OF MORE SHOWERS THIS WEEKEND
AS WAVES ROTATE OUT OF THE SOUTHERLY FLOW ALONG WHAT APPEARS TO
BE A STALLED COLD FRONTAL BOUNDARY OFFSHORE. CONFIDENCE IS QUITE
LOW REGARDING ANY OF THOSE POTENTIAL WEEKEND WAVES.
DETAILS...
TUESDAY...
THIS APPEARS TO BE THE /POTENTIALLY/ DRIEST PERIOD OF THE LONG
RANGE FORECAST. AFTER DIURNALLY DRIVEN CONVECTION WEAKENS MONDAY
NIGHT WITH LOSS OF INSTABILITY AND THE COOL FRONT SLIDING
OFFSHORE...MODELS INDICATE WEAK RIDGING BEHIND THE EXITING
SHORTWAVE FROM MON. STILL A BIT OF INSTABILITY LINGERING DURING
THE DAY...BUT WITH LACK OF ANY REAL FORCING. AS A RESULT MUCH OF
THE REGION MAY REMAIN DRY. TEMPERATURES AND DEW POINTS MAY BE A
BIT LOWER AS WELL BEHIND A COOL FRONT.
WEDNESDAY INTO THURSDAY...
DEEPENING WAVE TO THE WEST ALLOWS A STRONG /BY SUMMER STANDARDS/
LOW PRESSURE TO MOVE THROUGH ONTARIO AND QUEBEC. THIS LOW WILL DRAG
A WARM FRONT THROUGH THE REGION LATE WEDNESDAY AND WEDNESDAY NIGHT.
WILL NEED TO WATCH FOR GREATER CHANCES OF AFTERNOON CONVECTION
GIVEN DECENT INSTABILITY FROM SOUTHWEST RETURN FLOW AND LOW LEVEL
WARM ADVECTION BENEATH COOLING MID-LEVEL TEMPERATURES. THESE
FRONTS ARE ALSO TYPICALLY COINCIDENT WITH SOME LOW TO MID LEVEL
SHEAR. WILL CARRY CHANCE POPS FOR THUNDERSTORMS WITH THE POTENTIAL
ONCE AGAIN OR HEAVY RAIN GIVEN HIGH MOISTURE CONTENT.
ON THURSDAY THERE IS A BIT OF A QUESTION ON HOW QUICKLY A COLD
FRONT APPROACHES FROM THE WEST...WHICH WILL ULTIMATELY BE
DETERMINED BY THE AMPLITUDE OF THE MID LEVEL FLOW. USING THE
ECENS/GEFS BLEND SUGGEST SOME TIME SPENT WITHIN THE WARM SECTOR
THURSDAY. THIS WOULD LEAD TO ANOTHER ROUND OF AFTERNOON/EVENING
SHOWERS AND THUNDERSTORMS. WILL CONTINUE WITH CHANCE POPS FOR
THAT POSSIBILITY.
FRIDAY AND THIS WEEKEND...WITH GUIDANCE AT THE VERY LEAST
AGREEING THAT A COLD FRONT WILL SLOW SOMEWHAT FRIDAY AND FRIDAY
NIGHT...EXPECT AT LEAST THE POSSIBILITY FOR SOME MORE WET WEATHER
DURING THE DAY FRIDAY. WHAT HAPPENS FOR THIS WEEKEND WILL BE
DEPENDENT ON HOW CLOSE THIS FRONT STALLS TO OUR SOUTH AND EAST AS
WELL AS THE ABILITY FOR WEAK WAVES OF LOW PRESSURE TO ACT UPON IT.
HIGH PRESSURE TO THE EAST MAY VERY WELL RESULT IN THIS FRONT
WASHING OUR OVER THIS WEEKEND. THERE MAY STILL BE ENOUGH OF THIS
BOUNDARY LEFT TO PROVIDE A FOCUS FOR SHOWERS AND THUNDERSTORMS
EARLY THIS WEEKEND.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM /INTO MONDAY NIGHT/...MODERATE CONFIDENCE.
00Z UPDATE...
SHOULD BE A QUIET NIGHT FOR MAJORITY OF TERMINALS. GREATEST
CONFIDENCE OF CONTINUING SHRA/TSRA IS ACROSS NORTHERN AND WESTERN
PORTIONS OF MASSACHUSETTS INCLUDING SOUTHERN NEW HAMPSHIRE. HAVE
PREVAILED WITH VCSH FOR NOW. W/SW FLOW PREVAILING BECOMING LIGHT
TOWARDS THE MORNING HOURS. THIS WILL ALLOW DENSE FOG TO BECOME AN
ISSUE FOR THE SOUTH-SHORE TERMINALS INTO MORNING. GREATEST
CONFIDENCE OF IMPACTS DOWN TO A HALF MILE OR LESS ARE ACROSS
INTERIOR PORTIONS OF THE CAPE AS WELL AS NANTUCKET. FOG SHOULD
LIFT QUICKLY IN THE MORNING AS W/SW FLOW INCREASES.
DURING THE DAY MONDAY...A COLD FRONT WILL APPROACH FROM THE WEST
GRADUALLY WITH TIME. ANTICIPATING SHRA/TSRA AHEAD OF THE FRONT
WITH POTENTIAL IMPACTS OF LOW-VFR/MVFR CIGS AND MVFR-IFR VSBYS.
SOME OF THESE STORMS COULD BECOME SEVERE WITH POTENTIAL THREATS OF
HAIL...STRONG TO DAMAGING WINDS...AND HEAVY RAIN WITH LIGHTNING.
SOUTHWEST WINDS PREVAIL AHEAD OF THE FRONT...BACKING OUT OF THE
NORTHWEST WITH PASSAGE. STILL SOME UNCERTAINTY ON EXACT TIMING OF
THE FRONT AND PARENT THREATS...BUT FEEL TRENDS ARE SUCCINCT. HAVE
INSERTED VCTS FOR NOW...LIKELY TO BE AMENDED AS THREATS
MATERIALIZE.
KBOS AND KBDL TERMINALS...MODERATE CONFIDENCE IN TAF. WITH
CERTAINTY ON TRENDS BUT LOW CONFIDENCE ON TIMING SPECIFICS. HAVE
VCTS MENTION FOR THE MONDAY AFTERNOON PERIOD.
OUTLOOK...TUESDAY THROUGH FRIDAY...
CONTINUED HIGH CONFIDENCE IN OVERALL TRENDS BUT LOWER CONFIDENCE
IN EXACT TIMING OF ANY LOWER CATEGORIES THROUGH THE PERIOD.
MAINLY VFR IS EXPECTED UNTIL AT LEAST WEDNESDAY. THE ONLY CAVEATS
WILL BE THE THREAT FOR OVERNIGHT MVFR/IFR CONDITIONS IN LOCALIZED
FOG AND AN OCCASIONAL MVFR VSBY/CIG IN ISOLATED SHOWERS/T-STORMS
DURING THE AFTERNOONS/EVENINGS. THESE WILL BE VERY LOCALIZED AND
ARE NOT EXPECTED TO AFFECT ALL AIRPORTS.
A STRONGER SYSTEM MAY ALLOW FOR MORE WIDESPREAD MVFR/IFR
CONDITIONS WEDNESDAY INTO THURSDAY WITH MORE WIDESPREAD FOG AND
POTENTIAL FOR RAINFALL. THESE CONDITIONS LIKELY TO LINGER INTO
FRIDAY AS A COLD FRONT APPROACHES FROM THE WEST.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM /INTO SUNDAY NIGHT/...HIGH CONFIDENCE.
WINDS AND SEAS SHOULD REMAIN BELOW SCA THRESHOLDS THROUGH MONDAY.
ALONG THE NEAR-SHORE...EASTERLY FLOW WITH A SEA-BREEZE SHOULD WASH
OUT INTO THIS EVENING WITH WEST-SOUTHWEST WINDS LIKELY. OVERNIGHT
TONIGHT...FOG MAY BE LOCALLY DENSE AT TIMES WITH VISIBILITIES
DOWN TO A QUARTER MILE OR LESS ALONG THE SOUTH-SHORE...MODERATE
CONFIDENCE.
WEST-SOUTHWEST WINDS WILL PERSIST AHEAD OF AN APPROACHING COLD
FRONT FOR LATE MONDAY. COMBINED WITH LINGERING SWELL...SEAS WILL
BUILD ON THE SOUTHERN OUTER WATERS IN EXCESS OF 5 FEET. SHOWERS
AND THUNDERSTORMS ARE ANTICIPATED AHEAD OF THE COLD FRONT...
POSSIBLY SEVERE WITH WIND GUSTS IN EXCESS OF GALE FORCE.
OUTLOOK...TUESDAY THROUGH FRIDAY...
MODERATE CONFIDENCE THROUGH THE PERIOD.
THROUGH EARLY WEDNESDAY...CONDITIONS GENERALLY REMAIN BELOW
SMALL CRAFT THRESHOLDS THROUGH THE PERIOD SAVE FOR EARLY
TUESDAY...WHEN PERSISTENT SW WINDS AND A BUILDING SWELL MAY ALLOW
FOR SEAS TO REACH ABOUT 5 FT ACROSS THE OUTER COASTAL WATERS SOUTH
AND SOUTHEAST OF NEW ENGLAND.
LATE WEDNESDAY INTO FRIDAY...A STRONGER LOW PRESSURE WILL PASS
WELL N AND W OF THE WATERS. HOWEVER...SW WINDS WILL INCREASE AND
MAY REACH 25 KT AT TIMES. SEAS SHOULD BUILD THROUGH THIS PERIOD.
THE BEST CHANCE FOR 5 FOOT PLUS SEAS WILL BE ACROSS THE OCEAN
WATERS AND NEARSHORE WATERS SOUTH OF RI AND THE ISLANDS. SMALL
CRAFT ADVISORIES MAY BE NEEDED.
&&
.CLIMATE...
HERE ARE RECORD HIGHS FOR SOUTHERN NEW ENGLANDS OFFICIAL CLIMATE
SITES FOR JULY 7TH THROUGH THE 10TH
BOS PVD ORH BDL
7TH 99/1953 97/1993* 100/2010 95/1908
8TH 99/1937 99/1981 97/1993 97/1936*
9TH 99/1981* 99/1981 99/1936* 96/1937
10TH 101/1880 100/1993 100/1936* 95/1936*
* AND PREVIOUS YEARS
ALSO...SINCE WE ARE LOOKING AT AN EXTENDED PERIOD OF TEMPERATURES
ABOVE 90 DEGREES...HERE ARE THE LONGEST HEAT WAVES IN THE HISTORY
OF OUR 4 CLIMATE SITES.
HARTFORD/BRADLEY
JULY 24-AUGUST 2, 1995 - 10 DAYS
AUGUST 11-19, 2002 - 9 DAYS
AUGUST 27-SEPTEMBER 4, 1973 - 9 DAYS
JULY 27-AUGUST 3, 2006 - 8 DAYS
JULY 29-AUGUST 5, 2002 - 8 DAYS
JULY 16-23, 1991 - 8 DAYS
JULY 24-31, 1970 - 8 DAYS
AUGUST 28-SEPTEMBER 4, 1953 - 8 DAYS
AUGUST 10-17, 1944 - 8 DAYS
WORCESTER/AIRPORT
AUGUST 10-17, 1944 - 8 DAYS
JULY 4-11, 1912 - 8 DAYS
JUNE 26-JULY 3, 1901 - 8 DAYS
AUGUST 10-15, 1988 - 6 DAYS
JULY 25-29, 1963 - 5 DAYS
BOSTON/LOGAN AIRPORT
JULY 3-11, 1912 - 9 DAYS
AUGUST 11-18, 2002 - 8 DAYS
JULY 19-26, 1994 - 8 DAYS
AUGUST 10-17, 1944 - 8 DAYS
JUNE 28-JULY 5, 1872 - 8 DAYS
PROVIDENCE/T.F. GREEN
JULY 12-20, 1952 - 9 DAYS
JULY 28-AUGUST 3, 2006 - 7 DAYS
AUGUST 13-19, 2002 - 7 DAYS
JULY 15-21, 1977 - 7 DAYS
AUGUST 11-17, 1944 - 7 DAYS
JULY 7-13, 1944 - 7 DAYS
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SIPPRELL/BELK
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...BELK
AVIATION...SIPPRELL/BELK
MARINE...SIPPRELL/BELK
CLIMATE...STAFF
AREA FORECAST DISCUSSION
NWS ALBANY NY
725 PM EDT SUN JUL 7 2013
.SYNOPSIS...
THE BERMUDA HIGH WILL BEGIN TO WEAKEN AND MOVE A LITTLE FURTHER
SOUTHEAST THROUGH THIS AFTERNOON. THIS WILL ALLOW MOISTURE TO
MOVE BACK INTO THE REGION...INCREASING THE RISK OF SHOWERS AND
THUNDERSTORMS. TONIGHT INTO MONDAY...AN UPPER LEVEL DISTURBANCE
WILL MOVE BACK INTO FROM THE OHIO VALLEY...KEEPING OUR WEATHER
UNSETTLED.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE MAINLY IN THE WESTERN
MOHAWK VALLEY..SCHOHARIE VALLEY AND CAPITAL DISTRICT. LOCALLY
HEAVY RAIN IS PROMPTING SOME URBAN AND SMALL STREAM FLOOD
ADVISORIES...AND CHECKING CLOSELY FOR ANY POSSIBLE UPGRADES TO
FLASH FLOOD WARNINGS IF SOME OF THE THUNDERSTORMS PERSIST OVER
SOME AREAS. THE LATEST HRRR SUGGESTS ACTIVITY COULD PERSIST OVER
THE REGION INTO THE EARLY MORNING HOURS. SOME ADJUSTMENTS TO THE
RAIN CHANCES AND TEMPERATURES THROUGH THIS EVENING BASED ON
CURRENT OBSERVATIONS AND TRENDS OTHERWISE FEW OTHER CHANGES.
PREV AFD BELOW...
LOTS OF INSTABILITY SUPPORTING THE THUNDERSTORMS IN THE MID HUDSON
VALLEY...BERKSHIRES AND NW CT. THESE STORMS WILL PERIODICALLY PULSE
TO AROUND SEVERE LEVELS INTO THE EVENING AS THEY BUILD SOUTH AND
EAST THROUGH THE EVENING. WEAKER ACTIVITY IN THE WESTERN MOHAWK
VALLEY AND SCHOHARIE VALLEY EASTWARD THROUGH THE LAKE GEORGE
SARATOGA REGION...CAPITAL DISTRICT...SOUTHERN VT AND NORTHERN
BERKSHIRES SHOULD REMAIN WEAKER THAN THE SOUTHERN STORMS AS HEAT
AND INSTABILITY IS CUT OFF. STILL SOME SCATTERED WEAKER SHOWERS
AND THUNDERSTORMS INTO THIS EVENING FOR THOSE AREAS.
ACTIVITY SHOULD DECREASE LATE THIS EVENING AND OVERNIGHT BUT A
LOT OF CONVECTIVE DEBRIS CLOUDINESS SHOULD LINGER THROUGH THE
NIGHT ALONG WITH PATCHY FOG. UPPER SYSTEM IN OH VALLEY SHOULD
CONTINUE TO APPROACH WITH NEW SCATTERED SHOWERS AND THUNDERSTORMS
AFFECTING WESTERN AREAS AROUND SUNRISE. LOWS IN THE 60S TO AROUND
70.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
UPPER ENERGY TRACKS ACROSS THE REGION THROUGH TOMORROW NIGHT...SO
MORE SHOWERS AND THUNDERSTORMS WITH BETTER COVERAGE TOMORROW
AFTERNOON. WITH SUNSHINE A BIT LIMITED...HIGHS IN THE 80S MOST
AREAS...SOME UPPER 70S SOUTHERN ADIRONDACKS AND NEAR 90 MID HUDSON
VALLEY AND NW CT. NO FLASH FLOOD WATCH UNTIL WE GET A BETTER IDEA
OF HOW WIDESPREAD THE CONVECTION WILL BE TOMORROW. WILL HIGHLIGHT
ISOLATED FLASH FLOOD POTENTIAL FOR TOMORROW IN THE HAZARDOUS
WEATHER OUTLOOK...AND A WATCH COULD BE ISSUED TONIGHT IF
NECESSARY.
DECENT CONSENSUS FOR THE SYSTEM TO EXIT MONDAY EVENING AND
OVERNIGHT...SUGGESTING ANY SHOWER OR THUNDERSTORM ACTIVITY SHOULD
DECREASE IN COVERAGE TO ISOLATED THROUGH MONDAY NIGHT. SOME
SCATTERED ACTIVITY COULD LINGER IN WESTERN NEW ENGLAND THROUGH THE
NIGHT...THOUGH. LOWS IN THE 60S TO NEAR 70...SINCE THE WEAK COLD
FRONT THAT SHOULD TRACK THROUGH SHOULD NOT HAVE MUCH COOLING OR
DRYING BEHIND IT.
FLAT UPPER RIDGING BUILDS INTO THE REGION TUESDAY WHILE A NORTHERN
STREAM UPPER IMPULSE BEGINS TO DROP OUT OF CANADA TOWARD OUR
REGION TUESDAY NIGHT AND WEDNESDAY. STILL...WARM HUMID ATMOSPHERE
TUESDAY AFTERNOON COULD SUPPORT ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS...BUT MUCH LESS COVERAGE THAN ON MONDAY SINCE THERE
SHOULD BE NO LOW LEVEL FOCUS TO TRIGGER OR SUPPORT WIDESPREAD
ACTIVITY AND NO UPPER DYNAMICS. HIGHS TUESDAY WELL INTO THE 80S TO
NEAR 90 WITH INTERVALS OF CLOUDS AND SUN.
A STRONGER COLD FRONT ASSOCIATED WITH RELATIVELY STRONG UPPER
DYNAMICS DROPPING OUT OF CANADA COULD SUPPORT MORE ORGANIZED AND
WIDESPREAD SHOWERS AND THUNDERSTORMS BY WEDNESDAY AFTERNOON. WITH
INTERVALS OF CLOUDS AND SUN AT LEAST WEDNESDAY MORNING...HIGHS
SHOULD GET WELL INTO THE 80S TO AROUND 90 AGAIN. WILL HAVE TO
MONITOR SEVERE AND FLASH FLOOD POTENTIAL WITH THE POTENTIAL FOR
ORGANIZED STRONG THUNDERSTORMS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THIS WILL BE A PERIOD OF NEAR NORMAL TEMPERATURES WITH GARDEN
VARIETY SHOWERS AND/OR THUNDERSTORMS EACH DAY...WITH LESSER CHANCES
FROM THURSDAY NIGHT THROUGH FRIDAY NIGHT. A COLD FRONT MOVES
THROUGH THE AREA DURING THE EARLIEST PART OF THE EXTENDED
PERIOD...STALLING OUT ALONG THE EAST COAST DURING THE WEEKEND.
WITHOUT MUCH DRIER AIR BEHIND IT...THE CHANCE OF SHOWERS WILL MORE
OR LESS PERSIST.
DAYTIME HIGH TEMPERATURES WILL RANGE FROM THE LOWER 70S TO THE LOWER
OR MID 80S EACH DAY. THERE WILL BE A MORE NOTICEABLE CHANGE WITH
THE OVERNIGHT LOWS IN ASSOCIATION WITH THURSDAY NIGHT/S COLD FRONTAL
PASSAGE. LOWS WILL RANGE FROM THE LOWER 60S TO LOWER 70S THURSDAY
NIGHT. THEREAFTER THROUGH THE REMAINDER OF THE EXTENDED...LOWS WILL
BE MAINLY FROM THE MID 50S TO MID 60S.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
COMBINATION OF A MOIST SOUTHERLY FLOW OF AIR AHEAD OF AN UPPER LEVEL
LOW OVER THE STATE OF OHIO WILL CONTINUE WITH THE UNSETTLED
CONDITIONS THROUGH THIS TAF FORECAST PERIOD. THIS WILL KEEP THE
COMBINATION VFR/MVFR CONDITIONS ALONG WITH A LOW PROBABILITY OF
WHERE/WHEN SHOWERS AND THUNDERSTORMS WILL OCCUR. GIVEN CURRENT
RADAR TRENDS...WE WILL KEEP TEMPO GROUPS THROUGH THE EVENING HOURS
FOR THE TAF SITES AND TAPER THE PROBABILITIES OVERNIGHT. THERE IS A
GOOD CHANCE FOR BR AND/IR MIFG FORMATION OVERNIGHT ESPECIALLY WHERE
PRECIP HAS ALREADY OCCURRED.
CONDITIONS DO NOT CHANGE TOO MUCH ON MONDAY AS THE UPPER LOW IS
CLOSER AND THE CHANCE FOR ADDITIONAL SHOWERS/THUNDERSTORMS WITH A
COMBINATION OF VFR/MVFR CONDITIONS...WITH MOST OF THE DAYLIGHT HOURS
EXPECTED TO REMAIN VFR.
WINDS WILL BE LIGHT AND VARIABLE TONIGHT WITH A TREND FROM THE
WEST-SOUTHWEST DIRECTION DURING MONDAY AT SPEEDS LESS THAN 10KTS.
OUTLOOK...
TUE...MAINLY VFR. SCT -SHRA/-TSRA.
WED...VFR/MVFR/IFR DUE TO SCT TO NUM -SHRA/-TSRA.
THU-FRI...MAINLY VFR. SCT PM -SHRA/-TSRA.
MVFR/IFR OVERNIGHT FOG POSSIBLE TUE-FRI.
&&
.FIRE WEATHER...
NO FIRE WEATHER ISSUES ARE EXPECTED OVER THE NEXT SEVERAL DAYS.
MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE EACH AFTERNOON FOR THE
NEXT SEVERAL DAYS.
NORMAL RH RECOVERIES EACH NIGHT BETWEEN 80 TO 100 PERCENT WILL ALLOW
FOR WIDESPREAD DEW FORMATION. DAYTIME RH VALUES WILL GENERALLY BE IN
THE 40 TO 60 PERCENT RANGE.
&&
.HYDROLOGY...
THE MOHAWK RIVER AT UTICA CONTINUES TO EXPERIENCE MINOR FLOODING.
THE RIVER AND CREEK FLOWS NEAR THE WEST CENTRAL MOHAWK RIVER ARE
EXPECTED TO GRADUALLY RECEDE INTO THE WEEKEND...UNLESS ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS OCCUR OVER OR NEAR THE BASIN.
THERE WILL BE SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY DURING
THE AFTERNOON AND EVEN MORE COVERAGE OF SHOWERS AND THUNDERSTORMS
MONDAY WITH THE APPROACH OF A WEAK COLD FRONT AND UPPER AIR LOW
PRESSURE SYSTEM. A MOIST AND HUMID AIR MASS WILL ALLOW ANY SHOWER OR
THUNDERSTORM TO BE CAPABLE OF PRODUCING LOCALLY HEAVY
DOWNPOURS...AND A QUICK INCH OR MORE OF RAINFALL DUE TO THE
ANOMALOUS PRECIPITABLE WATER VALUES THIS EVENING AND AGAIN ON
MONDAY.
THERE WILL BE A CONTINUED THREAT FOR ISOLATED FLASH FLOODING...AS
WELL AS FLOODING OF POOR DRAINAGE AND LOW LYING AREAS. NO FLASH
FLOOD WATCHES ARE BEING ISSUED DUE TO THE EXPECTED ISOLATED NATURE
OF ANY FLOODING. IT IS ALSO DIFFICULT TO DETERMINE WHERE THE
HEAVIEST RAINFALL WILL OCCUR.
WHILE ADDITIONAL FLOODING IS NOT ANTICIPATED ON ANY MAIN STEM RIVER
POINTS...LOCALLY SHARP RISES ARE POSSIBLE DUE TO ANY CONVECTION THAT
MAY OCCUR OVER THE NEXT SEVERAL DAYS...ESPECIALLY FOR THOSE POINTS
THAT ARE MORE FLASHIER IN NATURE.
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...NAS
NEAR TERM...NAS
SHORT TERM...NAS
LONG TERM...ELH
AVIATION...BGM
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
716 PM EDT SUN JUL 7 2013
.SYNOPSIS...
THE BERMUDA HIGH WILL BEGIN TO WEAKEN AND MOVE A LITTLE FURTHER
SOUTHEAST THROUGH THIS AFTERNOON. THIS WILL ALLOW MOISTURE TO
MOVE BACK INTO THE REGION...INCREASING THE RISK OF SHOWERS AND
THUNDERSTORMS. TONIGHT INTO MONDAY...AN UPPER LEVEL DISTURBANCE
WILL MOVE BACK INTO FROM THE OHIO VALLEY...KEEPING OUR WEATHER
UNSETTLED.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE MAINLY IN THE WESTERN
MOHAWK VALLEY..SCHOHARIE VALLEY AND CAPITAL DISTRICT. LOCALLY
HEAVY RAIN IS PROMPTING SOME URBAN AND SMALL STREAM FLOOD
ADVISORIES...AND CHECKING CLOSELY FOR ANY POSSIBLE UPGRADES TO
FLASH FLOOD WARNINGS IF SOME OF THE THUNDERSTORMS PERSIST OVER
SOME AREAS. THE LATEST HRRR SUGGESTS ACTIVITY COULD PERSIST OVER
THE REGION INTO THE EARLY MORNING HOURS. SOME ADJUSTMENTS TO THE
RAIN CHANCES AND TEMPERATUTRES THROUGH THIS EVENING BASED ON
CURRENT OBSERVATIONS AND TRENDS OTHERWISE FEW OTHER CHANGES.
PREV AFD BELOW...
LOTS OF INSTABILITY SUPPORTING THE THUNDERSTORMS IN THE MID HUDSON
VALLEY...BERKSHIRES AND NW CT. THESE STORMS WILL PERIODICALLY PULSE
TO AROUND SEVERE LEVELS INTO THE EVENING AS THEY BUILD SOUTH AND
EAST THROUGH THE EVENING. WEAKER ACTIVITY IN THE WESTERN MOHAWK
VALLEY AND SCHOHARIE VALLEY EASTWARD THROUGH THE LAKE GEORGE
SARATOGA REGION...CAPITAL DISTRICT...SOUTHERN VT AND NORTHERN
BERKSHIRES SHOULD REMAIN WEAKER THAN THE SOUTHERN STORMS AS HEAT
AND INSTABILITY IS CUT OFF. STILL SOME SCATTERED WEAKER SHOWERS
AND THUNDERSTORMS INTO THIS EVENING FOR THOSE AREAS.
ACTIVITY SHOULD DECREASE LATE THIS EVENING AND OVERNIGHT BUT A
LOT OF CONVECTIVE DEBRIS CLOUDINESS SHOULD LINGER THROUGH THE
NIGHT ALONG WITH PATCHY FOG. UPPER SYSTEM IN OH VALLEY SHOULD
CONTINUE TO APPROACH WITH NEW SCATTERED SHOWERS AND THUNDERSTORMS
AFFECTING WESTERN AREAS AROUND SUNRISE. LOWS IN THE 60S TO AROUND
70.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
UPPER ENERGY TRACKS ACROSS THE REGION THROUGH TOMORROW NIGHT...SO
MORE SHOWERS AND THUNDERSTORMS WITH BETTER COVERAGE TOMORROW
AFTERNOON. WITH SUNSHINE A BIT LIMITED...HIGHS IN THE 80S MOST
AREAS...SOME UPPER 70S SOUTHERN ADIRONDACKS AND NEAR 90 MID HUDSON
VALLEY AND NW CT. NO FLASH FLOOD WATCH UNTIL WE GET A BETTER IDEA
OF HOW WIDESPREAD THE CONVECTION WILL BE TOMORROW. WILL HIGHLIGHT
ISOLATED FLASH FLOOD POTENTIAL FOR TOMORROW IN THE HAZARDOUS
WEATHER OUTLOOK...AND A WATCH COULD BE ISSUED TONIGHT IF
NECESSARY.
DECENT CONSENSUS FOR THE SYSTEM TO EXIT MONDAY EVENING AND
OVERNIGHT...SUGGESTING ANY SHOWER OR THUNDERSTORM ACTIVITY SHOULD
DECREASE IN COVERAGE TO ISOLATED THROUGH MONDAY NIGHT. SOME
SCATTERED ACTIVITY COULD LINGER IN WESTERN NEW ENGLAND THROUGH THE
NIGHT...THOUGH. LOWS IN THE 60S TO NEAR 70...SINCE THE WEAK COLD
FRONT THAT SHOULD TRACK THROUGH SHOULD NOT HAVE MUCH COOLING OR
DRYING BEHIND IT.
FLAT UPPER RIDGING BUILDS INTO THE REGION TUESDAY WHILE A NORTHERN
STREAM UPPER IMPULSE BEGINS TO DROP OUT OF CANADA TOWARD OUR
REGION TUESDAY NIGHT AND WEDNESDAY. STILL...WARM HUMID ATMOSPHERE
TUESDAY AFTERNOON COULD SUPPORT ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS...BUT MUCH LESS COVERAGE THAN ON MONDAY SINCE THERE
SHOULD BE NO LOW LEVEL FOCUS TO TRIGGER OR SUPPORT WIDESPREAD
ACTIVITY AND NO UPPER DYNAMICS. HIGHS TUESDAY WELL INTO THE 80S TO
NEAR 90 WITH INTERVALS OF CLOUDS AND SUN.
A STRONGER COLD FRONT ASSOCIATED WITH RELATIVELY STRONG UPPER
DYNAMICS DROPPING OUT OF CANADA COULD SUPPORT MORE ORGANIZED AND
WIDESPREAD SHOWERS AND THUNDERSTORMS BY WEDNESDAY AFTERNOON. WITH
INTERVALS OF CLOUDS AND SUN AT LEAST WEDNESDAY MORNING...HIGHS
SHOULD GET WELL INTO THE 80S TO AROUND 90 AGAIN. WILL HAVE TO
MONITOR SEVERE AND FLASH FLOOD POTENTIAL WITH THE POTENTIAL FOR
ORGANIZED STRONG THUNDERSTORMS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THIS WILL BE A PERIOD OF NEAR NORMAL TEMPERATURES WITH GARDEN
VARIETY SHOWERS AND/OR THUNDERSTORMS EACH DAY...WITH LESSER CHANCES
FROM THURSDAY NIGHT THROUGH FRIDAY NIGHT. A COLD FRONT MOVES
THROUGH THE AREA DURING THE EARLIEST PART OF THE EXTENDED
PERIOD...STALLING OUT ALONG THE EAST COAST DURING THE WEEKEND.
WITHOUT MUCH DRIER AIR BEHIND IT...THE CHANCE OF SHOWERS WILL MORE
OR LESS PERSIST.
DAYTIME HIGH TEMPERATURES WILL RANGE FROM THE LOWER 70S TO THE LOWER
OR MID 80S EACH DAY. THERE WILL BE A MORE NOTICEABLE CHANGE WITH
THE OVERNIGHT LOWS IN ASSOCIATION WITH THURSDAY NIGHT/S COLD FRONTAL
PASSAGE. LOWS WILL RANGE FROM THE LOWER 60S TO LOWER 70S THURSDAY
NIGHT. THEREAFTER THROUGH THE REMAINDER OF THE EXTENDED...LOWS WILL
BE MAINLY FROM THE MID 50S TO MID 60S.
&&
.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
PREDOMINATELY VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THIS
AFTERNOON MINUS ANY SHOWER/THUNDERSTORM ASSOCIATED MVFR/IFR FLYING
CONDITIONS. HAVE ONLY MENTIONED VCSH IN THE TAFS AT THIS TIME AS
COVERAGE WILL REMAIN SCATTERED AT BEST AND WILL AMEND AS NEEDED.
LATEST RADAR IMAGERY DEPICTS SCATTERED SHOWERS/THUNDERSTORMS
DEVELOPING ACROSS THE REGION AND THESE WILL PERSIST THROUGH THE
EVENING HOURS. ANY CONVECTION SHOULD DIMINISH BY MIDNIGHT WITH A
BRIEF LULL IN PRECIPITATION AHEAD OF THE NEXT APPROACHING SYSTEM.
INCREASING CLOUD COVER SHOULD LIMIT FOG POTENTIAL SOMEWHAT TONIGHT
BUT WILL CONTINUE WITH MVFR FOG FOR ALL TAF SITES EXCEPT KALB. AN
UPPER-LEVEL SHORTWAVE TROUGH AND SURFACE FRONTAL BOUNDARY WILL
APPROACH THE REGION TONIGHT AND MONDAY BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TO THE TAF SITES TO END THE TAF PERIOD.
SURFACE WINDS WILL BECOME SOUTH OR SOUTHWEST AT 5 TO 10 KTS...THEN
BECOME LIGHT AGAIN AFTER SUNSET.
OUTLOOK...
TUE...MAINLY VFR. SCT -SHRA/-TSRA.
WED...VFR/MVFR/IFR DUE TO SCT TO NUM -SHRA/-TSRA.
THU-FRI...MAINLY VFR. SCT PM -SHRA/-TSRA.
MVFR/IFR OVERNIGHT FOG POSSIBLE TUE-FRI.
&&
.FIRE WEATHER...
NO FIRE WEATHER ISSUES ARE EXPECTED OVER THE NEXT SEVERAL DAYS.
MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE EACH AFTERNOON FOR THE
NEXT SEVERAL DAYS.
NORMAL RH RECOVERIES EACH NIGHT BETWEEN 80 TO 100 PERCENT WILL ALLOW
FOR WIDESPREAD DEW FORMATION. DAYTIME RH VALUES WILL GENERALLY BE IN
THE 40 TO 60 PERCENT RANGE.
&&
.HYDROLOGY...
THE MOHAWK RIVER AT UTICA CONTINUES TO EXPERIENCE MINOR FLOODING.
THE RIVER AND CREEK FLOWS NEAR THE WEST CENTRAL MOHAWK RIVER ARE
EXPECTED TO GRADUALLY RECEDE INTO THE WEEKEND...UNLESS ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS OCCUR OVER OR NEAR THE BASIN.
THERE WILL BE SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY DURING
THE AFTERNOON AND EVEN MORE COVERAGE OF SHOWERS AND THUNDERSTORMS
MONDAY WITH THE APPROACH OF A WEAK COLD FRONT AND UPPER AIR LOW
PRESSURE SYSTEM. A MOIST AND HUMID AIR MASS WILL ALLOW ANY SHOWER OR
THUNDERSTORM TO BE CAPABLE OF PRODUCING LOCALLY HEAVY
DOWNPOURS...AND A QUICK INCH OR MORE OF RAINFALL DUE TO THE
ANOMALOUS PRECIPITABLE WATER VALUES THIS EVENING AND AGAIN ON
MONDAY.
THERE WILL BE A CONTINUED THREAT FOR ISOLATED FLASH FLOODING...AS
WELL AS FLOODING OF POOR DRAINAGE AND LOW LYING AREAS. NO FLASH
FLOOD WATCHES ARE BEING ISSUED DUE TO THE EXPECTED ISOLATED NATURE
OF ANY FLOODING. IT IS ALSO DIFFICULT TO DETERMINE WHERE THE
HEAVIEST RAINFALL WILL OCCUR.
WHILE ADDITIONAL FLOODING IS NOT ANTICIPATED ON ANY MAIN STEM RIVER
POINTS...LOCALLY SHARP RISES ARE POSSIBLE DUE TO ANY CONVECTION THAT
MAY OCCUR OVER THE NEXT SEVERAL DAYS...ESPECIALLY FOR THOSE POINTS
THAT ARE MORE FLASHIER IN NATURE.
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...NAS
NEAR TERM...NAS
SHORT TERM...NAS
LONG TERM...ELH
AVIATION...BGM
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS TAUNTON MA
438 PM EDT SAT JUL 6 2013
.SYNOPSIS...
OFFSHORE BERMUDA HIGH GRADUALLY WEAKENS ALLOWING FOR A RETURN OF
DISTURBED WEATHER INTO THE BEGINNING OF NEXT WEEK. THERE WILL BE
A CHANCE OF THUNDERSTORMS MOST DAYS THROUGH THE FORECAST PERIOD.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
INTO THIS EVENING...
WEAK CONVERGENCE BOUNDARY PRESSING SOUTH ACROSS SOUTHERN NEW
ENGLAND ACTING AS A FOCUS OF A LINE OF SCATTERED SHOWERS. HEAVY
RAIN LOOKS TO BE THE MAIN THREAT. THIS BOUNDARY APPEARS TO BE A
PUSH AHEAD OF A WEAK WAVE DISTURBANCE AND DRY SINKING AIRMASS TO
THE REAR /NOTABLY THE DIMINISHING CUMULUS FIELD IN WAKE ACROSS
UPSTATE NY AND THE DRY PUNCH BENEATH H5 IN THE 12Z BUFFALO UPPER-
AIR SOUNDING/.
WILL CONTINUE WITH SLIGHT CHANCE POPS OF SHOWERS AND T-STORMS AS
INSTABILITY IS PLENTIFUL IN A REGION OF WEAK UNIDIRECTIONAL SHEAR.
THE HRRR HAS BEEN DOING THE BEST IN FORECASTING THIS SITUATION.
TEMPERATURE AND DEWPOINT TRENDS REMAIN ON TRACK AND WILL HOLD
WITH PRESENT HEAT ADVISORIES. MANY LOCATIONS ARE REPORTING
TEMPERATURES OF 90 DEGREES FOR A 3RD OR 4TH STRAIGHT DAY...PUTTING
MUCH OF SOUTHERN NEW ENGLAND BY DEFINITION IN A HEAT WAVE.
TONIGHT...
OFFSHORE BERMUDA HIGH CONTINUES TO UNDERGO A GRADUAL WEAKENING
ALLOWING THE LONGWAVE FLOW PATTERN TO SHIFT SOUTH AND EAST. AS A
RESULT...MID- TO HIGH-LEVEL CLOUDS WILL FILTER ACROSS THE
REGION... AND COUPLED WITH THE MOIST AIRMASS AT THE SURFACE WILL
MAKE FOR ANOTHER MILD EVENING WITH MINS AROUND THE UPPER 60S. A
DRY NIGHT WITH WESTERLY FLOW. GREATEST FOG THREAT WILL BE ALONG
THE SOUTH SHORE...ESPECIALLY OVER NANTUCKET.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SUNDAY...
WITH THE TROUGH DIGGING THROUGH THE OHIO RIVER VALLEY REGION...
SUBSEQUENT WARM-AIR ADVECTION ALONG AND AHEAD HOLDS THE RIDGE STEADY
ACROSS NEW ENGLAND. CONFIDENCE OF THE WEATHER OUTCOMES IS WAVERING.
THE TIMING OF THE TROUGH IS KEY...WHETHER MID- TO UPPER-LEVEL
DIFLUENCE AHEAD OF THE TROUGH GETS INTO NEW ENGLAND. OTHERWISE IT
APPEARS RIDGING PREVAILS AS H5 TEMPERATURES SLIGHTLY WARM
DIMINISHING MID-LEVEL LAPSE RATES. ACTIVITY MAY BE SUPPRESSED
ACROSS THE REGION KEEPING IT WEST.
ASSUMING SHOWERS AND THUNDERSTORMS DO DEVELOP...THE GREATEST
LIKELIHOOD OF WHICH WILL BE ACROSS NY/PA FOCUSED ALONG THE SURFACE
FRONTAL BOUNDARIES...WESTERN PORTIONS OF NEW ENGLAND ARE UNDER
THE GREATEST THREAT...MAINLY HEAVY RAIN /PWATS AROUND 1.5 - 1.75
INCHES/ AND GUSTY WINDS. THE WARM/MOIST AIRMASS WILL REMAIN IN
PLACE ALLOWING FOR PLENTY OF INSTABILITY WITH DAYTIME DIURNAL
MIXING. WITH THIN CAPE COUPLED WITH MINOR UNIDIRECTIONAL WESTERLY
SHEAR...ANTICIPATING PULSE TO MULTI-CELLULAR CONVECTION WHICH MAY
NOT SUSTAIN WELL OR LONG ENOUGH. LOW CONFIDENCE AS TO A SEVERE
WEATHER THREAT...THE BETTER DYNAMICS AND LIFT SIT NORTH AND WEST
OF THE REGION. WILL BE MONITORING FOR ANY SURFACE CONVERGENCE
BOUNDARIES AND ALONG THE WESTERN SLOPES OF HIGHER TERRAIN AS AN
AID TO INVIGORATING POTENTIAL WEATHER.
HIGH TEMPERATURES ONCE AGAIN AROUND THE LOW 90S...FOR SOME LOCATIONS
THIS WILL BE THE 5TH DAY IN A ROW. WITH THE EXPECTED CLOUD COVER
TEMPERATURES ARE ANTICIPATED TO BE A DEGREE OR TWO LOWER WHICH
WILL ALLOW FOR HEAT INDEX VALUES TO REMAIN BELOW HEAT ADVISORY
THRESHOLDS. WILL ALLOW THE EVENING CREW TO TAKE A LOOK AT
TEMPERATURES ACCORDINGLY AND EVALUATE WHETHER HEADLINES WILL BE
NECESSARY. FOR NOW A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED TO
ADDRESS THE ANTICIPATED HEAT FOR SUNDAY.
SUNDAY NIGHT...
OHIO VALLEY REGION TROUGH PUSHES WEST INTO THE CENTRAL
APPALACHIANS RESULTING IN INCREASING DIFLUENCE ALOFT OVER NEW
ENGLAND LATE IN THE PERIOD. THERE REMAINS SOME TIMING AND
INFLUENCE OF THE TROUGH ON THE REGIONS WEATHER. IT APPEARS THAT
MID-LEVEL ENERGY LAGS THE SYSTEM AND CONSEQUENTIALLY IT COULD
REMAIN QUIET AFTER ALL DAYTIME SHOWER AND THUNDERSTORM ACTIVITY
DIMINISHES /THAT IS IF IT INITIATES/. HAVE KEPT THE GREATEST
CHANCES FOR WEATHER ALONG THE NORTH AND WEST PORTIONS OF THE
FORECAST AREA. SHOULD BE A LOT OF CLOUDS WITH INCREASING INFLUENCE
OF THE RIGHT-ENTRANCE REGION OF THE UPPER-LEVEL JET. ANOTHER MILD
NIGHT WITH MINS AROUND THE 70 DEGREE MARK UNDER WESTERLY FLOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* WARM AND HUMID CONDITIONS CONTINUE THROUGH MOST OF NEXT WEEK
* SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY...MAINLY INTERIOR
OVERVIEW AND MODEL PREFERENCES... 06/12Z GUIDANCE CONTINUES TO
EXHIBIT DECENT AGREEMENT WITH THEIR HANDLING THE SYNOPTIC FEATURES
THROUGH THIS PORTION OF THE FORECAST. THERE ARE SOME DISAGREEMENTS
WITH TIMING...WHICH LEADS TO ONLY AN AVERAGE CONFIDENCE. 06/12Z
ECMWF REMAINS SLOWER TO PROGRESS A MID-LEVEL TROUGH EAST THAN THE
GFS...BUT PERHAPS A BIT TOO SLOW.06/12Z GFS IS PERHAPS A LITTLE TOO
FAST BUT DOES HAVE DECENT SUPPORT FROM THE GEFS MEAN. THE 06/12Z
NAM LOOKED LIKE A GOOD COMPROMISE TIMING THROUGH TUESDAY.
THEREAFTER...USED A CONSENSUS BLEND FOR THE TIMING AS DID NOT HAVE
ENOUGH CONFIDENCE IN ANY ONE PARTICULAR MODEL SOLUTION.
ESSENTIALLY...THE PATTERN LOOKS TO BE FAIRLY UNSETTLED THROUGH MOST
OF NEXT WEEK AS THE BERMUDA HIGH SLOWLY MOVES EAST.
DETAILS...
MONDAY INTO TUESDAY...A WEAK SURFACE TROUGH AND MID-LEVEL SHORTWAVE
WILL LIKELY SPARK CONVECTION MONDAY. THE ISSUE WILL BE HOW MUCH
INSTABILITY CAN BE GENERATED WITH A COLD POOL MOVING NEARBY. THERE
SHOULD STILL BE SOME PROTECTIVE RIDGING TOWARD THE CAPE AND ISLANDS.
LAPSE RATES SHOULD BE MEAGER AT ABOUT 5.5-6.0C/KM. SHOULD THE SUN
BREAK OUT...ML CAPE VALUES COULD APPROACH 1000-1500J/KG...AND SHEAR
MAGNITUDES APPROACH 35-40 KT. THEREFORE...HOW STRONG THE CONVECTION
IS WILL BE DEPENDENT ON CLOUD COVER INITIALLY...BUT THERE IS ENOUGH
SUPPORT FOR ANY CONVECTION THAT DOES FORM TO BECOME SOMEWHAT
ORGANIZED. HEAVY RAIN STILL THE BIGGEST THREAT THOUGH WITH PWAT
VALUES APPROACHING 2.0 INCHES...SO WILL CONTINUE TO MENTION THIS IN
WX WITH ANY THUNDERSTORMS.
NOT OUT OF THE QUESTION MORE STORMS COULD FIRE ON TUE...BUT A WEAK
MID LEVEL RIDGE MAY BE ENOUGH TO FORCE BEST INSTABILITY/SHEAR AND
FOCUS FOR LIFT TO OUR NORTH DURING THE DAY.
WED INTO EARLY NEXT WEEKEND...
A BROAD MID-LEVEL TROUGH IS EXPECTED TO DEEPEN IN VICINITY OF THE
GREAT LAKES THROUGH THIS PERIOD ALLOWING A LOW PRESSURE TO PASS WELL
NORTH AND WEST OF OUR REGION. A SFC WARM FRONT WILL APPROACH AND
LIKELY CROSS THE REGION WEDNESDAY INTO EARLY THURSDAY. THIS COULD
PROVIDE ANOTHER FOCUS FOR MORE WIDESPREAD SHOWERS AND THUNDERSTORMS.
THE TIMING OF THE COLD FRONT ASSOCIATED WITH THIS LOW PRESSURE IS
STILL A BIT IN QUESTION AS IT WILL BE DETERMINED ON HOW AMPLIFIED
THE UPPER LEVEL PATTERN GETS BY NEXT WEEK. FOR NOW WILL ERR TOWARD
THE ENSEMBLE MEANS WHICH SUGGEST FRIDAY OR FRIDAY NIGHT. IN ANY
CASE...ANOTHER THREAT FOR THUNDERSTORMS AND RAINFALL.
TEMPERATURES DURING THIS PERIOD SHOULD BE SEASONABLE TO SLIGHTLY
ABOVE NORMAL. IT WILL LIKELY REMAIN VERY HUMID HOWEVER.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM /INTO SUNDAY NIGHT/...MODERATE CONFIDENCE.
VFR WITH WESTERLY WINDS DURING THE DAY...GUSTING AT TIMES AROUND
20 KTS. MONITORING THE POSSIBILITY OF SHRA/TSRA THIS AFTERNOON.
LOW CONFIDENCE ON OUTCOMES...BUT HIGHER CONFIDENCE WITH MAINLY
WESTERN INTERIOR TERMINALS BEING IMPACTED. PREVAILED WITH VCSH.
WINDS BECOME LIGHT THIS EVENING WITH SCT-BKN MID-HIGH CIGS. MAIN
CONCERN IS FOG ALONG THE SOUTH-SHORE. WENT WITH PERSISTENCE OF
TRENDS KEEPING KACK AT MVFR VSBYS WITH IFR CIGS WHICH WAS THE
OUTCOME LAST NIGHT.
A REPEAT OF SATURDAY IS EXPECTED SUNDAY...THOUGH THE CHANCES FOR
SHRA/TSRA INCREASE. GREATER CONFIDENCE IS UPON WESTERN INTERIOR
AND THOSE TERMINALS NORTH OF THE MASS-PIKE BEING IMPACTED. HAVE
PREVAILED VCSH FOR KBDL. WESTERLY WINDS GUSTING UP TO AROUND 20
KTS. ACTIVITY SHOULD PREVAIL INTO THE EVENING PERIOD FOR THE SAME
TERMINALS IMPACTED SUNDAY.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. THOUGH WINDS HAVE BACKED
SLIGHTLY OUT OF THE NW...WILL MAINTAIN A WESTERLY FLOW THROUGHOUT.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. PREVAIL VCSH THIS
AFTERNOON AND AGAIN SUNDAY WITH THE EXPECTATION FOR SHRA/TSRA TO
POTENTIALLY IMPACT THE TERMINAL.
OUTLOOK...MONDAY THROUGH THURSDAY...
HIGH CONFIDENCE IN OVERALL TRENDS...LOWER CONFIDENCE IN THE TIMING
OF ANY LOWER CATEGORIES THROUGH NEXT WEEK. LITTLE CHANGE IN FORECAST.
MAINLY VFR. THERE IS A LOW TO MODERATE PROBABILITY OF SHOWERS AND
THUNDERSTORMS AND ACCOMPANYING MVFR/IFR CONDITIONS EACH AFTN/EVE.
FOG IS LIKELY TO DEVELOP MOST NIGHTS...WITH THE HIGHEST
PROBABILITY OF THIS HAPPENING ALONG THE SOUTH COAST. THIS WILL
LIMIT CIGS AND VSBYS TO IFR/MVFR AT TIMES.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM /INTO SUNDAY NIGHT/...HIGH CONFIDENCE.
WINDS AND SEAS SHOULD REMAIN BELOW SCA THRESHOLDS THROUGH SUNDAY
NIGHT. WEST-SOUTHWEST WINDS WILL LIKELY GUST AROUND 20 KNOTS AT
TIMES...ESPECIALLY ALONG THE SOUTH-SHORE...CAPE AND ISLANDS. FOG
MAY BE AN ISSUE WITH VISIBILITIES DOWN TO A QUARTER MILE OR LESS.
GREATEST CONFIDENCE IS FOR FOG TO IMPACT NANTUCKET.
OUTLOOK...MONDAY THROUGH THURSDAY...
MODERATE CONFIDENCE THROUGH THE PERIOD.
PERSISTENT WEST TO SOUTHWEST WINDS AND LINGERING SWELL WILL ALLOW
SEAS TO REACH ABOUT 5 FT LATE MONDAY INTO TUESDAY ACROSS THE COASTAL
WATERS SOUTH AND SOUTHEAST OF SOUTHERN NEW ENGLAND. WINDS SHOULD
REMAIN BELOW 25 KT...EXCEPT FOR THE AFTERNOON AND EARLY EVENING
HOURS SURROUNDING CAPE COD AND THE ISLANDS...WHERE A FEW GUSTS COULD
APPROACH 25 KT MONDAY. OTHERWISE...SOME OVERNIGHT FOG AND STRATUS
MAY CAUSE OCCASIONAL REDUCTIONS IN VISIBILITY.
&&
.CLIMATE...
HERE ARE RECORD HIGHS FOR SOUTHERN NEW ENGLANDS OFFICIAL CLIMATE
SITES FOR JULY 5TH THROUGH THE 10TH
BOS PVD ORH BDL
6TH 101/1911 102/2010 102/2010 98/1911
7TH 99/1953 97/1993* 100/2010 95/1908
8TH 99/1937 99/1981 97/1993 97/1936*
9TH 99/1981* 99/1981 99/1936* 96/1937
10TH 101/1880 100/1993 100/1936* 95/1936*
* AND PREVIOUS YEARS
ALSO...SINCE WE ARE LOOKING AT AN EXTENDED PERIOD OF TEMPERATURES
ABOVE 90 DEGREES...HERE ARE THE LONGEST HEAT WAVES IN THE HISTORY
OF OUR 4 CLIMATE SITES.
HARTFORD/BRADLEY
JULY 24-AUGUST 2, 1995 - 10 DAYS
AUGUST 11-19, 2002 - 9 DAYS
AUGUST 27-SEPTEMBER 4, 1973 - 9 DAYS
JULY 27-AUGUST 3, 2006 - 8 DAYS
JULY 29-AUGUST 5, 2002 - 8 DAYS
JULY 16-23, 1991 - 8 DAYS
JULY 24-31, 1970 - 8 DAYS
AUGUST 28-SEPTEMBER 4, 1953 - 8 DAYS
AUGUST 10-17, 1944 - 8 DAYS
WORCESTER/AIRPORT
AUGUST 10-17, 1944 - 8 DAYS
JULY 4-11, 1912 - 8 DAYS
JUNE 26-JULY 3, 1901 - 8 DAYS
AUGUST 10-15, 1988 - 6 DAYS
JULY 25-29, 1963 - 5 DAYS
BOSTON/LOGAN AIRPORT
JULY 3-11, 1912 - 9 DAYS
AUGUST 11-18, 2002 - 8 DAYS
JULY 19-26, 1994 - 8 DAYS
AUGUST 10-17, 1944 - 8 DAYS
JUNE 28-JULY 5, 1872 - 8 DAYS
PROVIDENCE/T.F. GREEN
JULY 12-20, 1952 - 9 DAYS
JULY 28-AUGUST 3, 2006 - 7 DAYS
AUGUST 13-19, 2002 - 7 DAYS
JULY 15-21, 1977 - 7 DAYS
AUGUST 11-17, 1944 - 7 DAYS
JULY 7-13, 1944 - 7 DAYS
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR CTZ002>004.
MA...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR MAZ005>007-010-
011-013>019.
NH...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NHZ012.
RI...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR RIZ001>004.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...BELK
AVIATION...BELK/SIPPRELL
MARINE...BELK/SIPPRELL
CLIMATE...WFO BOX STAFF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
153 PM EDT SAT JUL 6 2013
.SYNOPSIS...
A BERMUDA HIGH WILL RESULT IN HOT AND HUMID WEATHER CONTINUING
INTO NEXT WEEK. THERE WILL BE A CHANCE OF THUNDERSTORMS MOST DAYS
THROUGH THE FORECAST PERIOD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
200 PM UPDATE...
MONITORING VISIBLE SATELLITE TRENDS...CUMULUS IS BUBBLY ACROSS
CENTRAL AND SOUTHERN NEW ENGLAND...WHEREAS ACROSS UPSTATE NY IT
IS SUPPRESSED. FROM NEAR-TERM FORECAST SOLUTIONS...FEEL THIS IS AN
OUTCOME OF SINKING DRIER AIR TO THE REAR OF A MID-LEVEL WEAK WAVE
IMPULSE /SEE THE DRY AIR INTRUSION JUST BELOW H5 IN THE BUFFALO NY
12Z SOUNDING/. THIS WAVE CONSEQUENTIALLY MAY RESULT IN SHOWERS
AND THUNDERSTORMS ACROSS SOUTHERN NEW ENGLAND LATER THIS
AFTERNOON.
IN MORE DETAIL...MLCAPE VALUES RANGE AROUND 1K-2K J/KG IN AN
ENVIRONMENT OF WEAK DEEP-LAYER UNI-DIRECTIONAL SHEAR. IF THE WEAK
IMPULSE CAN PROVIDE ENOUGH FORCING...THEN WIDESPREAD PULSE-LIKE
THUNDERSTORMS ARE CERTAINLY PLAUSIBLE THIS AFTERNOON...OTHERWISE
THE OVERALL ATMOSPHERIC DYNAMICS LOOK WEAK AND MOST OF THE FORCING
WILL BE SIMPLY A RESULT OF RISING THERMALS THROUGH THE BOUNDARY
LAYER. LATEST HRRR WOULD SUGGEST MUCH OF THE ACTIVITY IS A RESULT
OF RISING THERMALS AS MODEL REFLECTIVITY OUTPUT ILLUSTRATES WIDE-
SPREAD DISCREET SHOWERS. SOME ACTIVITY IS PREVALENT ON RADAR
ACROSS BERKSHIRE COUNTY AS OF 145 PM. ACTIVITY ACROSS VT/NH HASN/T
EXHIBITED MUCH MUSTER...WITH MANY OF THE SHOWERS QUICKLY
DISSIPATING AFTER GENERATION.
WILL CONTINUE WITH SLIGHT CHANCE POPS ACROSS THE INTERIOR.
TEMPERATURE AND DEWPOINT TRENDS REMAIN ON TRACK AND WILL HOLD WITH
PRESENT HEAT ADVISORIES. MANY LOCATIONS ARE REPORTING TEMPERATURES
OF 90 DEGREES FOR A 3RD OR 4TH STRAIGHT DAY...PUTTING MUCH OF
SOUTHERN NEW ENGLAND BY DEFINITION IN A HEAT WAVE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...
ANOTHER WARM AND HUMID NIGHT. THERE WILL BE PATCHY FOG BUT THE
WEST WIND AND CONVECTIVE DEBRIS FROM NEW YORK MAY LIMIT THE EXTENT
OF ANY FOG. DEWPOINTS WILL DROP BACK IN THE MID AND UPPER 60S
ALLOWING TEMPS TO REACH THE MID 60S TO LOWER 70S.
SUNDAY...
THE UPPER RIDGE SHIFTS FARTHER SOUTH AND A COLD FRONT SLIDES INTO
NORTHERN NEW ENGLAND. WE WILL REMAIN ON THE WARM HUMID SIDE OF THE
FRONT WITH TEMPS AT THE TOP OF THE MIXED LAYER STILL SUPPORTING
MAX TEMPS IN THE LOWER 90S. IF CLOUDS FILL IN TOO FAST THEN MAX
TEMPS MAY FALL SHORT OF 90...BUT WE ARE GOING WITH THE SUNNIER AND
BETTER MIXED SCENARIO.
THE UPPER LOW THAT HAS BEEN CAMPED OUT OVER THE MISSISSIPPI RIVER
VALLEY WILL EJECT THROUGH THE GREAT LAKES SUNDAY. THE APPROACHING
SHORTWAVE AND THE STALLED FRONT TO OUR NORTH WILL EACH HAVE
ASSOCIATED UPPER JETS PROVIDING SOME DYNAMIC SUPPORT FOR LIFT. THE
AIRMASS WILL CONTINUE TO BE SOUPY WITH PW/S AROUND 2 INCHES...SO
PRIME POTENTIAL WILL BE FOR HEAVY DOWNPOURS/FLASH FLOODING.
SURFACE BASED CAPE FORECASTS SHOW 1500-3000 J/KG...0-6 KM SHEAR
SHOWS 30-40 KNOTS ESPECIALLY IN WESTERN SECTIONS. THIS WILL MEAN A
SECONDARY POTENTIAL FOR STRONG WIND GUSTS AND POSSIBLE WIND
DAMAGE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...
* WARM AND HUMID CONTINUES THROUGH NEXT WEEK
* SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY MAINLY INTERIOR
OVERVIEW AND MODEL PREFERENCES...
GUIDANCE APPEARS TO BE PROGRESSIVELY BECOMING DEEPER AND DEEPER
WITH LONGWAVE NRN CANADIAN TROF THROUGH MID TO LATE NEXT WEEK. THE
CONSEQUENCE APPEARS TO BE THAT THE BROAD E CONUS AND WRN ATLANTIC
RIDGE ASSOCIATED WITH THE BERMUDA HIGH WILL CONTINUE TO LOSE ITS
GRIP THROUGH THE LONG TERM SUCH THAT A WEAK ZONAL JET PATTERN WILL
BE FULLY IN CONTROL BY MID WEEK. RECENT RUNS OF THE ECENS AND GFS
ALSO SUPPORT THEIR OPERATIONAL BRETHREN THAT A SHIFT IN THE
AMPLIFIED FLOW REGIME BY LATE WEEK WOULD FEATURE A BROAD TROF
ACROSS THE NRN CONUS IN CONJUNCTION WITH THE CANADIAN TROF. WHILE
GUIDANCE TYPICALLY STRUGGLES TO HANDLE BROAD PATTERN CHANGES IN
THE EXTENDED...SINCE THERE IS AT LEAST SOME SUPPORT ACROSS THE
BOARD...HAVE A BIT HIGHER CONFIDENCE THAN USUAL REGARDING A STRONG
LOW PRES AND IT/S ASSOCIATED WARM AND COLD FRONTS AFFECTING THE
REGION TOWARD THE END OF THE WEEK. THIS MAY EVENTUALLY LEAD TO A
DRIER AND ULTIMATELY COOLER AIRMASS FOLLOWING THE COLD FRONT. HPC
CONTINUES TO FAVOR THE ECENS ENSEMBLES AND A BLEND OF THE
OPERATIONAL GFS/ECMWF...SO IN TANDEM WITH THE PREVIOUS
FORECASTER...WILL CONTINUE TO USE THE HPC AND A BLEND OF THE
OPERATIONAL MODELS FOR THIS UPDATE.
ESSENTIALLY...THE PATTERN LOOKS TO BE FAIRLY UNSETTLED RIGHT INTO
THE WEEKEND. MON APPEARS TO HAVE THE HIGHEST CHANCE FOR PRECIP
INITIALLY AS A SHORTWAVE AND ASSOCIATED COLD FRONT ARE EXPECTED
TO CROSS THE REGION. WHILE CONVECTION ON TUE CANNOT BE RULED
OUT...COVERAGE LOOKS TO BE LOWER. THEN...FOR WED-WEEKEND...A
STRONGER LOW PRES ASSOCIATED WITH DEEPER TROF RIDGING THE WEAK JET
WILL DRAG A WARM FRONT THROUGH...THEN A COLD FRONT THROUGH THE
CLOSER TO THE WEEKEND...WHICH COULD INCREASE THE THREAT FOR
CONVECTION LATE IN THE WEEK. STILL SOME PLAYERS YET TO LINE
UP...BUT THERE IS DECENT AGREEMENT IN THE SYNOPTIC PATTERN THAT
SUPPORT THIS THINKING. DO HAVE FAIRLY HIGH CONFIDENCE THAT THE
HUMID AIRMASS REMAINS IN PLACE HOWEVER...WITH DWPTS IN THE UPPER
60S AND LOW 70S MOST OF THE WEEK. TEMPS WILL BE WARM...BUT A BIT
COOLER THAN IS EXPECTED THIS WEEKEND.
DETAILS...
SUN NIGHT INTO TUE...
SUN NIGHT CONVECTION MAY LINGER SOMEWHAT INTO THE OVERNIGHT HOURS
THANKS TO NEAR 30 KT SHEAR AND ML CAPE VALUES HOLDING AROUND 1000
J/KG INITIALLY. HOWEVER...SHOULD BE SOME LATE NIGHT DRYING AS
MESOSCALE RIDGING BUILDS OVER BEHIND THE EXITING CONVECTION. ON
MON HOWEVER...WITH THE TROF THAT SPARKED THE CONVECTION EXPECTED
TO BE IN CLOSER PROXIMITY...AND A SFC COLD FRONT EXPECTED TO SLIDE
THROUGH ANOTHER ROUND OF DIURNALLY DRIVEN THUNDERSTORMS AND
SHOWERS ARE POSSIBLE. THE QUESTION IS HOW MUCH INSTABILITY IS
AVAILABLE GIVEN LAPSE RATES ARE MEAGER AT ABOUT 5.5-6.0C/KM.
SHOULD THE SUN BREAK OUT...ML CAPE VALUES LOOK TO APPROACH
1000-1500J/KG...AND SHEAR MAGNITUDES APPROACH 35-40 KT.
THEREFORE...HOW STRONG THE CONVECTION IS WILL BE DEPENDENT ON
CLOUD COVER INITIALLY...BUT THERE IS ENOUGH SUPPORT FOR ANY
CONVECTION THAT DOES FORM TO BECOME SOMEWHAT ORGANIZED. HEAVY RAIN
STILL THE BIGGEST THREAT THOUGH WITH PWAT VALUES APPROACHING 2.0
INCHES...SO WILL CONTINUE TO MENTION THIS IN WX WITH ANY T-STORMS.
NOT OUT OF THE QUESTION MORE STORMS COULD FIRE ON TUE...BUT WEAK
MID LVL RIDGE MAY BE ENOUGH TO FORCE BEST INSTABILITY/SHEAR/AND
FOCUS FOR LIFT TO THE N DURING THE DAY. WILL LOWER POPS SOMEWHAT
FROM THOSE ON MON. IN ANY CASE...IT APPEARS THAT COVERAGE WOULD BE
LESS.
WED INTO EARLY NEXT WEEKEND...
BROAD TROF IS EXPECTED TO DEEPEN IN VICINITY OF THE GREAT LAKES
THROUGH THIS PERIOD ALLOWING A LOW PRES CENTER TO PASS WELL N AND
W OF THE REGION. A SFC WARM FRONT WILL APPROACH AND LIKELY CROSS
THE REGION ON WED INTO EARLY THU. THIS COULD PROVIDE ANOTHER FOCUS
FOR MORE WIDESPREAD SHRA/T-STORMS AND ALLOW ALLOW FOR MID LVL
TEMPS TO REACH THOSE SIMILAR TO LATE THIS WEEK AND THIS WEEKEND.
THEREFORE...A FEW TEMPS THU COULD APPROACH 90F WITH THE HUMID
AIRMASS REMAINING IN PLACE ALLOWING FOR SUNSHINE. THE TIMING OF
THE COLD FRONT IS STILL A BIT IN QUESTION AS IT WILL BE DETERMINED
ON HOW AMPLIFIED THE UPPER LVL PATTERN GETS BY NEXT WEEK...BUT FOR
NOW WILL ERR TOWARD THE ENSEMBLE MEANS WHICH SUGGEST FRI OR FRI
NIGHT. IN ANY CASE...ANOTHER THREAT FOR STORMS AND RAINFALL.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM /INTO SUNDAY NIGHT/...MODERATE CONFIDENCE.
VFR WITH WESTERLY WINDS DURING THE DAY...GUSTING AT TIMES AROUND
20 KTS. MONITORING THE POSSIBILITY OF SHRA/TSRA THIS AFTERNOON.
LOW CONFIDENCE ON OUTCOMES...BUT HIGHER CONFIDENCE WITH MAINLY
WESTERN INTERIOR TERMINALS BEING IMPACTED. PREVAILED WITH VCSH.
WINDS BECOME LIGHT THIS EVENING WITH SCT-BKN MID-HIGH CIGS. MAIN
CONCERN IS FOG ALONG THE SOUTH-SHORE. WENT WITH PERSISTENCE OF
TRENDS KEEPING KACK AT MVFR VSBYS WITH IFR CIGS WHICH WAS THE
OUTCOME LAST NIGHT.
A REPEAT OF SATURDAY IS EXPECTED SUNDAY...THOUGH THE CHANCES FOR
SHRA/TSRA INCREASE. GREATER CONFIDENCE IS UPON WESTERN INTERIOR
AND THOSE TERMINALS NORTH OF THE MASS-PIKE BEING IMPACTED. HAVE
PREVAILED VCSH FOR KBDL. WESTERLY WINDS GUSTING UP TO AROUND 20
KTS. ACTIVITY SHOULD PREVAIL INTO THE EVENING PERIOD FOR THE SAME
TERMINALS IMPACTED SUNDAY.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. THOUGH WINDS HAVE BACKED
SLIGHTLY OUT OF THE NW...WILL MAINTAIN A WESTERLY FLOW THROUGHOUT.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. PREVAIL VCSH THIS
AFTERNOON AND AGAIN SUNDAY WITH THE EXPECTATION FOR SHRA/TSRA TO
POTENTIALLY IMPACT THE TERMINAL.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
HIGH CONFIDENCE IN OVERALL TRENDS...LOWER CONFIDENCE IN THE TIMING
OF ANY LOWER CATEGORIES THROUGH THE WEEK. LITTLE CHANGE IN
FORECAST.
MAINLY VFR. THERE IS A LOW TO MODERATE PROBABILITY OF SHOWERS AND
THUNDERSTORMS AND ACCOMPANYING MVFR/IFR CONDITIONS EACH AFTN/EVE.
FOG IS LIKELY TO DEVELOP MOST NIGHTS...WITH THE HIGHEST
PROBABILITY OF THIS HAPPENING ALONG THE SOUTH COAST. THIS WILL
LIMIT CIGS AND VSBYS TO IFR/MVFR AT TIMES.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE.
WINDS AND SEAS SHOULD REMAIN BELOW SCA THRESHOLDS THROUGH SUNDAY.
WINDS MAY GUST AROUND 20 KNOTS OR THE LOW 20S ALONG THE NEAR
SHORE WATERS OF THE SOUTH COAST THIS AFTERNOON. FOG WILL HAVE LESS
OF A PRESENCE THAN ON PREVIOUS DAYS...BUT PATCHES MAY LINGER
ESPECIALLY SOUTH AND EAST OF NANTUCKET.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
MODERATE CONFIDENCE THROUGH THE PERIOD.
PERSISTENT WEST TO SOUTHWEST WINDS AND LINGERING SWELL WILL ALLOW
SEAS TO REACH ABOUT 5 FT LATE MONDAY INTO TUESDAY ESPECIALLY ON
THE WATERS SOUTH AND SOUTHEAST OF SOUTHERN NEW ENGLAND. WINDS
SHOULD REMAIN BELOW SMALL CRAFT THRESHOLDS SAVE FOR THE AFTERNOON
AND EARLY EVENING HOURS SURROUNDING CAPE COD AND THE
ISLANDS...WHERE A FEW GUSTS APPROACHING 25 KT ARE POSSIBLE ON
MONDAY. OTHERWISE...SOME OVERNIGHT FOG AND STRATUS MAY CAUSE
OCCASIONAL REDUCTIONS IN VISIBILITY.
&&
.CLIMATE...
HERE ARE RECORD HIGHS FOR SOUTHERN NEW ENGLANDS OFFICIAL CLIMATE
SITES FOR JULY 5TH THROUGH THE 10TH
BOS PVD ORH BDL
6TH 101/1911 102/2010 102/2010 98/1911
7TH 99/1953 97/1993* 100/2010 95/1908
8TH 99/1937 99/1981 97/1993 97/1936*
9TH 99/1981* 99/1981 99/1936* 96/1937
10TH 101/1880 100/1993 100/1936* 95/1936*
* AND PREVIOUS YEARS
ALSO...SINCE WE ARE LOOKING AT AN EXTENDED PERIOD OF TEMPERATURES
ABOVE 90 DEGREES...HERE ARE THE LONGEST HEAT WAVES IN THE HISTORY
OF OUR 4 CLIMATE SITES.
HARTFORD/BRADLEY
JULY 24-AUGUST 2, 1995 - 10 DAYS
AUGUST 11-19, 2002 - 9 DAYS
AUGUST 27-SEPTEMBER 4, 1973 - 9 DAYS
JULY 27-AUGUST 3, 2006 - 8 DAYS
JULY 29-AUGUST 5, 2002 - 8 DAYS
JULY 16-23, 1991 - 8 DAYS
JULY 24-31, 1970 - 8 DAYS
AUGUST 28-SEPTEMBER 4, 1953 - 8 DAYS
AUGUST 10-17, 1944 - 8 DAYS
WORCESTER/AIRPORT
AUGUST 10-17, 1944 - 8 DAYS
JULY 4-11, 1912 - 8 DAYS
JUNE 26-JULY 3, 1901 - 8 DAYS
AUGUST 10-15, 1988 - 6 DAYS
JULY 25-29, 1963 - 5 DAYS
BOSTON/LOGAN AIRPORT
JULY 3-11, 1912 - 9 DAYS
AUGUST 11-18, 2002 - 8 DAYS
JULY 19-26, 1994 - 8 DAYS
AUGUST 10-17, 1944 - 8 DAYS
JUNE 28-JULY 5, 1872 - 8 DAYS
PROVIDENCE/T.F. GREEN
JULY 12-20, 1952 - 9 DAYS
JULY 28-AUGUST 3, 2006 - 7 DAYS
AUGUST 13-19, 2002 - 7 DAYS
JULY 15-21, 1977 - 7 DAYS
AUGUST 11-17, 1944 - 7 DAYS
JULY 7-13, 1944 - 7 DAYS
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR CTZ002>004.
MA...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR MAZ005>007-010-
011-013>019.
NH...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NHZ012.
RI...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR RIZ001>004.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/DOODY
NEAR TERM...SIPPRELL
SHORT TERM...WTB
LONG TERM...DOODY
AVIATION...DOODY/SIPPRELL
MARINE...WTB/DOODY
CLIMATE...WFO BOX STAFF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1040 AM EDT SAT JUL 6 2013
.SYNOPSIS...
A BERMUDA HIGH PRESSURE SYSTEM WILL RESULT IN HOT AND HUMID WEATHER
CONTINUING INTO NEXT WEEK. THERE WILL BE A CHANCE OF THUNDERSTORMS
MOST DAYS THROUGH THE FORECAST PERIOD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030 AM UPDATE...
MINOR MODIFICATIONS MADE TO THE ONGOING FORECAST. TEMPERATURES AND
DEWPOINTS REMAIN ON TRACK...REFLECTING HAZY...HOT AND HUMID
CONDITIONS CONTRIBUTING TO THE CONTINUING HEAT ADVISORIES. CUMULUS
CLOUDS BUBBLING ACROSS THE REGION...BECOMING THICK...AN OUTCOME
LIKELY CONSEQUENTIAL OF WEAK AREAS OF LIFT MOVING THROUGH THE
LONGWAVE PATTERN AS IT SHIFTS SOUTH AND EAST IN RESPONSE TO THE
WEAKENING BERMUDA HIGH. THICKER CLOUDS MAY PERTURB THE FORECAST IN
KEEPING CONDITIONS SLIGHTLY COOLER. BUT WITH THE CONSECUTIVE DAYS
OF HOT AND HUMID CONDITIONS...WILL KEEP WITH THE HEAT ADVISORIES
MAKING NO CHANGES.
AS TO THE POTENTIAL OF SHOWERS AND THUNDERSTORMS...BOTH THE RAP
AND HRRR HINT AT SOME ACTIVITY ALONG AND AROUND THE MASSACHUSETTS
TURNPIKE...THOUGH WIDELY SCATTERED AND ISOLATED. CUMULUS CLOUDS
PER WEBCAMS IS LOOKING SOMEWHAT BUBBLY...MAYBE AN EARLY INDICATION
OF THE CONVECTIVE-NATURE OF THE ATMOSPHERE. LOOKING AT THE SPC
MESOANALYSIS...LOTS OF INSTABILITY AND WEAK EFFECTIVE SHEAR...AND
AS MENTIONED EARLIER...ENHANCED LIFT THROUGH THE REGION DUE TO A
COMBINATION OF WEAK AREAS OF ASCENT THROUGH THE LONGWAVE FLOW
PATTERN COUPLED WITH A BROAD RIGHT-ENTRANCE REGION OF THE UPPER
LEVEL JET /YET THE FLAT FLOW LEAVES LESS TO BE DESIRED/ COULD
RESULT IN SOME WEATHER LATER THIS AFTERNOON. PER SATELLITE...THE
BETTER MOIST AXIS AND DYNAMICS ARE NORTH AND WEST OF THE REGION...
BUT WITH THE DEGRADING RIDGE ALLOWING THE ENERGY TO SHIFT SOUTH
AND EAST...THERE IS CERTAINLY A THREAT FOR ANY STORMS TO PRODUCE
HEAVY RAINFALL AND GUSTY WINDS. MID-LEVEL LAPSE RATES ARE WEAK...
NOT EXPECTING ANY STORMS TO HAVE LONGEVITY.
HAVE UPDATED POP GRIDS ACCORDINGLY WITH A SLIGHT RISK CHANCE
ACROSS THE INTERIOR. HAVE CONTINUED WITH HEAVY RAIN AND GUSTY WIND
POTENTIAL. KEEPING A CLOSE EYE ON ANY LOCALIZED AREAS OF
CONVERGENCE PERHAPS ASSOCIATED WITH THERMAL TROUGHING...WHILE
MONITORING THE WESTERN SLOPES OF HIGHER TERRAIN FOR OROGRAPHIC
LIFTING PROCESSES.
HIGHS AROUND THE LOW-90S WITH A WEST-SOUTHWEST WIND CONTINUE.
COOLEST CONDITIONS ALONG THE SOUTH-SHORE WITH THE ONSHORE BREEZE.
COMBINED WITH DEWPOINTS IN THE 70S...HEAT INDEX VALUES WILL REACH
THE CENTURY MARK OR HIGHER FOR AREAS IN THE HEAT ADVISORY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...
ANOTHER WARM AND HUMID NIGHT. THERE WILL BE PATCHY FOG BUT THE
WEST WIND AND CONVECTIVE DEBRIS FROM NEW YORK MAY LIMIT THE EXTENT
OF ANY FOG. DEWPOINTS WILL DROP BACK IN THE MID AND UPPER 60S
ALLOWING TEMPS TO REACH THE MID 60S TO LOWER 70S.
SUNDAY...
THE UPPER RIDGE SHIFTS FARTHER SOUTH AND A COLD FRONT SLIDES INTO
NORTHERN NEW ENGLAND. WE WILL REMAIN ON THE WARM HUMID SIDE OF THE
FRONT WITH TEMPS AT THE TOP OF THE MIXED LAYER STILL SUPPORTING
MAX TEMPS IN THE LOWER 90S. IF CLOUDS FILL IN TOO FAST THEN MAX
TEMPS MAY FALL SHORT OF 90...BUT WE ARE GOING WITH THE SUNNIER AND
BETTER MIXED SCENARIO.
THE UPPER LOW THAT HAS BEEN CAMPED OUT OVER THE MISSISSIPPI RIVER
VALLEY WILL EJECT THROUGH THE GREAT LAKES SUNDAY. THE APPROACHING
SHORTWAVE AND THE STALLED FRONT TO OUR NORTH WILL EACH HAVE
ASSOCIATED UPPER JETS PROVIDING SOME DYNAMIC SUPPORT FOR LIFT. THE
AIRMASS WILL CONTINUE TO BE SOUPY WITH PW/S AROUND 2 INCHES...SO
PRIME POTENTIAL WILL BE FOR HEAVY DOWNPOURS/FLASH FLOODING.
SURFACE BASED CAPE FORECASTS SHOW 1500-3000 J/KG...0-6 KM SHEAR
SHOWS 30-40 KNOTS ESPECIALLY IN WESTERN SECTIONS. THIS WILL MEAN A
SECONDARY POTENTIAL FOR STRONG WIND GUSTS AND POSSIBLE WIND
DAMAGE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...
* WARM AND HUMID CONTINUES THROUGH NEXT WEEK
* SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY MAINLY INTERIOR
OVERVIEW AND MODEL PREFERENCES...
GUIDANCE APPEARS TO BE PROGRESSIVELY BECOMING DEEPER AND DEEPER
WITH LONGWAVE NRN CANADIAN TROF THROUGH MID TO LATE NEXT WEEK. THE
CONSEQUENCE APPEARS TO BE THAT THE BROAD E CONUS AND WRN ATLANTIC
RIDGE ASSOCIATED WITH THE BERMUDA HIGH WILL CONTINUE TO LOSE ITS
GRIP THROUGH THE LONG TERM SUCH THAT A WEAK ZONAL JET PATTERN WILL
BE FULLY IN CONTROL BY MID WEEK. RECENT RUNS OF THE ECENS AND GFS
ALSO SUPPORT THEIR OPERATIONAL BRETHREN THAT A SHIFT IN THE
AMPLIFIED FLOW REGIME BY LATE WEEK WOULD FEATURE A BROAD TROF
ACROSS THE NRN CONUS IN CONJUNCTION WITH THE CANADIAN TROF. WHILE
GUIDANCE TYPICALLY STRUGGLES TO HANDLE BROAD PATTERN CHANGES IN
THE EXTENDED...SINCE THERE IS AT LEAST SOME SUPPORT ACROSS THE
BOARD...HAVE A BIT HIGHER CONFIDENCE THAN USUAL REGARDING A STRONG
LOW PRES AND IT/S ASSOCIATED WARM AND COLD FRONTS AFFECTING THE
REGION TOWARD THE END OF THE WEEK. THIS MAY EVENTUALLY LEAD TO A
DRIER AND ULTIMATELY COOLER AIRMASS FOLLOWING THE COLD FRONT. HPC
CONTINUES TO FAVOR THE ECENS ENSEMBLES AND A BLEND OF THE
OPERATIONAL GFS/ECMWF...SO IN TANDEM WITH THE PREVIOUS
FORECASTER...WILL CONTINUE TO USE THE HPC AND A BLEND OF THE
OPERATIONAL MODELS FOR THIS UPDATE.
ESSENTIALLY...THE PATTERN LOOKS TO BE FAIRLY UNSETTLED RIGHT INTO
THE WEEKEND. MON APPEARS TO HAVE THE HIGHEST CHANCE FOR PRECIP
INITIALLY AS A SHORTWAVE AND ASSOCIATED COLD FRONT ARE EXPECTED
TO CROSS THE REGION. WHILE CONVECTION ON TUE CANNOT BE RULED
OUT...COVERAGE LOOKS TO BE LOWER. THEN...FOR WED-WEEKEND...A
STRONGER LOW PRES ASSOCIATED WITH DEEPER TROF RIDGING THE WEAK JET
WILL DRAG A WARM FRONT THROUGH...THEN A COLD FRONT THROUGH THE
CLOSER TO THE WEEKEND...WHICH COULD INCREASE THE THREAT FOR
CONVECTION LATE IN THE WEEK. STILL SOME PLAYERS YET TO LINE
UP...BUT THERE IS DECENT AGREEMENT IN THE SYNOPTIC PATTERN THAT
SUPPORT THIS THINKING. DO HAVE FAIRLY HIGH CONFIDENCE THAT THE
HUMID AIRMASS REMAINS IN PLACE HOWEVER...WITH DWPTS IN THE UPPER
60S AND LOW 70S MOST OF THE WEEK. TEMPS WILL BE WARM...BUT A BIT
COOLER THAN IS EXPECTED THIS WEEKEND.
DETAILS...
SUN NIGHT INTO TUE...
SUN NIGHT CONVECTION MAY LINGER SOMEWHAT INTO THE OVERNIGHT HOURS
THANKS TO NEAR 30 KT SHEAR AND ML CAPE VALUES HOLDING AROUND 1000
J/KG INITIALLY. HOWEVER...SHOULD BE SOME LATE NIGHT DRYING AS
MESOSCALE RIDGING BUILDS OVER BEHIND THE EXITING CONVECTION. ON
MON HOWEVER...WITH THE TROF THAT SPARKED THE CONVECTION EXPECTED
TO BE IN CLOSER PROXIMITY...AND A SFC COLD FRONT EXPECTED TO SLIDE
THROUGH ANOTHER ROUND OF DIURNALLY DRIVEN THUNDERSTORMS AND
SHOWERS ARE POSSIBLE. THE QUESTION IS HOW MUCH INSTABILITY IS
AVAILABLE GIVEN LAPSE RATES ARE MEAGER AT ABOUT 5.5-6.0C/KM.
SHOULD THE SUN BREAK OUT...ML CAPE VALUES LOOK TO APPROACH
1000-1500J/KG...AND SHEAR MAGNITUDES APPROACH 35-40 KT.
THEREFORE...HOW STRONG THE CONVECTION IS WILL BE DEPENDENT ON
CLOUD COVER INITIALLY...BUT THERE IS ENOUGH SUPPORT FOR ANY
CONVECTION THAT DOES FORM TO BECOME SOMEWHAT ORGANIZED. HEAVY RAIN
STILL THE BIGGEST THREAT THOUGH WITH PWAT VALUES APPROACHING 2.0
INCHES...SO WILL CONTINUE TO MENTION THIS IN WX WITH ANY T-STORMS.
NOT OUT OF THE QUESTION MORE STORMS COULD FIRE ON TUE...BUT WEAK
MID LVL RIDGE MAY BE ENOUGH TO FORCE BEST INSTABILITY/SHEAR/AND
FOCUS FOR LIFT TO THE N DURING THE DAY. WILL LOWER POPS SOMEWHAT
FROM THOSE ON MON. IN ANY CASE...IT APPEARS THAT COVERAGE WOULD BE
LESS.
WED INTO EARLY NEXT WEEKEND...
BROAD TROF IS EXPECTED TO DEEPEN IN VICINITY OF THE GREAT LAKES
THROUGH THIS PERIOD ALLOWING A LOW PRES CENTER TO PASS WELL N AND
W OF THE REGION. A SFC WARM FRONT WILL APPROACH AND LIKELY CROSS
THE REGION ON WED INTO EARLY THU. THIS COULD PROVIDE ANOTHER FOCUS
FOR MORE WIDESPREAD SHRA/T-STORMS AND ALLOW ALLOW FOR MID LVL
TEMPS TO REACH THOSE SIMILAR TO LATE THIS WEEK AND THIS WEEKEND.
THEREFORE...A FEW TEMPS THU COULD APPROACH 90F WITH THE HUMID
AIRMASS REMAINING IN PLACE ALLOWING FOR SUNSHINE. THE TIMING OF
THE COLD FRONT IS STILL A BIT IN QUESTION AS IT WILL BE DETERMINED
ON HOW AMPLIFIED THE UPPER LVL PATTERN GETS BY NEXT WEEK...BUT FOR
NOW WILL ERR TOWARD THE ENSEMBLE MEANS WHICH SUGGEST FRI OR FRI
NIGHT. IN ANY CASE...ANOTHER THREAT FOR STORMS AND RAINFALL.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM...
TODAY AND TONIGHT...HIGH CONFIDENCE.
MAINLY VFR CONDITIONS. SOME LOCALIZED LATE NIGHT AND EARLY
MORNING FOG MAY BRING 3 TO 5 MILE VSBYS. HOWEVER...GIVEN A
WESTERLY TRAJECTORY TO THE WIND NOT EXPECTING WIDESPREAD LOW
CLOUDS OR FOG. SLIGHT CHANCE OF AN AFTERNOON
THUNDERSHOWER...PARTICULARLY IN THE W INTERIOR.
SUNDAY...MODERATE TO HIGH CONFIDENCE.
MAINLY VFR. SCATTERED AFTERNOON/EVENING SHOWERS/TSTMS MAY BRING
BRIEF MVFR OR IFR CONDITIONS. BEST CHANCE FOR ANY TSTMS WILL BE IN
THE CT VALLEY AND IN SOUTHERN NH.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. ISOLATED CHANCE OF AN
AFTERNOON T-STORM IN VICINITY OF THE AIRPORT.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
HIGH CONFIDENCE IN OVERALL TRENDS...LOWER CONFIDENCE IN THE TIMING
OF ANY LOWER CATEGORIES THROUGH THE WEEK. LITTLE CHANGE IN
FORECAST.
MAINLY VFR. THERE IS A LOW TO MODERATE PROBABILITY OF SHOWERS AND
THUNDERSTORMS AND ACCOMPANYING MVFR/IFR CONDITIONS EACH AFTN/EVE.
FOG IS LIKELY TO DEVELOP MOST NIGHTS...WITH THE HIGHEST
PROBABILITY OF THIS HAPPENING ALONG THE SOUTH COAST. THIS WILL
LIMIT CIGS AND VSBYS TO IFR/MVFR AT TIMES.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE.
WINDS AND SEAS SHOULD REMAIN BELOW SCA THRESHOLDS THROUGH SUNDAY.
WINDS MAY GUST AROUND 20 KNOTS OR THE LOW 20S ALONG THE NEAR
SHORE WATERS OF THE SOUTH COAST THIS AFTERNOON. FOG WILL HAVE LESS
OF A PRESENCE THAN ON PREVIOUS DAYS...BUT PATCHES MAY LINGER
ESPECIALLY SOUTH AND EAST OF NANTUCKET.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
MODERATE CONFIDENCE THROUGH THE PERIOD.
PERSISTENT WEST TO SOUTHWEST WINDS AND LINGERING SWELL WILL ALLOW
SEAS TO REACH ABOUT 5 FT LATE MONDAY INTO TUESDAY ESPECIALLY ON
THE WATERS SOUTH AND SOUTHEAST OF SOUTHERN NEW ENGLAND. WINDS
SHOULD REMAIN BELOW SMALL CRAFT THRESHOLDS SAVE FOR THE AFTERNOON
AND EARLY EVENING HOURS SURROUNDING CAPE COD AND THE
ISLANDS...WHERE A FEW GUSTS APPROACHING 25 KT ARE POSSIBLE ON
MONDAY. OTHERWISE...SOME OVERNIGHT FOG AND STRATUS MAY CAUSE
OCCASIONAL REDUCTIONS IN VISIBILITY.
&&
.CLIMATE...
HERE ARE RECORD HIGHS FOR SOUTHERN NEW ENGLANDS OFFICIAL CLIMATE
SITES FOR JULY 5TH THROUGH THE 10TH
BOS PVD ORH BDL
6TH 101/1911 102/2010 102/2010 98/1911
7TH 99/1953 97/1993* 100/2010 95/1908
8TH 99/1937 99/1981 97/1993 97/1936*
9TH 99/1981* 99/1981 99/1936* 96/1937
10TH 101/1880 100/1993 100/1936* 95/1936*
* AND PREVIOUS YEARS
ALSO...SINCE WE ARE LOOKING AT AN EXTENDED PERIOD OF TEMPERATURES
ABOVE 90 DEGREES...HERE ARE THE LONGEST HEAT WAVES IN THE HISTORY
OF OUR 4 CLIMATE SITES.
HARTFORD/BRADLEY
JULY 24-AUGUST 2, 1995 - 10 DAYS
AUGUST 11-19, 2002 - 9 DAYS
AUGUST 27-SEPTEMBER 4, 1973 - 9 DAYS
JULY 27-AUGUST 3, 2006 - 8 DAYS
JULY 29-AUGUST 5, 2002 - 8 DAYS
JULY 16-23, 1991 - 8 DAYS
JULY 24-31, 1970 - 8 DAYS
AUGUST 28-SEPTEMBER 4, 1953 - 8 DAYS
AUGUST 10-17, 1944 - 8 DAYS
WORCESTER/AIRPORT
AUGUST 10-17, 1944 - 8 DAYS
JULY 4-11, 1912 - 8 DAYS
JUNE 26-JULY 3, 1901 - 8 DAYS
AUGUST 10-15, 1988 - 6 DAYS
JULY 25-29, 1963 - 5 DAYS
BOSTON/LOGAN AIRPORT
JULY 3-11, 1912 - 9 DAYS
AUGUST 11-18, 2002 - 8 DAYS
JULY 19-26, 1994 - 8 DAYS
AUGUST 10-17, 1944 - 8 DAYS
JUNE 28-JULY 5, 1872 - 8 DAYS
PROVIDENCE/T.F. GREEN
JULY 12-20, 1952 - 9 DAYS
JULY 28-AUGUST 3, 2006 - 7 DAYS
AUGUST 13-19, 2002 - 7 DAYS
JULY 15-21, 1977 - 7 DAYS
AUGUST 11-17, 1944 - 7 DAYS
JULY 7-13, 1944 - 7 DAYS
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR CTZ002>004.
MA...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR MAZ005>007-010-
011-013>019.
NH...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NHZ012.
RI...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR RIZ001>004.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/DOODY
NEAR TERM...SIPPRELL
SHORT TERM...WTB
LONG TERM...DOODY
AVIATION...WTB/DOODY
MARINE...WTB/DOODY
CLIMATE...WFO BOX STAFF
PLEASE REFERENCE THE PREVIOUS LONG TERM FORECAST DISCUSSION BELOW.
20
/PREVIOUS LONG TERM DISCUSSION/SATURDAY NIGHT THROUGH THURSDAY/
THE EXTENDED PERIOD CONTINUES WET WITH PERSISTENT UPPER LOW OVER
THE MISSOURI VALLEY SPAWNING ADDITIONAL SHORTWAVE ENERGY SATURDAY
NIGHT. THIS UPPER SUPPORT ALONG WITH PWATS REMAINING WELL ABOVE 2
INCHES WILL ALLOW FOR LIKELY POPS EVEN INTO THE OVERNIGHT PERIOD
WITH HEALTHY AMOUNTS OF QPF IN THE .30 TO .50 RANGE FOR SIX HOUR
PERIODS. BY SUNDAY AFTERNOON...UPPER LOW WILL TRANSITION INTO THE
OHIO VALLEY WITH GFS DEPICTING UPPER TROUGH AXIS INTO NORTHERN
GEORGIA. WITH CONTINUED AMPLE MOISTURE...EXPECT CATEGORICAL POPS
GIVEN SHORTWAVE ENERGY AVAILABLE TO FUEL STORM DEVELOPMENT.
AS LOW FINALLY KICKS OUT THROUGH MIDWEEK...MOISTURE AXIS PIVOTS
BUT REMAINS OVER THE NORTH GEORGIA PORTION. ALTHOUGH UPPER ENERGY
WILL NOT BE AS PREVALENT...SHOULD SEE MORE THAN ENOUGH INGREDIENTS
TO WARRANT HIGH END CHANCE TO LIKELY POPS THROUGH WEDNESDAY. GFS
INDICATES 48 HOUR TOTALS ENDING THU MORNING OF AN ADDITIONAL 2
INCHES FOR THE NORTHERN TIER WHICH WOULD CREATE ADDITIONAL FLOODING
CONCERNS PENDING WHAT TAKES PLACE THE NEXT FEW DAYS.
BY LATE WED INTO THU...UPPER LOW OVER THE GULF BECOMES MORE OF A
PROMINENT FEATURE AS INFLUENCES OF ATLANTIC UPPER HIGH ABATE.
MEANWHILE...NORTHERN STREAM SHORTWAVE DIGS SOUTHWARD WITH A
SURFACE BOUNDARY ENTERING NORTH GEORGIA THU AFTERNOON. MOISTURE
POOLING ALONG THIS FEATURE WILL INCREASE POPS ONCE AGAIN AND WILL
CARRY HIGH MID RANGE POPS IN GRIDS FOR NOW.
GIVEN TIME OF YEAR...BOUNDARY DOES NOT MAKE IT VERY FAR INTO THE
FORECAST AREA BEFORE STALLING. ADDITIONAL SHORTWAVE ENERGY IN
DEVELOPING NORTHWEST FLOW ALOFT REGIME WILL KEEP POPS AT OR ABOVE
CLIMO THROUGH THE EXTENDED PERIOD WITH TEMPS AT OR BELOW NORMAL.
DEESE
HYDROLOGY...
THE LATEST QPF PROJECTIONS OFF THE MODELS INDICATE ANOTHER 1 TO 2
1/2 INCHES ARE POSSIBLE ACROSS THE MOUNTAINS AND DOWN THE WEST SIDE
OF THE CWA THROUGH SUNDAY. WITH THE GROUND SATURATED OVER MOST OF
THOSE AREAS ALREADY...ANOTHER 1 TO 2 INCHES OF RAIN WILL PUSH RIVERS
AND STREAMS INTO FLOOD. THEREFORE WILL ISSUE A FLOOD WATCH FOR AREAS
NORTH OF A LINE FROM LAGRANGE TO FAYETTEVILLE TO HOMER THROUGH 12Z
SUNDAY. FOR THOSE AREAS SOUTH OF THIS NEW WATCH...WHILE ISOLATED
POCKETS OF HEAVY ARE POSSIBLE IN THE THUNDERSTORMS...WIDESPREAD
FLOODING IS NOT EXPECTED AND THEREFORE THE FLASH FLOOD WATCH WILL
EXPIRE AT 8 PM THIS EVENING AND WILL NOT BE REISSUED.
&&
.AVIATION...
06Z UPDATE...
MAINLY IFR CONDITIONS AT TAF TIME THOUGH AHN AND ODDLY FTY ARE
HOLDING ONTO IMPROVED CONDITIONS FOR THE TIME BEING. EXPECT CIGS
TO REMAIN LOW THROUGH THE MID-MORNING HOURS WITH ONLY A GRADUAL
INCREASE DURING THE DAY. AHN/CSG/MCN WILL LIKELY GO LOW VFR IN THE
AFTERNOON. HAVE KEPT PROB30 FOR AFTERNOON TSRA. EXPECT IFR CIGS
AGAIN TOMORROW. WINDS GENERALLY SE THROUGH THE PERIOD 5-10KT.
//ATL CONFIDENCE...06Z UPDATE...
HIGH ON WINDS.
MEDIUM ON ALL OTHER ELEMENTS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 70 84 72 / 80 80 60 60
ATLANTA 82 71 82 72 / 100 90 70 50
BLAIRSVILLE 77 68 77 64 / 100 90 90 60
CARTERSVILLE 80 71 82 70 / 100 90 90 60
COLUMBUS 85 72 85 73 / 80 60 70 30
GAINESVILLE 80 70 80 71 / 100 90 80 60
MACON 86 71 87 71 / 60 60 60 30
ROME 79 71 81 71 / 100 90 90 60
PEACHTREE CITY 83 70 82 71 / 90 80 70 30
VIDALIA 89 73 89 72 / 50 20 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SUNDAY MORNING FOR THE FOLLOWING ZONES:
BANKS...BARROW...BARTOW...CARROLL...CATOOSA...CHATTOOGA...
CHEROKEE...CLAYTON...COBB...COWETA...DADE...DAWSON...DEKALB...
DOUGLAS...FANNIN...FAYETTE...FLOYD...FORSYTH...GILMER...GORDON...
GWINNETT...HALL...HARALSON...HEARD...JACKSON...LUMPKIN...
MERIWETHER...MURRAY...NORTH FULTON...PAULDING...PICKENS...POLK...
SOUTH FULTON...TOWNS...TROUP...UNION...WALKER...WHITE...
WHITFIELD.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
100 PM CDT SAT JUL 6 2013
.DISCUSSION...
ISSUED 1045 AM CDT SAT JUL 6 2013
FORECAST GENERALLY LOOKS ON TRACK TODAY AND JUST A FEW MINOR
ADJUSTMENTS TO SKY COVER AND WX/POPS GRIDS TODAY. WILL CONTINUE A
CHANCE OF SHOWERS AND A FEW THUNDERSTORMS OVER EASTERN IL TODAY
MAINLY EAST OF I-55 WITH BEST CHANCES EAST OF I-57 WHERE MORE
CLOUDS EXPECTED HERE AND COOLER HIGHS IN THE UPPER 70S TO NEAR 80F.
MORE SUNSHINE FROM I-55 WEST WITH HIGHS IN THE MIDDLE 80S. RATHER
HUMID ACROSS THE AREA TODAY WITH DEWPOINTS IN THE MID TO UPPER 60S.
579 DM 500 MB LOW OVER SE MO TO MOVE EAST INTO SOUTHERN IL THIS
EVENING AND INTO CENTRAL INDIANA BY MIDDAY SUNDAY. TROPICAL FETCH
OF MOISTURE FROM THE GULF OF MEXICO NORTHWARD INTO THE OHIO/TN
VALLEYS AND INTO EASTERN IL AS WELL TO KEEP BEST CHANCES OF
CONVECTION TIED TO THAT PART OF THE STATE THROUGH THIS EVENING.
07
&&
.AVIATION...
ISSUED 100 PM CDT SAT JUL 6 2013
MVFR TO VFR BROKEN CEILINGS 2.5-5K FT WILL BE POSSIBLE AT TIMES
THIS AFTERNOON WITH ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE
SE OF I-55...MAINLY AT DEC AND CMI AS 580 DM 500 LOW OVER SE MO
DRIFTS EAST INTO SOUTHERN IL THIS EVENING AND INTO CENTRAL INDIANA
BY 18Z/1 PM SUNDAY. BETTER CHANCE OF SHOWERS AND STRONGER
THUNDERSTORMS WITH IFR VSBYS FROM HEAVY RAINS WILL BE SOUTH OF
I-72 FROM MID AFTERNOON UNTIL SUNSET. SSW WINDS 5-10 KTS TO BECOME
LIGHT SOUTH AFTER SUNSET AS ISOLATED CONVECTION AND CUMULUS CLOUDS
DISSIPATE. SOME FOG TO DEVELOP AGAIN OVERNIGHT INTO EARLY SAT
MORNING ESPECIALLY OVER EASTERN IL WITH VSBYS DOWN TO 1-3 MILES.
HI- RESOLUTION MODELS SHOWING MORE SHOWERS AND ISOLATED
THUNDERSTORMS DEVOPING LATE TONIGHT/EARLY SUNDAY MORNING NEAR THE
MS RIVER OF WEST CENTRAL IL AND SPREADING EAST INTO CENTRAL IL
DURING SUNDAY MORNING AS IT WEAKENS. WILL ADD VCSH AFTER 14Z/9 AM
SUNDAY FOR ALL BUT CMI AIRPORT.
07
&&
.PREV DISCUSSION...
ISSUED 258 AM CDT SAT JUL 6 2013
SHORT TERM...TODAY THROUGH MONDAY
DEEP LAYER MOISTURE CONTINUES TO STREAM NORTHWARD ON THE PERIPHERY
OF THE BERMUDA HIGH...AS SHOWN BY WIDE SWATH OF 850MB DEWPOINTS
AROUND 15C FROM THE GULF COAST TO THE EASTERN GREAT LAKES. MOST
OF THIS MOISTURE HAS REMAINED EAST OF CENTRAL ILLINOIS OVER THE
PAST FEW DAYS...HOWEVER SOME OF IT WILL GET PULLED A BIT FURTHER
WESTWARD TODAY AS PERSISTENT UPPER LOW OVER MISSOURI FINALLY
BEGINS TO SHIFT EASTWARD. WATER VAPOR IMAGERY FROM EARLIER THIS
EVENING SHOWED A WELL-DEFINED SHORT-WAVE LIFTING NORTHWARD ON THE
EASTERN FLANK OF THE LOW AROUND MEMPHIS TENNESSEE. THIS FEATURE
HAS PULLED QUITE A BIT OF HIGH CLOUD COVER WESTWARD INTO CENTRAL
ILLINOIS...AND IS BEGINNING TO TRIGGER SHOWERS ACROSS FAR SOUTHERN
ILLINOIS. 04Z HRRR PREDICTED THIS DEVELOPMENT BETWEEN 06Z AND 07Z
QUITE NICELY...SO WILL FOLLOW CLOSELY FOR THE IMMEDIATE SHORT-TERM
FORECAST. SHOWERS/THUNDER ACROSS SOUTHERN ILLINOIS WILL SPREAD
N/NE OVER THE NEXT FEW HOURS...WITH CURRENT TRAJECTORIES KEEPING
THE BULK OF THE RAIN ACROSS FAR SE ILLINOIS INTO INDIANA THIS
MORNING. AS UPPER LOW/COOL POOL ALOFT BEGINS TO SHIFT
EASTWARD...SCATTERED SHOWERS/THUNDER WILL DEVELOP FURTHER WEST
LATER THIS MORNING INTO THE AFTERNOON. BASED ON MOST HIGH-RES
MODEL OUTPUT...IT APPEARS SHOWERS WILL MAINLY BE FOCUSED EAST OF
I-55. FOR POP FORECAST TODAY...HAVE DECIDED TO INCREASE TO LIKELY
ACROSS THE FAR SE KILX CWA WHERE CURRENT DEVELOPMENT ACROSS
SOUTHERN ILLINOIS WILL IMPACT DURING THE MORNING HOURS. WILL CARRY
CHANCE POPS ACROSS ALL OF EAST-CENTRAL ILLINOIS...WITH SLIGHT
CHANCE AS FAR WEST AS I-55. AFTER A FEW LINGERING SHOWERS ACROSS
THE EAST THIS EVENING...DRY WEATHER IS EXPECTED ACROSS THE BOARD
OVERNIGHT.
UPPER LOW WILL BEGIN TO PULL AWAY FROM THE REGION ON SUNDAY...AS
IT GRADUALLY GETS SHUNTED EASTWARD BY PREVAILING JET STREAM OVER
THE NORTHERN TIER OF STATES. WITH LITTLE OR NO UPPER FORCING
REMAINING IN PLACE AND NO SUBSTANTIAL SURFACE BOUNDARY IN THE
VICINITY...THINK RAIN CHANCES WILL BE SLIM ON SUNDAY. DESPITE
RISING HEIGHTS AND OTHER MITIGATING FACTORS...MODELS INSIST THAT
WIDELY SCATTERED CONVECTION WILL DEVELOP DURING THE AFTERNOON. WILL
CARRY SLIGHT CHANCE POPS...BUT THINK SUNDAY WILL MAINLY BE A WARM
AND DRY DAY.
THINGS BEGIN TO GET A LITTLE MORE CHALLENGING EARLY NEXT WEEK...AS
CENTRAL ILLINOIS BECOMES POSITIONED ON THE NORTHERN FLANK OF AN
UPPER-LEVEL HIGH CENTERED OVER THE SOUTHERN PLAINS. THIS
PARTICULAR PATTERN HAS BEEN QUITE COMMON OVER THE PAST COUPLE OF
MONTHS...AND HAS LED TO COPIOUS RAINFALL ACROSS THE AREA. WITH
THIS PATTERN ONCE AGAIN ESTABLISHING ITSELF...WILL NEED TO KEEP A
CLOSE EYE ON THE DEVELOPMENT/TRACK OF NOCTURNAL MCS ACTIVITY
STARTING SUNDAY NIGHT. MODELS ARE IN POOR AGREEMENT CONCERNING
EXACT DETAILS...ALTHOUGH IT APPEARS THE PRIMARY TIME FRAME PARTS
OF CENTRAL ILLINOIS COULD BE IMPACTED BY A CONVECTIVE SYSTEM WOULD
BE MONDAY NIGHT. MOISTURE/INSTABILITY PARAMETERS ARE NOT THAT
FAVORABLE SUNDAY NIGHT...WITH MOST MODELS TRYING TO DEVELOP
CONVECTION ACROSS IOWA OVERNIGHT THEN DROPPING REMNANTS INTO
ILLINOIS ON MONDAY. WILL CARRY CHANCE POPS ACROSS THE NORTHWEST
CWA AFTER MIDNIGHT ACCORDINGLY...WITH CHANCE POPS SPREADING
FURTHER E/SE ON MONDAY.
LONG TERM...TUESDAY THROUGH FRIDAY
AFTER ANOTHER MCS TRACKS E/SE OUT OF IOWA ACROSS NORTH-CENTRAL
ILLINOIS LATE MONDAY NIGHT INTO TUESDAY...A NORTHERN STREAM-SHORT
WAVE WILL PUSH A COLD FRONT TOWARD THE AREA TUESDAY NIGHT INTO
WEDNESDAY. GFS/ECMWF IN GOOD AGREEMENT WITH TIMING OF FROPA ON
WEDNESDAY. WITH PLENTY OF MOISTURE IN PLACE AHEAD OF THE
FRONT...WILL CARRY LIKELY POPS ACROSS THE WEST TUESDAY
NIGHT...THEN FURTHER EAST INTO EAST-CENTRAL AND SOUTHEAST ILLINOIS
ON WEDNESDAY. MODEL CONSENSUS TAKES FRONT INTO THE OHIO RIVER
VALLEY WEDNESDAY NIGHT...WITH HIGH PRESSURE BUILDING INTO THE
UPPER MIDWEST/GREAT LAKES FOR THE END OF THE WEEK. GIVEN GOOD
MODEL AGREEMENT...HAVE SCALED BACK POPS WEDNESDAY EVENING TO
INCLUDE ONLY THE FAR SE CWA. AFTER THAT...HAVE GONE DRY FOR
THURSDAY AND FRIDAY...WITH SLIGHTLY COOLER TEMPS IN THE LOWER 80S.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CDT SAT JUL 6 2013
.DISCUSSION...
ISSUED 1045 AM CDT SAT JUL 6 2013
FORECAST GENERALLY LOOKS ON TRACK TODAY AND JUST A FEW MINOR
ADJUSTMENTS TO SKY COVER AND WX/POPS GRIDS TODAY. WILL CONTINUE A
CHANCE OF SHOWERS AND A FEW THUNDERSTORMS OVER EASTERN IL TODAY
MAINLY EAST OF I-55 WITH BEST CHANCES EAST OF I-57 WHERE MORE
CLOUDS EXPECTED HERE AND COOLER HIGHS IN THE UPPER 70S TO NEAR 80F.
MORE SUNSHINE FROM I-55 WEST WITH HIGHS IN THE MIDDLE 80S. RATHER
HUMID ACROSS THE AREA TODAY WITH DEWPOINTS IN THE MID TO UPPER 60S.
579 DM 500 MB LOW OVER SE MO TO MOVE EAST INTO SOUTHERN IL THIS
EVENING AND INTO CENTRAL INDIANA BY MIDDAY SUNDAY. TROPICAL FETCH
OF MOISTURE FROM THE GULF OF MEXICO NORTHWARD INTO THE OHIO/TN
VALLEYS AND INTO EASTERN IL AS WELL TO KEEP BEST CHANCES OF
CONVECTION TIED TO THAT PART OF THE STATE THROUGH THIS EVENING.
07
&&
.AVIATION...
ISSUED 640 AM CDT SAT JUL 6 2013
FOG HAS STAYED UNDER CONTROL AS OPPOSED TO YESTERDAY MORNING...
WITH MVFR VISIBILITIES GENERALLY ABOVE 2SM. SMALL AREA OF CEILINGS
BELOW 1000 FEET WAS LOCATED SOUTH OF KCMI AND WILL NEED TO MONITOR
THIS CLOSELY FOR ANY NORTHWARD ADVECTION OVER THE NEXT FEW HOURS.
HAVE NOT MADE MUCH CHANGE TO THE GOING TAF FORECASTS IN THE 14-06Z
TIME FRAME...WITH SCATTERED CONVECTION DEVELOPING OVER EAST
CENTRAL ILLINOIS LATER THIS MORNING. OCCURRENCE OF THUNDER APPEARS
MOST LIKELY AROUND KCMI...AND CANNOT BE RULED OUT FURTHER WEST
TOWARD KDEC/KBMI ALTHOUGH THE STORMS WILL BE MUCH FARTHER APART
THAT FAR WEST. HAVE KEPT WESTERN PARTS OF CENTRAL ILLINOIS DRY
THROUGH THE DAY. OVERNIGHT...MVFR VISIBILITIES LIKELY AGAIN
SIMILAR TO THIS MORNING.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 258 AM CDT SAT JUL 6 2013
SHORT TERM...TODAY THROUGH MONDAY
DEEP LAYER MOISTURE CONTINUES TO STREAM NORTHWARD ON THE PERIPHERY
OF THE BERMUDA HIGH...AS SHOWN BY WIDE SWATH OF 850MB DEWPOINTS
AROUND 15C FROM THE GULF COAST TO THE EASTERN GREAT LAKES. MOST
OF THIS MOISTURE HAS REMAINED EAST OF CENTRAL ILLINOIS OVER THE
PAST FEW DAYS...HOWEVER SOME OF IT WILL GET PULLED A BIT FURTHER
WESTWARD TODAY AS PERSISTENT UPPER LOW OVER MISSOURI FINALLY
BEGINS TO SHIFT EASTWARD. WATER VAPOR IMAGERY FROM EARLIER THIS
EVENING SHOWED A WELL-DEFINED SHORT-WAVE LIFTING NORTHWARD ON THE
EASTERN FLANK OF THE LOW AROUND MEMPHIS TENNESSEE. THIS FEATURE
HAS PULLED QUITE A BIT OF HIGH CLOUD COVER WESTWARD INTO CENTRAL
ILLINOIS...AND IS BEGINNING TO TRIGGER SHOWERS ACROSS FAR SOUTHERN
ILLINOIS. 04Z HRRR PREDICTED THIS DEVELOPMENT BETWEEN 06Z AND 07Z
QUITE NICELY...SO WILL FOLLOW CLOSELY FOR THE IMMEDIATE SHORT-TERM
FORECAST. SHOWERS/THUNDER ACROSS SOUTHERN ILLINOIS WILL SPREAD
N/NE OVER THE NEXT FEW HOURS...WITH CURRENT TRAJECTORIES KEEPING
THE BULK OF THE RAIN ACROSS FAR SE ILLINOIS INTO INDIANA THIS
MORNING. AS UPPER LOW/COOL POOL ALOFT BEGINS TO SHIFT
EASTWARD...SCATTERED SHOWERS/THUNDER WILL DEVELOP FURTHER WEST
LATER THIS MORNING INTO THE AFTERNOON. BASED ON MOST HIGH-RES
MODEL OUTPUT...IT APPEARS SHOWERS WILL MAINLY BE FOCUSED EAST OF
I-55. FOR POP FORECAST TODAY...HAVE DECIDED TO INCREASE TO LIKELY
ACROSS THE FAR SE KILX CWA WHERE CURRENT DEVELOPMENT ACROSS
SOUTHERN ILLINOIS WILL IMPACT DURING THE MORNING HOURS. WILL CARRY
CHANCE POPS ACROSS ALL OF EAST-CENTRAL ILLINOIS...WITH SLIGHT
CHANCE AS FAR WEST AS I-55. AFTER A FEW LINGERING SHOWERS ACROSS
THE EAST THIS EVENING...DRY WEATHER IS EXPECTED ACROSS THE BOARD
OVERNIGHT.
UPPER LOW WILL BEGIN TO PULL AWAY FROM THE REGION ON SUNDAY...AS
IT GRADUALLY GETS SHUNTED EASTWARD BY PREVAILING JET STREAM OVER
THE NORTHERN TIER OF STATES. WITH LITTLE OR NO UPPER FORCING
REMAINING IN PLACE AND NO SUBSTANTIAL SURFACE BOUNDARY IN THE
VICINITY...THINK RAIN CHANCES WILL BE SLIM ON SUNDAY. DESPITE
RISING HEIGHTS AND OTHER MITIGATING FACTORS...MODELS INSIST THAT
WIDELY SCATTERED CONVECTION WILL DEVELOP DURING THE AFTERNOON. WILL
CARRY SLIGHT CHANCE POPS...BUT THINK SUNDAY WILL MAINLY BE A WARM
AND DRY DAY.
THINGS BEGIN TO GET A LITTLE MORE CHALLENGING EARLY NEXT WEEK...AS
CENTRAL ILLINOIS BECOMES POSITIONED ON THE NORTHERN FLANK OF AN
UPPER-LEVEL HIGH CENTERED OVER THE SOUTHERN PLAINS. THIS
PARTICULAR PATTERN HAS BEEN QUITE COMMON OVER THE PAST COUPLE OF
MONTHS...AND HAS LED TO COPIOUS RAINFALL ACROSS THE AREA. WITH
THIS PATTERN ONCE AGAIN ESTABLISHING ITSELF...WILL NEED TO KEEP A
CLOSE EYE ON THE DEVELOPMENT/TRACK OF NOCTURNAL MCS ACTIVITY
STARTING SUNDAY NIGHT. MODELS ARE IN POOR AGREEMENT CONCERNING
EXACT DETAILS...ALTHOUGH IT APPEARS THE PRIMARY TIME FRAME PARTS
OF CENTRAL ILLINOIS COULD BE IMPACTED BY A CONVECTIVE SYSTEM WOULD
BE MONDAY NIGHT. MOISTURE/INSTABILITY PARAMETERS ARE NOT THAT
FAVORABLE SUNDAY NIGHT...WITH MOST MODELS TRYING TO DEVELOP
CONVECTION ACROSS IOWA OVERNIGHT THEN DROPPING REMNANTS INTO
ILLINOIS ON MONDAY. WILL CARRY CHANCE POPS ACROSS THE NORTHWEST
CWA AFTER MIDNIGHT ACCORDINGLY...WITH CHANCE POPS SPREADING
FURTHER E/SE ON MONDAY.
LONG TERM...TUESDAY THROUGH FRIDAY
AFTER ANOTHER MCS TRACKS E/SE OUT OF IOWA ACROSS NORTH-CENTRAL
ILLINOIS LATE MONDAY NIGHT INTO TUESDAY...A NORTHERN STREAM-SHORT
WAVE WILL PUSH A COLD FRONT TOWARD THE AREA TUESDAY NIGHT INTO
WEDNESDAY. GFS/ECMWF IN GOOD AGREEMENT WITH TIMING OF FROPA ON
WEDNESDAY. WITH PLENTY OF MOISTURE IN PLACE AHEAD OF THE
FRONT...WILL CARRY LIKELY POPS ACROSS THE WEST TUESDAY
NIGHT...THEN FURTHER EAST INTO EAST-CENTRAL AND SOUTHEAST ILLINOIS
ON WEDNESDAY. MODEL CONSENSUS TAKES FRONT INTO THE OHIO RIVER
VALLEY WEDNESDAY NIGHT...WITH HIGH PRESSURE BUILDING INTO THE
UPPER MIDWEST/GREAT LAKES FOR THE END OF THE WEEK. GIVEN GOOD
MODEL AGREEMENT...HAVE SCALED BACK POPS WEDNESDAY EVENING TO
INCLUDE ONLY THE FAR SE CWA. AFTER THAT...HAVE GONE DRY FOR
THURSDAY AND FRIDAY...WITH SLIGHTLY COOLER TEMPS IN THE LOWER 80S.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
641 AM CDT SAT JUL 6 2013
.DISCUSSION...
ISSUED 258 AM CDT SAT JUL 6 2013
SHORT TERM...TODAY THROUGH MONDAY
DEEP LAYER MOISTURE CONTINUES TO STREAM NORTHWARD ON THE PERIPHERY
OF THE BERMUDA HIGH...AS SHOWN BY WIDE SWATH OF 850MB DEWPOINTS
AROUND 15C FROM THE GULF COAST TO THE EASTERN GREAT LAKES. MOST
OF THIS MOISTURE HAS REMAINED EAST OF CENTRAL ILLINOIS OVER THE
PAST FEW DAYS...HOWEVER SOME OF IT WILL GET PULLED A BIT FURTHER
WESTWARD TODAY AS PERSISTENT UPPER LOW OVER MISSOURI FINALLY
BEGINS TO SHIFT EASTWARD. WATER VAPOR IMAGERY FROM EARLIER THIS
EVENING SHOWED A WELL-DEFINED SHORT-WAVE LIFTING NORTHWARD ON THE
EASTERN FLANK OF THE LOW AROUND MEMPHIS TENNESSEE. THIS FEATURE
HAS PULLED QUITE A BIT OF HIGH CLOUD COVER WESTWARD INTO CENTRAL
ILLINOIS...AND IS BEGINNING TO TRIGGER SHOWERS ACROSS FAR SOUTHERN
ILLINOIS. 04Z HRRR PREDICTED THIS DEVELOPMENT BETWEEN 06Z AND 07Z
QUITE NICELY...SO WILL FOLLOW CLOSELY FOR THE IMMEDIATE SHORT-TERM
FORECAST. SHOWERS/THUNDER ACROSS SOUTHERN ILLINOIS WILL SPREAD
N/NE OVER THE NEXT FEW HOURS...WITH CURRENT TRAJECTORIES KEEPING
THE BULK OF THE RAIN ACROSS FAR SE ILLINOIS INTO INDIANA THIS
MORNING. AS UPPER LOW/COOL POOL ALOFT BEGINS TO SHIFT
EASTWARD...SCATTERED SHOWERS/THUNDER WILL DEVELOP FURTHER WEST
LATER THIS MORNING INTO THE AFTERNOON. BASED ON MOST HIGH-RES
MODEL OUTPUT...IT APPEARS SHOWERS WILL MAINLY BE FOCUSED EAST OF
I-55. FOR POP FORECAST TODAY...HAVE DECIDED TO INCREASE TO LIKELY
ACROSS THE FAR SE KILX CWA WHERE CURRENT DEVELOPMENT ACROSS
SOUTHERN ILLINOIS WILL IMPACT DURING THE MORNING HOURS. WILL CARRY
CHANCE POPS ACROSS ALL OF EAST-CENTRAL ILLINOIS...WITH SLIGHT
CHANCE AS FAR WEST AS I-55. AFTER A FEW LINGERING SHOWERS ACROSS
THE EAST THIS EVENING...DRY WEATHER IS EXPECTED ACROSS THE BOARD
OVERNIGHT.
UPPER LOW WILL BEGIN TO PULL AWAY FROM THE REGION ON SUNDAY...AS
IT GRADUALLY GETS SHUNTED EASTWARD BY PREVAILING JET STREAM OVER
THE NORTHERN TIER OF STATES. WITH LITTLE OR NO UPPER FORCING
REMAINING IN PLACE AND NO SUBSTANTIAL SURFACE BOUNDARY IN THE
VICINITY...THINK RAIN CHANCES WILL BE SLIM ON SUNDAY. DESPITE
RISING HEIGHTS AND OTHER MITIGATING FACTORS...MODELS INSIST THAT
WIDELY SCATTERED CONVECTION WILL DEVELOP DURING THE AFTERNOON. WILL
CARRY SLIGHT CHANCE POPS...BUT THINK SUNDAY WILL MAINLY BE A WARM
AND DRY DAY.
THINGS BEGIN TO GET A LITTLE MORE CHALLENGING EARLY NEXT WEEK...AS
CENTRAL ILLINOIS BECOMES POSITIONED ON THE NORTHERN FLANK OF AN
UPPER-LEVEL HIGH CENTERED OVER THE SOUTHERN PLAINS. THIS
PARTICULAR PATTERN HAS BEEN QUITE COMMON OVER THE PAST COUPLE OF
MONTHS...AND HAS LED TO COPIOUS RAINFALL ACROSS THE AREA. WITH
THIS PATTERN ONCE AGAIN ESTABLISHING ITSELF...WILL NEED TO KEEP A
CLOSE EYE ON THE DEVELOPMENT/TRACK OF NOCTURNAL MCS ACTIVITY
STARTING SUNDAY NIGHT. MODELS ARE IN POOR AGREEMENT CONCERNING
EXACT DETAILS...ALTHOUGH IT APPEARS THE PRIMARY TIME FRAME PARTS
OF CENTRAL ILLINOIS COULD BE IMPACTED BY A CONVECTIVE SYSTEM WOULD
BE MONDAY NIGHT. MOISTURE/INSTABILITY PARAMETERS ARE NOT THAT
FAVORABLE SUNDAY NIGHT...WITH MOST MODELS TRYING TO DEVELOP
CONVECTION ACROSS IOWA OVERNIGHT THEN DROPPING REMNANTS INTO
ILLINOIS ON MONDAY. WILL CARRY CHANCE POPS ACROSS THE NORTHWEST
CWA AFTER MIDNIGHT ACCORDINGLY...WITH CHANCE POPS SPREADING
FURTHER E/SE ON MONDAY.
LONG TERM...TUESDAY THROUGH FRIDAY
AFTER ANOTHER MCS TRACKS E/SE OUT OF IOWA ACROSS NORTH-CENTRAL
ILLINOIS LATE MONDAY NIGHT INTO TUESDAY...A NORTHERN STREAM-SHORT
WAVE WILL PUSH A COLD FRONT TOWARD THE AREA TUESDAY NIGHT INTO
WEDNESDAY. GFS/ECMWF IN GOOD AGREEMENT WITH TIMING OF FROPA ON
WEDNESDAY. WITH PLENTY OF MOISTURE IN PLACE AHEAD OF THE
FRONT...WILL CARRY LIKELY POPS ACROSS THE WEST TUESDAY
NIGHT...THEN FURTHER EAST INTO EAST-CENTRAL AND SOUTHEAST ILLINOIS
ON WEDNESDAY. MODEL CONSENSUS TAKES FRONT INTO THE OHIO RIVER
VALLEY WEDNESDAY NIGHT...WITH HIGH PRESSURE BUILDING INTO THE
UPPER MIDWEST/GREAT LAKES FOR THE END OF THE WEEK. GIVEN GOOD
MODEL AGREEMENT...HAVE SCALED BACK POPS WEDNESDAY EVENING TO
INCLUDE ONLY THE FAR SE CWA. AFTER THAT...HAVE GONE DRY FOR
THURSDAY AND FRIDAY...WITH SLIGHTLY COOLER TEMPS IN THE LOWER 80S.
BARNES
&&
.AVIATION...
ISSUED 640 AM CDT SAT JUL 6 2013
FOG HAS STAYED UNDER CONTROL AS OPPOSED TO YESTERDAY MORNING...
WITH MVFR VISIBILITIES GENERALLY ABOVE 2SM. SMALL AREA OF CEILINGS
BELOW 1000 FEET WAS LOCATED SOUTH OF KCMI AND WILL NEED TO MONITOR
THIS CLOSELY FOR ANY NORTHWARD ADVECTION OVER THE NEXT FEW HOURS.
HAVE NOT MADE MUCH CHANGE TO THE GOING TAF FORECASTS IN THE 14-06Z
TIME FRAME...WITH SCATTERED CONVECTION DEVELOPING OVER EAST
CENTRAL ILLINOIS LATER THIS MORNING. OCCURRENCE OF THUNDER APPEARS
MOST LIKELY AROUND KCMI...AND CANNOT BE RULED OUT FURTHER WEST
TOWARD KDEC/KBMI ALTHOUGH THE STORMS WILL BE MUCH FARTHER APART
THAT FAR WEST. HAVE KEPT WESTERN PARTS OF CENTRAL ILLINOIS DRY
THROUGH THE DAY. OVERNIGHT...MVFR VISIBILITIES LIKELY AGAIN
SIMILAR TO THIS MORNING.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
258 AM CDT SAT JUL 6 2013
.DISCUSSION...
ISSUED 258 AM CDT SAT JUL 6 2013
SHORT TERM...TODAY THROUGH MONDAY
DEEP LAYER MOISTURE CONTINUES TO STREAM NORTHWARD ON THE PERIPHERY
OF THE BERMUDA HIGH...AS SHOWN BY WIDE SWATH OF 850MB DEWPOINTS
AROUND 15C FROM THE GULF COAST TO THE EASTERN GREAT LAKES. MOST
OF THIS MOISTURE HAS REMAINED EAST OF CENTRAL ILLINOIS OVER THE
PAST FEW DAYS...HOWEVER SOME OF IT WILL GET PULLED A BIT FURTHER
WESTWARD TODAY AS PERSISTENT UPPER LOW OVER MISSOURI FINALLY
BEGINS TO SHIFT EASTWARD. WATER VAPOR IMAGERY FROM EARLIER THIS
EVENING SHOWED A WELL-DEFINED SHORT-WAVE LIFTING NORTHWARD ON THE
EASTERN FLANK OF THE LOW AROUND MEMPHIS TENNESSEE. THIS FEATURE
HAS PULLED QUITE A BIT OF HIGH CLOUD COVER WESTWARD INTO CENTRAL
ILLINOIS...AND IS BEGINNING TO TRIGGER SHOWERS ACROSS FAR SOUTHERN
ILLINOIS. 04Z HRRR PREDICTED THIS DEVELOPMENT BETWEEN 06Z AND 07Z
QUITE NICELY...SO WILL FOLLOW CLOSELY FOR THE IMMEDIATE SHORT-TERM
FORECAST. SHOWERS/THUNDER ACROSS SOUTHERN ILLINOIS WILL SPREAD
N/NE OVER THE NEXT FEW HOURS...WITH CURRENT TRAJECTORIES KEEPING
THE BULK OF THE RAIN ACROSS FAR SE ILLINOIS INTO INDIANA THIS
MORNING. AS UPPER LOW/COOL POOL ALOFT BEGINS TO SHIFT
EASTWARD...SCATTERED SHOWERS/THUNDER WILL DEVELOP FURTHER WEST
LATER THIS MORNING INTO THE AFTERNOON. BASED ON MOST HIGH-RES
MODEL OUTPUT...IT APPEARS SHOWERS WILL MAINLY BE FOCUSED EAST OF
I-55. FOR POP FORECAST TODAY...HAVE DECIDED TO INCREASE TO LIKELY
ACROSS THE FAR SE KILX CWA WHERE CURRENT DEVELOPMENT ACROSS
SOUTHERN ILLINOIS WILL IMPACT DURING THE MORNING HOURS. WILL CARRY
CHANCE POPS ACROSS ALL OF EAST-CENTRAL ILLINOIS...WITH SLIGHT
CHANCE AS FAR WEST AS I-55. AFTER A FEW LINGERING SHOWERS ACROSS
THE EAST THIS EVENING...DRY WEATHER IS EXPECTED ACROSS THE BOARD
OVERNIGHT.
UPPER LOW WILL BEGIN TO PULL AWAY FROM THE REGION ON SUNDAY...AS
IT GRADUALLY GETS SHUNTED EASTWARD BY PREVAILING JET STREAM OVER
THE NORTHERN TIER OF STATES. WITH LITTLE OR NO UPPER FORCING
REMAINING IN PLACE AND NO SUBSTANTIAL SURFACE BOUNDARY IN THE
VICINITY...THINK RAIN CHANCES WILL BE SLIM ON SUNDAY. DESPITE
RISING HEIGHTS AND OTHER MITIGATING FACTORS...MODELS INSIST THAT
WIDELY SCATTERED CONVECTION WILL DEVELOP DURING THE AFTERNOON. WILL
CARRY SLIGHT CHANCE POPS...BUT THINK SUNDAY WILL MAINLY BE A WARM
AND DRY DAY.
THINGS BEGIN TO GET A LITTLE MORE CHALLENGING EARLY NEXT WEEK...AS
CENTRAL ILLINOIS BECOMES POSITIONED ON THE NORTHERN FLANK OF AN
UPPER-LEVEL HIGH CENTERED OVER THE SOUTHERN PLAINS. THIS
PARTICULAR PATTERN HAS BEEN QUITE COMMON OVER THE PAST COUPLE OF
MONTHS...AND HAS LED TO COPIOUS RAINFALL ACROSS THE AREA. WITH
THIS PATTERN ONCE AGAIN ESTABLISHING ITSELF...WILL NEED TO KEEP A
CLOSE EYE ON THE DEVELOPMENT/TRACK OF NOCTURNAL MCS ACTIVITY
STARTING SUNDAY NIGHT. MODELS ARE IN POOR AGREEMENT CONCERNING
EXACT DETAILS...ALTHOUGH IT APPEARS THE PRIMARY TIME FRAME PARTS
OF CENTRAL ILLINOIS COULD BE IMPACTED BY A CONVECTIVE SYSTEM WOULD
BE MONDAY NIGHT. MOISTURE/INSTABILITY PARAMETERS ARE NOT THAT
FAVORABLE SUNDAY NIGHT...WITH MOST MODELS TRYING TO DEVELOP
CONVECTION ACROSS IOWA OVERNIGHT THEN DROPPING REMNANTS INTO
ILLINOIS ON MONDAY. WILL CARRY CHANCE POPS ACROSS THE NORTHWEST
CWA AFTER MIDNIGHT ACCORDINGLY...WITH CHANCE POPS SPREADING
FURTHER E/SE ON MONDAY.
LONG TERM...TUESDAY THROUGH FRIDAY
AFTER ANOTHER MCS TRACKS E/SE OUT OF IOWA ACROSS NORTH-CENTRAL
ILLINOIS LATE MONDAY NIGHT INTO TUESDAY...A NORTHERN STREAM-SHORT
WAVE WILL PUSH A COLD FRONT TOWARD THE AREA TUESDAY NIGHT INTO
WEDNESDAY. GFS/ECMWF IN GOOD AGREEMENT WITH TIMING OF FROPA ON
WEDNESDAY. WITH PLENTY OF MOISTURE IN PLACE AHEAD OF THE
FRONT...WILL CARRY LIKELY POPS ACROSS THE WEST TUESDAY
NIGHT...THEN FURTHER EAST INTO EAST-CENTRAL AND SOUTHEAST ILLINOIS
ON WEDNESDAY. MODEL CONSENSUS TAKES FRONT INTO THE OHIO RIVER
VALLEY WEDNESDAY NIGHT...WITH HIGH PRESSURE BUILDING INTO THE
UPPER MIDWEST/GREAT LAKES FOR THE END OF THE WEEK. GIVEN GOOD
MODEL AGREEMENT...HAVE SCALED BACK POPS WEDNESDAY EVENING TO
INCLUDE ONLY THE FAR SE CWA. AFTER THAT...HAVE GONE DRY FOR
THURSDAY AND FRIDAY...WITH SLIGHTLY COOLER TEMPS IN THE LOWER 80S.
BARNES
&&
.AVIATION...
ISSUED 1151 PM CDT FRI JUL 5 2013
PESKY UPPER LOW THAT HAS RESIDED SOUTHWEST OF THE CENTRAL ILLINOIS
TERMINALS WILL FINALLY PUSH EAST NORTHEAST DURING THE 06Z TAF
VALID TIME AND TRACK THROUGH ILLINOIS. A DISTURBANCE ROUNDING THE
BASE OF THE UPPER LOW IS CURRENTLY LIFTING NORTH NORTHEAST THROUGH
THE MID MISSISSIPPI VALLEY. THIS FEATURE IS SPILLING MORE HIGH
CLOUDINESS ACROSS THE TERMINALS THAN PREVIOUSLY EXPECTED. THIS IS
ACTUALLY A GOOD THING FROM AN AVIATION WEATHER PERSPECTIVE. THE
CIGS THROUGH THE NIGHT WILL BE WELL INTO THE VFR CATEGORY...AND
THE CLOUD COVER LOOKS LIKE IT WILL BE THICK ENOUGH TO KEEP THE
DENSE FOG THREAT TO A MINIMUM. WITH THAT THINKING IN MIND...HAVE
KEPT VSBYS MVFR AT ALL BUT KCMI WHERE THE LOW LEVEL MOISTURE IS A
BIT RICHER. THE BULK OF THE PRECIPITATION ASSOCIATED WITH THE
PASSAGE OF THE UPPER SYSTEM SHOULD STAY SOUTHEAST OF THE SYSTEM
TRACK...KEEPING MOST OF THE TERMINALS DRY THROUGH THE PERIOD.
HOWEVER...HAVE MENTIONED A VCSH SATURDAY AFTERNOON AT KCMI AND
KDEC. SOUTH TO SOUTHEAST WINDS...GENERALLY AOB 10 KTS...SHOULD
LINGER THROUGH THE PERIOD.
BAK
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1150 PM CDT FRI JUL 5 2013
.DISCUSSION...
ISSUED 858 PM CDT FRI JUL 5 2013
MUCH AS IT HAS BEEN THE PAST COUPLE EVENINGS...DIURNAL CLOUDS
HAVE FADED AND WINDS ARE LIGHT SOUTH TO SOUTHEAST. BY AND
LARGE...GIVEN THE STAGNANT PATTERN...EXPECT QUIET WEATHER TO
PERSIST OVERNIGHT. THE MAIN QUESTION IS IF SIGNIFICANT FOG
DEVELOPMENT WILL OCCUR. FOG BECAME PRETTY WIDESPREAD ACROSS
CENTRAL AND SOUTHEAST ILLINOIS EARLY THIS MORNING...ALTHOUGH FOG
WAS ONLY PATCHY THE PREVIOUS COUPLE OF NIGHTS. DEW POINTS CONTINUE
TO CLIMB A COUPLE DEGREES EACH DAY...WHICH WOULD SUGGEST FOG WILL
BE AT LEAST AS BAD TONIGHT AS IT WAS THIS MORNING. HOWEVER...MODEL
GUIDANCE IS NOT VERY BULLISH ON HEAVY FOG DEVELOPMENT. IN
FACT...THE HRRR NAILED CONDITIONS LAST NIGHT AND IS LESS BULLISH
FOR TONIGHT. SREF PROGS ALSO SUGGEST A LOW PROBABILITY OF DENSE
FOG.
SO...CONSIDERING THE CURRENT MODEL GUIDANCE...AND THE FACT THAT
THE LOW LEVELS OF THE 00Z ILX SOUNDING ARE A LITTLE DRIER/BETTER
MIXED THAN LAST NIGHT...DO NOT EXPECT FOG TO BE AS WIDESPREAD AS
LAST NIGHT. GOING FORECAST IS IN PRETTY GOOD SHAPE. PLAN TO UPDATE
FOR THE EXPECTED OVERNIGHT TRENDS...MOST NOTABLY TO REMOVE POPS
DUE TO THE MINIMAL PCPN COVERAGE UPSTREAM AND ITS STRONGLY DIURNAL
CHARACTER THE PAST FEW DAYS.
BAK
&&
.AVIATION...
ISSUED 1151 PM CDT FRI JUL 5 2013
PESKY UPPER LOW THAT HAS RESIDED SOUTHWEST OF THE CENTRAL ILLINOIS
TERMINALS WILL FINALLY PUSH EAST NORTHEAST DURING THE 06Z TAF
VALID TIME AND TRACK THROUGH ILLINOIS. A DISTURBANCE ROUNDING THE
BASE OF THE UPPER LOW IS CURRENTLY LIFTING NORTH NORTHEAST THROUGH
THE MID MISSISSIPPI VALLEY. THIS FEATURE IS SPILLING MORE HIGH
CLOUDINESS ACROSS THE TERMINALS THAN PREVIOUSLY EXPECTED. THIS IS
ACTUALLY A GOOD THING FROM AN AVIATION WEATHER PERSPECTIVE. THE
CIGS THROUGH THE NIGHT WILL BE WELL INTO THE VFR CATEGORY...AND
THE CLOUD COVER LOOKS LIKE IT WILL BE THICK ENOUGH TO KEEP THE
DENSE FOG THREAT TO A MINIMUM. WITH THAT THINKING IN MIND...HAVE
KEPT VSBYS MVFR AT ALL BUT KCMI WHERE THE LOW LEVEL MOISTURE IS A
BIT RICHER. THE BULK OF THE PRECIPITATION ASSOCIATED WITH THE
PASSAGE OF THE UPPER SYSTEM SHOULD STAY SOUTHEAST OF THE SYSTEM
TRACK...KEEPING MOST OF THE TERMINALS DRY THROUGH THE PERIOD.
HOWEVER...HAVE MENTIONED A VCSH SATURDAY AFTERNOON AT KCMI AND
KDEC. SOUTH TO SOUTHEAST WINDS...GENERALLY AOB 10 KTS...SHOULD
LINGER THROUGH THE PERIOD.
BAK
&&
.PREV DISCUSSION...
ISSUED 215 PM CDT FRI JUL 5 2013
SHORT TERM...TONIGHT THROUGH MONDAY
HEAT AND HUMIDITY TO RETURN TO THE REGION LATER IN THE WEEKEND WITH
AN INCREASING THREAT FOR MORE WIDESPREAD RAINFALL...ESPECIALLY ACRS
THE NORTH...STARTING SUNDAY NIGHT AND RUNNING THROUGH WEDNESDAY NIGHT.
PESKY UPPER LOW OVER EAST CENTRAL MISSOURI FORECAST BY MODELS TO SLOWLY
TRACK EAST ACROSS PARTS OF SOUTH CENTRAL IL ON SATURDAY INTO SATURDAY
NIGHT. ISOLATED CONVECTION STILL A POSSIBILITY THIS EVENING IN ADVANCE
OF THE WEAK FEATURE...ESPECIALLY OVER WEST CENTRAL/SW IL BEFORE
DISSIPATING WITH THE LOSS OF DAYTIME HEATING. ALL FORECAST SOUNDINGS
SUGGEST A REPEAT PERFORMANCE WITH RESPECT TO FOG LATE TONIGHT AND INTO
SATURDAY MORNING AS THE LIGHT WIND REGIME COUPLED WITH ABUNDANT LOW
LEVEL MOISTURE WILL LEAD TO AREAS OF FOG...ESPECIALLY ALONG AND EAST
OF I-55.
COMBINATION OF REMNANT UPPER LEVEL LOW AND AREA OF DEEPER MOISTURE
WORKING BACK NORTH AHEAD OF THE FEATURE ON SATURDAY WILL LEAD TO
HIGHER RAIN CHANCES ACRS THE EAST WITH MORE ISOLATED COVERAGE A BIT
FURTHER WEST DURING THE DAY. WARMEST TEMPERATURES TOMORROW WILL BE
ACRS THE WEST...WITH CLOUDS AND SCATTERED SHOWERS HOLDING TEMPS
DOWN OVER THE EAST. MET GUID KEEPING TEMPERATURES IN THE MIDDLE 70S
OVER EXTREME EAST CENTRAL THROUGH SOUTHEAST ILLINOIS SATURDAY AFTN.
FOR NOW...WILL GO WITH MORE OF A METMAV COMPROMISE AND PUSH READINGS
CLOSE TO 80. MODEL CONSENSUS SUGGESTS UPPER WAVE SHOULD EDGE TO OUR
EAST BY 06Z SUNDAY TAKING THE BETTER RAIN CHANCES WITH IT. WILL CARRY
LOW CHANCE POPS OVER OUR FAR EAST SATURDAY EVENING IN CASE THE SYSTEM
IS SLOWER IN MOVING OUT OF OUR AREA OF CONCERN.
ASSUMING THE UPPER LOW IS OFF TO OUR EAST BY SUNDAY...OUR FLOW
BECOMES A BIT MORE PROGRESS...AT LEAST COMPARED TO WHAT WE HAVE
BEEN SEEING AROUND HERE FOR THE PAST WEEK. THE STRONGER FLOW WILL
EDGE NORTH OF THE AREA AS 500 MB HEIGHTS BUILD IN RESPONSE TO A MORE
SIGNIFICANT UPPER WAVE THAT WILL EVENTUALLY BRING A FRONT THROUGH
THE MIDWEST LATE WED/EARLY THURSDAY OF NEXT WEEK. A LEAD SHORTWAVE
IS FORECAST TO TRACK NORTH OF OUR AREA LATE SUNDAY NIGHT INTO MONDAY
WHICH WILL HELP DRAG A WEAK FRONT SOUTHEAST INTO THE LOWER LAKES ON
MONDAY. MODEL CONSENSUS NOT VERY GOOD WITH RESPECT TO THE TRACK OF
THE MCS EXPECTED TO DEVELOP IN THE VERY MOIST AXIS SITUATED JUST
AHEAD OF THE FRONTAL BOUNDARY. FORECAST SURFACE DEW POINTS LATE SUNDAY
AFTERNOON ARE AROUND 70 DEGREES ACRS THE NORTH...AND IN THE TROPICAL
LOW TO MID 70S ON MONDAY AS THE FRONT LOOKS TO BECOME STATIONARY JUST
TO OUR NORTH WITH AFTERNOON TEMPERATURES RISING INTO THE UPPER 80S
/POSSIBLY LOW 90S. PRECIP WATER VALUES STILL AOA 2 INCHES ALONG
AND JUST NORTH OF THE FRONTAL BOUNDARY WHICH SHOULD START TO EDGE
BACK NORTH LATER IN THE DAY MONDAY AHEAD OF THE MORE SIGNIFICANT
UPPER LEVEL SHORTWAVE FORECAST TO GRADUALLY DIG INTO THE LOWER
LAKES JUST AFTER THIS FORECAST PERIOD.
LONG TERM...TUESDAY THROUGH FRIDAY
STRONGER FLOW AT 500 MB TO REMAIN TO OUR NORTH INTO LATE TUESDAY
BEFORE AFOREMENTIONED UPPER WAVE DIGS SOUTHEAST INTO THE LOWER
LAKES BY WED. THIS WILL KEEP AT LEAST OUR NORTHERN AREAS WITH THE
CHANCE FOR CONVECTION TUESDAY INTO WEDNESDAY NIGHT BEFORE THE COOL
FRONT EDGES SLOWLY SOUTHEAST OUT OF OUR AREA BY THURSDAY. SEVERAL
ENSEMBLE MEMBERS INDICATING UPPER PATTERN WON`T BE VERY FAVORABLE
FOR GETTING THE FRONT OUT OF OUR AREA UNTIL LATE IN THE WEEK SO
CONFIDENCE ON FRONTAL PLACEMENT AND POPS LATE WED/THURSDAY NOT
VERY HIGH AT THIS TIME. 850 MB THERMAL RIDGE AXIS INTO CENTRAL IL
ON TUESDAY AND WEDNESDAY AHEAD OF THE UPPER WAVE...SO DEPENDING ON
AMOUNT OF CLOUD COVERAGE AND CONVECTION...WE COULD SEE AFTERNOON
TEMPERATURES AROUND 90 BOTH DAYS. FOR NOW...LOOKS TO BE ENOUGH
RESIDUAL CLOUD COVER AROUND FROM CONVECTION IN OR CLOSE TO OUR
FORECAST AREA BOTH DAYS...SO WILL GO A BIT MORE CONSERVATIVE WITH
THE HIGHS ON TUE/WED...HOWEVER SURFACE DEW POINTS ARE FORECAST TO
BE IN THE LOW TO MID 70S WHICH WILL DRIVE APPARENT TEMPS WELL INTO
THE 90S. STILL APPEARS THE BEST CHANCE FOR WIDESPREAD SHOWERS AND
THUNDERSTORMS OVER OUR AREA WILL BE ASSOCIATED WITH THE PASSAGE OF
THE WEAK COOL FRONT ON WEDNESDAY WITH TEMPS AND HUMIDITIES LOWERING
A FEW DEGREES BY THE END OF THE WEEK.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
109 PM EDT SAT JUL 6 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 250 AM EDT SAT JUL 6 2013
INDIANA WEATHER WILL BE DOMINATED BY HIGH PRESSURE TO THE SOUTHEAST
INTO MIDWEEK. CHANCES FOR THUNDERSTORMS WILL CONTINUE AS WAVES
ALOFT RIPPLE THROUGH THE REGION AROUND THE PERIPHERY OF THE HIGH.
WEDNESDAY AND THURSDAY A COLD FRONT IS EXPECTED TO SLOWLY PASS
FROM THE NORTHWEST. THE COLD FRONT SHOULD BE FOLLOWED BY A HIGH
PRESSURE SYSTEM AND DRIER WEATHER ON FRIDAY.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1014 AM EDT SAT JUL 6 2013
IT HAS BEEN A WET START FOR MUCH OF THE FORECAST AREA THIS MORNING
AS AN UPPER LEVEL WAVE TRACKS NORTH THROUGH THE REGION. MUCH OF
THE WIDESPREAD AND LIGHTER SHOWERS HAVE BEEN CONFINED TO THE
EASTERN HALF OF THE FORECAST AREA...WHILE CONVECTION HAS BEEN MORE
SCATTERED BUT HEAVIER FURTHER WEST ACROSS CENTRAL INDIANA. TEMPS
REMAINED IN THE UPPER 60S AND LOWER 70S AT 14Z.
MAIN FOCUS FOR THE UPDATE IS TO INSERT SOME TIMING INTO PRECIP
COVERAGE GOING FORWARD AS MORE WIDESPREAD RAINFALL ALREADY
SHIFTING NORTHEAST INTO OHIO AT THIS TIME. HRRR HAS DONE A
REASONABLY GOOD JOB ON THE PRECIP COVERAGE TO THIS POINT...EVEN
CAPTURING THE DEVELOPMENT OF THE HEAVIER SCATTERED CONVECTION
WHICH HAS MIGRATED NORTHWEST INTO THE WABASH VALLEY THIS MORNING
DESPITE SOME ERRORS IN LOCATION AND TIMING. WILL MAINTAIN
CATEGORICAL POPS AT LEAST INITIALLY OVER EASTERN COUNTIES TO
ACCOUNT FOR ONGOING PRECIP...BUT WILL TREND BACK TO CHANCE POPS
OVER ENTIRE AREA FOR THE AFTERNOON AS THE UPPER WAVE SHIFTS OFF TO
THE N/NE. ADDITIONAL FORCING ALOFT WITH THE APPROACH OF THE UPPER
LOW WILL KEEP SCATTERED CONVECTION GOING THROUGH THE AFTERNOON AND
AS SOME WEAK INSTABILITY DEVELOPS WITH PEAK HEATING...EXPECT TO
SEE ISOLATED THUNDER DESPITE THE THICK CLOUD COVER. PULLED TEMPS
BACK A DEGREE OR SO BASED ON CURRENT TRENDS. EXTENSIVE CLOUD COVER
WILL SERVE TO KEEP TEMPS IN THE 70S TODAY.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 250 AM EDT SAT JUL 6 2013
FORECAST PROBLEM REMAINS RAIN CHANCES.
ALL MODELS MOVE MOISTURE OUT OVERNIGHT...ALTHOUGH MET AND ECM
START WITH MORE. VERY SHARP DROP IN MET POPS COMPARED TO DAYTIME
PERIOD SEEMS A LITTLE TOO MUCH SINCE MOISTURE STILL FAIRLY HIGH AT
00Z. MAV POPS LOOK BETTER CONSIDERING THIS LINE OF THOUGHT. ENOUGH
MOISTURE SHOULD REMAIN SO PARTLY CLOUDY AS OPPOSED TO CLEAR OVERNIGHT
WELL ORGANIZED FORCING DOESNT OCCUR WITH ANY MODEL SUNDAY THROUGH
TUESDAY. HOWEVER THERE WILL STILL BE ENOUGH MOISTURE AROUND TO
SUPPORT SCATTERED STUFF FIRING DURING AFTERNOON HEATING. GOING
WITH WHICHEVER GUIDANCE IS WETTER. EVEN WHERE IT DOESN`T
RAIN...PLENTY OF CLOUDS AROUND DURING DAYS. WILL BE CLEARER AT
NIGHT AND WILL HAVE TO WATCH FOR FOG.
NAM COOLER THAN OTHER MODELS AT 850...ESPECIALLY INTO MONDAY.
MAINLY GOING MAV TEMPS. SOMEHOW MET DOES STAY WARMER THAN MAV
SUNDAY NIGHT. THIS SEEMS SO OUT OF SYNC WITH WHAT IT IS DOING
OTHERWISE WILL STICK WITH MAV FOR THEN.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 147 AM EDT SAT JUL 6 2013
DETERMINISTIC MODELS IN DECENT AGREEMENT ON THE SYNOPTIC PATTERN
ALONG WITH QPF...AND THEY ARE NOT FAR OFF THE CONSISTENT ECMWF
ENSEMBLE. GFS AND ECMWF MAINLY DIFFER IN HANDLING OF AN UPPER TROUGH
MOVING ACROSS THE GREAT LAKES TUESDAY NIGHT WITH THE 00Z GFS MUCH
QUICKER THAN THE 12Z ECMWF. VARIOUS IMPULSES IN FAST NORTHWEST UPPER
FLOW ALSO DIFFER AND NORMALLY DO WITH THAT TYPE OF FLOW.
STILL...BOTH MODELS HAVE QPF THROUGH THURSDAY MORNING WHICH MATCHES
NICELY WITH THE REGIONAL INITIALIZATION AND FORECAST CONSISTENCY.
THE EXTENDED SYNOPTIC PATTERN WILL FEATURE LIGHT RETURN FLOW ACROSS
THE OHIO VALLEY WITH UPPER FLOW...JUST NORTHWEST OF ZONAL...
DOWNSTREAM OF A WEAK WESTERN RIDGE. THIS WILL RESULT IN MOISTURE
INCREASING ACROSS THE OHIO VALLEY AS WELL AS RISING TEMPERATURES AND
THEREFORE INSTABILITY. DISTURBANCES IN THE UPPER FLOW...ALONG WITH A
COLD FRONT THAT WILL DROP SOUTHEAST ACROSS CENTRAL INDIANA WEDNESDAY
NIGHT...WILL LIFT THE WARM...MOIST AND UNSTABLE AIR AND TRIGGER
SCATTERED TO NUMEROUS THUNDERSTORMS THROUGH WEDNESDAY NIGHT. LEFT
SMALL POPS SOUTH CLOSER TO THE FRONT ON THURSDAY PER MODELS AND
ALLBLEND...OTHERWISE HIGH PRESSURE WILL BRING DRY WEATHER TO
CENTRAL INDIANA LATE WEEK.
REGARDING TEMPERATURES...REGIONAL INITIALIZATION OUTPUT LOOKS GOOD
WITH NEAR NORMAL HIGHS IN THE MID 80S TUESDAY AND WEDNESDAY
AHEAD OF THE COLD FRONT AND JUST SLIGHTLY BELOW NORMAL TEMPERATURES
IN THE LOWER TO MID 80S THURSDAY AND FRIDAY BEHIND IT.
&&
.AVIATION /DISCUSSION FOR 0618Z TAF ISSUANCE/...
ISSUED AT 101 PM EDT SAT JUL 6 2013
SCATTERED TO NUMEROUS SHOWERS CONTINUE OVER/AROUND THE TAF SITES
AND SHOULD CONTINUE TO BE AROUND THROUGH THE DAY. VFR TO MVFR CAN
BE EXPECTED. COULD SEE SOME ISOLATED TO WIDELY SCATTERED
THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND WILL KEEP THE VCTS
GOING FROM LATE THIS AFTERNOON INTO THE EVENING HOURS. WITH AMPLE
MOISTURE TONIGHT BUT LITTLE FORCING AVAILABLE AND WINDS LESS THAN 5
KTS EXPECT TO SEE SOME IFR OR LOWER CEILINGS AND VSBYS DEVELOP
OVERNIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...RYAN
SHORT TERM...JK
LONG TERM....MK
AVIATION...CP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1050 AM EDT SAT JUL 6 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 250 AM EDT SAT JUL 6 2013
INDIANA WEATHER WILL BE DOMINATED BY HIGH PRESSURE TO THE SOUTHEAST
INTO MIDWEEK. CHANCES FOR THUNDERSTORMS WILL CONTINUE AS WAVES
ALOFT RIPPLE THROUGH THE REGION AROUND THE PERIPHERY OF THE HIGH.
WEDNESDAY AND THURSDAY A COLD FRONT IS EXPECTED TO SLOWLY PASS
FROM THE NORTHWEST. THE COLD FRONT SHOULD BE FOLLOWED BY A HIGH
PRESSURE SYSTEM AND DRIER WEATHER ON FRIDAY.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1014 AM EDT SAT JUL 6 2013
IT HAS BEEN A WET START FOR MUCH OF THE FORECAST AREA THIS MORNING
AS AN UPPER LEVEL WAVE TRACKS NORTH THROUGH THE REGION. MUCH OF
THE WIDESPREAD AND LIGHTER SHOWERS HAVE BEEN CONFINED TO THE
EASTERN HALF OF THE FORECAST AREA...WHILE CONVECTION HAS BEEN MORE
SCATTERED BUT HEAVIER FURTHER WEST ACROSS CENTRAL INDIANA. TEMPS
REMAINED IN THE UPPER 60S AND LOWER 70S AT 14Z.
MAIN FOCUS FOR THE UPDATE IS TO INSERT SOME TIMING INTO PRECIP
COVERAGE GOING FORWARD AS MORE WIDESPREAD RAINFALL ALREADY
SHIFTING NORTHEAST INTO OHIO AT THIS TIME. HRRR HAS DONE A
REASONABLY GOOD JOB ON THE PRECIP COVERAGE TO THIS POINT...EVEN
CAPTURING THE DEVELOPMENT OF THE HEAVIER SCATTERED CONVECTION
WHICH HAS MIGRATED NORTHWEST INTO THE WABASH VALLEY THIS MORNING
DESPITE SOME ERRORS IN LOCATION AND TIMING. WILL MAINTAIN
CATEGORICAL POPS AT LEAST INITIALLY OVER EASTERN COUNTIES TO
ACCOUNT FOR ONGOING PRECIP...BUT WILL TREND BACK TO CHANCE POPS
OVER ENTIRE AREA FOR THE AFTERNOON AS THE UPPER WAVE SHIFTS OFF TO
THE N/NE. ADDITIONAL FORCING ALOFT WITH THE APPROACH OF THE UPPER
LOW WILL KEEP SCATTERED CONVECTION GOING THROUGH THE AFTERNOON AND
AS SOME WEAK INSTABILITY DEVELOPS WITH PEAK HEATING...EXPECT TO
SEE ISOLATED THUNDER DESPITE THE THICK CLOUD COVER. PULLED TEMPS
BACK A DEGREE OR SO BASED ON CURRENT TRENDS. EXTENSIVE CLOUD COVER
WILL SERVE TO KEEP TEMPS IN THE 70S TODAY.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 250 AM EDT SAT JUL 6 2013
FORECAST PROBLEM REMAINS RAIN CHANCES.
ALL MODELS MOVE MOISTURE OUT OVERNIGHT...ALTHOUGH MET AND ECM
START WITH MORE. VERY SHARP DROP IN MET POPS COMPARED TO DAYTIME
PERIOD SEEMS A LITTLE TOO MUCH SINCE MOISTURE STILL FAIRLY HIGH AT
00Z. MAV POPS LOOK BETTER CONSIDERING THIS LINE OF THOUGHT. ENOUGH
MOISTURE SHOULD REMAIN SO PARTLY CLOUDY AS OPPOSED TO CLEAR OVERNIGHT
WELL ORGANIZED FORCING DOESNT OCCUR WITH ANY MODEL SUNDAY THROUGH
TUESDAY. HOWEVER THERE WILL STILL BE ENOUGH MOISTURE AROUND TO
SUPPORT SCATTERED STUFF FIRING DURING AFTERNOON HEATING. GOING
WITH WHICHEVER GUIDANCE IS WETTER. EVEN WHERE IT DOESN`T
RAIN...PLENTY OF CLOUDS AROUND DURING DAYS. WILL BE CLEARER AT
NIGHT AND WILL HAVE TO WATCH FOR FOG.
NAM COOLER THAN OTHER MODELS AT 850...ESPECIALLY INTO MONDAY.
MAINLY GOING MAV TEMPS. SOMEHOW MET DOES STAY WARMER THAN MAV
SUNDAY NIGHT. THIS SEEMS SO OUT OF SYNC WITH WHAT IT IS DOING
OTHERWISE WILL STICK WITH MAV FOR THEN.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 147 AM EDT SAT JUL 6 2013
DETERMINISTIC MODELS IN DECENT AGREEMENT ON THE SYNOPTIC PATTERN
ALONG WITH QPF...AND THEY ARE NOT FAR OFF THE CONSISTENT ECMWF
ENSEMBLE. GFS AND ECMWF MAINLY DIFFER IN HANDLING OF AN UPPER TROUGH
MOVING ACROSS THE GREAT LAKES TUESDAY NIGHT WITH THE 00Z GFS MUCH
QUICKER THAN THE 12Z ECMWF. VARIOUS IMPULSES IN FAST NORTHWEST UPPER
FLOW ALSO DIFFER AND NORMALLY DO WITH THAT TYPE OF FLOW.
STILL...BOTH MODELS HAVE QPF THROUGH THURSDAY MORNING WHICH MATCHES
NICELY WITH THE REGIONAL INITIALIZATION AND FORECAST CONSISTENCY.
THE EXTENDED SYNOPTIC PATTERN WILL FEATURE LIGHT RETURN FLOW ACROSS
THE OHIO VALLEY WITH UPPER FLOW...JUST NORTHWEST OF ZONAL...
DOWNSTREAM OF A WEAK WESTERN RIDGE. THIS WILL RESULT IN MOISTURE
INCREASING ACROSS THE OHIO VALLEY AS WELL AS RISING TEMPERATURES AND
THEREFORE INSTABILITY. DISTURBANCES IN THE UPPER FLOW...ALONG WITH A
COLD FRONT THAT WILL DROP SOUTHEAST ACROSS CENTRAL INDIANA WEDNESDAY
NIGHT...WILL LIFT THE WARM...MOIST AND UNSTABLE AIR AND TRIGGER
SCATTERED TO NUMEROUS THUNDERSTORMS THROUGH WEDNESDAY NIGHT. LEFT
SMALL POPS SOUTH CLOSER TO THE FRONT ON THURSDAY PER MODELS AND
ALLBLEND...OTHERWISE HIGH PRESSURE WILL BRING DRY WEATHER TO
CENTRAL INDIANA LATE WEEK.
REGARDING TEMPERATURES...REGIONAL INITIALIZATION OUTPUT LOOKS GOOD
WITH NEAR NORMAL HIGHS IN THE MID 80S TUESDAY AND WEDNESDAY
AHEAD OF THE COLD FRONT AND JUST SLIGHTLY BELOW NORMAL TEMPERATURES
IN THE LOWER TO MID 80S THURSDAY AND FRIDAY BEHIND IT.
&&
.AVIATION /DISCUSSION FOR THE 061500Z TAF ISSUANCE/...
ISSUED AT 1050 AM EDT SAT JUL 6 2013
MVFR TO IFR CONDITIONS SHOWERS CONTINUE BUT VFR IS MAKING IT/S WAY
NORTH WITH SOME DRIER AIR MOVING IN FROM THE SOUTHWEST. PUSHED BACK
INCLUSION OF VCTS UNTIL 18Z. PREVIOUS DISCUSSION FOLLOWS...
MVFR CONDITIONS AND WIDESPREAD SHOWERS SHOULD BE OVER ALL BUT
POSSIBLY LAF BY 12Z. EXPECT THE SHOWERS TO FALL APART SOME BY 16Z
WITH REDEVELOPMENT LIKELY SHORTLY THEREAFTER WITH CONVECTIVE
TEMPERATURES ONLY IN THE MID 70S. WILL GO WITH SHOWERS TO START OFF
WITH AT ALL BUT LAF AND VCSH AT LAF THROUGH 16Z. THEN...MVFR OR VFR
SHOWERS WITH VCTS 16Z-00Z. ACTIVITY SHOULD SCATTER AFTER 00Z AND
WITH INSTABILITY DECREASING...VCSH SHOULD BE OK. THEN...MORE IFR
CONDITIONS EXPECTED AFTER 06Z AS SOUTH AND SOUTHWEST WINDS GO LIGHT
TO CALM.
SOUTH AND SOUTH WEST WINDS WILL BE 6 KNOTS OR LESS THROUGH THE
PERIOD EXCEPT PERHAPS SLIGHTLY HIGHER AFTER 15Z SUNDAY AT IND.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...RYAN
SHORT TERM...JK
LONG TERM....MK
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1014 AM EDT SAT JUL 6 2013
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 250 AM EDT SAT JUL 6 2013
INDIANA WEATHER WILL BE DOMINATED BY HIGH PRESSURE TO THE SOUTHEAST
INTO MIDWEEK. CHANCES FOR THUNDERSTORMS WILL CONTINUE AS WAVES
ALOFT RIPPLE THROUGH THE REGION AROUND THE PERIPHERY OF THE HIGH.
WEDNESDAY AND THURSDAY A COLD FRONT IS EXPECTED TO SLOWLY PASS
FROM THE NORTHWEST. THE COLD FRONT SHOULD BE FOLLOWED BY A HIGH
PRESSURE SYSTEM AND DRIER WEATHER ON FRIDAY.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1014 AM EDT SAT JUL 6 2013
IT HAS BEEN A WET START FOR MUCH OF THE FORECAST AREA THIS MORNING
AS AN UPPER LEVEL WAVE TRACKS NORTH THROUGH THE REGION. MUCH OF
THE WIDESPREAD AND LIGHTER SHOWERS HAVE BEEN CONFINED TO THE
EASTERN HALF OF THE FORECAST AREA...WHILE CONVECTION HAS BEEN MORE
SCATTERED BUT HEAVIER FURTHER WEST ACROSS CENTRAL INDIANA. TEMPS
REMAINED IN THE UPPER 60S AND LOWER 70S AT 14Z.
MAIN FOCUS FOR THE UPDATE IS TO INSERT SOME TIMING INTO PRECIP
COVERAGE GOING FORWARD AS MORE WIDESPREAD RAINFALL ALREADY
SHIFTING NORTHEAST INTO OHIO AT THIS TIME. HRRR HAS DONE A
REASONABLY GOOD JOB ON THE PRECIP COVERAGE TO THIS POINT...EVEN
CAPTURING THE DEVELOPMENT OF THE HEAVIER SCATTERED CONVECTION
WHICH HAS MIGRATED NORTHWEST INTO THE WABASH VALLEY THIS MORNING
DESPITE SOME ERRORS IN LOCATION AND TIMING. WILL MAINTAIN
CATEGORICAL POPS AT LEAST INITIALLY OVER EASTERN COUNTIES TO
ACCOUNT FOR ONGOING PRECIP...BUT WILL TREND BACK TO CHANCE POPS
OVER ENTIRE AREA FOR THE AFTERNOON AS THE UPPER WAVE SHIFTS OFF TO
THE N/NE. ADDITIONAL FORCING ALOFT WITH THE APPROACH OF THE UPPER
LOW WILL KEEP SCATTERED CONVECTION GOING THROUGH THE AFTERNOON AND
AS SOME WEAK INSTABILITY DEVELOPS WITH PEAK HEATING...EXPECT TO
SEE ISOLATED THUNDER DESPITE THE THICK CLOUD COVER. PULLED TEMPS
BACK A DEGREE OR SO BASED ON CURRENT TRENDS. EXTENSIVE CLOUD COVER
WILL SERVE TO KEEP TEMPS IN THE 70S TODAY.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 250 AM EDT SAT JUL 6 2013
FORECAST PROBLEM REMAINS RAIN CHANCES.
ALL MODELS MOVE MOISTURE OUT OVERNIGHT...ALTHOUGH MET AND ECM
START WITH MORE. VERY SHARP DROP IN MET POPS COMPARED TO DAYTIME
PERIOD SEEMS A LITTLE TOO MUCH SINCE MOISTURE STILL FAIRLY HIGH AT
00Z. MAV POPS LOOK BETTER CONSIDERING THIS LINE OF THOUGHT. ENOUGH
MOISTURE SHOULD REMAIN SO PARTLY CLOUDY AS OPPOSED TO CLEAR OVERNIGHT
WELL ORGANIZED FORCING DOESNT OCCUR WITH ANY MODEL SUNDAY THROUGH
TUESDAY. HOWEVER THERE WILL STILL BE ENOUGH MOISTURE AROUND TO
SUPPORT SCATTERED STUFF FIRING DURING AFTERNOON HEATING. GOING
WITH WHICHEVER GUIDANCE IS WETTER. EVEN WHERE IT DOESN`T
RAIN...PLENTY OF CLOUDS AROUND DURING DAYS. WILL BE CLEARER AT
NIGHT AND WILL HAVE TO WATCH FOR FOG.
NAM COOLER THAN OTHER MODELS AT 850...ESPECIALLY INTO MONDAY.
MAINLY GOING MAV TEMPS. SOMEHOW MET DOES STAY WARMER THAN MAV
SUNDAY NIGHT. THIS SEEMS SO OUT OF SYNC WITH WHAT IT IS DOING
OTHERWISE WILL STICK WITH MAV FOR THEN.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 147 AM EDT SAT JUL 6 2013
DETERMINISTIC MODELS IN DECENT AGREEMENT ON THE SYNOPTIC PATTERN
ALONG WITH QPF...AND THEY ARE NOT FAR OFF THE CONSISTENT ECMWF
ENSEMBLE. GFS AND ECMWF MAINLY DIFFER IN HANDLING OF AN UPPER TROUGH
MOVING ACROSS THE GREAT LAKES TUESDAY NIGHT WITH THE 00Z GFS MUCH
QUICKER THAN THE 12Z ECMWF. VARIOUS IMPULSES IN FAST NORTHWEST UPPER
FLOW ALSO DIFFER AND NORMALLY DO WITH THAT TYPE OF FLOW.
STILL...BOTH MODELS HAVE QPF THROUGH THURSDAY MORNING WHICH MATCHES
NICELY WITH THE REGIONAL INITIALIZATION AND FORECAST CONSISTENCY.
THE EXTENDED SYNOPTIC PATTERN WILL FEATURE LIGHT RETURN FLOW ACROSS
THE OHIO VALLEY WITH UPPER FLOW...JUST NORTHWEST OF ZONAL...
DOWNSTREAM OF A WEAK WESTERN RIDGE. THIS WILL RESULT IN MOISTURE
INCREASING ACROSS THE OHIO VALLEY AS WELL AS RISING TEMPERATURES AND
THEREFORE INSTABILITY. DISTURBANCES IN THE UPPER FLOW...ALONG WITH A
COLD FRONT THAT WILL DROP SOUTHEAST ACROSS CENTRAL INDIANA WEDNESDAY
NIGHT...WILL LIFT THE WARM...MOIST AND UNSTABLE AIR AND TRIGGER
SCATTERED TO NUMEROUS THUNDERSTORMS THROUGH WEDNESDAY NIGHT. LEFT
SMALL POPS SOUTH CLOSER TO THE FRONT ON THURSDAY PER MODELS AND
ALLBLEND...OTHERWISE HIGH PRESSURE WILL BRING DRY WEATHER TO
CENTRAL INDIANA LATE WEEK.
REGARDING TEMPERATURES...REGIONAL INITIALIZATION OUTPUT LOOKS GOOD
WITH NEAR NORMAL HIGHS IN THE MID 80S TUESDAY AND WEDNESDAY
AHEAD OF THE COLD FRONT AND JUST SLIGHTLY BELOW NORMAL TEMPERATURES
IN THE LOWER TO MID 80S THURSDAY AND FRIDAY BEHIND IT.
&&
.AVIATION /DISCUSSION FOR THE 061200Z TAF ISSUANCE/...
ISSUED AT 625 AM EDT SAT JUL 6 2013
MVFR CONDITIONS AND WIDESPREAD SHOWERS SHOULD BE OVER ALL BUT
POSSIBLY LAF BY 12Z. EXPECT THE SHOWERS TO FALL APART SOME BY 16Z
WITH REDEVELOPMENT LIKELY SHORTLY THEREAFTER WITH CONVECTIVE
TEMPERATURES ONLY IN THE MID 70S. WILL GO WITH SHOWERS TO START OFF
WITH AT ALL BUT LAF AND VCSH AT LAF THROUGH 16Z. THEN...MVFR OR VFR
SHOWERS WITH VCTS 16Z-00Z. ACTIVITY SHOULD SCATTER AFTER 00Z AND
WITH INSTABILITY DECREASING...VCSH SHOULD BE OK. THEN...MORE IFR
CONDITIONS EXPECTED AFTER 06Z AS SOUTH AND SOUTHWEST WINDS GO LIGHT
TO CALM.
SOUTH AND SOUTH WEST WINDS WILL BE 6 KNOTS OR LESS THROUGH THE
PERIOD EXCEPT PERHAPS SLIGHTLY HIGHER AFTER 15Z SUNDAY AT IND.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...RYAN
SHORT TERM...JK
LONG TERM....MK
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
505 PM MDT SUN JUL 7 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1254 PM MDT SUN JUL 7 2013
LATEST WV IMAGERY AND RAP ANALYSIS SHOW H5 RIDGE STILL IN PLACE
ACROSS SOUTHERN PLAINS WITH SERIES OF WEAK SHORTWAVE TROUGHS
ROTATING AROUND WESTERN AND NORTHERN EXTENT OF RIDGE THROUGH
WESTERLY FLOW. AT THE SURFACE A COLD FRONT HAS STALLED ALONG THE
KS/NE BORDER WITH A SURFACE TROUGH EXTENDING SOUTH ALONG THE KS/CO
BORDER.
A WEAK SHORTWAVE TROUGH EXPECTED TO DROP SOUTH OUT OF WESTERN
NEBRASKA LATE THIS AFTERNOON AND TONIGHT WILL COMBINE WITH THESE
SURFACE FEATURES TO INITIATE SCATTERED THUNDERSTORMS ACROSS THE CWA.
PRIMARY FOCUS SHOULD BE ALONG FRONT WHERE HIGH TD VALUES NORTH OF
THE FRONT HAVE RESULTED IN ML CAPE 1000-1500 J/KG AS OF THE LATEST
RAP ANALYSIS. BETTER DEEP SHEER IS EXPECTED TO BE IN PLACE NORTH OF
THE FRONT WHERE 0-6KM BULK SHEER AROUND 35KT BY 00Z COULD SUPPORT A
SEVERE WIND AND HAIL THREAT. THERE IS LESS INSTABILITY AND MORE CIN
TO OVERCOME FURTHER SOUTH ALONG THE SURFACE TROUGH...HOWEVER AS
DAYTIME HEATING CONTINUES AND THE SHORTWAVE TROUGH MOVES SOUTH WE
SHOULD BE ABLE TO SEE AT LEAST ISOLATED THUNDERSTORMS DEVELOPING
ALONG THE SURFACE TROUGH THIS AFTERNOON/EVENING. PWAT VALUES
1.2-1.3" REPRESENT AN ANOMALOUSLY WET ATMOSPHERE FOR THIS TIME OF
YEAR...AND AS WAS THE CASE YESTERDAY MANY OF THESE STORMS WILL BE
SLOW MOVERS...SO HEAVY RAIN WILL BE A CONCERN WHERE STORMS DEVELOP.
LEE TROUGH IS EXPECTED TO BEGIN TO DEEPEN LATE TONIGHT WITH LLJ
BUILDING ACROSS THE NE HALF OF THE CWA. WITH INCREASING ISENTROPIC
ASCENT AND H85 SUPPORT WE COULD SEE LINGERING THUNDERSTORMS IN
PROXIMITY OF THE FRONTAL ZONE ACROSS OUR NE CWA...SO I KEPT ISO
THUNDER MENTION MOST OF THE NIGHT FOR THOSE LOCATIONS. THERE IS
SOME INDICATION WITH VERY MOIST E-NE BL FLOW OF FOG DEVELOPING IN
SW NEBRASKA...HOWEVER WITH BL LIKELY MIXED WITH LLJ INCREASING AND
FRONT POSSIBLY SHIFTING NORTH I WASNT CONFIDENT ENOUGH TO ADD
MENTION.
DESPITE LARGE SCALE FORCING IN PLACE MONDAY IT DOES LOOK LIKE A
TROUGH AXIS/DRYLINE ALONG KS/CO BORDER COULD HELP INITIATE
THUNDERSTORMS BY THE AFTERNOON WITH INSTABILITY BUILDING ACROSS THE
EASTERN CWA. I WASNT CONFIDENT ENOUGH TO ADD MORE THAN SLIGHT CHANCE
MENTION AT THIS POINT. H85 TEMPS ARE ACTUALLY ADVERTISED TO BE 2-3C
WARMER THAN THE LAST FEW DAYS WHEN HIGHS HAVE BEEN AROUND 100F...SO
WE COULD BE LOOKING AT NEAR RECORD HIGH TEMPS ACROSS THE CWA MONDAY
WITH VALUES IN THE 100S ACROSS THE AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 1251 PM MDT SUN JUL 7 2013
AN UPPER RIDGE CENTERED OVER THE SOUTHERN ROCKIES WILL BE THE
DOMINATING INFLUENCE THROUGH THE LONG TERM PERIOD. TEMPERATURES
WILL BE ABOVE NORMAL...ALTHOUGH A WEAK COLD FRONT ON TUESDAY WILL
KNOCK TEMPERATURES DOWN A FEW DEGREES THROUGH THURSDAY...THEY WILL
WARM AGAIN FOR THE LATE WEEK AND WEEKEND. POSITION OF THE RIDGE
EARLY IN THE PERIOD WILL BE CLOSER TO THE FOUR CORNERS AND ALLOW
SHORTWAVE TROUGHS ROTATING AROUND IT TO BRING A CHANCE FOR SCATTERED
THUNDERSTORMS. AS THE RIDGE BUILDS EASTWARD LATER IN THE
WEEK...THUNDERSTORM CHANCES WILL BECOME MORE ISOLATED. SEVERE
WEATHER IS NOT ANTICIPATED WITH THE WEAK FLOW ALOFT LIMITING UPDRAFT
ORGANIZATION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 500 PM MDT SUN JUL 7 2013
VFR CONDITIONS EXPECTED AT KGLD AND KMCK. WINDS EARLY TONIGHT WILL
BE ERRATIC AND POSSIBLY GUSTY FROM THUNDERSTORM OUTFLOW
BOUNDARIES. LATE TONIGHT THROUGH OVERNIGHT WINDS AT KGLD GENERALLY
FROM THE SOUTHEAST AROUND 10KTS WHILE AT KMCK NORTHEAST AT 11KTS.
FOR MONDAY WINDS AT KGLD LIGHT FROM THE SOUTHWEST BACKING TO THE
SOUTHEAST THEN SOUTH AT 6-12KTS. MAY SEE SOME GUSTINESS LATE IN
THE DAY. FOR KMCK LIGHT WINDS THROUGH EARLY AFTERNOON THEN
SOUTHEAST AT 10-15KTS WITH HIGHER GUSTS. FOR BOTH TERMINALS
THROUGH 06Z CANT RULE OUT A SHOWER/THUNDERSTORM.
HOWEVER...CONFIDENCE NOT HIGH ENOUGH TO INCLUDE IN TAFS BUT WILL
MONITOR. DRY CONDITIONS EXPECTED LATE TONIGHT THROUGH EARLY
AFTERNOON MONDAY THEN ANOTHER SMALL THREAT FOR THUNDERSTORMS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DJR
LONG TERM...024
AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
500 PM MDT SAT JUL 6 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 1251 PM MDT SAT JUL 6 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW H5 RIDGE STILL IN PLACE
ACROSS SOUTHERN PLAINS...WITH WESTERLY FLOW ACROSS THE NORTHERN
PLAINS. SURFACE TROUGH IS CURRENTLY IN PLACE ACROSS WESTERLY
NEBRASKA EXTENDING SOUTH ACROSS NW KS AND SE CO.
DESPITE LITTLE BEING APPARENT IN THE 500 MB HEIGHT FIELD BEYOND SOME
WEAK RIPPLES WV IMAGERY AND PV/VORT FIELDS CONTINUE TO INDICATE
VIGOROUS SHORTWAVE ACTIVITY ROTATING AROUND THE NORTHERN PART OF THE
RIDGE. ONE SUCH FEATURE IS PROGGED TO PASS OVER OUR CWA BY THIS
EVENING...WHICH SHOULD HELP INCREASE THUNDERSTORM CHANCES ACROSS THE
REGION. I COULDNT RULE OUT BETTER COVERAGE THAN THE LAST FEW NIGHTS
WITH SURFACE TROUGH POSSIBLY ACTING TO AID THUNDERSTORM INITIATION AS
SHORTWAVE PASSES THROUGH THE REGION. I STILL EXPECT ACTIVITY TO
INITIALLY START OVER HIGHER TERRAIN THIS AFTERNOON AND BEGIN TO
SPREAD EAST WITH SHORTWAVE. LATEST HRRR/RAP SUPPORT THIS ACTIVITY
INCREASING IN COVERAGE BY 00-03Z AS THIS INTERACTS WITH SHORTWAVE
TROUGH AXIS AND BETTER INSTABILITY ACROSS THE CENTRAL/EASTERN PART
OF CWA. THERE IS SOME LINGERING ELEVATED INSTABILITY
OVERNIGHT...HOWEVER LLJ IS EAST OF CWA ALONG WITH BEST ISOTROPIC
SUPPORT...SO BEYOND SOME LINGERING SHOWERS/T-STORMS WITH SHORTWAVE
LATE TONIGHT IN THE EAST WITH SHORTWAVE I THINK MOST OF THIS
ACTIVITY WILL BE TAPERING OFF FAIRLY QUICKLY AFTER SUNSET.
HODOGRAPHS/SHEER PROFILES ARE RELATIVELY WEAK AND WITH MARGINAL CAPE
I AM NOT SURE WE WOULD SEE MUCH OF A SEVERE HAIL RISK. INVERTED V
TYPE SOUNDINGS AND DCAPE VALUES IN THE 500-1500 J/KG RANGE RAISE
CONCERNS FOR SEVERE GUST POTENTIAL WITH ANY COLLAPSING UPDRAFTS...SO
THIS WILL NEED TO BE MONITORED.
WITH LITTLE CHANGING REGARDING LARGE SCALE PATTERN AND MODELS
INDICATING POSSIBLE EARLIER INITIATION SUN I KEPT MENTION OF
THUNDERSTORM CHANCES SUNDAY AFTERNOON...WITH ONLY MINOR ADJUSTMENTS
TO TIMING. HOT AIRMASS WILL STILL BE IN PLACE SUN...WITH EXPECTED
CLOUD COVER THE ONE LIMITING FACTOR. FEWER CLOUDS...AND WE SHOULD
AGAIN SEE HIGHS APPROACH 100F ACROSS THE ENTIRE AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 1255 PM MDT SAT JUL 6 2013
AN UPPER RIDGE CENTERED OVER THE CENTRAL AND SOUTHERN ROCKIES WILL
BE THE DOMINATING INFLUENCE IN THE LONG TERM PERIOD. TEMPERATURES
WILL BE ABOVE NORMAL THE ENTIRE PERIOD...WITH THE HOTTEST DAYS
BEING FRIDAY AND SATURDAY. A WEAK COLD FRONT WILL MOVE THROUGH
TUESDAY AND TUESDAY NIGHT WITH SLIGHTLY COOLER TEMPERATURES IN ITS
WAKE. THERE WILL BE SEVERAL OPPORTUNITIES FOR SCATTERED
THUNDERSTORMS ASSOCIATED WITH WEAK SHORTWAVE TROUGHS ROTATING
AROUND THE RIDGE...BUT WITH THE WEAK FLOW ALOFT SEVERE WEATHER IS
NOT ANTICIPATED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 500 PM MDT SAT JUL 6 2013
VFR EXPECTED AT KGLD AND KMCK THROUGH THE PERIOD. SFC TROUGH WITH
LGT/VRB WINDS TO LINGER NEAR BOTH TERMINALS THROUGH 18Z SUNDAY
BEFORE BECOMING EASTERLY THEN SOUTHEASTERLY AT 10KTS OR SO. AS HAS
BEEN THE CASE THE PAST FEW DAYS SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE DURING THE LATE AFTERNOON AND EVENING HOURS. PINPOINTING
WHETHER OR NOT THEY WILL DIRECTLY IMPACT EITHER TERMINAL RATHER
DIFFICULT. RIGHT NOW CONFIDENCE NOT HIGH ENOUGH TO INCLUDE A TSRA
MENTION IN EITHER TAF.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
100 PM MDT SAT JUL 6 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 1251 PM MDT SAT JUL 6 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW H5 RIDGE STILL IN PLACE
ACROSS SOUTHERN PLAINS...WITH WESTERLY FLOW ACROSS THE NORTHERN
PLAINS. SURFACE TROUGH IS CURRENTLY IN PLACE ACROSS WESTERLY
NEBRASKA EXTENDING SOUTH ACROSS NW KS AND SE CO.
DESPITE LITTLE BEING APPARENT IN THE 500 MB HEIGHT FIELD BEYOND SOME
WEAK RIPPLES WV IMAGERY AND PV/VORT FIELDS CONTINUE TO INDICATE
VIGOROUS SHORTWAVE ACTIVITY ROTATING AROUND THE NORTHERN PART OF THE
RIDGE. ONE SUCH FEATURE IS PROGGED TO PASS OVER OUR CWA BY THIS
EVENING...WHICH SHOULD HELP INCREASE THUNDERSTORM CHANCES ACROSS THE
REGION. I COULDNT RULE OUT BETTER COVERAGE THAN THE LAST FEW NIGHTS
WITH SURFACE TROUGH POSSIBLY ACTING TO AID THUNDERSTORM INITIATION AS
SHORTWAVE PASSES THROUGH THE REGION. I STILL EXPECT ACTIVITY TO
INITIALLY START OVER HIGHER TERRAIN THIS AFTERNOON AND BEGIN TO
SPREAD EAST WITH SHORTWAVE. LATEST HRRR/RAP SUPPORT THIS ACTIVITY
INCREASING IN COVERAGE BY 00-03Z AS THIS INTERACTS WITH SHORTWAVE
TROUGH AXIS AND BETTER INSTABILITY ACROSS THE CENTRAL/EASTERN PART
OF CWA. THERE IS SOME LINGERING ELEVATED INSTABILITY
OVERNIGHT...HOWEVER LLJ IS EAST OF CWA ALONG WITH BEST ISOTROPIC
SUPPORT...SO BEYOND SOME LINGERING SHOWERS/T-STORMS WITH SHORTWAVE
LATE TONIGHT IN THE EAST WITH SHORTWAVE I THINK MOST OF THIS
ACTIVITY WILL BE TAPERING OFF FAIRLY QUICKLY AFTER SUNSET.
HODOGRAPHS/SHEER PROFILES ARE RELATIVELY WEAK AND WITH MARGINAL CAPE
I AM NOT SURE WE WOULD SEE MUCH OF A SEVERE HAIL RISK. INVERTED V
TYPE SOUNDINGS AND DCAPE VALUES IN THE 500-1500 J/KG RANGE RAISE
CONCERNS FOR SEVERE GUST POTENTIAL WITH ANY COLLAPSING UPDRAFTS...SO
THIS WILL NEED TO BE MONITORED.
WITH LITTLE CHANGING REGARDING LARGE SCALE PATTERN AND MODELS
INDICATING POSSIBLE EARLIER INITIATION SUN I KEPT MENTION OF
THUNDERSTORM CHANCES SUNDAY AFTERNOON...WITH ONLY MINOR ADJUSTMENTS
TO TIMING. HOT AIRMASS WILL STILL BE IN PLACE SUN...WITH EXPECTED
CLOUD COVER THE ONE LIMITING FACTOR. FEWER CLOUDS...AND WE SHOULD
AGAIN SEE HIGHS APPROACH 100F ACROSS THE ENTIRE AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 1255 PM MDT SAT JUL 6 2013
AN UPPER RIDGE CENTERED OVER THE CENTRAL AND SOUTHERN ROCKIES WILL
BE THE DOMINATING INFLUENCE IN THE LONG TERM PERIOD. TEMPERATURES
WILL BE ABOVE NORMAL THE ENTIRE PERIOD...WITH THE HOTTEST DAYS
BEING FRIDAY AND SATURDAY. A WEAK COLD FRONT WILL MOVE THROUGH
TUESDAY AND TUESDAY NIGHT WITH SLIGHTLY COOLER TEMPERATURES IN ITS
WAKE. THERE WILL BE SEVERAL OPPORTUNITIES FOR SCATTERED
THUNDERSTORMS ASSOCIATED WITH WEAK SHORTWAVE TROUGHS ROTATING
AROUND THE RIDGE...BUT WITH THE WEAK FLOW ALOFT SEVERE WEATHER IS
NOT ANTICIPATED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1115 AM MDT SAT JUL 6 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT BOTH KGLD AND KMCK
TERMINALS THROUGH THE TAF PERIOD. WITH SURFACE TROUGH AXIS
DIRECTLY OVER BOTH TERMINALS LIGHT AND VARIABLE WINDS WILL
PERSIST...GENERALLY LESS THAN 6KT. PRIMARY AVIATION CONCERN IS
HIGH BASED (10-15FT) THUNDERSTORMS EXPECTED TO INITIALLY DEVELOP
OVER EASTERN COLORADO THIS AFTERNOON AND THEN INCREASE IN COVERAGE
ALONG TROUGH AXIS. CONFIDENCE WAS HIGH ENOUGH TO INCLUDE
VCTS...HOWEVER COVERAGE WILL BE SCATTERED SO TIMING AND OCCURRENCE
AT EITHER TERMINAL WILL NEED TO BE FINE TUNED ONCE THIS ACTIVITY
BEGINS TO INITIATE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1251 PM MDT SAT JUL 6 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 1251 PM MDT SAT JUL 6 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW H5 RIDGE STILL IN PLACE
ACROSS SOUTHERN PLAINS...WITH WESTERLY FLOW ACROSS THE NORTHERN
PLAINS. SURFACE TROUGH IS CURRENTLY IN PLACE ACROSS WESTERLY
NEBRASKA EXTENDING SOUTH ACROSS NW KS AND SE CO.
DESPITE LITTLE BEING APPARENT IN THE 500 MB HEIGHT FIELD BEYOND SOME
WEAK RIPPLES WV IMAGERY AND PV/VORT FIELDS CONTINUE TO INDICATE
VIGOROUS SHORTWAVE ACTIVITY ROTATING AROUND THE NORTHERN PART OF THE
RIDGE. ONE SUCH FEATURE IS PROGGED TO PASS OVER OUR CWA BY THIS
EVENING...WHICH SHOULD HELP INCREASE THUNDERSTORM CHANCES ACROSS THE
REGION. I COULDNT RULE OUT BETTER COVERAGE THAN THE LAST FEW NIGHTS
WITH SURFACE TROUGH POSSIBLY ACTING TO AID THUNDERSTORM INITIATION AS
SHORTWAVE PASSES THROUGH THE REGION. I STILL EXPECT ACTIVITY TO
INITIALLY START OVER HIGHER TERRAIN THIS AFTERNOON AND BEGIN TO
SPREAD EAST WITH SHORTWAVE. LATEST HRRR/RAP SUPPORT THIS ACTIVITY
INCREASING IN COVERAGE BY 00-03Z AS THIS INTERACTS WITH SHORTWAVE
TROUGH AXIS AND BETTER INSTABILITY ACROSS THE CENTRAL/EASTERN PART
OF CWA. THERE IS SOME LINGERING ELEVATED INSTABILITY
OVERNIGHT...HOWEVER LLJ IS EAST OF CWA ALONG WITH BEST ISOTROPIC
SUPPORT...SO BEYOND SOME LINGERING SHOWERS/T-STORMS WITH SHORTWAVE
LATE TONIGHT IN THE EAST WITH SHORTWAVE I THINK MOST OF THIS
ACTIVITY WILL BE TAPERING OFF FAIRLY QUICKLY AFTER SUNSET.
HODOGRAPHS/SHEER PROFILES ARE RELATIVELY WEAK AND WITH MARGINAL CAPE
I AM NOT SURE WE WOULD SEE MUCH OF A SEVERE HAIL RISK. INVERTED V
TYPE SOUNDINGS AND DCAPE VALUES IN THE 500-1500 J/KG RANGE RAISE
CONCERNS FOR SEVERE GUST POTENTIAL WITH ANY COLLAPSING UPDRAFTS...SO
THIS WILL NEED TO BE MONITORED.
WITH LITTLE CHANGING REGARDING LARGE SCALE PATTERN AND MODELS
INDICATING POSSIBLE EARLIER INITIATION SUN I KEPT MENTION OF
THUNDERSTORM CHANCES SUNDAY AFTERNOON...WITH ONLY MINOR ADJUSTMENTS
TO TIMING. HOT AIRMASS WILL STILL BE IN PLACE SUN...WITH EXPECTED
CLOUD COVER THE ONE LIMITING FACTOR. FEWER CLOUDS...AND WE SHOULD
AGAIN SEE HIGHS APPROACH 100F ACROSS THE ENTIRE AREA.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 217 AM MDT SAT JUL 6 2013
THE MAIN UPPER FLOW PATTERN AT 500 MB FOR THE LONG TERM PERIOD WILL
REMAIN TO THE NORTH AND EAST OF THE TRI STATE AREA. ZONAL FLOW WILL
RETURN TO THE AREA FOR THE DAYTIME HOURS TUESDAY...THEN RIDGE BEGINS
TO AMPLIFY TUESDAY NIGHT INTO WEDNESDAY. A SERIES OF SHORTWAVE
TROUGHS WILL MOVE THROUGH THE HIGH PLAINS THROUGH THE PERIOD...WHICH
COULD SPARK AFTERNOON AND EVENING CONVECTION. CENTER OF RIDGE AXIS
WILL BUILD INTO THE CENTRAL PLAINS FOR THURSDAY AFTERNOON AND
EVENING AS 500 MB HIGH CENTERS OVER THE FOUR CORNERS REGION. SOME
LOCAL VORT MAXES COULD PROGRESS INTO THE TRI STATE AREA FOR
WEDNESDAY EVENING...POSSIBLY PROVIDING THE BEST CHANCE FOR
CONVECTIVE ACTIVITY ACROSS THE REGION. LONG RANGE MODELS ARE FAIRLY
CONSISTENT IN BRINGING A STRONGER 850 JET INTO THE AREA FOR
WEDNESDAY NIGHT...WITH RIGHT FRONT QUADRANT LINING UP FOR THE
SOUTHERN AND EASTERN COUNTIES OF THE CWA. 850 THETA E VALUES BETWEEN
345 AND 355 K AND GFS SOUNDING SHOW SUFFICIENT MID LEVEL MOISTURE
AVAILABLE FOR THUNDERSTORM SUPPORT.
SURFACE LOW PRESSURE SYSTEM WILL DEVELOP IN EASTERN COLORADO AND
WILL CONTINUE TO BE PRESENT THROUGH THE ENTIRE PERIOD. A WEAK
FRONTAL SYSTEM WILL MOVE THROUGH THE TRI STATE AREA TUESDAY
EVENING...WHICH WILL HELP DEVELOP THUNDERSTORMS. THE SURFACE FRONT
WILL STALL AND BECOME STATIONARY OVER KANSAS FOR WEDNESDAY...WHICH
COULD PROVIDE CHANCES OF THUNDERSTORM DEVELOPMENT ACROSS THE AREA.
HIGH TEMPERATURES LOOK TO BE THE WARMEST FOR TUESDAY WITH VALUES
REACHING THE UPPER 90S. THE WEAK FRONT MOVING INTO THE AREA WILL
KEEP TEMPERATURES SLIGHTLY COOLER IN THE LOWER 90S. STRONGEST
CHANCE FOR PRECIPITATION FOR THE AREA IS FOR TUESDAY AND WEDNESDAY
WITH FRONTAL ENCROACHMENT. WARM AIR ADVECTION WILL ERODE STATIONARY
FRONT SYSTEM FOR THURSDAY AND WILL PUSH BOUNDARY TOWARDS THE
NORTHERN CENTRAL PLAINS...DIMINISHING CHANCES FOR PRECIPITATION FOR
THURSDAY THROUGH SATURDAY. STRONG WARM AIR ADVECTION WILL BRING
TEMPERATURES ACROSS THE AREA IN THE UPPER 90S TO LOW 100S FOR FRIDAY
AND SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1115 AM MDT SAT JUL 6 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT BOTH KGLD AND KMCK
TERMINALS THROUGH THE TAF PERIOD. WITH SURFACE TROUGH AXIS
DIRECTLY OVER BOTH TERMINALS LIGHT AND VARIABLE WINDS WILL
PERSIST...GENERALLY LESS THAN 6KT. PRIMARY AVIATION CONCERN IS
HIGH BASED (10-15FT) THUNDERSTORMS EXPECTED TO INITIALLY DEVELOP
OVER EASTERN COLORADO THIS AFTERNOON AND THEN INCREASE IN COVERAGE
ALONG TROUGH AXIS. CONFIDENCE WAS HIGH ENOUGH TO INCLUDE
VCTS...HOWEVER COVERAGE WILL BE SCATTERED SO TIMING AND OCCURRENCE
AT EITHER TERMINAL WILL NEED TO BE FINE TUNED ONCE THIS ACTIVITY
BEGINS TO INITIATE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...DR
AREA FORECAST DISCUSSION
NWS WICHITA KS
1239 PM CDT SAT JUL 6 2013
.UPDATE...
ISSUED AT 1230 PM CDT SAT JUL 6 2013
UPDATED THE FORECAST TO INCREASE CLOUDS AND LOWER HIGHS AS
PERSISTENT CLOUDS/LIGHT RAIN SHOWERS AND SPRINKLES AIDED BY A
WEAKENING AND VEERING LLJ WILL DAMPEN THE DIURNAL CLIMB. THE KRSL
AND KGRB AREAS MAY STILL CLIMB INTO THE MID/UPPER 90S BUT FURTHER
EAST LOWER 90S WILL BE MORE COMMON.
MWM
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 253 AM CDT SAT JUL 6 2013
ELEVATED EARLY MORNING CONVECTION HAS DEVELOPED AND MOVED INTO
THE AREA AGAIN...THIS TIME ACROSS CENTRAL KANSAS. THE RUC AND
HRRR SHOW MODEST LOW LEVEL MOISTURE TRANSPORT AND SUPPORT FOR
THIS CONVECTION AS FAR EAST AS ABOUT THE KANSAS TURNPIKE THRU
MID-MORNING BEFORE WANING AGAIN BY MIDDAY. OTHERWISE GUSTY SOUTH
WINDS AND EVEN WARMER TEMPERATURES ARE EXPECTED ACROSS MUCH OF
THE FORECAST AREA TODAY. THE UPPER RIDGE WILL CONTINUE TO BUILD
EAST ACROSS THE AREA INTO SUNDAY AND MONDAY...AND WILL TAKE A
MODIFIED PERSISTENCE TYPE APPROACH FOR MAXS WITH DIURNALLY GUSTY
SOUTH WINDS AS WELL EACH DAY. DIURNAL CONVECTION OFF THE HIGH
PLAINS COULD DRIFT CLOSE TO CENTRAL KANSAS DURING THE NEXT FEW
NIGHTS AS WELL...THOUGH WILL KEEP THE FORECAST DRY AND HANDLE ON
A SHORT TERM BASIS SIMILAR TO THE PAST COUPLE OF DAYS.
DARMOFAL
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 253 AM CDT SAT JUL 6 2013
A FAIRLY DECENT UPPER SHORTWAVE TROF IS STILL EXPECTED TO MOVE
ACROSS THE NORTHERN TIER OF STATES A TOP THE ELONGATED WEST-EAST
ORIENTED RIDGE AXIS ACROSS THE AREA BY MID-WEEK. THIS IS EXPECTED
TO ALLOW A MODEST COLD FRONT TO SINK SOUTH INTO KANSAS WITH VERY
SLIGHT AND RATHER BRIEF COOLING POSSIBLE. LITTLE CHANGE TO THE
GOING FORECAST WITH SLIGHT TO MODEST CHANCES FOR PRECIP AS
WELL...BEFORE THE CENTER OF THE UPPER RIDGE AND HEAT BUILD BACK
IN ACROSS THE AREA BY THE END OF THE WEEK.
DARMOFAL
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1230 PM CDT SAT JUL 6 2013
VFR WILL PREVAIL THROUGH THE NEXT 24 HOURS AT ALL TAF SITES.
WIDESPREAD MID CLOUDS IN THE 12K-15K FT RANGE HAVE LIMITED MIXING
ACROSS MUCH OF CENTRAL AND SOUTH CENTRAL KANSAS ALLOWING WIND
SPEEDS TO REMAIN LOWER COMPARED TO YESTERDAY. WITH SOME CLEARING
EXPECTED LATE...SOUTHERLY WINDS IN THE 25 KT RANGE WITH GUSTS INTO
THE 35 KT RANGE WILL STILL BE POSSIBLE ACROSS SOUTH CENTRAL KS
AFTER 21-22Z...HOWEVER TRENDED SPEEDS DOWN DUE TO CLOUDS/SPRINKLES
AND LACK OF DEEP VERTICAL MIXING.
MWM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 91 73 98 74 / 20 20 20 10
HUTCHINSON 92 73 99 74 / 20 20 20 10
NEWTON 91 72 97 74 / 20 20 20 10
ELDORADO 91 72 97 73 / 20 20 20 10
WINFIELD-KWLD 91 73 97 75 / 20 10 10 10
RUSSELL 98 71 101 72 / 20 20 20 10
GREAT BEND 97 71 101 72 / 20 20 20 10
SALINA 92 73 100 74 / 20 20 20 10
MCPHERSON 91 73 100 74 / 20 20 20 10
COFFEYVILLE 92 71 96 73 / 10 10 10 10
CHANUTE 91 70 94 72 / 10 10 10 10
IOLA 91 69 93 72 / 10 10 10 10
PARSONS-KPPF 91 71 95 73 / 10 10 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
705 AM CDT SAT JUL 6 2013
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 253 AM CDT SAT JUL 6 2013
ELEVATED EARLY MORNING CONVECTION HAS DEVELOPED AND MOVED INTO
THE AREA AGAIN...THIS TIME ACROSS CENTRAL KANSAS. THE RUC AND
HRRR SHOW MODEST LOW LEVEL MOISTURE TRANSPORT AND SUPPORT FOR
THIS CONVECTION AS FAR EAST AS ABOUT THE KANSAS TURNPIKE THRU
MID-MORNING BEFORE WANING AGAIN BY MIDDAY. OTHERWISE GUSTY SOUTH
WINDS AND EVEN WARMER TEMPERATURES ARE EXPECTED ACROSS MUCH OF
THE FORECAST AREA TODAY. THE UPPER RIDGE WILL CONTINUE TO BUILD
EAST ACROSS THE AREA INTO SUNDAY AND MONDAY...AND WILL TAKE A
MODIFIED PERSISTENCE TYPE APPROACH FOR MAXS WITH DIURNALLY GUSTY
SOUTH WINDS AS WELL EACH DAY. DIURNAL CONVECTION OFF THE HIGH
PLAINS COULD DRIFT CLOSE TO CENTRAL KANSAS DURING THE NEXT FEW
NIGHTS AS WELL...THOUGH WILL KEEP THE FORECAST DRY AND HANDLE ON
A SHORT TERM BASIS SIMILAR TO THE PAST COUPLE OF DAYS.
DARMOFAL
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 253 AM CDT SAT JUL 6 2013
A FAIRLY DECENT UPPER SHORTWAVE TROF IS STILL EXPECTED TO MOVE
ACROSS THE NORTHERN TIER OF STATES A TOP THE ELONGATED WEST-EAST
ORIENTED RIDGE AXIS ACROSS THE AREA BY MID-WEEK. THIS IS EXPECTED
TO ALLOW A MODEST COLD FRONT TO SINK SOUTH INTO KANSAS WITH VERY
SLIGHT AND RATHER BRIEF COOLING POSSIBLE. LITTLE CHANGE TO THE
GOING FORECAST WITH SLIGHT TO MODEST CHANCES FOR PRECIP AS
WELL...BEFORE THE CENTER OF THE UPPER RIDGE AND HEAT BUILD BACK
IN ACROSS THE AREA BY THE END OF THE WEEK.
DARMOFAL
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 705 AM CDT SAT JUL 6 2013
SCT -SHRA WITH A FEW -TSRA THAT ARE PESTERING PRIMARILY CNTRL & SC
KS ALONG & W OF I-135 SHOULD DISSIPATE ~15Z. A FEW -SHRA/ISOLATED
ARE ALSO OCCURRING OVER EXTREME SE KS NEAR THE MO BORDER & WILL DO
LIKEWISE. LIKE YESTERDAY S WINDS WILL INCREASE CONSIDERABLY LATE
THIS MORNING & WOULD BE STRONGEST OVER CNTRL & SC KS WHERE
SUSTAINED A 25-30KTS WITH 30-39KT/35-45MPH GUSTS ARE LIKELY THIS
AFTERNOON. WINDS WOULD GREATLY DIMINISH EARLY THIS EVENING...
ESPECIALLY OVER KCNU...AS DECOUPLING ENSUES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 96 73 98 74 / 10 10 10 10
HUTCHINSON 97 73 99 74 / 20 10 10 10
NEWTON 95 72 97 74 / 20 10 10 10
ELDORADO 95 72 97 73 / 10 10 10 10
WINFIELD-KWLD 95 73 97 75 / 10 10 10 10
RUSSELL 99 71 101 72 / 20 10 10 10
GREAT BEND 99 71 101 72 / 20 10 10 10
SALINA 98 73 100 74 / 20 10 10 10
MCPHERSON 98 73 100 74 / 20 10 10 10
COFFEYVILLE 94 71 96 73 / 10 10 10 10
CHANUTE 92 70 94 72 / 10 10 10 10
IOLA 91 69 93 72 / 10 10 10 10
PARSONS-KPPF 93 71 95 73 / 10 10 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS WICHITA KS
253 AM CDT SAT JUL 6 2013
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 253 AM CDT SAT JUL 6 2013
ELEVATED EARLY MORNING CONVECTION HAS DEVELOPED AND MOVED INTO
THE AREA AGAIN...THIS TIME ACROSS CENTRAL KANSAS. THE RUC AND
HRRR SHOW MODEST LOW LEVEL MOISTURE TRANSPORT AND SUPPORT FOR
THIS CONVECTION AS FAR EAST AS ABOUT THE KANSAS TURNPIKE THRU
MID-MORNING BEFORE WANING AGAIN BY MIDDAY. OTHERWISE GUSTY SOUTH
WINDS AND EVEN WARMER TEMPERATURES ARE EXPECTED ACROSS MUCH OF
THE FORECAST AREA TODAY. THE UPPER RIDGE WILL CONTINUE TO BUILD
EAST ACROSS THE AREA INTO SUNDAY AND MONDAY...AND WILL TAKE A
MODIFIED PERSISTENCE TYPE APPROACH FOR MAXS WITH DIURNALLY GUSTY
SOUTH WINDS AS WELL EACH DAY. DIURNAL CONVECTION OFF THE HIGH
PLAINS COULD DRIFT CLOSE TO CENTRAL KANSAS DURING THE NEXT FEW
NIGHTS AS WELL...THOUGH WILL KEEP THE FORECAST DRY AND HANDLE ON
A SHORT TERM BASIS SIMILAR TO THE PAST COUPLE OF DAYS.
DARMOFAL
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 253 AM CDT SAT JUL 6 2013
A FAIRLY DECENT UPPER SHORTWAVE TROF IS STILL EXPECTED TO MOVE
ACROSS THE NORTHERN TIER OF STATES A TOP THE ELONGATED WEST-EAST
ORIENTED RIDGE AXIS ACROSS THE AREA BY MID-WEEK. THIS IS EXPECTED
TO ALLOW A MODEST COLD FRONT TO SINK SOUTH INTO KANSAS WITH VERY
SLIGHT AND RATHER BRIEF COOLING POSSIBLE. LITTLE CHANGE TO THE
GOING FORECAST WITH SLIGHT TO MODEST CHANCES FOR PRECIP AS
WELL...BEFORE THE CENTER OF THE UPPER RIDGE AND HEAT BUILD BACK
IN ACROSS THE AREA BY THE END OF THE WEEK.
DARMOFAL
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1151 PM CDT FRI JUL 5 2013
SIMILAR TO THE PAST SEVERAL NIGHTS AND EARLY MORNINGS...THINKING
WIDELY SCATTERED SHOWERS/THUNDERSTORMS WILL BE POSSIBLE ACROSS
THE REGION BETWEEN ABOUT 08-16Z...DUE TO ISENTROPIC ASCENT ALONG
EASTERN FRINGE OF ELEVATED MIXED LAYER. CONSEQUENTLY...VCSH STILL
LOOKS GOOD FOR ALL SITES EXCEPT KCNU. LATER SHIFTS WILL NEED TO
MONITOR FOR POSSIBLE VCTS AND/OR TS INSERTION. NOT ANTICIPATING
STRONG/SEVERE STORMS. OTHERWISE...RATHER DENSE MID AND HIGH LEVEL
CLOUDS ANTICIPATED SATURDAY...ALONG WITH CONTINUED STRONG/GUSTY
SOUTHERLY WINDS.
ADK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 96 73 98 74 / 10 10 10 10
HUTCHINSON 97 73 99 74 / 20 10 10 10
NEWTON 95 72 97 74 / 20 10 10 10
ELDORADO 95 72 97 73 / 10 10 10 10
WINFIELD-KWLD 95 73 97 75 / 10 10 10 10
RUSSELL 99 71 101 72 / 20 10 10 10
GREAT BEND 99 71 101 72 / 20 10 10 10
SALINA 98 73 100 74 / 20 10 10 10
MCPHERSON 98 73 100 74 / 20 10 10 10
COFFEYVILLE 94 71 96 73 / 10 10 10 10
CHANUTE 92 70 94 72 / 10 10 10 10
IOLA 91 69 93 72 / 10 10 10 10
PARSONS-KPPF 93 71 95 73 / 10 10 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 AM CDT SAT JUL 6 2013
...UPDATE TO AVIATION FOR 06 COORDINATED UNIVERSAL TIME TAFS...
.SYNOPSIS...
ISSUED AT 1000 PM CDT FRI JUL 5 2013
THE 06.00Z 250 HPA RAOB MAP SHOWED 60 KT WESTERLY FLOW ON THE NORTHERN
PERIPHERY OF AN UPPER LEVEL ANTICYCLONE FROM KBOI TO KRIV. ACROSS THE
PLAINS AND DOWNSTREAM, NORTHERLY FLOW OF 40 KT WAS OBSERVED AT KDDC.
THE STRONGEST WINDS ON THE CONUS RAOB NETWORK EXTENDED FROM KJAN TO
KAPX WITH AN ABSOLUTE PEAK MAGNITUDE AROUND 100 KT OVER KILX. @ 500
HPA, THE UBIQUITOUS ANTICYCLONE WEAKENED AND MOVED A BIT EAST WITH
GEOPOTENTIAL HEIGHTS AROUND 590 DM OVER KFGZ. MID LEVEL TEMPERATURES
WERE A LITTLE LESS WARM AS WELL WITH -7 DEG AT THE AFOREMENTIONED UL
SITE. DOWNSTREAM, AN OPENED UP TROF EXTENDED ACROSS THE MISSISSIPPI
RIVER VALLEY. @ 700 HPA, KDDC TEMPERATURES WERE UP TO 11 DEG C COMPARED
TO 8 DEG C AT 05.00Z. LOWER DOWN THE ATMOSPHERIC COLUMN, THE CONTINUED
WARMING WAS PREVALENT AT 850 HPA AT KDDC WITH OBSERVED AT 27 DEG C UP
FROM 23 DEG C 24 HOURS AGO. AT THE SFC, A LEE TROF WAS NOTED ACROSS
FAR EASTERN COLORADO INTO FAR WESTERN KANSAS. INVEST 94L WAS LOCATED
ACROSS THE WESTERN GULF OF MEXICO BASIN. TROPICAL DEPRESSION DALILA
WAS AT 17.1N 112.6W @ 06.03Z AND TROPICAL STORM ERICK WAS AT 16.7N
103.5W @ 06.03Z
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 200 PM CDT FRI JUL 5 2013
AGAIN FOR THIS EVENING, WINDS WILL START OUT BREEZY FROM THE SOUTH
TO SOUTHWEST AT 18G28KT AS HAPPENED THURSDAY EVENING, THEN WILL
BECOME SOUTH TO SOUTHEAST AT 13 TO 15 KNOTS AFTER 00Z. THERE HAVE
BEEN A FEW ALTOCUMULUS CLOUDS IN THE 10-12 THOUSAND FOOT RANGE
AND FLOWING CIRRUS IN THE 25 THOUSAND FOOT RANGE THIS AFTERNOON.
WITH THE COMBINATION OF THESE FEATURES, I THINK THE TEMPERATURES
WILL FALL SLOWLY OVERNIGHT TO MINIMUMS IN THE MID 60S TO THE LOWER
70S. THE SHORT RANGE MODELS OF THE RUC AND NAM BOTH SUPPORT LOWS
IN THIS RANGE. WINDS WILL HELP SLIGHTLY IN KEEPING THE
TEMPERATURES ELEVATED.
ON SATURDAY, IT LOOKS HOTTER AS THE NAM AND ECMWF MODELS BRING IN
THE +32C ISOTHERM AT 850MB AND +15C AIR AT 700MB INTO OUR WESTERN
ZONES NEAR THE COLORADO BORDER. THE SOUTHWESTERLY FLOW WILL BRING
WARM AIR FROM THE SOUTH AND SOUTHWEST. ADDITIONALLY, A DOWNSLOPE
AFFECT FROM THE NORTHWESTERLY FLOW AT MID AND HIGHER LAYERS WILL
KICK IN. EVEN THROUGH THERE WILL BE SOME CIRRUS CEILINGS OVERHEAD,
MUCH OF THE CIRRUS WILL BE THIN AND NOT NEGATIVELY EFFECT SURFACE
WARMING. HIGHS AROUND 100F WILL RETURN TO SOUTHWESTERN KANSAS ON
SATURDAY, ESPECIALLY FROM LIBERAL TO GARDEN CITY TO DODGE CITY TO
HAYS. OTHER AREAS NEAR THE COLORADO BORDER WILL STILL TOP OUT IN
THE UPPER 90S.
THERE IS A SURFACE TROUGH THAT WILL ENCROACH ON THE WESTERN BORDER
NEAR COLORADO LATE IN THE DAY. A FEW THUNDERSTORMS MAY FORM ALONG
AND NEAR THE COLORADO BORDER, AHEAD OF THE TROUGH LATE SATURDAY.
ALSO THERE IS A WEAK UPPER WAVE COMING OVER NORTHWESTERN KANSAS BY
00Z SUNDAY, WHICH WILL ADD UPPER LEVEL SUPPORT FOR A FEW STORMS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 251 PM CDT FRI JUL 5 2013
SATURDAY NIGHT INTO SUNDAY WILL SEE THE UPPER RIDGE EXPAND OUT OF
THE DESERT SOUTHWEST BUT ALSO TURN RELATIVELY FLAT AS IT ELONGATES
OVER THE SOUTHERN HALF OF THE COUNTRY. THIS WILL LEAVE WESTERN AND
CENTRAL KANSAS AT THE TAIL END OF THE WESTERLIES WITH JUST ENOUGH
CROSS MOUNTAIN FLOW TO DEEPEN THE LEE TROUGH ALONG THE
KANSAS...COLORADO BORDER. IN ADDITION...A MODEST 60 KNOT UPPER JET
STREAK OVER THE DAKOTAS WILL AID IN PUSHING A WEAK COLD FRONT
SOUTHWARD OVER THE NORTHERN PLAINS BUT THEN STALLING NEAR THE
KANSAS...NEBRASKA BORDER BY EARLY SUNDAY. CONDITIONS WILL WARM
QUICKLY UNDER THIS REGIME AS 700 HPA TEMPERATURES ABOVE 14 C
ACROSS THE ROCKIES AND DESERT SOUTHWEST...SPREAD EASTWARD INTO THE
ADJACENT HIGH PLAINS WITH A RESULTANT STRONG CAPPING ELEVATED
MIXED LAYER. NONETHELESS...BOTH SATURDAY EVENING AND AGAIN SUNDAY
EVENING WILL SEE HIGHER BASED CONVECTION DEVELOPING ALONG THE LEE
TROUGH OR FARTHER WEST OVER ELEVATED TERRAIN REGIONS OF
COLORADO...MOVING VERY SLOWLY EAST INTO FAR WESTERN KANSAS.
COVERAGE WILL BE ISOLATED OR AT BEST SCATTERED AT TIMES WITH LOW
PROBABILITY PRECIPITATION CHANCES EXISTING MAINLY WEST OF HIGHWAY
283 BOTH EVENINGS. SEVERE THREAT WITH THIS CONVECTION WILL BE
MINIMAL AS SHEAR PROFILES ARE WEAK AND DO NOT SUPPORT ROTATING
UPDRAFTS BUT INVERTED V PROFILES COULD SUPPORT SOME ISOLATED
DAMAGING WIND POTENTIAL. TEMPERATURE WISE...STRONG INSOLATION WILL
PERMIT MIXING UP 700 HPA WITH RESULTANT AFTERNOON MAXIMUM
TEMPERATURES AROUND 100 FOR SUNDAY.
MONDAY INTO MONDAY NIGHT IS LOOKING LIKE A NEAR COPY OF SUNDAY AS
THE UPPER PATTERN REMAINS DOMINATED BY THE FLAT BUT ELONGATED
RIDGE OVER THE SOUTHERN HALF OF THE COUNTRY. THIS WILL LEAVE THE
LEE TROUGH SITTING ALONG THE COLORADO BORDER WHILE A WEAK COLD
FRONT REMAINS STALLED NEAR THE NEBRASKA BORDER WITH KANSAS. WITH
700 HPA TEMPERATURES AROUND 14C AND MIXING UP TO THIS LEVEL
LIKELY...HIGHS AROUND 100 APPEAR POSSIBLE YET AGAIN. IN
ADDITION...SIMILAR TO BOTH SATURDAY AND SUNDAY EVENING ISOLATED
THUNDERSTORMS WILL BE POSSIBLE FOR LOCATIONS MAINLY WEST OF A
LIBERAL TO WAKEENEY LINE AS STORMS FORMING OVER HIGHER TERRAIN IN
COLORADO MOVE SLOWLY EAST.
TUESDAY WILL SEE THE UPPER RIDGE AXIS BOTH AMPLIFY AND RETROGRADE
FAR ENOUGH WEST TO ALLOW A WEAK COLD FRONT TO SLIP INTO NORTHERN
OKLAHOMA DURING THE EVENING TO OVERNIGHT HOURS. INITIALLY THIS
WILL RESULT IN ANOTHER 100+ DEGREE DAY OVER SOUTHWEST INTO CENTRAL
KANSAS AS STRONG SOLAR INSOLATION ALONG WITH PREFRONTAL WARMING
ALLOW TEMPERATURES TO SORE INTO THE TRIPLE DIGITS.
HOWEVER...ARRIVAL OF THIS FRONT WILL ALSO BRING AN INCREASED
CHANCE FOR THUNDERSTORMS TUESDAY EVENING TO OVERNIGHT. ATTENTION
THEN TURNS TOWARD WEDNESDAY AND THURSDAY AS SLIGHTLY COOLER
CONDITIONS EXIST BEHIND THE FRONT BOTH DAYS ALONG WITH A DECENT
SETUP FOR A NOCTURNAL MCS MOVING OUT OF COLORADO AND NORTHERN NEW
MEXICO. NONETHELESS...THE RIDGE THEN BUILDS BACK EAST INTO THE
PLAINS BY FRIDAY WITH THE FRONT MOVING QUICKLY NORTH OF KANSAS.
THIS WILL PERMIT TEMPERATURES TO RISE BACK INTO THE TRIPLE DIGITS FOR
HIGHS WITH GENERALLY DRY CONDITIONS EXISTING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT JUL 6 2013
KDDC WSR-88D SHOWS RETURNED ECHOS DIMINISHING WITHIN THE LAST HOUR.
THIS WAS THE FIRST CONCERN, SO DO NOT THINK THERE WILL BE ANY FLIGHT
CATEGORY REDUCTIONS AS CONVECTION WEAKENS IN THE VERY NEAR TERM. CONVECTION
WILL BE POSSIBLE AGAIN TOMORROW, BUT WILL LEAVE TS/CB GROUPS OUT FOR
NOW DUE TO UNCERTAINTY IN TEMPORAL AND SPATIAL DISTRIBUTION OF SAID
ACTIVITY. WILL KEEP THE MID TO HIGH LEVEL CLOUD DECK GOING THROUGH TAF
PD WITH VFR CIGS. WIND VECTORS WILL INCREASE IN MAGNITUDE 15-22 KT DURING
THE 15Z-23Z TIME FRAME VIA MIXING ETC.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 68 100 70 100 / 10 10 10 10
GCK 69 100 69 99 / 20 10 20 10
EHA 68 98 70 97 / 30 20 20 20
LBL 66 100 70 100 / 20 10 10 10
HYS 69 100 71 102 / 10 10 10 10
P28 69 100 73 100 / 10 10 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...BURKE
LONG TERM...AJOHNSON
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS CARIBOU ME
927 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A COLD FRONT MOVING SOUTH WILL STALL NEAR THE COAST TONIGHT. THE
FRONT WILL REMAIN NEAR THE COAST MONDAY WHILE WEAK LOW PRESSURE MOVES
ALONG THE FRONT. THIS FRONT WILL LINGER THROUGH TUESDAY BEFORE
LIFTING NORTH WEDNESDAY.&&
.NEAR TERM /THROUGH MONDAY/...
UPDATE 2130 EDT: MUCH DRIER AIR CONTINTUES TO FILTER INTO THE
CROWN OF MAINE...HOWEVER THE FRONT IS NOT MAKING SIGNIFICANT
PROGRESS INTO THE CENTRAL HIGHLANDS BASED ON CURRENT OBSERVATIONS.
THE CHALLENGE IS PINPOINTING WHERE THE FRONT WILL STALL AND
PRECIPITATION SETS UP AS A WAVE APPROACHES THE STATE LATE TONIGHT
AND MONDAY. THE HRRR BRINGS PRECIPITATION IN DURING THAT TIME
PERIOD IN THE VICINITY OF THE FRONT/S CURRENT LOCATION. THE
FORECAST IS IN DECENT SHAPE. THE MID SHIFT CAN TAKE A CLOSER LOOK
AT IT ONCE THE 00Z MODELS COME IN.
UPDATE 1835 EDT: A COLD FRONT HAS PUSHED INTO THE CENTRAL
HIGHLANDS OF MAINE THIS EVENING AND WILL CONTINUE TO PUSH SOUTH
OVERNIGHT. DEWPOINTS HAVE DROPPED INTO THE 30S AND 40S ACROSS THE
CROWN OF MAINE BEHIND THE FRONT...BUT REMAIN IN THE 60S ACROSS
DOWNEAST PORTIONS OF THE STATE. EXPECT SMOKE FROM WILDFIRES IN
QUEBEC TO FILTER INTO THE NORTHERN HALF OF THE STATE OVERNIGHT AS
WINDS HAVE SHIFTED TO THE NORTHWEST. UPDATED THE FORECAST TO
REMOVE POPS ACROSS THE CROWN OF MAINE.
A COLD FRONT MOVING SOUTH ACROSS THE REGION WILL CONTINUE TO BRING
A CHANCE OF SOME SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS
FOR THE LATE AFTERNOON INTO EARLY THIS EVENING. AS OF THE MID
AFTERNOON THIS FRONT HAS PUSHED SOUTH OF THE CARIBOU / PRESQUE
ISLE REGION SO ADDITIONAL SHOWERS WILL REMAIN SOUTH OF THIS AREA.
SHOWERS/STORMS SHOULD DIMINISH THIS EVENING WITH THE LOSS OF
DAYTIME HEATING.
THE FORECAST BECOMES A BIT TRICKIER FOR THE OVERNIGHT PERIOD INTO
MONDAY. AN UPPER LEVEL DISTURBANCE AND ASSOCIATED AREA OF MOISTURE
FROM THE SOUTH WILL MOVE NORTH AND EAST DURING THIS TIME WITH
GUIDANCE CONTINUING TO INDICATE THE DEVELOPMENT OF WEAK LOW
PRESSURE AT THE SURFACE AS THIS FEATURE INTERACTS WITH THE FRONT
WHICH WILL BECOME STALLED OUT NEAR THE COAST LATE TONIGHT. THE
EXACT PLACEMENT OF THE FRONT AND ASSOCIATED EVOLUTION OF THE
SURFACE LOW WILL BE COMPLICATED BY A SURFACE HIGH TRYING TO
ADVANCE SOUTH FROM JAMES BAY. THE TREND CONTINUES TO BE FOR THIS
HIGH TO BE A BIT STRONGER AND PUSH PRECIPITATION FURTHER SOUTH
INTO MONDAY AND THE LATEST FORECAST FOLLOWS THIS THINKING. WILL
CONTINUE TO MENTION HIGH CHANCE AND LOW LIKELY PROBABILITIES OF
PRECIPITATION OVER CENTRAL AND SOUTHERN AREAS FOR LATE TONIGHT
INTO MONDAY BUT REDUCED QPF AMOUNTS TO UNDER A QUARTER OF AN INCH.
NORTHERN AREAS LOOK TO SEE A FAIRLY DECENT DAY FOR TOMORROW BASED
ON THE LATEST TRENDS WITH MOST OF THE RAIN/SHOWERS STAYING SOUTH.
HIGHS MONDAY WILL BE MUCH COOLER DUE TO THE NORTHERLY WINDS BEHIND
THE FRONT ALONG WITH CLOUD COVER. THESE NORTHERLY WINDS WILL ALSO
FILTER IN AREAS OF SMOKE FROM QUEBEC BEGINNING THIS AFTERNOON IN
THE NORTH AND REACHING INTERIOR DOWNEAST LOCALS BY LATE TONIGHT.
EXPECT HIGHS MONDAY GENERALLY IN THE LOW TO MID 70S.&&
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A FRONTAL BOUNDARY WILL STALL ACROSS THE GULF OF MAINE MONDAY
NIGHT. A WEAK AREA OF LOW PRESSURE WILL TRACK EAST ALONG THE
BOUNDARY MONDAY NIGHT THROUGH EARLY TUESDAY. THIS WILL BRING THE
CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE REGION...ESPECIALLY
ACROSS CENTRAL AND DOWNEAST MAINE. THE LOW WILL EXIT EAST THROUGH
THE MARITIMES DURING TUESDAY WITH SHOWER CHANCES DECREASING DURING
THE AFTERNOON ALTHOUGH IT WILL REMAIN MOSTLY CLOUDY. LOW PRESSURE
TRACKING NORTHWEST OF THE REGION DRAW THE STALLED OUT FRONTAL
BOUNDARY ACROSS THE GULF OF MAINE BACK NORTH OF THE REGION LATER
TUESDAY NIGHT AND WEDNESDAY. THIS WILL RESULT IN A CONTINUED
CHANCE FOR SHOWERS TUESDAY NIGHT AND AGAIN ON WEDNESDAY. EXPECT
PATCHY FOG BE A CONCERN TUESDAY NIGHT AND INTO WEDNESDAY WITH A
MOIST SOUTHERLY IN PLACE. TEMPERATURES WILL BE NEAR NORMAL FOR
THIS TIME OF YEAR.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A COLD FRONT WILL CROSS THE AREA FROM NORTHWEST TO SOUTHEAST WEDNESDAY
NIGHT AND THURSDAY. SHOWERS AND THUNDERSTORMS WILL BE LIKELY WITH
THE FRONT. THURSDAY NIGHT AND FRIDAY WE WILL PROBABLY DRY OUT,
ALTHOUGH CAN`T RULE OUT THE FRONT GETTING HUNG UP JUST OFFSHORE
AND RAIN PERSISTING RIGHT ALONG THE COAST.
THEN FRIDAY NIGHT THROUGH THE WEEKEND, WE SEE AN EXTREMELY STRONG
HIGH PRESSURE SYSTEM IN THE NORTH ATLANTIC MIGRATE WEST TO JUST
SOUTH OF NOVA SCOTIA. THIS WOULD LEAD TO ABOVE NORMAL TEMPERATURES
FROM NEW ENGLAND INTO EASTERN CANADA. THE AMOUNT OF PRECIPITATION
FOR SATURDAY THROUGH MONDAY IS FAIRLY UNCERTAIN DUE TO EXTREME
SENSITIVITY TO EXACTLY WHERE THE HIGH PRESSURE SETS UP.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
NEAR TERM: AREAS OF SMOKE MAY REDUCE VISIBILITIES AT TIMES FOR THE
NORTHERN SITES TONIGHT INTO MONDAY. BASED ON UPSTREAM OBSERVATIONS,
DO NOT EXPECT CONDITIONS TO REACH MVFR LEVELS BUT THIS WILL NEED
TO BE MONITORED. EXPECT VFR IN THE SOUTH THROUGH TONIGHT WITH MVFR
LIKELY MONDAY DUE TO LOW STRATUS AND SHOWERS.
SHORT TERM: EXPECT MAINLY VFR/MVFR ACROSS NORTHERN SITES(FVE/CAR/PQI/HUL)
AND MVFR/IFR (KBGR/KBHB)IN SHOWERS/TSTM/PATCHY FOG. EXPECT
MVFR/IFR TO PERSIST ALL SITES EARLY TUESDAY BEFORE IMPROVING TO
VFR. CONDITIONS WILL ONCE AGAIN DETERIORATE TO MVFR/IFR TUESDAY
NIGHT AND INTO WEDNESDAY IN LOW CLOUDS/PATCHY FOG/SHOWERS. MVFR
CONDITIONS WILL PERSIST INTO THURSDAY AS A COLD FRONT CROSSES THE
REGION WITH SHOWERS AND TSTMS. VFR RETURNS FOR FRIDAY.
&&
.MARINE...
NEAR TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA LEVELS
THROUGH MONDAY.
SHORT TERM:WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS
MONDAY NIGHT THROUGH WEDNESDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...FITZSIMMONS/OKULSKI
SHORT TERM...DUDA
LONG TERM...FOISY
AVIATION...FITZSIMMONS/OKULSKI/DUDA
MARINE...FITZSIMMONS/OKULSKI/DUDA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
355 PM EDT SAT JUL 6 2013
.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN AND DRIFT SLOWLY SOUTHWARD LATE TONIGHT
INTO EARLY NEXT WEEK AS LOW PRESSURE LIFTS INTO THE NORTHEAST
STATES. EXPECT INCREASING PRECIPITATION CHANCES LATE SUNDAY
THROUGH MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
LATEST WX ANALYSIS SHOWS HIGH PRESSURE AT THE SURFACE AND ALOFT
ORIENTED JUST OFFSHORE. TO THE WEST, A CLOSED LOW IS NOTED OVER
THE MID MISSISSIPPI VLY. IN BETWEEN THESE TWO FEATURES, THE
MOISTURE PLUME REMAINS CONFINED TO THE WEST OF THE MOUNTAINS,
EXTENDING NORTH FROM THE EAST-CENTRAL GULF COAST TO THE OHIO AND
TN RIVER VALLEYS.
NO MAJOR CHANGES TO THE GOING FORECAST NEEDED ATTM, W/GOOD MODEL
AGREEMENT IN LIFTING THE CLOSED LOW OVER THE LOWER MO RIVER VALLEY
SLOWLY NEWD TODAY. DEEP MOISTURE WILL REMAIN WEST OF THE
MOUNTAINS (PW VALUES OVER THE LOCAL AREA AOB 1.5 INCHES...HIGHEST
ACROSS THE PIEDMONT). FORCING WILL REMAIN STRONGEST WELL TO OUR
WEST ON THE WESTERN PERIPHERY OF THE BERMUDA RIDGE. GIVEN THE LACK
OF APPRECIABLE MID/UPPER LEVEL FORCING OVER THE LOCAL AREA,
EXPECTING MOST AREAS WILL REMAIN DRY ONCE AGAIN THROUGH THE AFTN
W/LITTLE MORE THAN SOME DIURNAL CU THAT WL DIMINISH/DISSIPATE THIS
EVENING. SOME ISOLATED SHRAS JUST SOUTH OF I-85 INTO NORTH CENTRAL
NC PIEDMONT. NEW HRRR KEEPS MOST OF THIS ACTIVITY SOUTH OF THE
CWA, SO HAVE REMOVED SHRA MENTION FOR MOST OF THE AREA AWAY FROM
MECKLENBERG/LUNENBURG COUNTIES.
MAINLY CLEAR, WARM AND HUMID TONIGHT. ONCE AGAIN AS WITH THE PAST
FEW NIGHTS, COULD SEE SOME PATCHY FOG/STRATUS TOWARDS DAWN BUT
NOT EXPECTING ANY SIGNIFICANT OPERATIONAL ISSUES. ERY MORNING LOWS
IN THE LOW TO MID 70S.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
UPPER LEVEL PATTERN WILL CONTINUE TO EVOLVE INTO A MORE SUMMER-
LIKE PATTERN THROUGH THE SHORT TERM PERIOD. AS THE DAMPENING UPPER
LOW MOVES BY TO OUR NORTH SUNDAY NIGHT AND MONDAY, A GRADUAL
PROGRESSION TO QUASI-ZONAL FLOW ALOFT ACROSS THE CONUS IS EXPECTED
BY MONDAY NIGHT. MODELS CONTINUE TO HANDLE THE DE-AMPLIFICATION
AND FORWARD MIGRATION OF THE MIDWEST UPPER LOW WELL. THE LOW WILL
EJECT NEWD INTO THE OH VALLEY ON SUNDAY, WITH DEVELOPING WESTERLY
FLOW OVER THE OHIO VLY/NORTHERN MID-ATL SLOWLY ERODING/WEAKENING
BERMUDA HIGH PRESSURE THAT HAS BEEN DOMINATING THE LOCAL AREA THE
PAST SEVERAL DAYS. RESULT WILL SEE SFC HIGH BECOME SHUNTED SOUTH
THROUGH THE FORECAST PERIOD, WHICH WILL VEER WINDS AROUND TO THE
SW ACROSS THE MID ATLANTIC, AND EVENTUALLY WILL BRING A PROFILE
MORE FAVORABLE FOR WIDESPREAD CONVECTIVE ACTIVITY BY LATER SUNDAY
AND ESPECIALLY MONDAY.
RAIN CHCS SLOWLY RAMP UP THROUGH THE PERIOD. N-S ORIENTED MOISTURE
PLUME WILL BEGIN TO ORIENT MORE SW TO NE AND PROPAGATE NEWD IN
SWLY FLOW...REACHING THE ERN VA PIEDMONT BY LATE SUN AFTERNOON.
HOWEVER...BEST DYNAMICS WILL REMAIN WEST OF THE REGION. WILL
MAINTAIN SLIGHT CHANCE POPS OVER THE PIEDMONT SUN AFTERNOON FOR
DIURNALLY FORCED CONVECTION. SHORTWAVE ON THE LEADING EDGE OF THE
MOISTURE PLUME IS PROGGED TO LIFT THROUGH WRN NC INTO WRN VA LATE
SUNDAY. SHOWERS AND THUNDERSTORMS SHOULD BE ONGOING ALONG THE
SHORTWAVE AND LEE SIDE TROUGH AS THEY LIFT INTO THE REGION.
RETAINED SLIGHT CHC/LOW CHC POP OVERNIGHT SUNDAY/MON AS MODELS
SPREAD THE PRECIP INTO THE LOCAL AREA...POSSIBLY REACHING AS FAR
AS RICHMOND LATE SUN NIGHT.
THE AFOREMENTIONED MIDWEST LOW WILL WEAKEN SLOWLY AS IT LIFTS
FROM THE OH VALLEY SUNDAY NIGHT INTO THE NE STATES ON MON.
DEVELOPING/INCREASING DEEP LAYERED SW FLOW OVER THE MID ATLANTIC
WILL SERVE TO INCREASE PRECIPITABLE WATER VALUES TO AROUND 2
INCHES ON MON. THIS INCREASINGLY MOIST AIRMASS, IN TANDEM
W/DIVERGENCE ALOFT AND THE LIFTING UPPER LOW WILL PROVIDE AMPLE
FORCING FOR ASCENT TO ALLOW FOR MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS TO DEVELOP MONDAY. EXPECT CONVECTION TO BE FOCUSED
PRIMARILY ALONG THE LEE TROUGH MON AFTN, WITH PCPN MOVING NEWD
INTO MONDAY EVENING. HV CONTINUED TO ORIENT BEST RAIN CHANCES
ACROSS THE PIEDMONT INTO N VA AND THE LOWER EASTERN SHORE ALONG
THE AXIS OF BEST FORCING (40-50%). HV RETAINED LOWER/SLIGHT CHC
POP OVER SOUTHERN TIDEWATER/NE NC ZONES CONSIDERING PCPN TIMING
COINCIDING WITH LOSS OF HEATING AND WEAKER DYNAMICS.
IF GFS IS CORRECT IN BRINGING SOME LATE MORNING CLEARING MONDAY,
POTENTIAL DOES EXIST FOR SOME STRONG TSTMS MONDAY AFTN. DEEP
LAYER SHEAR DOES REMAIN MARGINAL (12Z/GFS 0-6KM BULK SHEAR ~25-30
KT). HOWEVER, GIVEN STRONGER MID/UPR LVL WINDS W/PASSAGE OF UPPER
LOW AND SUFFICIENT CAPE (SREF PROBABILITIES SHOWS HIGH LIKELIHOOD
OF MLCAPE ON THE ORDER OF 1000-1500 J/KG INLAND), A FEW ISOLATED
STRONGER CELLS COULD DEVELOP. BRIEF HVY RAINFALL AND GUSTY WINDS
WOULD BE THE PRIMARY CONCERN W/ANY OF THE STRONGER STORMS.
FOR TEMPERATURES...STEADY HEIGHTS AND LOW LEVEL THICKNESSES WILL
SUPPORT NORMAL TO SLIGHTLY ABOVE NORMAL TEMPS SUN/MON. EXPECT
DAYTIME TEMPS TO REMAIN IN THE LOW 90S W/ABUNDANT LOW LEVEL
MOISTURE ALLOWING SEASONABLY HUMID CONDITIONS TO CONTINUE ACROSS
THE AREA. MILD OVERNIGHT TEMPS IN THE LOW 70S W/ SOME MORE PATCHY
FOG/LOW STRATUS POSSIBLE EACH MORNING.
TUESDAY...
AS MENTIONED ABOVE, UPPER FLOW BECOMES QUASI-ZONAL ALOFT FOR THE
MIDWEEK PERIOD IN THE WAKE OF THE UPPER TROUGH. FORCING BECOMES A
LOT LESS FOCUSED BEHIND THE TROUGH. HOWEVER, GIVEN ANOTHER WARM
AND MODERATELY HUMID DAY...BROAD LARGE SCALE TROUGHINESS AND
SEVERAL WEAK SHORTWAVES PUSHING ACROSS DURING THE PERIOD, EXPECT
THAT WE`LL STILL SEE ANOTHER ROUND OF ISOLATED/WIDELY SCT TSRAS.
HIGHS ONCE AGAIN U80S COASTAL AREAS TO AROUND 90 INLAND.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
LONG TERM PERIOD STARTS OFF TUE NGT INTO WED WITH ZONAL FLOW ALOFT
OVER THE MID ATLANTIC AND AN UPR-LVL LO STARTING TO DIG OVER THE
GREAT LAKES REGION. ALTHO BEST FORCING AND MOISTURE WILL STAY NW OF
THE LOCAL AREA WED...DID INCLUDE A 20-30% CHC FOR SHRAS/TSTMS DUE TO
DIURNALLY-DRIVEN CONVECTION IN THE WARM SECTOR. BETTER CHC FOR RAIN
(40-50%) COMES LATE THU AS THE UPR-LVL TROF AND ASSOCIATED COLD FRONT
APPROACH FROM THE OH VALLEY AND DEEP-LAYER MOISTURE INCREASES. THE
FRONT WILL SLOW DOWN/STALL OVER THE AREA FRI (AND ALSO SAT?) LEADING
TO CONTINUED CHCS FOR SHRAS/TSTMS.
SLY FLOW AND ABUNDANT LO-LVL MOISTURE WILL CONTINUE TO PRODUCE HUMID
CONDS (DEWPTS AVG IN THE LWR 70S) WITH HI TEMPS IN THE UPR 80S/LWR
90S AND LO TEMPS AVG IN THE LWR 70S.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
SCT CU AND SW WINDS AROUND 10 KNOTS WILL PREDOMINATE AT THE TAF
SITES THE REMAINDER OF THE AFTN. SOME VARIABILITY IS PSBL DURING
PART OF THE AFTN AT ORF BUT INDICATIONS OF A NE WIND DEVELOPING ARE
NOT AS STRONG AS THEY WERE AT THIS TIME YESTERDAY.
ON SUNDAY MORNING...SIGNALS FOR FOG AND STRATUS ARE GETTING WEAKER
BY THE DAY. WITH THE GROUND DRYING OUT AND DAYTIME TEMPERATURES
ON THE RISE...FOG IS UNLIKELY. SOME PATCHY STRATUS IS PSBL...BUT ANY
STRATUS IS EXPECTED TO BE LESS EXTENSIVE THAN IT HAS BEEN IN RECENT
DAYS.
OUTLOOK...THE DAYTIME HOURS SUNDAY SHOULD BE SIMILAR TO TODAY.
THERE IS NO SIGNIFICANT CHANCE FOR CONVECTION SUNDAY BUT THOSE
POSSIBILITIES INCREASE SHARPLY MONDAY AFTN...ESPECIALLY AT RIC. A
CHANCE FOR SCT AFTN THUNDERSTORMS REMAIN IN THE FCST THIS COMING
WEEK. NO WIDESPREAD IFR IS INDICATED THROUGH THURSDAY.
&&
.MARINE...
GENLY BENIGN SUB-SCA CONDS OVER THE MARINE AREA THRU AT LEAST THE
MIDDLE OF NEXT WEEK. BERMUDA HI PRES WILL SLOWLY WEAKEN/DRIFT EWRD
TNGT THRU SUN NGT AS UPR-LVL LO PRES APPROACHES FROM THE WEST. NO
STRONG SFC FRONT/FROPA WILL BE ASSOCIATED WITH THIS UPR-LVL
SYSTM...MAINLY JUST A STATIONARY TROF OVER THE LEE OF THE
APPALACHIANS. WINDS THRU THE PERIOD WILL AVG 10-15KT OUT OF THE
S/SW...BUT DIRECTIONS MAY SHIFT DURING THE AFTN HRS NEAR THE COAST
WITH SEA BREEZE EFFECTS (E.G. SERLY ALONG THE WESTERN SIDE OF THE
BAY). EXPECT 1-2FT WAVES OVER THE BAY AND 2-3FT SEAS OVER CSTL
WTRS...APPROACHING 4FT OUT 20NM ON MON.
&&
.EQUIPMENT...
KAKQ RADAR HAS RETURNED TO SERVICE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM/SAM
NEAR TERM...MAM
SHORT TERM...MAM
LONG TERM...MAS
AVIATION...LSA
MARINE...MAS
EQUIPMENT...AKQ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
147 PM EDT SAT JUL 6 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 340 AM EDT SAT JUL 6 2013
IT WILL REMAIN VERY SUMMER-LIKE WITH HIGHS IN THE 80S THROUGH THE
WEEKEND. HUMIDITY VALUES WILL ALSO GRADUALLY INCREASE. SCATTERED
SHOWERS AND THUNDERSTORMS WILL MOVE IN FROM THE SOUTH BY LATE THIS
AFTERNOON ACROSS THE I-94 CORRIDOR. THIS SCATTERED PRECIPITATION
SHOULD CONTINUE TO SPREAD NORTH AND REACH I-96 TOWARD MIDNIGHT. THE
THREAT OF SHOWERS WILL GRADUALLY END INTO SUNDAY. MORE SCATTERED
SHOWERS AND STORMS WILL BE POSSIBLE MONDAY AS A FRONT MOVES INTO THE
REGION.
THIS FRONT IS EXPECTED TO ONLY SLOWLY MOVE THROUGH THE REGION...SO
THE RISK OF SHOWERS AND STORMS SHOULD LINGER TUESDAY AND WEDNESDAY.
THEN IT APPEARS WE WILL DRY OUT FOR THE LATTER HALF OF THE WEEK.
DAYTIME HIGHS SHOULD REMAIN IN THE 80S THROUGH NEXT WEEK.
&&
.UPDATE...
ISSUED AT 11206 PM EDT SAT JUL 6 2013
I INCREASED THE THE POP TO NEAR 50 PCT ALONG AND SOUTH OF
INTERSTATE 94 THIS AFTERNOON BASED ON THE MOISTURE BEING
TRANSPORTED NORTH INTO OUR SOUTHERN CWA FROM THE SYSTEM TO OUR SW.
RAP SOUNDING ARE SHOWING 1300 TO 1500 J/KG IN THAT AREA AND GIVEN
THERE IS STILL SOME SUNSHINE I HAVE TO IMAGINE THE INSTABILITY WILL
INCREASE FARTHER. ALSO THE HRRR...RAP AND NAM SHOW A RATHER
EXTENSIVE AREA OF SHOWERS DURING THE MID TO LATE AFTERNOON NEAR
AND SOUTH OF INTERSTATE 96. SEEMS THE SE CWA WILL HAVE THE BEST
CHANCE OF SEEING STORMS AS THAT AREA IS CLOSEST TO THE BETTER LOW
LEVEL MOISTURE TRANSPORT.
THERE COULD BE SOME LIMITED LAKE BREEZE CONVECTION BETWEEN US-31
AND US-131 BUT WITH SOUTHWEST WINDS ALREADY PREVAILING IT WOULD
SEEM SURFACE CONVERGENCE SHOULD NOT BE ALL THAT STRONG. ALSO BASED
ON RAP SOUNDING NEAR GRR THERE SEEMS TO BE A CAP AROUND 450 MB SO
THAT SHOULD HELP PUT A LID ON HOW BIG THE SHOWERS CAN GET NEAR AND
NORTH OF GRR.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 340 AM EDT SAT JUL 6 2013
BETTER CHANCES OF SHOWERS AND STORMS APPEAR TO EXIST INTO TONIGHT.
TEMPS WILL STAY WARM WITH INCREASING HUMIDITY INTO MONDAY.
A LARGE CLUSTER OF SHOWERS AND STORMS WAS OVER WESTERN AND CENTRAL
SECTIONS OF KY AND TN THIS MORNING...ASSOCIATED WITH ANOTHER WAVE
THAT WAS MOVING NORTHWARD. THE UPPER FLOW OVER MI WILL GRADUALLY
BECOME MORE DIVERGENT BY THIS EVENING WHICH FAVORS THAT THIS WAVE
WILL IMPACT SW MI. I REMOVED POPS FROM THE GRIDS FOR THIS
MORNING...BUT MAINTAINED THE POPS AFTER 21Z AS THE I-94 CORRIDOR
SHOULD START TO SEE THE SCATTERED SHOWERS AND STORMS MOVE BY THAT
TIME.
THE CHALLENGE INTO TONIGHT WILL BE HOW FAR NORTH WILL THIS WAVE
BRING RAIN. BELIEVE WITH THE UPPER FLOW MORE DIVERGENT THERE SHOULD
NOT BE MUCH TO STOP IT...ALTHOUGH IT WILL BE RUNNING INTO SLIGHTLY
DRIER AIR AS THE PCPN TRIES TO MOVE NORTH OF I-96. THE WAVE WILL
ALSO BEGIN TO GET PUSHED TO THE EAST BY THE UPPER LOW THAT ARRIVES
INTO THE SOUTHERN GREAT LAKES LATE TONIGHT. SO BELIEVE THE PCPN MAY
REACH A MKG-MOP LINE LATE TONIGHT BEFORE GETTING PUSHED EAST INTO
SUNDAY. MOST OF SUNDAY NIGHT SHOULD BE DRY AS WE SHOULD FALL IN
BETWEEN SYSTEMS.
THE PATTERN BECOMES A BIT MORE PROGRESSIVE INTO MONDAY AS A COLD
FRONT OVER CENTRAL WI MOVES INTO LOWER MI. THIS WILL BRING IN
ANOTHER RISK OF SCATTERED SHOWERS AND STORMS...ESPECIALLY FOR
SOUTHERN AND EASTERN PORTIONS OF THE CWA WHERE THE HIGHEST DEW
POINTS SHOULD RESULT IN THE BEST INSTABILITY.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 AM EDT SAT JUL 6 2013
BEST CHANCE OF RAIN IN THE EXTENDED STILL LOOKS TO BE TUESDAY INTO
WEDNESDAY AS UPPER TROUGH AXIS AND SFC LOW MOVES THROUGH. MODELS
ARE IN DECENT AGREEMENT WITH THE GFS HAVING TRENDED TO THE MORE
AMPLIFIED TROUGH SHOWN BY THE ECMWF. PLENTY OF MOISTURE AVAILABLE
AND MCS DEVELOPMENT IS POSSIBLE TUESDAY NIGHT INTO WEDNESDAY MORNING
WITH HEAVY RAIN THREAT. SEVERE WEATHER POSSIBLE AT THAT TIME AS WELL
WITH DEEP LAYERED SHEAR SUFFICIENT FOR STRONG TO SEVERE STORMS
ESPECIALLY ACROSS THE NORTHERN FORECAST AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 140 PM EDT SAT JUL 6 2013
ADDED SOME IFR TRW ACTIVITY FOR KBTL AND KJXN THIS AFTERNOON.
RADAR SHOWS DEVELOPING SHOWERS AROUND KADG AND KJYM MOVING NW. IFR
EARLIER AT KDFI WHEN THE SHOWERS WERE WEAKER. SO THESE PASSING
CELLS HAVE AN INCREASED CHANCE TO PRODUCE BRIEF IFR DOWNPOURS. NO
LIGHTNING YET WITH THESE CELLS BUT CLOUD TOPS ARE DOWN TO -30 DEG
C...SO THE RISK IS INCREASING. HOW FAR NORTH AND WEST THEY GO IS A
CHALLENGE. FOR NOW WILL KEEP THE FORECAST AT MAINLY VCTS...BUT
AVIATORS SHOULD MONITOR TRENDS CLOSELY THIS AFTERNOON.
I ADDED MVFR CEILINGS TO MOST TAF SITES FOR OVERNIGHT. LOW LEVEL
MOISTURE IS MOVING IN FROM THE SOUTH. UPSTREAM THERE WAS A LOT OF
MVFR CLOUDS LAST NIGHT AND FOG AS WELL. WILL NEED TO MONITOR THE
IFR FOR LATER TONIGHT AS WELL...ESPECIALLY IF IT RAINS.
LOW LEVEL MOISTURE PERSISTS SUNDAY MORNING...SO THE CONDITIONS MAY
BE SLOW TO IMPROVE.
&&
.MARINE...
ISSUED AT 340 AM EDT SAT JUL 6 2013
A SSW FLOW WILL CONTINUE FOR MUCH OF THE SHORT TERM...BUT REMAIN 15
KNOTS OR LESS. THIS FLOW WILL RESULT IN FAIRLY LOW WAVES...ALTHOUGH
TWO FOOTERS WILL BE COMMON TOWARD THE POINTS REGION.
&&
.HYDROLOGY...
ISSUED AT 340 AM EDT SAT JUL 6 2013
WITH THE SCATTERED NATURE OF THE PCPN THROUGH THE SHORT TERM NO
HYDRO ISSUES ARE EXPECTED. MOST RIVER BASINS SHOULD SEE AN AVERAGE
OF A QUARTER INCH OR LESS THROUGH MONDAY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...OSTUNO
AVIATION...MJS
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 PM EDT SAT JUL 6 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT SAT JUL 6 2013
A VERY MILD EARLY MORNING ACROSS UPPER MICHIGAN WITH MANY TEMPS
STILL IN THE UPPER 60S-MID 70S AS SOUTHERLY WINDS CONTINUE TO GUST
TO 20+KT...ESPECIALLY IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR. A
FEW SHOWERS AND ISOLATED STORMS OVER MN THROUGH WESTERN LAKE
SUPERIOR ASSOCIATED WITH A WEAKENING VORTICITY MAXIMUM OVER NW
ONTARIO CONTINUE TO MOVE NORTHEAST. THE RAP AND THE LOCAL RAPID
UPDATE WRF-ARW RUNS SUGGEST THAT SOME ADDITIONAL SHOWERS COULD
DEVELOP OVER FAR WESTERN UPPER MICHIGAN AS THE WEAK Q-VECTOR
CONVERGENCE ASSOCIATED WITH THIS VORT PASSES BY. HOWEVER...GIVEN THE
DRY AIRMASS PER THE 00Z MPX AND GRB RAOBS...AND BEST SYNOPTIC
SUPPORT REMAINING OVER THE WESTERN AND NORTHERN LAKE...THERE IS NOT
GREAT CONFIDENCE THAT ANY SHOWER ACTIVITY WILL ACTUALLY OCCUR EARLY
THIS MORNING. HOWEVER...GIVEN THE CURRENT MOTION OF SHOWER ACTIVITY
JUST SOUTH OF DLH...PCPN CANNOT BE TOTALLY RULED OUT FROM IWD TO THE
KEWEENAW THIS MORNING. AS SUCH...HAVE OPTED TO MAINTAIN ISOLATED
POPS THIS MORNING FOR THIS REGION. AS THE SURFACE TROUGH OVER NW
ONTARIO SAGS SOUTHWARD TODAY...THIS WILL LIKELY SERVE AS THE FOCUS
FOR ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT MAINLY ACROSS THE
WESTERN HALF OF UPPER MICHIGAN THIS AFTERNOON...ESPECIALLY AS THE
NEXT WEAK WAVE OVER THE DAKOTAS MOVES INTO THE AREA. MLCAPE VALUES
RISE TO AROUND 1200 J/KG THIS AFTERNOON ACROSS THE WEST...BUT THE
CAPE IS FAIRLY SKINNY WITH 700-500MB LAPSE RATES OF ONLY AROUND 6
C/KM. ALTHOUGH THE FRONTAL ZONE AND/OR LAKE BREEZE BOUNDARY MAY HELP
ENHANCE LOCAL BULK SHEAR...OVERALL THE 0-6KM SHEAR REMAINS QUITE LOW
WITH ONLY 15-20 KT OF DEEP SHEAR. COULD NOT RULE OUT SOME MULTI-CELL
CLUSTERS THIS AFTERNOON ACROSS THE WEST...BUT IT SEEMS UNLIKELY THAT
ANY SIGNIFICANT SEVERE WILL OCCUR ACROSS THE AREA TODAY...ESPECIALLY
WITH THE WEAKENING 850MB WIND FIELDS THIS AFTERNOON. BEST CHANCES
FOR SHOWERS AND STORMS WILL LIKELY BE LATE THIS AFTERNOON INTO EARLY
THIS EVENING ACROSS THE WEST AND NORTH CENTRAL AS THE UPPER VORT
PASSES BY JUST TO THE NORTH. IN FACT...MANY OF THE HIGHER RES NWP
SUGGEST THE BEST CHANCE OF SHOWERS/STORMS ALONG AND JUST NORTH OF
THE STATIONARY FRONT...WHICH WOULD PLACE THE HEAVIEST PCPN OVER LAKE
SUPERIOR...THE KEWEENAW EXTENDING SOUTHWARD INTO NRN MARQUETTE AND
BARAGA COUNTIES. ONCE THIS WAVE PASSES BY...EXPECT WEAK DRY
ADVECTION AND NEGATIVE THETA-E ADVECTION AT 850MB ESPECIALLY ACROSS
EASTERN AND CENTRAL UPPER MICHIGAN...HELPING TO BRING ANY SHOWERS
AND STORMS GENERALLY TO AN END IN THOSE AREAS. WITH THE FRONTAL
BOUNDARY AND BETTER MOISTURE REMAINING FROM EASTERN LAKE SUPERIOR
THROUGH THE KEWEENAW TO NW WISCONSIN...WILL NEED TO MAINTAIN CHANCE
POPS FOR THE WESTERN 1/3 OF FORECAST AREA FOR THE ENTIRE OVERNIGHT
PERIOD...BUT THE EXPECTATION IS THAT BEST CHANCES FOR PCPN WILL BE
THIS EVENING...WITH SOME TYPE OF LULL AFTER MIDNIGHT BEFORE THE NEXT
ROUND OF SHOWERS AND STORMS MOVE IN SUN MORNING.
IN ADDITION TO THE RAINFALL IN THE KEWEENAW...WEAK UPSLOPE E OR SE
FLOW IS EXPECTED TO DEVELOP LATE THIS AFTERNOON AND ESPECIALLY
TONIGHT. GIVEN THE INCREASED LOW LEVEL MOISTURE FROM ANY RAINFALL
AND ALSO COOLER AIR OFF THE LAKE...PATCHY FOG MAY DEVELOP FROM CMX
TO COPPER HARBOR TONIGHT. WIND FIELDS WILL BE VERY LIGHT...SO THERE
IS AT LEAST A SMALL CHANCE FOR DENSE FOG TO DEVELOP
TONIGHT...ESPECIALLY AFTER THE RAIN DIMINISHES.
LOW LEVEL MOISTURE WILL BE ON THE INCREASE TODAY...THUS MAKING IT
MUCH MORE HUMID THAN FRIDAY. ALTHOUGH TEMPS MAY END UP BEING SEVERAL
DEGREES COOLER DUE TO INCREASED CLOUD COVER...IT WILL LIKELY FEEL
SIMILAR OR SLIGHTLY WORSE THAN FRIDAY DUE TO THE INCREASED HUMIDITY.
TEMPS WILL STILL TOP OUT WELL INTO THE 80S IN MOST PLACES AWAY FROM
LAKE MICHIGAN...HOWEVER THE WEAKENING LOW LEVEL WINDS WILL ALLOW
LAKE BREEZES TO FORM WHICH SHOULD HELP KEEP AREAS NEAR THE SHORELINE
OF LAKE SUPERIOR TO BE COOLER THAN FRIDAY AS WELL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 455 AM EDT SAT JUL 6 2013
SUN INTO SUN NIGHT...MODELS SUGGEST THAT A WEAKENING SHORTWAVE
TROUGH AND STRONGEST 700-300 MB QVECTOR CONV WILL MOVE FROM SRN
MANITOBA INTO NRN ONTARIO WITH AN ASSOCIATED SFC TROUGH TRAILING
THROUGH THE NRN GREAT LAKES. ONGOING CONVECTION FROM NE MN INTO WRN
LAKE SUPERIOR AND NW WI MAY MOVE INTO W UPPER MI IN THE MORNING. IF
ENOUGH BREAKS IN THE CLOUD COVER DEVELOP...AFTERNOON MLCAPE VALUES
COULD CLIMB TO 1000-1500 J/KG SUPPORTING ADDITIONAL SCT/NMRS
SHRA/TSRA WITH THE TROUGH...OUTFLOW AND LAKE BREEZE BOUNDARIES OVER
THE AREA. HOWEVER...0-6KM BULK SHEAR VALUES TO 30 KT WILL BE
MARGINAL TO SUPPORT ORGANIZED STRONGER/SVR STORMS. WITH PWAT VALUES
TO AROUND 1.75 INCHES...SOME LOCALLY HEAVY RAIN MAY BE POSSIBLE.
CONFIDENCE IN WIDESPREAD PCPN COVERAGE WAS LIMITED AS THE GFS/GEM
AND HIGHER RES MODELS WERE SIGNFICANTLY MORE AGGRESSIVE WITH THE
AFTERNOON PCPN COMPARED TO THE NAM/ECMWF. ANY EVENING SHRA/TSRA ARE
EXPECTED TO DIMINISH OVERNIGHT AS WEAK SHORTWAVE RIDGING MOVES IN AND
THE FRONT MOVES OFF TO THE SOUTH.
MON...ALTHOUGH THE WEAKENING FRONTAL BOUNDARY IS EXPECTED TO REMAIN
SOUTH OF UPPER MI...THE POTENTIAL REMAINS FOR WEAK SHRTWVS TO MOVE
THROUGH THE AREA THAT COULD RESULT IN ADDITIONAL PCPN KEEPING SLIGHT
CHANCE POPS GOING OVER MAINLY THE SOUTH CENTRAL AND EAST.
TUE-FRI...THE MODELS WERE IN REASONABLE AGREEMENT WITH THE
STRONGER SHORTWAVE TROUGH MOVING INTO THE NRN GREAT LAKES.
QVECTOR CONV AND MOISTURE ADVECTION AHEAD OF THIS FEATURE WILL
SUPPORT INCREASING SHRA/TSRA CHANCES MAINLY FROM TUE NIGHT INTO EARLY
WED. ALTHOUGH THE GFS DISPLAYED CONSIDERABLE CONVECTIVE
FEEDBACK...THE GEM/ECMWF ALSO SUPPORT THE IDEA OF KEEPING STRONGER
CONVECTION CLOSER TO THE SFC FRONTAL BOUNDARY TO THE SOUTH WHICH
WOULD DISRUPT MOISTURE TRANSPORT TOWARD UPPER MI AND LIMIT PCPN
CHANCES/AMOUNTS. A RETURN TO COOLER CONDITIONS WITH TEMPS BLO NORMAL
ARE EXPECTED BY THU WITH ONLY A CHANCE OF SOME LINGERING LIGHT
SHOWERS WITH WRAP- AROUND MOISTURE AND TRAILING WEAK SHRTWVS AROUND
THE DEPARTING MID LEVEL LOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 130 PM EDT SAT JUL 6 2013
A WEAK SURFACE TROUGH/FRONTAL BOUNDARY STRETCHING FROM WEST TO EAST
ACROSS LAKE SUPERIOR WILL REMAIN NEARLY STATIONARY THROUGH SUNDAY AS
A COUPLE OF UPPER LEVEL DISTURBANCES MOVE ACROSS THE AREA. THESE
DISTURBANCES SHOULD ENHANCE THE SHRA/ISOLATED THUNDER CHANCES ACROSS
MAINLY WESTERN UPPER MICHIGAN AND THE KEWEENAW LATER THIS AFTERNOON
AND EVENING AND THEN ACROSS THE ENTIRE AREA SUNDAY MORNING. WILL TRY
TO DELINEATE THIS IN THE TAFS ALTHOUGH VFR CONDITIONS SHOULD PERSIST
EVEN UNDER MOST OF THE SHOWERS. SOME UNCERTAINTY DOES EXIST WITH THE
CIG/VIS FORECAST TONIGHT AT CMX AS WEAK FRONT SAGS JUST SOUTH OF CMX
TONIGHT. LIGHT SOUTHEASTERLY FLOW MAY ALLOW FOR MVFR CIGS FOR A TIME
THERE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 455 AM EDT SAT JUL 6 2013
SOUTH TO SOUTHWEST WINDS OF 25 KNOTS CAN BE EXPECTED THIS MORNING
ESPECIALLY ACROSS THE EASTERN HALF OF LAKE SUPERIOR AHEAD OF THE LOW
PRESSURE TROUGH. CANNOT RULE OUT A FEW GUSTS TO 30 KT ESPECIALLY ON
THE CMAN STATIONS OR LARGER SHIPS. AS THE TROUGH DRIFTS SOUTHWARD
OVER LAKE SUPERIOR TODAY...EXPECT THE WINDS TO DIMINISH TO 5-15 KT
TONIGHT AND REMAIN BELOW 15 KT THOUGH TUESDAY AS WEAK HIGH PRESSURE
BUILDS ACROSS THE LAKE LATE SUNDAY INTO MONDAY. ANOTHER LOW DEVELOPS
OVER THE PLAINS ON TUESDAY THEN DEEPENS AS IT APPROACHES LAKE
SUPERIOR ON WEDNESDAY. WILL NEED TO WATCH THIS FOR STRONGER NW WINDS
BEHIND THE SYSTEM LATER WED INTO WED NIGHT.
DUE TO EXPECTED RAINFALL OVER THE LAKE AND INCREASED LOW LEVEL
MOISTURE...FOG WILL BECOME A CONCERN LATER TODAY AND ESPECIALLY
TONIGHT INTO SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...JLB
AVIATION...MZ
MARINE...MRD
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1203 PM EDT SAT JUL 6 2013
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 340 AM EDT SAT JUL 6 2013
IT WILL REMAIN VERY SUMMER-LIKE WITH HIGHS IN THE 80S THROUGH THE
WEEKEND. HUMIDITY VALUES WILL ALSO GRADUALLY INCREASE. SCATTERED
SHOWERS AND THUNDERSTORMS WILL MOVE IN FROM THE SOUTH BY LATE THIS
AFTERNOON ACROSS THE I-94 CORRIDOR. THIS SCATTERED PRECIPITATION
SHOULD CONTINUE TO SPREAD NORTH AND REACH I-96 TOWARD MIDNIGHT. THE
THREAT OF SHOWERS WILL GRADUALLY END INTO SUNDAY. MORE SCATTERED
SHOWERS AND STORMS WILL BE POSSIBLE MONDAY AS A FRONT MOVES INTO THE
REGION.
THIS FRONT IS EXPECTED TO ONLY SLOWLY MOVE THROUGH THE REGION...SO
THE RISK OF SHOWERS AND STORMS SHOULD LINGER TUESDAY AND WEDNESDAY.
THEN IT APPEARS WE WILL DRY OUT FOR THE LATTER HALF OF THE WEEK.
DAYTIME HIGHS SHOULD REMAIN IN THE 80S THROUGH NEXT WEEK.
&&
.UPDATE...
ISSUED AT 11206 PM EDT SAT JUL 6 2013
I INCREASED THE THE POP TO NEAR 50 PCT ALONG AND SOUTH OF
INTERSTATE 94 THIS AFTERNOON BASED ON THE MOISTURE BEING
TRANSPORTED NORTH INTO OUR SOUTHERN CWA FROM THE SYSTEM TO OUR SW.
RAP SOUNDING ARE SHOWING 1300 TO 1500 J/KG IN THAT AREA AND GIVEN
THERE IS STILL SOME SUNSHINE I HAVE TO IMAGINE THE INSTABILITY WILL
INCREASE FARTHER. ALSO THE HRRR...RAP AND NAM SHOW A RATHER
EXTENSIVE AREA OF SHOWERS DURING THE MID TO LATE AFTERNOON NEAR
AND SOUTH OF INTERSTATE 96. SEEMS THE SE CWA WILL HAVE THE BEST
CHANCE OF SEEING STORMS AS THAT AREA IS CLOSEST TO THE BETTER LOW
LEVEL MOISTURE TRANSPORT.
THERE COULD BE SOME LIMITED LAKE BREEZE CONVECTION BETWEEN US-31
AND US-131 BUT WITH SOUTHWEST WINDS ALREADY PREVAILING IT WOULD
SEEM SURFACE CONVERGENCE SHOULD NOT BE ALL THAT STRONG. ALSO BASED
ON RAP SOUNDING NEAR GRR THERE SEEMS TO BE A CAP AROUND 450 MB SO
THAT SHOULD HELP PUT A LID ON HOW BIG THE SHOWERS CAN GET NEAR AND
NORTH OF GRR.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 340 AM EDT SAT JUL 6 2013
BETTER CHANCES OF SHOWERS AND STORMS APPEAR TO EXIST INTO TONIGHT.
TEMPS WILL STAY WARM WITH INCREASING HUMIDITY INTO MONDAY.
A LARGE CLUSTER OF SHOWERS AND STORMS WAS OVER WESTERN AND CENTRAL
SECTIONS OF KY AND TN THIS MORNING...ASSOCIATED WITH ANOTHER WAVE
THAT WAS MOVING NORTHWARD. THE UPPER FLOW OVER MI WILL GRADUALLY
BECOME MORE DIVERGENT BY THIS EVENING WHICH FAVORS THAT THIS WAVE
WILL IMPACT SW MI. I REMOVED POPS FROM THE GRIDS FOR THIS
MORNING...BUT MAINTAINED THE POPS AFTER 21Z AS THE I-94 CORRIDOR
SHOULD START TO SEE THE SCATTERED SHOWERS AND STORMS MOVE BY THAT
TIME.
THE CHALLENGE INTO TONIGHT WILL BE HOW FAR NORTH WILL THIS WAVE
BRING RAIN. BELIEVE WITH THE UPPER FLOW MORE DIVERGENT THERE SHOULD
NOT BE MUCH TO STOP IT...ALTHOUGH IT WILL BE RUNNING INTO SLIGHTLY
DRIER AIR AS THE PCPN TRIES TO MOVE NORTH OF I-96. THE WAVE WILL
ALSO BEGIN TO GET PUSHED TO THE EAST BY THE UPPER LOW THAT ARRIVES
INTO THE SOUTHERN GREAT LAKES LATE TONIGHT. SO BELIEVE THE PCPN MAY
REACH A MKG-MOP LINE LATE TONIGHT BEFORE GETTING PUSHED EAST INTO
SUNDAY. MOST OF SUNDAY NIGHT SHOULD BE DRY AS WE SHOULD FALL IN
BETWEEN SYSTEMS.
THE PATTERN BECOMES A BIT MORE PROGRESSIVE INTO MONDAY AS A COLD
FRONT OVER CENTRAL WI MOVES INTO LOWER MI. THIS WILL BRING IN
ANOTHER RISK OF SCATTERED SHOWERS AND STORMS...ESPECIALLY FOR
SOUTHERN AND EASTERN PORTIONS OF THE CWA WHERE THE HIGHEST DEW
POINTS SHOULD RESULT IN THE BEST INSTABILITY.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 AM EDT SAT JUL 6 2013
BEST CHANCE OF RAIN IN THE EXTENDED STILL LOOKS TO BE TUESDAY INTO
WEDNESDAY AS UPPER TROUGH AXIS AND SFC LOW MOVES THROUGH. MODELS
ARE IN DECENT AGREEMENT WITH THE GFS HAVING TRENDED TO THE MORE
AMPLIFIED TROUGH SHOWN BY THE ECMWF. PLENTY OF MOISTURE AVAILABLE
AND MCS DEVELOPMENT IS POSSIBLE TUESDAY NIGHT INTO WEDNESDAY MORNING
WITH HEAVY RAIN THREAT. SEVERE WEATHER POSSIBLE AT THAT TIME AS WELL
WITH DEEP LAYERED SHEAR SUFFICIENT FOR STRONG TO SEVERE STORMS
ESPECIALLY ACROSS THE NORTHERN FORECAST AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 730 AM EDT SAT JUL 6 2013
SOME LIGHT FOG EARLY THIS MORNING WILL DISSIPATE AND VFR
CONDITIONS ARE EXPECTED TODAY. ISOLATED SHOWERS ARE EXPECTED BY
THIS AFTERNOON. THEN FAIR WEATHER TONIGHT WITH SOME PATCHY IFR IN
FOG DEVELOPING AFTER MIDNIGHT. WINDS WILL BE SOUTH TO SOUTHWEST AOB
10 KNOTS.
&&
.MARINE...
ISSUED AT 340 AM EDT SAT JUL 6 2013
A SSW FLOW WILL CONTINUE FOR MUCH OF THE SHORT TERM...BUT REMAIN 15
KNOTS OR LESS. THIS FLOW WILL RESULT IN FAIRLY LOW WAVES...ALTHOUGH
TWO FOOTERS WILL BE COMMON TOWARD THE POINTS REGION.
&&
.HYDROLOGY...
ISSUED AT 340 AM EDT SAT JUL 6 2013
WITH THE SCATTERED NATURE OF THE PCPN THROUGH THE SHORT TERM NO
HYDRO ISSUES ARE EXPECTED. MOST RIVER BASINS SHOULD SEE AN AVERAGE
OF A QUARTER INCH OR LESS THROUGH MONDAY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...OSTUNO
AVIATION...OSTUNO
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
751 AM EDT SAT JUL 6 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT SAT JUL 6 2013
A VERY MILD EARLY MORNING ACROSS UPPER MICHIGAN WITH MANY TEMPS
STILL IN THE UPPER 60S-MID 70S AS SOUTHERLY WINDS CONTINUE TO GUST
TO 20+KT...ESPECIALLY IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR. A
FEW SHOWERS AND ISOLATED STORMS OVER MN THROUGH WESTERN LAKE
SUPERIOR ASSOCIATED WITH A WEAKENING VORTICITY MAXIMUM OVER NW
ONTARIO CONTINUE TO MOVE NORTHEAST. THE RAP AND THE LOCAL RAPID
UPDATE WRF-ARW RUNS SUGGEST THAT SOME ADDITIONAL SHOWERS COULD
DEVELOP OVER FAR WESTERN UPPER MICHIGAN AS THE WEAK Q-VECTOR
CONVERGENCE ASSOCIATED WITH THIS VORT PASSES BY. HOWEVER...GIVEN THE
DRY AIRMASS PER THE 00Z MPX AND GRB RAOBS...AND BEST SYNOPTIC
SUPPORT REMAINING OVER THE WESTERN AND NORTHERN LAKE...THERE IS NOT
GREAT CONFIDENCE THAT ANY SHOWER ACTIVITY WILL ACTUALLY OCCUR EARLY
THIS MORNING. HOWEVER...GIVEN THE CURRENT MOTION OF SHOWER ACTIVITY
JUST SOUTH OF DLH...PCPN CANNOT BE TOTALLY RULED OUT FROM IWD TO THE
KEWEENAW THIS MORNING. AS SUCH...HAVE OPTED TO MAINTAIN ISOLATED
POPS THIS MORNING FOR THIS REGION. AS THE SURFACE TROUGH OVER NW
ONTARIO SAGS SOUTHWARD TODAY...THIS WILL LIKELY SERVE AS THE FOCUS
FOR ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT MAINLY ACROSS THE
WESTERN HALF OF UPPER MICHIGAN THIS AFTERNOON...ESPECIALLY AS THE
NEXT WEAK WAVE OVER THE DAKOTAS MOVES INTO THE AREA. MLCAPE VALUES
RISE TO AROUND 1200 J/KG THIS AFTERNOON ACROSS THE WEST...BUT THE
CAPE IS FAIRLY SKINNY WITH 700-500MB LAPSE RATES OF ONLY AROUND 6
C/KM. ALTHOUGH THE FRONTAL ZONE AND/OR LAKE BREEZE BOUNDARY MAY HELP
ENHANCE LOCAL BULK SHEAR...OVERALL THE 0-6KM SHEAR REMAINS QUITE LOW
WITH ONLY 15-20 KT OF DEEP SHEAR. COULD NOT RULE OUT SOME MULTI-CELL
CLUSTERS THIS AFTERNOON ACROSS THE WEST...BUT IT SEEMS UNLIKELY THAT
ANY SIGNIFICANT SEVERE WILL OCCUR ACROSS THE AREA TODAY...ESPECIALLY
WITH THE WEAKENING 850MB WIND FIELDS THIS AFTERNOON. BEST CHANCES
FOR SHOWERS AND STORMS WILL LIKELY BE LATE THIS AFTERNOON INTO EARLY
THIS EVENING ACROSS THE WEST AND NORTH CENTRAL AS THE UPPER VORT
PASSES BY JUST TO THE NORTH. IN FACT...MANY OF THE HIGHER RES NWP
SUGGEST THE BEST CHANCE OF SHOWERS/STORMS ALONG AND JUST NORTH OF
THE STATIONARY FRONT...WHICH WOULD PLACE THE HEAVIEST PCPN OVER LAKE
SUPERIOR...THE KEWEENAW EXTENDING SOUTHWARD INTO NRN MARQUETTE AND
BARAGA COUNTIES. ONCE THIS WAVE PASSES BY...EXPECT WEAK DRY
ADVECTION AND NEGATIVE THETA-E ADVECTION AT 850MB ESPECIALLY ACROSS
EASTERN AND CENTRAL UPPER MICHIGAN...HELPING TO BRING ANY SHOWERS
AND STORMS GENERALLY TO AN END IN THOSE AREAS. WITH THE FRONTAL
BOUNDARY AND BETTER MOISTURE REMAINING FROM EASTERN LAKE SUPERIOR
THROUGH THE KEWEENAW TO NW WISCONSIN...WILL NEED TO MAINTAIN CHANCE
POPS FOR THE WESTERN 1/3 OF FORECAST AREA FOR THE ENTIRE OVERNIGHT
PERIOD...BUT THE EXPECTATION IS THAT BEST CHANCES FOR PCPN WILL BE
THIS EVENING...WITH SOME TYPE OF LULL AFTER MIDNIGHT BEFORE THE NEXT
ROUND OF SHOWERS AND STORMS MOVE IN SUN MORNING.
IN ADDITION TO THE RAINFALL IN THE KEWEENAW...WEAK UPSLOPE E OR SE
FLOW IS EXPECTED TO DEVELOP LATE THIS AFTERNOON AND ESPECIALLY
TONIGHT. GIVEN THE INCREASED LOW LEVEL MOISTURE FROM ANY RAINFALL
AND ALSO COOLER AIR OFF THE LAKE...PATCHY FOG MAY DEVELOP FROM CMX
TO COPPER HARBOR TONIGHT. WIND FIELDS WILL BE VERY LIGHT...SO THERE
IS AT LEAST A SMALL CHANCE FOR DENSE FOG TO DEVELOP
TONIGHT...ESPECIALLY AFTER THE RAIN DIMINISHES.
LOW LEVEL MOISTURE WILL BE ON THE INCREASE TODAY...THUS MAKING IT
MUCH MORE HUMID THAN FRIDAY. ALTHOUGH TEMPS MAY END UP BEING SEVERAL
DEGREES COOLER DUE TO INCREASED CLOUD COVER...IT WILL LIKELY FEEL
SIMILAR OR SLIGHTLY WORSE THAN FRIDAY DUE TO THE INCREASED HUMIDITY.
TEMPS WILL STILL TOP OUT WELL INTO THE 80S IN MOST PLACES AWAY FROM
LAKE MICHIGAN...HOWEVER THE WEAKENING LOW LEVEL WINDS WILL ALLOW
LAKE BREEZES TO FORM WHICH SHOULD HELP KEEP AREAS NEAR THE SHORELINE
OF LAKE SUPERIOR TO BE COOLER THAN FRIDAY AS WELL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 455 AM EDT SAT JUL 6 2013
SUN INTO SUN NIGHT...MODELS SUGGEST THAT A WEAKENING SHORTWAVE
TROUGH AND STRONGEST 700-300 MB QVECTOR CONV WILL MOVE FROM SRN
MANITOBA INTO NRN ONTARIO WITH AN ASSOCIATED SFC TROUGH TRAILING
THROUGH THE NRN GREAT LAKES. ONGOING CONVECTION FROM NE MN INTO WRN
LAKE SUPERIOR AND NW WI MAY MOVE INTO W UPPER MI IN THE MORNING. IF
ENOUGH BREAKS IN THE CLOUD COVER DEVELOP...AFTERNOON MLCAPE VALUES
COULD CLIMB TO 1000-1500 J/KG SUPPORTING ADDITIONAL SCT/NMRS
SHRA/TSRA WITH THE TROUGH...OUTFLOW AND LAKE BREEZE BOUNDARIES OVER
THE AREA. HOWEVER...0-6KM BULK SHEAR VALUES TO 30 KT WILL BE
MARGINAL TO SUPPORT ORGANIZED STRONGER/SVR STORMS. WITH PWAT VALUES
TO AROUND 1.75 INCHES...SOME LOCALLY HEAVY RAIN MAY BE POSSIBLE.
CONFIDENCE IN WIDESPREAD PCPN COVERAGE WAS LIMITED AS THE GFS/GEM
AND HIGHER RES MODELS WERE SIGNFICANTLY MORE AGGRESSIVE WITH THE
AFTERNOON PCPN COMPARED TO THE NAM/ECMWF. ANY EVENING SHRA/TSRA ARE
EXPECTED TO DIMINISH OVERNIGHT AS WEAK SHORTWAVE RIDGING MOVES IN AND
THE FRONT MOVES OFF TO THE SOUTH.
MON...ALTHOUGH THE WEAKENING FRONTAL BOUNDARY IS EXPECTED TO REMAIN
SOUTH OF UPPER MI...THE POTENTIAL REMAINS FOR WEAK SHRTWVS TO MOVE
THROUGH THE AREA THAT COULD RESULT IN ADDITIONAL PCPN KEEPING SLIGHT
CHANCE POPS GOING OVER MAINLY THE SOUTH CENTRAL AND EAST.
TUE-FRI...THE MODELS WERE IN REASONABLE AGREEMENT WITH THE
STRONGER SHORTWAVE TROUGH MOVING INTO THE NRN GREAT LAKES.
QVECTOR CONV AND MOISTURE ADVECTION AHEAD OF THIS FEATURE WILL
SUPPORT INCREASING SHRA/TSRA CHANCES MAINLY FROM TUE NIGHT INTO EARLY
WED. ALTHOUGH THE GFS DISPLAYED CONSIDERABLE CONVECTIVE
FEEDBACK...THE GEM/ECMWF ALSO SUPPORT THE IDEA OF KEEPING STRONGER
CONVECTION CLOSER TO THE SFC FRONTAL BOUNDARY TO THE SOUTH WHICH
WOULD DISRUPT MOISTURE TRANSPORT TOWARD UPPER MI AND LIMIT PCPN
CHANCES/AMOUNTS. A RETURN TO COOLER CONDITIONS WITH TEMPS BLO NORMAL
ARE EXPECTED BY THU WITH ONLY A CHANCE OF SOME LINGERING LIGHT
SHOWERS WITH WRAP- AROUND MOISTURE AND TRAILING WEAK SHRTWVS AROUND
THE DEPARTING MID LEVEL LOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 746 AM EDT SAT JUL 6 2013
A WEAK TROUGH OVER WESTERN LAKE SUPERIOR WILL BECOME NEARLY
STATIONARY OVER THE AREA THROUGH SUNDAY MORNING. THIS WILL SERVE AS
THE FOCUS FOR SHOWERS AND THUNDERSTORMS AS UPPER DISTURBANCES MOVE
ACROSS THE AREA. THE FIRST DISTURBANCE WILL MOVE JUST WEST AND NORTH
OF THE AREA LATER TODAY AND TONIGHT. THIS WILL ALLOW THE SHOWER AND
THUNDERSTORM ACTIVITY CURRENTLY OVER WRN MN TO SPREAD INTO WESTERN
UPPER MICHIGAN LATE THIS AFTERNOON INTO THIS EVENING. STILL UNCLEAR
HOW WIDESPREAD THE ACTIVITY WILL BE...BUT THE EXPECTATION IS THAT
CMX AND IWD HAVE THE BEST CHANCES FOR SHOWERS AND STORMS LATE THIS
AFTERNOON INTO TONIGHT. DUE TO UNCERTAINTY OF HOW WIDESPREAD THE
ACTIVITY WILL BE AND EXACT TIMING...WILL NOT BE SPECIFIC WITH TIMING
IN THE TERMINALS. SINCE THE FRONT WILL BE NEAR OR SLIGHTLY SOUTH OF
CMX...THERE IS A POTENTIAL FOR MVFR OR IFR CIGS/VSBYS ACROSS THE
KEWEENAW OVERNIGHT DUE TO THE UPSLOPE E-SE WINDS IN FOG. SAW IS
EXPECTED TO STAY GENERALLY DRY...ALTHOUGH THERE IS A SMALL CHANCE
FOR SHOWERS AND STORMS THIS EVENING...BUT NOT ENOUGH CONFIDENCE TO
PLACE IN THE TERMINAL.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 455 AM EDT SAT JUL 6 2013
SOUTH TO SOUTHWEST WINDS OF 25 KNOTS CAN BE EXPECTED THIS MORNING
ESPECIALLY ACROSS THE EASTERN HALF OF LAKE SUPERIOR AHEAD OF THE LOW
PRESSURE TROUGH. CANNOT RULE OUT A FEW GUSTS TO 30 KT ESPECIALLY ON
THE CMAN STATIONS OR LARGER SHIPS. AS THE TROUGH DRIFTS SOUTHWARD
OVER LAKE SUPERIOR TODAY...EXPECT THE WINDS TO DIMINISH TO 5-15 KT
TONIGHT AND REMAIN BELOW 15 KT THOUGH TUESDAY AS WEAK HIGH PRESSURE
BUILDS ACROSS THE LAKE LATE SUNDAY INTO MONDAY. ANOTHER LOW DEVELOPS
OVER THE PLAINS ON TUESDAY THEN DEEPENS AS IT APPROACHES LAKE
SUPERIOR ON WEDNESDAY. WILL NEED TO WATCH THIS FOR STRONGER NW WINDS
BEHIND THE SYSTEM LATER WED INTO WED NIGHT.
DUE TO EXPECTED RAINFALL OVER THE LAKE AND INCREASED LOW LEVEL
MOISTURE...FOG WILL BECOME A CONCERN LATER TODAY AND ESPECIALLY
TONIGHT INTO SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...JLB
AVIATION...MRD
MARINE...MRD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
459 AM EDT SAT JUL 6 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT SAT JUL 6 2013
A VERY MILD EARLY MORNING ACROSS UPPER MICHIGAN WITH MANY TEMPS
STILL IN THE UPPER 60S-MID 70S AS SOUTHERLY WINDS CONTINUE TO GUST
TO 20+KT...ESPECIALLY IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR. A
FEW SHOWERS AND ISOLATED STORMS OVER MN THROUGH WESTERN LAKE
SUPERIOR ASSOCIATED WITH A WEAKENING VORTICITY MAXIMUM OVER NW
ONTARIO CONTINUE TO MOVE NORTHEAST. THE RAP AND THE LOCAL RAPID
UPDATE WRF-ARW RUNS SUGGEST THAT SOME ADDITIONAL SHOWERS COULD
DEVELOP OVER FAR WESTERN UPPER MICHIGAN AS THE WEAK Q-VECTOR
CONVERGENCE ASSOCIATED WITH THIS VORT PASSES BY. HOWEVER...GIVEN THE
DRY AIRMASS PER THE 00Z MPX AND GRB RAOBS...AND BEST SYNOPTIC
SUPPORT REMAINING OVER THE WESTERN AND NORTHERN LAKE...THERE IS NOT
GREAT CONFIDENCE THAT ANY SHOWER ACTIVITY WILL ACTUALLY OCCUR EARLY
THIS MORNING. HOWEVER...GIVEN THE CURRENT MOTION OF SHOWER ACTIVITY
JUST SOUTH OF DLH...PCPN CANNOT BE TOTALLY RULED OUT FROM IWD TO THE
KEWEENAW THIS MORNING. AS SUCH...HAVE OPTED TO MAINTAIN ISOLATED
POPS THIS MORNING FOR THIS REGION. AS THE SURFACE TROUGH OVER NW
ONTARIO SAGS SOUTHWARD TODAY...THIS WILL LIKELY SERVE AS THE FOCUS
FOR ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT MAINLY ACROSS THE
WESTERN HALF OF UPPER MICHIGAN THIS AFTERNOON...ESPECIALLY AS THE
NEXT WEAK WAVE OVER THE DAKOTAS MOVES INTO THE AREA. MLCAPE VALUES
RISE TO AROUND 1200 J/KG THIS AFTERNOON ACROSS THE WEST...BUT THE
CAPE IS FAIRLY SKINNY WITH 700-500MB LAPSE RATES OF ONLY AROUND 6
C/KM. ALTHOUGH THE FRONTAL ZONE AND/OR LAKE BREEZE BOUNDARY MAY HELP
ENHANCE LOCAL BULK SHEAR...OVERALL THE 0-6KM SHEAR REMAINS QUITE LOW
WITH ONLY 15-20 KT OF DEEP SHEAR. COULD NOT RULE OUT SOME MULTI-CELL
CLUSTERS THIS AFTERNOON ACROSS THE WEST...BUT IT SEEMS UNLIKELY THAT
ANY SIGNIFICANT SEVERE WILL OCCUR ACROSS THE AREA TODAY...ESPECIALLY
WITH THE WEAKENING 850MB WIND FIELDS THIS AFTERNOON. BEST CHANCES
FOR SHOWERS AND STORMS WILL LIKELY BE LATE THIS AFTERNOON INTO EARLY
THIS EVENING ACROSS THE WEST AND NORTH CENTRAL AS THE UPPER VORT
PASSES BY JUST TO THE NORTH. IN FACT...MANY OF THE HIGHER RES NWP
SUGGEST THE BEST CHANCE OF SHOWERS/STORMS ALONG AND JUST NORTH OF
THE STATIONARY FRONT...WHICH WOULD PLACE THE HEAVIEST PCPN OVER LAKE
SUPERIOR...THE KEWEENAW EXTENDING SOUTHWARD INTO NRN MARQUETTE AND
BARAGA COUNTIES. ONCE THIS WAVE PASSES BY...EXPECT WEAK DRY
ADVECTION AND NEGATIVE THETA-E ADVECTION AT 850MB ESPECIALLY ACROSS
EASTERN AND CENTRAL UPPER MICHIGAN...HELPING TO BRING ANY SHOWERS
AND STORMS GENERALLY TO AN END IN THOSE AREAS. WITH THE FRONTAL
BOUNDARY AND BETTER MOISTURE REMAINING FROM EASTERN LAKE SUPERIOR
THROUGH THE KEWEENAW TO NW WISCONSIN...WILL NEED TO MAINTAIN CHANCE
POPS FOR THE WESTERN 1/3 OF FORECAST AREA FOR THE ENTIRE OVERNIGHT
PERIOD...BUT THE EXPECTATION IS THAT BEST CHANCES FOR PCPN WILL BE
THIS EVENING...WITH SOME TYPE OF LULL AFTER MIDNIGHT BEFORE THE NEXT
ROUND OF SHOWERS AND STORMS MOVE IN SUN MORNING.
IN ADDITION TO THE RAINFALL IN THE KEWEENAW...WEAK UPSLOPE E OR SE
FLOW IS EXPECTED TO DEVELOP LATE THIS AFTERNOON AND ESPECIALLY
TONIGHT. GIVEN THE INCREASED LOW LEVEL MOISTURE FROM ANY RAINFALL
AND ALSO COOLER AIR OFF THE LAKE...PATCHY FOG MAY DEVELOP FROM CMX
TO COPPER HARBOR TONIGHT. WIND FIELDS WILL BE VERY LIGHT...SO THERE
IS AT LEAST A SMALL CHANCE FOR DENSE FOG TO DEVELOP
TONIGHT...ESPECIALLY AFTER THE RAIN DIMINISHES.
LOW LEVEL MOISTURE WILL BE ON THE INCREASE TODAY...THUS MAKING IT
MUCH MORE HUMID THAN FRIDAY. ALTHOUGH TEMPS MAY END UP BEING SEVERAL
DEGREES COOLER DUE TO INCREASED CLOUD COVER...IT WILL LIKELY FEEL
SIMILAR OR SLIGHTLY WORSE THAN FRIDAY DUE TO THE INCREASED HUMIDITY.
TEMPS WILL STILL TOP OUT WELL INTO THE 80S IN MOST PLACES AWAY FROM
LAKE MICHIGAN...HOWEVER THE WEAKENING LOW LEVEL WINDS WILL ALLOW
LAKE BREEZES TO FORM WHICH SHOULD HELP KEEP AREAS NEAR THE SHORELINE
OF LAKE SUPERIOR TO BE COOLER THAN FRIDAY AS WELL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 455 AM EDT SAT JUL 6 2013
SUN INTO SUN NIGHT...MODELS SUGGEST THAT A WEAKENING SHORTWAVE
TROUGH AND STRONGEST 700-300 MB QVECTOR CONV WILL MOVE FROM SRN
MANITOBA INTO NRN ONTARIO WITH AN ASSOCIATED SFC TROUGH TRAILING
THROUGH THE NRN GREAT LAKES. ONGOING CONVECTION FROM NE MN INTO WRN
LAKE SUPERIOR AND NW WI MAY MOVE INTO W UPPER MI IN THE MORNING. IF
ENOUGH BREAKS IN THE CLOUD COVER DEVELOP...AFTERNOON MLCAPE VALUES
COULD CLIMB TO 1000-1500 J/KG SUPPORTING ADDITIONAL SCT/NMRS
SHRA/TSRA WITH THE TROUGH...OUTFLOW AND LAKE BREEZE BOUNDARIES OVER
THE AREA. HOWEVER...0-6KM BULK SHEAR VALUES TO 30 KT WILL BE
MARGINAL TO SUPPORT ORGANIZED STRONGER/SVR STORMS. WITH PWAT VALUES
TO AROUND 1.75 INCHES...SOME LOCALLY HEAVY RAIN MAY BE POSSIBLE.
CONFIDENCE IN WIDESPREAD PCPN COVERAGE WAS LIMITED AS THE GFS/GEM
AND HIGHER RES MODELS WERE SIGNFICANTLY MORE AGGRESSIVE WITH THE
AFTERNOON PCPN COMPARED TO THE NAM/ECMWF. ANY EVENING SHRA/TSRA ARE
EXPECTED TO DIMINISH OVERNIGHT AS WEAK SHORTWAVE RIDGING MOVES IN AND
THE FRONT MOVES OFF TO THE SOUTH.
MON...ALTHOUGH THE WEAKENING FRONTAL BOUNDARY IS EXPECTED TO REMAIN
SOUTH OF UPPER MI...THE POTENTIAL REMAINS FOR WEAK SHRTWVS TO MOVE
THROUGH THE AREA THAT COULD RESULT IN ADDITIONAL PCPN KEEPING SLIGHT
CHANCE POPS GOING OVER MAINLY THE SOUTH CENTRAL AND EAST.
TUE-FRI...THE MODELS WERE IN REASONABLE AGREEMENT WITH THE
STRONGER SHORTWAVE TROUGH MOVING INTO THE NRN GREAT LAKES.
QVECTOR CONV AND MOISTURE ADVECTION AHEAD OF THIS FEATURE WILL
SUPPORT INCREASING SHRA/TSRA CHANCES MAINLY FROM TUE NIGHT INTO EARLY
WED. ALTHOUGH THE GFS DISPLAYED CONSIDERABLE CONVECTIVE
FEEDBACK...THE GEM/ECMWF ALSO SUPPORT THE IDEA OF KEEPING STRONGER
CONVECTION CLOSER TO THE SFC FRONTAL BOUNDARY TO THE SOUTH WHICH
WOULD DISRUPT MOISTURE TRANSPORT TOWARD UPPER MI AND LIMIT PCPN
CHANCES/AMOUNTS. A RETURN TO COOLER CONDITIONS WITH TEMPS BLO NORMAL
ARE EXPECTED BY THU WITH ONLY A CHANCE OF SOME LINGERING LIGHT
SHOWERS WITH WRAP- AROUND MOISTURE AND TRAILING WEAK SHRTWVS AROUND
THE DEPARTING MID LEVEL LOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 143 AM EDT SAT JUL 6 2013
AS A LO PRES TROF APRCHS FM THE NW EARLY THIS MRNG...EXPECT LLWS TO
PERSIST UNDER TIGHTER PRES GRADIENT/STRONGER SW FLOW IN THE PRESENCE
OF NOCTURNAL COOLING THAT PUTS A CAP ON SFC WIND SPEEDS. SOME -SHRA
AND POSSIBLY A TS IN ADVANCE OF THIS TROF MIGHT IMPACT IWD AND
PERHAPS CMX TOWARD SUNRISE...BUT RELATIVE DRYNESS OF THE LLVLS SHOWN
ON THE 00Z MPX AND GRB RAOBS/RECENT SFC OBS INDICATE VFR CONDITIONS
WL PREDOMINATE EVEN IF ANY -SHRA MAKE IT TO THOSE SITES. THE LO PRES
TROF IS FCST TO STALL OVER NW UPR MI ON SAT...SO MORE SHRA/TS MAY
DVLP AT ALL 3 SITES IN THE AFTN WITH DAYTIME HEATING/
DESTABILIZATION. THE BEST CHC FOR HEAVIER SHRA WL BE AT CMX CLOSER
TO THE POSITION OF THE TROF. ALTHOUGH MVFR CONDITIONS ARE POSSIBLE
UNDER THE HEAVIER SHRA AT ANY OF THE SITES...THE BEST CHC FOR LOWER
VSBYS/CIGS WL BE AT CMX...WHICH MIGHT BE JUST N OF THE SFC TROF AND
WITHIN A SHALLOW COOLER WEDGE OF AIR THAT WOULD ENHANCE THE
POTENTIAL FOR LOWER CLDS/FOG.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 455 AM EDT SAT JUL 6 2013
SOUTH TO SOUTHWEST WINDS OF 25 KNOTS CAN BE EXPECTED THIS MORNING
ESPECIALLY ACROSS THE EASTERN HALF OF LAKE SUPERIOR AHEAD OF THE LOW
PRESSURE TROUGH. CANNOT RULE OUT A FEW GUSTS TO 30 KT ESPECIALLY ON
THE CMAN STATIONS OR LARGER SHIPS. AS THE TROUGH DRIFTS SOUTHWARD
OVER LAKE SUPERIOR TODAY...EXPECT THE WINDS TO DIMINISH TO 5-15 KT
TONIGHT AND REMAIN BELOW 15 KT THOUGH TUESDAY AS WEAK HIGH PRESSURE
BUILDS ACROSS THE LAKE LATE SUNDAY INTO MONDAY. ANOTHER LOW DEVELOPS
OVER THE PLAINS ON TUESDAY THEN DEEPENS AS IT APPROACHES LAKE
SUPERIOR ON WEDNESDAY. WILL NEED TO WATCH THIS FOR STRONGER NW WINDS
BEHIND THE SYSTEM LATER WED INTO WED NIGHT.
DUE TO EXPECTED RAINFALL OVER THE LAKE AND INCREASED LOW LEVEL
MOISTURE...FOG WILL BECOME A CONCERN LATER TODAY AND ESPECIALLY
TONIGHT INTO SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...JLB
AVIATION...KC
MARINE...MRD
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
915 PM MDT SUN JUL 7 2013
.UPDATE...
UPDATED FORECAST TO DROP THE SEVERE THUNDERSTORM WATCH FOR CENTRAL
ZONES. HAVE KEPT THE WATCH FOR ROSEBUD...CUSTER...FALLON AND
CARTER WHERE THERE IS ONGOING CONVECTION. CLUSTER OF STRONGER
STORMS OVER NORTHERN ROSEBUD COUNTY ARE WORKING EASTWARD ACROSS
AN AREA THAT HAS YET TO BE WORKED OVER BY CONVECTION THIS
EVENING...GIVING THESE STORMS A SLIGHT CHANCE TO REACH SEVERE
LEVELS OVER THE NEXT FEW HOURS AS THEY MOVE EAST ACROSS NORTHERN
CUSTER AND FALLON COUNTIES. LINE OF STRONGER STORMS OVER CARTER
COUNTY SHOULD BE EXITING THAT AREA IN THE NEXT HOUR BRINGING AN
END TO SEVERE THREAT THERE. STRONG WIND GUSTS HAVE BEEN THE MAIN
REPORTED SEVERE ELEMENT WITH STORMS TONIGHT...AND LIKELY WILL
CONTINUE TO BE THROUGH THE REST OF THE EVENING. TWEAKED POPS DOWN
FOR THE REST OF THE NIGHT BUT LEFT LINGERING SLIGHT CHANCE POPS
THROUGH THE OVERNIGHT HOURS. REST OF FORECAST LOOKS ON TRACK. WILL
UPDATE AGAIN ONCE THE REST OF THE SEVERE THUNDERSTORM WATCH IS
EXPIRED. CHAMBERS
&&
.SHORT TERM...VALID FOR MON AND TUE...
MAIN FORECAST ISSUE IS SEVERE WX POTENTIAL THIS AFTERNOON/EVENING
AND AGAIN TOMORROW.
WATER VAPOR IMAGERY SHOWS WSW FLOW ALOFT WITH SHORTWAVE ENERGY
APPROACHING FROM THE GREAT BASIN. A STRONGER TROF CAN BE SEEN
ALONG THE PAC NW COAST...AND THIS FEATURE WILL BE A PLAYER FOR US
MONDAY AND MONDAY NIGHT. PWATS IN PLACE ARE QUITE HIGH AND IN THE
VICINITY OF AN INCH...PERHAPS A BIT HIGHER IN OUR EAST. LOW LEVEL
E-SE WINDS ARE INCREASING...PROVIDING GREATER SHEAR AND LOW LEVEL
MOISTURE THAN WE SAW ON SATURDAY...AND LATEST 850MB ANALYSIS
SUGGESTS NOSE OF 850MB DEWPTS TO +13C IN FAR SE MT. WE REMAIN
UNDER RRQ OF 60KT H3 JET TO OUR NORTH...THUS MODEST SYNOPTIC
ASCENT IS PRESENT. OVERALL INGREDIENTS ARE IN PLACE FOR SEVERE
WEATHER LATE THIS AFTN AND EVENING. RECENT HRRR RUNS AGREE WITH
THIS ASSESSMENT AND HAVE BEEN CONSISTENT.
CONVECTION BEGINNING TO INITIATE OVER OUR SW MTNS WITH A FEW
LIGHTNING STRIKES NOTED SOUTH OF LIVINGSTON. A LONE CELL HAS
EMERGED FROM THE CU FIELD SE OF BROADUS. WILL BE INTERESTING TO
SEE WHAT SERN CELL WILL DO OVER THE NEXT COUPLE HOURS...SFC TEMPS
NEAR THE MID 80S MAY BE ENOUGH TO BREAK CAP THAT HAS BEEN IN
PLACE. OTHERWISE FOCUS SHOULD BE IN OUR WEST AS ACTIVITY SPREADS
OFF THE HIGH TERRAIN...SHIFTING EAST OVER TIME.
GREATEST SEVERE POTENTIAL THIS AFTN AND EVENING WILL BE EAST OF
BILLINGS IN REGION OF GREATER INSTABILITY AND SHEAR...ESPECIALLY
AS LOW LEVEL JET KICKS IN THIS EVENING. FOR MONDAY...OUR ENTIRE
AREA WILL BE AT AN ELEVATED RISK FOR SEVERE STORMS DUE TO
COMBINATION OF ASCENT FROM PAC NW TROF AND SURFACE COLD FRONT.
LARGE HAIL AND DAMAGING WINDS MAIN THREATS. HEAVY RAIN WILL
CONTINUE TO BE A POSSIBILITY BOTH TODAY AND TOMORROW DUE TO THE
MOISTURE RICH AIRMASS IN PLACE.
PASSAGE OF TROF...SURGE OF DRIER AIR AND SHIFT TO NW FLOW ALOFT
WILL SIGNAL THE BEGINNINGS OF A PATTERN SHIFT ON TUESDAY...AS THE
MOIST AIRMASS FINALLY GETS CLEANED OUT. COULD BE SOME MORNING
SHOWERS ON TUESDAY ALONG PV MAX...BUT OTHERWISE EXPECT DRIER AND
MORE STABLE CONDITIONS AS COOLER SFC RIDGE BUILDS IN FROM THE NW.
HAVE LOWERED POPS TUESDAY AFTERNOON AND NIGHT.
AS FOR TEMPS...MONDAY WILL BE THE WARMER OF THE NEXT TWO DAYS...
WITH PREFRONTAL CONDITIONS PERHAPS ALLOWING FOR TEMPS NEAR 90F.
TUESDAY WILL BE POSTFRONTAL AND COOLER WITH UPPER 70S TO MID 80S
FOR HIGHS...OR A LITTLE BELOW NORMAL.
JKL
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
MINIMAL CHANGES TO THE EXTENDED PERIOD...DUE IN LARGE PART TO
MODEL INCONSISTENCY FOR LATTER PORTIONS OF THE PERIOD.
THE PERIOD BEGINS WED UNDER AN UPPER LEVEL RIDGE...SO EXPECT HOT
AND MAINLY DRY CONDITIONS. MODELS DO SHOW SOME SHORTWAVE ACTIVITY
ROUNDING THE RIDGE...WITH SE LOW LEVEL FLOW OVER SOUTHEAST MONTANA
LATE WED AFTN/EVE...SO I KEPT A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST ACROSS THE SE. RIDGING DOMINATES
THROUGH MUCH OF THE DAY THURS...SO HOT AND DRY CONDITIONS WILL
AGAIN BE THE RULE. A WEAK COLD FRONT...ALONG WITH SHORTWAVE
ACTIVITY...WILL MOVE ACROSS THE REGION THURS NIGHT...SO WE MAY SEE
SOME CONVECTIVE ACTIVITY THURS EVE/NIGHT OVER THE WESTERN
MOUNTAINS...AND OVER THE EAST...WHERE SHEAR IS BETTER AND THE
ATMOSPHERE IS LESS CAPPED. FRI LOOKS TO BE A TAD COOLER BEHIND THE
FRONT...BUT STILL QUITE WARM.
MODEL SOLUTIONS DIVERGE SAT AND SUN. THE ECMWF BRINGS ANOTHER
COLD FRONT THROUGH THE REGION SAT AND KEEP THE REGION UNDER THE
INFLUENCE OF A WEAK UPPER LEVEL TROF SUN. MEANWHILE...THE GFS
KEEPS THE AREA MAINLY UNDER THE INFLUENCE OF SOUTHWESTERLY FLOW
ALOFT AROUND AN UPPER LEVEL RIDGE. BECAUSE OF THE LARGE MODEL
DIFFERENCES...I LEFT THE FORECAST FROM SAT TO THE END OF THE
EXTENDED PRETTY MUCH AS I INHERITED IT.
TEMPS WED AND THURS LOOK TO BE IN THE MID 80S TO MID 90S...WITH
SLIGHTLY COOLER WEATHER FRI. NOT QUITE SURE WHAT TEMPS WILL BE SAT
AND SUN. IF THE GFS IS CORRECT...UPPER 80S TO 90S. IF THE ECMWF
IS CORRECT...UPPER 70S TO MID 80S. FOR NOW...KEPT SAT AND SUN
TEMPS IN THE MID 80S TO AROUND 90...SORT OF A BLEND OF THE GFS AND
ECMWF. STC
&&
.AVIATION...
CONVECTIVE ACTIVITY WILL DIMINISH THROUGH MIDNIGHT WITH JUST AN
ISOLATED SHOWER OR THUNDERSTORM AFTER MIDNIGHT IN MOST AREAS.
STRONG WIND GUSTS AND MVFR TO IFR CONDITIONS IN HEAVY RAIN ARE THE
MAIN THREATS FROM STORMS TONIGHT. OUTSIDE OF STORMS EXPECT VFR
CONDITIONS. LOCAL AREAS OF FOG ARE POSSIBLE EARLY MONDAY MORNING
IN AREAS THAT SAW HEAVY RAIN THIS EVENING...BUT SO FAR THIS
DOESN`T INCLUDE AREA TAF LOCATIONS. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 062/089 061/084 059/091 064/094 064/090 061/091 060/089
33/T 32/T 11/U 11/B 22/T 22/T 22/T
LVM 053/088 050/085 048/091 056/094 052/090 051/091 050/089
33/T 31/B 11/U 11/B 22/T 22/T 22/T
HDN 060/091 061/085 056/092 064/095 064/091 061/092 060/090
33/T 32/T 11/U 11/B 22/T 22/T 22/T
MLS 065/088 062/084 059/092 066/095 063/090 062/091 061/089
34/T 53/T 11/U 12/T 22/T 22/T 22/T
4BQ 061/090 060/084 056/090 062/093 063/089 061/090 060/088
33/T 43/T 11/U 12/T 22/T 22/T 33/T
BHK 060/084 060/079 055/086 061/089 063/085 062/086 061/084
44/T 54/T 12/T 22/T 22/T 22/T 33/T
SHR 056/090 056/083 052/089 059/093 058/089 056/090 055/088
33/T 32/T 11/U 11/U 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...SEVERE THUNDERSTORM WATCH 396 IN EFFECT UNTIL 11 PM MDT THIS
EVENING FOR ZONES 31>33-36-37.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
717 PM MDT SUN JUL 7 2013
.SHORT TERM...VALID FOR MON AND TUE...
UPDATE....HAVE REMOVED WESTERN COUNTIES FROM SEVERE TSTM WATCH.
THIS AIRMASS IS VERY WORKED OVER BY PREVIOUS SHOWER ACTIVITY.
SCATTERED CONVECTION CONTINUES OTHERWISE...WITH LARGEST SEVERE
THREAT FOR THIS EVENING BEING IN OUR FAR EAST.
PREVIOUS DISCUSSION ISSUED 407 PM...
MAIN FORECAST ISSUE IS SEVERE WX POTENTIAL THIS AFTERNOON/EVENING
AND AGAIN TOMORROW.
WATER VAPOR IMAGERY SHOWS WSW FLOW ALOFT WITH SHORTWAVE ENERGY
APPROACHING FROM THE GREAT BASIN. A STRONGER TROF CAN BE SEEN
ALONG THE PAC NW COAST...AND THIS FEATURE WILL BE A PLAYER FOR US
MONDAY AND MONDAY NIGHT. PWATS IN PLACE ARE QUITE HIGH AND IN THE
VICINITY OF AN INCH...PERHAPS A BIT HIGHER IN OUR EAST. LOW LEVEL
E-SE WINDS ARE INCREASING...PROVIDING GREATER SHEAR AND LOW LEVEL
MOISTURE THAN WE SAW ON SATURDAY...AND LATEST 850MB ANALYSIS
SUGGESTS NOSE OF 850MB DEWPTS TO +13C IN FAR SE MT. WE REMAIN
UNDER RRQ OF 60KT H3 JET TO OUR NORTH...THUS MODEST SYNOPTIC
ASCENT IS PRESENT. OVERALL INGREDIENTS ARE IN PLACE FOR SEVERE
WEATHER LATE THIS AFTN AND EVENING. RECENT HRRR RUNS AGREE WITH
THIS ASSESSMENT AND HAVE BEEN CONSISTENT.
CONVECTION BEGINNING TO INITIATE OVER OUR SW MTNS WITH A FEW
LIGHTNING STRIKES NOTED SOUTH OF LIVINGSTON. A LONE CELL HAS
EMERGED FROM THE CU FIELD SE OF BROADUS. WILL BE INTERESTING TO
SEE WHAT SERN CELL WILL DO OVER THE NEXT COUPLE HOURS...SFC TEMPS
NEAR THE MID 80S MAY BE ENOUGH TO BREAK CAP THAT HAS BEEN IN
PLACE. OTHERWISE FOCUS SHOULD BE IN OUR WEST AS ACTIVITY SPREADS
OFF THE HIGH TERRAIN...SHIFTING EAST OVER TIME.
GREATEST SEVERE POTENTIAL THIS AFTN AND EVENING WILL BE EAST OF
BILLINGS IN REGION OF GREATER INSTABILITY AND SHEAR...ESPECIALLY
AS LOW LEVEL JET KICKS IN THIS EVENING. FOR MONDAY...OUR ENTIRE
AREA WILL BE AT AN ELEVATED RISK FOR SEVERE STORMS DUE TO
COMBINATION OF ASCENT FROM PAC NW TROF AND SURFACE COLD FRONT.
LARGE HAIL AND DAMAGING WINDS MAIN THREATS. HEAVY RAIN WILL
CONTINUE TO BE A POSSIBILITY BOTH TODAY AND TOMORROW DUE TO THE
MOISTURE RICH AIRMASS IN PLACE.
PASSAGE OF TROF...SURGE OF DRIER AIR AND SHIFT TO NW FLOW ALOFT
WILL SIGNAL THE BEGINNINGS OF A PATTERN SHIFT ON TUESDAY...AS THE
MOIST AIRMASS FINALLY GETS CLEANED OUT. COULD BE SOME MORNING
SHOWERS ON TUESDAY ALONG PV MAX...BUT OTHERWISE EXPECT DRIER AND
MORE STABLE CONDITIONS AS COOLER SFC RIDGE BUILDS IN FROM THE NW.
HAVE LOWERED POPS TUESDAY AFTERNOON AND NIGHT.
AS FOR TEMPS...MONDAY WILL BE THE WARMER OF THE NEXT TWO DAYS...
WITH PREFRONTAL CONDITIONS PERHAPS ALLOWING FOR TEMPS NEAR 90F.
TUESDAY WILL BE POSTFRONTAL AND COOLER WITH UPPER 70S TO MID 80S
FOR HIGHS...OR A LITTLE BELOW NORMAL.
JKL
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
MINIMAL CHANGES TO THE EXTENDED PERIOD...DUE IN LARGE PART TO
MODEL INCONSISTENCY FOR LATTER PORTIONS OF THE PERIOD.
THE PERIOD BEGINS WED UNDER AN UPPER LEVEL RIDGE...SO EXPECT HOT
AND MAINLY DRY CONDITIONS. MODELS DO SHOW SOME SHORTWAVE ACTIVITY
ROUNDING THE RIDGE...WITH SE LOW LEVEL FLOW OVER SOUTHEAST MONTANA
LATE WED AFTN/EVE...SO I KEPT A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST ACROSS THE SE. RIDGING DOMINATES
THROUGH MUCH OF THE DAY THURS...SO HOT AND DRY CONDITIONS WILL
AGAIN BE THE RULE. A WEAK COLD FRONT...ALONG WITH SHORTWAVE
ACTIVITY...WILL MOVE ACROSS THE REGION THURS NIGHT...SO WE MAY SEE
SOME CONVECTIVE ACTIVITY THURS EVE/NIGHT OVER THE WESTERN
MOUNTAINS...AND OVER THE EAST...WHERE SHEAR IS BETTER AND THE
ATMOSPHERE IS LESS CAPPED. FRI LOOKS TO BE A TAD COOLER BEHIND THE
FRONT...BUT STILL QUITE WARM.
MODEL SOLUTIONS DIVERGE SAT AND SUN. THE ECMWF BRINGS ANOTHER
COLD FRONT THROUGH THE REGION SAT AND KEEP THE REGION UNDER THE
INFLUENCE OF A WEAK UPPER LEVEL TROF SUN. MEANWHILE...THE GFS
KEEPS THE AREA MAINLY UNDER THE INFLUENCE OF SOUTHWESTERLY FLOW
ALOFT AROUND AN UPPER LEVEL RIDGE. BECAUSE OF THE LARGE MODEL
DIFFERENCES...I LEFT THE FORECAST FROM SAT TO THE END OF THE
EXTENDED PRETTY MUCH AS I INHERITED IT.
TEMPS WED AND THURS LOOK TO BE IN THE MID 80S TO MID 90S...WITH
SLIGHTLY COOLER WEATHER FRI. NOT QUITE SURE WHAT TEMPS WILL BE SAT
AND SUN. IF THE GFS IS CORRECT...UPPER 80S TO 90S. IF THE ECMWF
IS CORRECT...UPPER 70S TO MID 80S. FOR NOW...KEPT SAT AND SUN
TEMPS IN THE MID 80S TO AROUND 90...SORT OF A BLEND OF THE GFS AND
ECMWF. STC
&&
.AVIATION...
THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS SOUTHERN AND
WESTERN PORTIONS OF THE REGION...AND MOVE EASTWARD THROUGH THE
LATE AFTERNOON/EVENING HOURS. SOME OF THE STORMS WILL CONTAIN
HAIL AND ERRATIC...GUSTY WINDS AND HEAVY PRECIP...WHICH MAY
PRODUCE BRIEF IFR/LIFR FLIGHT CONDITIONS. VFR CONDITIONS WILL
PREVAIL OUTSIDE OF THUNDERSTORMS. MORE THUNDERSTORMS ARE
ANTICIPATED ACROSS THE REGION TOMORROW AFTERNOON/EVENING AHEAD OF
A COLD FRONT. STC
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 062/089 061/084 059/091 064/094 064/090 061/091 060/089
43/T 32/T 11/U 11/B 22/T 22/T 22/T
LVM 053/088 050/085 048/091 056/094 052/090 051/091 050/089
43/T 31/B 11/U 11/B 22/T 22/T 22/T
HDN 060/091 061/085 056/092 064/095 064/091 061/092 060/090
43/T 32/T 11/U 11/B 22/T 22/T 22/T
MLS 065/088 062/084 059/092 066/095 063/090 062/091 061/089
44/T 53/T 11/U 12/T 22/T 22/T 22/T
4BQ 061/090 060/084 056/090 062/093 063/089 061/090 060/088
53/T 43/T 11/U 12/T 22/T 22/T 33/T
BHK 060/084 060/079 055/086 061/089 063/085 062/086 061/084
54/T 54/T 12/T 22/T 22/T 22/T 33/T
SHR 056/090 056/083 052/089 059/093 058/089 056/090 055/088
43/T 32/T 11/U 11/U 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...SEVERE THUNDERSTORM WATCH 396 IN EFFECT UNTIL 11 PM MDT THIS
EVENING FOR ZONES 29>33-35>38-57-58.
WY...SEVERE THUNDERSTORM WATCH 396 IN EFFECT UNTIL 11 PM MDT THIS
EVENING FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1200 AM MDT Fri Jul 5 2013
UPDATED AVIATION SECTION
.DISCUSSION...
Update forthcoming. An upper trof will continue to move across the
area overnight. With enough low level moisture present, and CAPE
values 600 to 800 J/kg across a broad portion of the county warning
area, thunderstorms have developed and will continue to develop for
the next few hours. These storms have generally been producing brief
heavy rain and small hail. While convective activity should decrease
after midnight, HRRR analysis and the latest RUC both indicate
thunderstorms continuing beyond midnight, especially over Judith
Basin and Fergus counties. Overnight temperatures look good.
Emanuel
&&
.AVIATION...
Updated 0600Z.
VFR conditions will prevail with MVFR conditions possible in the
vicinity of showers and/or thunderstorms. Showers and thunderstorms
will continue to develop over the area and move north and east
through the night. Convective activity will decrease to isolated
storms around 08z. Westerly flow aloft will develop over the area by
18z.
&&
.PREV DISCUSSION...Issued 220 PM MDT Fri Jul 5 2013
Tonight through Sunday...Increased moisture and instability ahead of
a trough moving east across southern Canada will bring scattered
showers and thunderstorms to the area later this afternoon and
evening. Expect best chances for precipitation across Southwest and
South Central Montana though a lot of locations may see showery
light rain this evening. As the trough moves slowly across Montana
through Saturday night an unsettled pattern will continue to bring a
chance for showers and thunderstorms to Central Montana. The pattern
starts to shift back to a high pressure setup sometime Sunday and
conditions will dry out and begin to warm up once again.
Sunday night through Friday...A broad upper level trough over
Western Canada will maintain near zonal westerly flow aloft over
the the area through first half of next week before the upper
level ridge builds back into the region. Several shortwaves
embedded within the flow aloft will move across the region during
the period, bringing near daily chances for at least isolated
showers and thunderstorms as the air mass destabilizes each
afternoon with peak heating. Surface pressure gradients through
the first part of the week will allow for light easterly winds
transporting low level moisture into the area and keeping
dewpoints relatively high over Central and North Central Montana.
This moisture is not anticipated to make it into the valleys of
Southwest Montana and should limit thunderstorm potential in the
area. Temperatures will remain near seasonal averages through
early next week before increasing late in the week as the ridge
of high pressure rebuilds and brings above seasonal average
temperatures back into the region. Suk
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 53 79 53 81 / 40 20 20 20
CTB 49 74 49 76 / 50 40 30 20
HLN 54 82 54 85 / 40 20 20 20
BZN 50 83 51 85 / 50 20 20 20
WEY 42 77 42 79 / 50 40 40 40
DLN 50 82 50 83 / 40 20 10 20
HVR 56 79 55 80 / 40 30 30 30
LWT 52 75 52 77 / 60 40 40 30
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
331 PM CDT SAT JUL 6 2013
.DISCUSSION...
OFF-AND-ON THUNDERSTORM CHANCES OVER THE NEXT SEVERAL DAYS ARE THE
MAIN FORECAST CONCERNS.
MORNING UPPER AIR CHARTS SHOWED HIGH PRESSURE IN THE SOUTHWEST
STATES AND OFF THE ATLANTIC COAST WITH A WEAK LOW IN THE MIDDLE
MOVING INTO THE OHIO VALLEY REGION. FAST WESTERLY FLOW COVERED THE
NORTHERN TIER OF THE CONUS. OUR AREA REMAINED IN THE TRANSITION ZONE
OF HIGHER HEIGHTS TO THE SOUTH AND FAST FLOW TO THE NORTH. AT THE
SURFACE...A WIND SHIFT LINE WAS NOTED IN CENTRAL SOUTH DAKOTA AND
WESTERN NEBRASKA...TIED TO A SHORTWAVE EXTENDING FROM THE NORTHERN
PLAINS INTO NEBRASKA. AND A COLD FRONT WAS PUSHING INTO THE WESTERN
DAKOTAS.
LIGHT SHOWERS OR SPRINKLES THAT MOVED ACROSS EASTERN NEBRASKA THIS
MORNING HAVE LEFT OUR AREA CAPPED TO CONVECTION SO FAR THIS
AFTERNOON. RAP SOUNDINGS SUGGEST SURFACE-BASED CAPES WERE TOPPING
1000 J/KG...BUT INHIBITION WAS STILL ROBUST. BUT WITH TEMPERATURES
WARMING A FEW MORE DEGREES LATE IN THE DAY...COULD SEE AN ISOLATED
SHOWER OR STORM POP UP THIS EVENING...PROBABLY IN WESTERN IOWA. THEN
LATER TONIGHT...WIND SHIFT LINE WILL SETTLE SOUTHEAST INTO OUR AREA
AS SHORTWAVE MOVES OFF TO THE EAST. INSTABILITY WAS STRONG IN
CENTRAL/WESTERN SOUTH DAKOTA NEAR/AHEAD OF WIND SHIFT...SO AM
EXPECTING STORMS TO FIRE THERE LATE THIS AFTERNOON OR EVENING. THIS
ACTIVITY SHOULD PUSH OFF TO THE EAST BUT COULD SKIRT OUR NORTHERN
CWA. OTHERWISE MORE GENERAL THUNDER CHANCES ARE POSSIBLE WITH WIND
SHIFT LINE AS IT MOVES INTO EASTERN NEBRASKA AFTER MIDNIGHT.
SURFACE BOUNDARY WILL REMAIN IN OUR AREA DURING THE DAY SUNDAY. NOT
MUCH NOTED IN MID LEVEL FLOW TO KICK UP CONVECTION ALONG THE
FRONT...SO WILL HAVE TO WAIT UNTIL LATE AFTERNOON WHEN INSTABILITY
IS MAXIMIZED. THEN FRONT/WIND SHIFT SHOULD BE OVER NORTHEAST
NEBRASKA...SO HAVE MAINTAINED A SMALL CHANCE FOR THUNDERSTORMS
THERE. BETTER CHANCES FOR STORMS WILL COME SUNDAY NIGHT INTO MONDAY
AS ANOTHER SHORTWAVE MOVES INTO THE PLAINS. MEANWHILE FRONTAL
BOUNDARY WILL SETTLE SOUTH SUNDAY NIGHT...THE LIFT BACK NORTH ON
MONDAY. COMBINATION OF TEMPERATURES CLIMBING INTO THE 90S AND
COOLING TEMPERATURES ALOFT WITH SHORTWAVE WILL PRODUCE CAPES
APPROACHING 3000 J/KG WITH 30KT OF 0-6KM BULK SHEAR MONDAY
AFTERNOON. SO WILL CONTINUE OUR SMALL CHANCES FOR STORMS SUNDAY
NIGHT AS BOUNDARY SETTLES SOUTH...AND HIGHER CHANCES MONDAY
AFTERNOON IN THE NORTH WHERE BOUNDARY/INSTABILITY WILL BE MAXIMIZED.
SOME SEVERE STORMS ARE POSSIBLE GIVEN INSTABILITY/SHEAR.
STORMS CHANCES SHOULD CONTINUE MONDAY NIGHT INTO TUESDAY AS FRONTAL
BOUNDARY REMAINS IN OUR AREA...REINFORCED BEHIND EXITING SHORTWAVE.
INSTABILITY WILL AGAIN APPROACH 3000 J/KG ALONG BOUNDARY TUESDAY
AFTERNOON...WITH A TAD GREATER SHEAR. SO AGAIN SEVERE IS POSSIBLE
TUESDAY AFTERNOON.
FRONT IS FORECAST TO SETTLE SOUTH OF OUR AREA ON WEDNESDAY...SO WILL
KEEP WEDNESDAY AND THURSDAY DRY. UPPER RIDGE BEGINS TO BUILD INTO
OUR AREA FRIDAY AND SATURDAY SIGNALING A RETURN TO WARMER
TEMPERATURES. AS RIDGE BUILDS...WARM ADVECTION REGIME ON FRIDAY
COULD SPARK STORMS...BUT DRY AFTER THAT AS MID LEVEL TEMPS WARM.
TEMPERATURES INTO MONDAY AND TUESDAY WILL EASILY REACH THE 90S...BUT
COULD HOLD IN THE 80S WHERE STORMS/CLOUDS LINGER. A LITTLE COOLER
WEDNESDAY AND THURSDAY WITH HIGHS IN THE 80S...BUT A RETURN TO 90S
LOOK LIKELY FRIDAY AND SATURDAY.
DERGAN
&&
.AVIATION...18Z TAFS FOR KOMA...KLNK...KOFK.
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH ISOLATED
THUNDERSTORMS POSSIBLE AFTER 00Z AS SURFACE TROUGH APPROACHES
EASTERN NEBRASKA AND WEAK UPPER WAVES MOVE ACROSS THE REGION.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1252 PM CDT SAT JUL 6 2013
.UPDATE...
ISSUED AT 622 AM CDT SAT JUL 6 2013
THE RAP13 IS BACKING OFF ON THE LOW LEVEL MOISTURE POOLING BEHIND
THE COLD FRONT AND FORCING ALOFT FOR SCATTERED STORM COVERAGE IS
FORECAST TO BE OVER WYOMING THIS AFTERNOON. THE FORECAST RAIN CHANCES
HAVE BEEN LOWERED TO ISOLATED STORM COVERAGE THIS AFTERNOON AND
TONIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CDT SAT JUL 6 2013
THE LOW LEVEL JET FORCED CONVECTION EAST OF HIGHWAY 83 THIS MORNING
EXITS EAST AROUND 12Z-13Z TO BE REPLACED BY THE CONVECTION ONGOING
ACROSS ERN WY. ALL MODELS SHOW THE WY CONVECTION DECAYING BEFORE IT
REACHES THE FCST AREA...PRESUMABLY PRODUCING SPRINKLES AND
CLOUDINESS ACROSS THE FCST AREA THIS MORNING. RADAR BASED TIMING
TOOLS SHOW THIS WEAK CONVECTION OR ASSOCIATED CLOUDINESS EXITING THE
FCST AREA BY 18Z. THIS WOULD SET UP A WINDOW OF PARTLY CLOUDY SKIES
FOR THE AFTN WITH HOT TEMPERATURES DEVELOPING ALONG AND AHEAD OF A
SFC FRONT WHICH SHOULD DRAPE FROM KLXN NORTH TO KANW. THE RUC THEN
SHOWS MOISTURE POOLING BEHIND THE SFC FRONT AND THE HRRR THEN
SUGGESTS PARTIAL DESTABILIZATION AND ISOLATED CONVECTION DEVELOPING
THIS AFTERNOON. GIVEN THAT PRECIPITABLE WATER INCREASES TO AROUND
1.33 INCHES AND AS HIGH AS 1.5 INCHES NORTH...SCATTERED CONVECTION
WOULD APPEAR OPERATIVE IN THIS ENVIRONMENT. ITS NOT CLEAR HOW MUCH
FORCING IS AVAILABLE THIS FAR SOUTH FOR STORM DEVELOPMENT AND THE
MODELS GO QUIET TONIGHT SUGGESTING A DIURNAL FORCING MECHANISM IS
UNDERWAY. SO THE FORECAST CALLS FOR SCATTERED DIURNALLY FORCED
CONVECTION THIS AFTERNOON WITH HIGHS IN THE 80S AND 90S. THE
CONVECTION WEAKENS THIS EVENING WITH LOWS TONIGHT IN THE 60S TO
AROUND 70.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 316 AM CDT SAT JUL 6 2013
THE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL SLOWLY BUILD NORTHEAST
TOWARD THE AREA THROUGH THE WEEK...AND BY WEEKS END WILL BE
CENTERED NEARLY OVERHEAD. THROUGH MIDWEEK...TSTM CHANCES WILL
CONTINUE...WITH EMBEDDED DISTURBANCES MOVING ACROSS IN FAIRLY FAST
WEST TO NORTHWEST FLOW ALOFT ON THE NORTHERN EDGE OF THE UPPER
HIGH. AS THE HIGH BUILDS OVERHEAD BY WEEKS END...THE UPPER FLOW
DIMINISHES OVER OUR AREA WITH THE TSTM CHANCES SHIFTING NORTH.
SUNDAY AND MONDAY...THERE IS SOME POTENTIAL FOR STRONG AND EVEN A
FEW SEVERE STORMS. A STATIONARY FRONT WILL BECOME ESTABLISHED EAST
TO WEST ACROSS THE AREA...AND SERVE AS THE FOCUS FOR SCATTERED
AFTERNOON AND EVENING TSTMS. AS MENTIONED WINDS ALOFT WILL BE
FAIRLY STRONG...AND BULK SHEAR IS MORE THAN SUFFICIENT TO HELP
SUSTAIN ANY TSTM THAT DEVELOPS. IN ADDITION INSTABILITY WILL BE
QUITE STRONG...WITH MOISTURE/DEW POINTS POOLING INVOF THE THE
FRONT.
TEMPERATURE WISE...UNTIL THE UPPER HIGH BUILDS NORTH OVER THE AREA
BY WEEKS END...SEASONAL HIGHS IN THE UPPER 80S TO LOWER 90S ARE
EXPECTED. THEN AS THE HIGH BUILDS OVERHEAD BY THURSDAY AND
ESPECIALLY FRIDAY...HOT WEATHER DEVELOPS. HIGHS BY FRIDAY WILL BE
APPROACHING THE CENTURY MARK...ESPECIALLY ACROSS SOUTHWEST
NEBRASKA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1250 PM CDT SAT JUL 6 2013
EXPECT VFR CONDITIONS THROUGH THE FORECAST PERIOD ACROSS THE
AREA...EXCEPT IN AND NEAR ANY THUNDERSTORMS. A STALLED
NORTH/SOUTH SFC BOUNDARY REMAINS ACROSS WESTERN/CENTRAL NEB THIS
AFTERNOON. MEANWHILE AN UPPER LEVEL DISTURBANCE WILL PUSH ACROSS
THE CENTRAL ROCKIES THIS AFTERNOON. AS THE WAVE PUSHES ONTO THE
HIGH PLAINS LATER TODAY/OVERNIGHT...ISOLATED THUNDERSTORMS ARE
POSSIBLE. UNCERTAIN ON DEVELOPMENT IS DUE TO LIMITED MOISTURE
WITH DEW PTS ONLY IN THE UPPER 50S TO AROUND 60...THUS NO MENTION
FOR SHOWERS OR THUNDERSTORMS IN THE TAF. ALSO LOW LEVEL JET IS
PROJECTED TO CURVE EAST OF THE AREA OVERNIGHT...LEADING TO
POSSIBLE OVERNIGHT ENHANCEMENT/DEVELOPMENT OF CONVECTION TO BE
EAST OF THE TERMINAL SITES.
WINDS ALONG THE BOUNDARY ARE FAIRLY LIGHT...LESS THAN 10 KTS. TO
THE EAST OF THE BOUNDARY WINDS ARE SOUTHERLY AND INCREASE THE
FURTHER EAST YOU GET...WHERE GUSTS AROUND 20 KTS ARE POSSIBLE
OVER PORTIONS OF NORTH CENTRAL. TO THE WEST OF THE BOUNDARY OVER
THE EASTERN PANHANDLE...NORTHWEST WINDS WILL GUST TO AROUND 20
KTS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CDC
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...MASEK
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
627 AM CDT SAT JUL 6 2013
.UPDATE...
ISSUED AT 622 AM CDT SAT JUL 6 2013
THE RAP13 IS BACKING OFF ON THE LOW LEVEL MOISTURE POOLING BEHIND
THE COLD FRONT AND FORCING ALOFT FOR SCATTERED STORM COVERAGE IS
FORECAST TO BE OVER WYOMING THIS AFTERNOON. THE FORECAST RAIN CHANCES
HAVE BEEN LOWERED TO ISOLATED STORM COVERAGE THIS AFTERNOON AND
TONIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CDT SAT JUL 6 2013
THE LOW LEVEL JET FORCED CONVECTION EAST OF HIGHWAY 83 THIS MORNING
EXITS EAST AROUND 12Z-13Z TO BE REPLACED BY THE CONVECTION ONGOING
ACROSS ERN WY. ALL MODELS SHOW THE WY CONVECTION DECAYING BEFORE IT
REACHES THE FCST AREA...PRESUMABLY PRODUCING SPRINKLES AND
CLOUDINESS ACROSS THE FCST AREA THIS MORNING. RADAR BASED TIMING
TOOLS SHOW THIS WEAK CONVECTION OR ASSOCIATED CLOUDINESS EXITING THE
FCST AREA BY 18Z. THIS WOULD SET UP A WINDOW OF PARTLY CLOUDY SKIES
FOR THE AFTN WITH HOT TEMPERATURES DEVELOPING ALONG AND AHEAD OF A
SFC FRONT WHICH SHOULD DRAPE FROM KLXN NORTH TO KANW. THE RUC THEN
SHOWS MOISTURE POOLING BEHIND THE SFC FRONT AND THE HRRR THEN
SUGGESTS PARTIAL DESTABILIZATION AND ISOLATED CONVECTION DEVELOPING
THIS AFTERNOON. GIVEN THAT PRECIPITABLE WATER INCREASES TO AROUND
1.33 INCHES AND AS HIGH AS 1.5 INCHES NORTH...SCATTERED CONVECTION
WOULD APPEAR OPERATIVE IN THIS ENVIRONMENT. ITS NOT CLEAR HOW MUCH
FORCING IS AVAILABLE THIS FAR SOUTH FOR STORM DEVELOPMENT AND THE
MODELS GO QUIET TONIGHT SUGGESTING A DIURNAL FORCING MECHANISM IS
UNDERWAY. SO THE FORECAST CALLS FOR SCATTERED DIURNALLY FORCED
CONVECTION THIS AFTERNOON WITH HIGHS IN THE 80S AND 90S. THE
CONVECTION WEAKENS THIS EVENING WITH LOWS TONIGHT IN THE 60S TO
AROUND 70.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 316 AM CDT SAT JUL 6 2013
THE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL SLOWLY BUILD NORTHEAST
TOWARD THE AREA THROUGH THE WEEK...AND BY WEEKS END WILL BE
CENTERED NEARLY OVERHEAD. THROUGH MIDWEEK...TSTM CHANCES WILL
CONTINUE...WITH EMBEDDED DISTURBANCES MOVING ACROSS IN FAIRLY FAST
WEST TO NORTHWEST FLOW ALOFT ON THE NORTHERN EDGE OF THE UPPER
HIGH. AS THE HIGH BUILDS OVERHEAD BY WEEKS END...THE UPPER FLOW
DIMINISHES OVER OUR AREA WITH THE TSTM CHANCES SHIFTING NORTH.
SUNDAY AND MONDAY...THERE IS SOME POTENTIAL FOR STRONG AND EVEN A
FEW SEVERE STORMS. A STATIONARY FRONT WILL BECOME ESTABLISHED EAST
TO WEST ACROSS THE AREA...AND SERVE AS THE FOCUS FOR SCATTERED
AFTERNOON AND EVENING TSTMS. AS MENTIONED WINDS ALOFT WILL BE
FAIRLY STRONG...AND BULK SHEAR IS MORE THAN SUFFICIENT TO HELP
SUSTAIN ANY TSTM THAT DEVELOPS. IN ADDITION INSTABILITY WILL BE
QUITE STRONG...WITH MOISTURE/DEW POINTS POOLING INVOF THE THE
FRONT.
TEMPERATURE WISE...UNTIL THE UPPER HIGH BUILDS NORTH OVER THE AREA
BY WEEKS END...SEASONAL HIGHS IN THE UPPER 80S TO LOWER 90S ARE
EXPECTED. THEN AS THE HIGH BUILDS OVERHEAD BY THURSDAY AND
ESPECIALLY FRIDAY...HOT WEATHER DEVELOPS. HIGHS BY FRIDAY WILL BE
APPROACHING THE CENTURY MARK...ESPECIALLY ACROSS SOUTHWEST
NEBRASKA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 622 AM CDT SAT JUL 6 2013
VFR IS EXPECTED TODAY AND TONIGHT. A WEAK UPPER LEVEL DISTURBANCE
WILL APPROACH THE FORECAST AREA FROM THE WEST TONIGHT. ISOLATED
THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AS A RESULT OF STRONG
HEATING AND ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE
TONIGHT WITH THE APPROACH OF THE UPPER LEVEL DISTURBANCE FROM THE WEST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CDC
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
337 AM CDT SAT JUL 6 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CDT SAT JUL 6 2013
THE LOW LEVEL JET FORCED CONVECTION EAST OF HIGHWAY 83 THIS MORNING
EXITS EAST AROUND 12Z-13Z TO BE REPLACED BY THE CONVECTION ONGOING
ACROSS ERN WY. ALL MODELS SHOW THE WY CONVECTION DECAYING BEFORE IT
REACHES THE FCST AREA...PRESUMABLY PRODUCING SPRINKLES AND
CLOUDINESS ACROSS THE FCST AREA THIS MORNING. RADAR BASED TIMING
TOOLS SHOW THIS WEAK CONVECTION OR ASSOCIATED CLOUDINESS EXITING THE
FCST AREA BY 18Z. THIS WOULD SET UP A WINDOW OF PARTLY CLOUDY SKIES
FOR THE AFTN WITH HOT TEMPERATURES DEVELOPING ALONG AND AHEAD OF A
SFC FRONT WHICH SHOULD DRAPE FROM KLXN NORTH TO KANW. THE RUC THEN
SHOWS MOISTURE POOLING BEHIND THE SFC FRONT AND THE HRRR THEN
SUGGESTS PARTIAL DESTABILIZATION AND ISOLATED CONVECTION DEVELOPING
THIS AFTERNOON. GIVEN THAT PRECIPITABLE WATER INCREASES TO AROUND
1.33 INCHES AND AS HIGH AS 1.5 INCHES NORTH...SCATTERED CONVECTION
WOULD APPEAR OPERATIVE IN THIS ENVIRONMENT. ITS NOT CLEAR HOW MUCH
FORCING IS AVAILABLE THIS FAR SOUTH FOR STORM DEVELOPMENT AND THE
MODELS GO QUIET TONIGHT SUGGESTING A DIURNAL FORCING MECHANISM IS
UNDERWAY. SO THE FORECAST CALLS FOR SCATTERED DIURNALLY FORCED
CONVECTION THIS AFTERNOON WITH HIGHS IN THE 80S AND 90S. THE
CONVECTION WEAKENS THIS EVENING WITH LOWS TONIGHT IN THE 60S TO
AROUND 70.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 316 AM CDT SAT JUL 6 2013
THE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL SLOWLY BUILD NORTHEAST
TOWARD THE AREA THROUGH THE WEEK...AND BY WEEKS END WILL BE
CENTERED NEARLY OVERHEAD. THROUGH MIDWEEK...TSTM CHANCES WILL
CONTINUE...WITH EMBEDDED DISTURBANCES MOVING ACROSS IN FAIRLY FAST
WEST TO NORTHWEST FLOW ALOFT ON THE NORTHERN EDGE OF THE UPPER
HIGH. AS THE HIGH BUILDS OVERHEAD BY WEEKS END...THE UPPER FLOW
DIMINISHES OVER OUR AREA WITH THE TSTM CHANCES SHIFTING NORTH.
SUNDAY AND MONDAY...THERE IS SOME POTENTIAL FOR STRONG AND EVEN A
FEW SEVERE STORMS. A STATIONARY FRONT WILL BECOME ESTABLISHED EAST
TO WEST ACROSS THE AREA...AND SERVE AS THE FOCUS FOR SCATTERED
AFTERNOON AND EVENING TSTMS. AS MENTIONED WINDS ALOFT WILL BE
FAIRLY STRONG...AND BULK SHEAR IS MORE THAN SUFFICIENT TO HELP
SUSTAIN ANY TSTM THAT DEVELOPS. IN ADDITION INSTABILITY WILL BE
QUITE STRONG...WITH MOISTURE/DEW POINTS POOLING INVOF THE THE
FRONT.
TEMPERATURE WISE...UNTIL THE UPPER HIGH BUILDS NORTH OVER THE AREA
BY WEEKS END...SEASONAL HIGHS IN THE UPPER 80S TO LOWER 90S ARE
EXPECTED. THEN AS THE HIGH BUILDS OVERHEAD BY THURSDAY AND
ESPECIALLY FRIDAY...HOT WEATHER DEVELOPS. HIGHS BY FRIDAY WILL BE
APPROACHING THE CENTURY MARK...ESPECIALLY ACROSS SOUTHWEST
NEBRASKA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1225 AM CDT SAT JUL 6 2013
THUNDERSTORMS THAT DEVELOPED FURTHER WEST ASSOCIATED WITH WEAK UPPER
PV ANOMALIES AHEAD OF DEVELOPING UPPER LOW IN THE PAC NW HAVE
DISSIPATED AS EXPECTED THIS EVENING AS THEY MOVED INTO AN
UNFAVORABLE MOISTURE ENVIRONMENT AND MORE STABLE AIR ALOFT AND
THEREFORE NO MENTIONOF PRECIP TONIGHT FOR KLBF OR KVTN TAFS.
HOWEVER...STRONG LLJ IS IN PLACE ACROSS THE AREA AND REDEVELOPMENT
IS POSSIBLE...THOUGH AGAIN MOISTURE IS LACKING. KLNX WSR-88D
INDICATES 50KTS AT 500M SO LLWS REMAINS INTHE FCST...DESPITE SOME
BRIEF GUSTY WINDS AT KLBF POSSIBLY ASSOCIATED WITH WEAK OUTFLOW FROM
SHRA/TSRA FURTHER EAST.
SATURDAY LOOKS SIMILAR TO FRIDAY IN CONVECTIVE POTENTIAL IN THAT
INSTABILITY WILL BE WEAK WITH WARMER TEMPERATURES ALOFT AND LIMITED
LOW LEVEL MOISTURE AVAILABILITY. HOWEVER WITH A SFC TROF IN PLACE
ACROSS THE AREA SOME BETTER FORCING MAY PROVIDED SLIGHTLY BETTER
CHCS. HOWEVER CONFIDENCE IS ANY TSRA NEAR THE TERMINALS AT THIS POINT IS
LOW AND THEREFORE NOT INCLUDED. OTHERWISE VFR CONDITIONS PREVAIL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...JWS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
102 AM CDT SAT JUL 6 2013
.UPDATE...
ISSUED AT 1258 AM CDT SAT JUL 6 2013
UPDATED THE FORECAST TO RAISE LOW TEMPERATURES. WARM AIR ADVECTION
AND SKY COVER WILL PREVENT PRETTY MUCH ALL LOCATIONS FROM DROPPING
BELOW 70 TONIGHT. ALSO KEPT A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS FOR THE REST OF THE OVERNIGHT...ALTHOUGH OUR
NORTHERN THIRD STANDS LITTLE CHANCE OF HAVING THUNDER...DUE TO
LESS INSTABILITY...BUT THE HEALTHY LOW-LEVEL JET SHOULD KEEP SOME
ACTIVITY GOING ALL NIGHT.
UPDATE ISSUED AT 645 PM CDT FRI JUL 5 2013
WENT AHEAD AND UPDATED THE FORECAST TO INCREASE CLOUD COVER AND
INTRODUCE A SMALL CHANCE FOR SOME LIGHT SHOWERS OR SPRINKLES FOR
MUCH OF THE AREA THROUGH THE EVENING HOURS. LATEST UPDATE FROM SPC
MESOANALYSIS PAGE CONTINUES TO INDICATE VERY LITTLE INSTABILITY TO
WORK WITH AND WITH NO LIGHTNING OBSERVED SO FAR WITH THIS SHOWER
ACTIVITY...DID NOT MENTION ANY THUNDER THROUGH THE OVERNIGHT
HOURS. OTHERWISE...WHILE THERE ARE NOW SMALL CHANCES FOR
PRECIP THIS EVENING...DO NOT EXPECT MUCH IN THE WAY OF
ACCUMULATION AS WITH HIGH BASES OF THESE SHOWERS MOST PLACES WILL
HAVE TROUBLE ACCUMULATING ANY PRECIP AT ALL.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 348 PM CDT FRI JUL 5 2013
MAIN FORECAST CONCERNS WILL BE SHOWERS TONIGHT AND TEMPERATURES.
SATELLITE AND SURFACE OBSERVATIONS SHOW SOME MID AND HIGH LEVEL
CLOUDS ACROSS THE AREA AND ANOTHER BAND OF THEM TO THE WEST. THE
BAND TO THE WEST WILL BE MOVING INTO THE AREA DURING THE NIGHT.
THERE IS AN UPPER LEVEL WAVE THAT MOVES THROUGH THE AREA...MAINLY TO
THE NORTH OF THE FORECAST AREA. MODELS HAVE VARYING METHODS OF HOW
THEY HANDLE THE WAVE TONIGHT. THE NAM AND THE HRRR BOTH BRING SOME
PRECIPITATION TO THE NORTHERN PART OF THE FORECAST AREA WHILE THE
GFS AND THE 4KM WRF REMAIN DRY. HAVE KEPT AT LEAST SOME OF THE
SHOWERS THAT WERE IN THE FORECAST. IT IS A SMALL CHANCE OF LIGHT
SHOWERS. EXPECT THAT IT WILL BE SIMILAR TO LAST NIGHT AND THIS
MORNING WITH A FEW SPOTTY SHOWERS OR SPRINKLES. TEMPERATURES ARE
EXPECTED TO BE ON THE WARM SIDE.
ON SATURDAY ANOTHER UPPER LEVEL WAVE MOVES THROUGH THE AREA. AT THE
SURFACE A LOW PRESSURE SYSTEM AND WEAK COLD FRONT ON THE HIGH PLAINS
DRIFTS TO THE EAST DURING THE DAY. AS THE WAVE MOVES OVER THE NAM
AND THE 4KM WRF DEVELOP SOME THUNDERSTORMS ALONG THE FRONT. THE MAIN
QUESTION IS WHETHER THEY MOVE INTO THE FORECAST AREA DURING THE
AFTERNOON. THE LATEST RUNS OF THE MODELS HAVE TRENDED A LITTLE
FURTHER WEST WITH THE FRONT SO EXPECT THAT THE THUNDERSTORMS WILL
HOLD OFF UNTIL THE EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 348 PM CDT FRI JUL 5 2013
THE UPPER AIR PATTERN WILL BECOME MORE OF A ZONAL FLOW REGIME SUNDAY
THROUGH WEDNESDAY WITH THE JET STREAM FLOWING ACROSS THE NORTHERN
TIER OF OUR COUNTRY. THIS IS A CHANGE FROM THE MORE MERIDIONAL FLOW
AND UPPER TROUGH THAT HAS DOMINATED OUR REGION FOR THE LAST SEVERAL
DAYS. CONSEQUENTLY...EXPECT WARMER TEMPERATURES THAT SHOULD BE AT
LEAST NEAR NORMAL TO LIKELY ABOVE NORMAL MOST DAYS THROUGH THE
PERIOD. THE BIGGER SYNOPTIC SYSTEMS WILL REMAIN WELL NORTH OF US
THROUGH THE PERIOD WITH OUR PRECIPITATION CHANCES COMING FROM WEAKER
FORCED EVENTS SUCH AS MINOR FRONTAL BOUNDARIES AND WIND SHIFT
TROUGHS. WE WILL ALSO HAVE TO WATCH OUT FOR CONVECTION THAT FORMS
OVER THE HIGH PLAINS THAT COULD WORK INTO OUR AREA FROM THE WEST
DURING THE EVENING AND OVERNIGHT PERIODS. OVERALL...PRECIPITATION
CHANCES WILL BE LOW AND RAIN EVENTS WILL LIKELY BE MORE ISOLATED IN
NATURE. THAT BEING SAID...THERE ARE NUMEROUS SMALL CHANCES OF
PRECIPITATION IN THE FORECAST BUT IF YOU ARE LOOKING FOR RAIN I
WOULD NOT GET YOUR HOPES UP TOO MUCH AS THESE ARE ALL LOW END WEAKLY
FORCED EVENTS. HIGH TEMPERATURES THROUGH THE PERIOD WILL GENERALLY
BE IN THE 90S WITH MAYBE SEVERAL 100 DEGREE DAYS ACROSS NORTHERN
KANSAS. IF THE UPPER RIDGE DOES BUILD IN TO THE CENTRAL PLAINS
NEXT FRIDAY IT COULD LEAD TO A VERY HOT START TO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1258 AM CDT SAT JUL 6 2013
VFR CONDITIONS. SOME SHOWERS WILL BE IN THE VICINITY...BUT SPARSE
ENOUGH TO KEEP JUST A VCSH IN THE FORECAST FOR OVERNIGHT. ALSO...A
SLIGHT CHANCE OF A THUNDERSHOWER EXISTS FOR SATURDAY EVENING...BUT
AGAIN...SHOULD BE SPARSE. THE WIND COULD HAVE A BIT OF A GUST ON
SATURDAY...AS HAS BEEN THE CASE THE PAST COUPLE OF DAYS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...JCB
LONG TERM...WESELY
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS ELKO NV
335 AM PDT SAT JUL 6 2013
.SYNOPSIS...ISOLATED TO SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP
ACROSS PORTIONS OF CENTRAL AND EASTERN NEVADA DURING THE LATE
MORNING AND AFTERNOON HOURS. SOME STORMS IN FAR EASTERN NEVADA MAY
BE STRONG WITH STRONG WIND GUSTS. LOOK FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS MONDAY...WITH ABOVE NORMAL TEMPERATURES
CONTINUING.
&&
.SHORT TERM...TODAY THROUGH SUNDAY. LEFTOVER DEBRIS CLOUD EXISTS
ACROSS CENTRAL AND EASTERN NEVADA THIS MORNING. SHORT RANGE PROGS
ARE SHOWING POSITIVE 1000-500 MUCAPE VALUES IN PORTIONS OF WHITE
PINE COUNTY THIS MORNING...WHERE ISOLATED CONVECTIVE CONTINUES TO
DEVELOP. HRRR ALSO DEPICTS THIS AND HAVE KEPT ISOLATED THUNDER IN
THE WEATHER GRIDS FOR THIS MORNING FOR THIS AREA AND EASTERN ELKO
COUNTY.
MODELS CONTINUE TO SHOW A WEST COAST TROUGH SITTING ACROSS THE
WESTERN UNITED STATES THIS MORNING...WITH AN UPPER RIDGE OVER THE
SOUTHWEST UNITED STATES. AN UPPER JET ACROSS NORTHEAST NEVADA WILL
SLOWLY SAG SOUTH AND EAST...EVENTUALLY MOVING OUT OF THE AREA
LATER TODAY. CAPE VALUES OF 400-1000 J/KG...AS WELL AS 0-6KM SHEAR OF
35-40 KNOTS AND MODEST INSTABILITY ARE FORECAST TO RESIDE OVER
EASTERN NEVADA DURING THE LATE MORNING AND EARLY AFTERNOON HOURS.
THE TARGET AREAS APPEAR TO BE EASTERN ELKO AND EASTERN WHITE PINE
COUNTIES. STORM MOTION IN THESE AREAS WILL AGAIN BE QUITE
FAST...WITH SPEEDS OF 15-25 MPH FORECAST. ONCE AGAIN...STORMS THAT
DEVELOP DURING THIS TIME COULD BE STRONG TO SEVERE.
HOWEVER...BELIEVE THAT INITIATION WILL OCCUR DURING THE LATTER
PORTIONS OF THE AFTERNOON...BUT STILL PUT ENHANCED WORDING IN THE
AFFECTED ZONES. MAIN THREATS WILL BE STRONG WINDS TO 60 MPH WITH
SMALL HAIL. FOR THE REST OF THE FORECAST AREA...EXPECTING A TIGHT
MOISTURE GRADIENT TO SET UP SOUTHWEST TO NORTHEAST DURING THE DAY
AS DRIER AIR TRIES TO INFILTRATE DURING THE AFTERNOON
HOURS...WHICH WILL CREATE A DISTINCT LINE IN STORM FORMATION. HAVE
TRIED TO PAINT THIS IN THE POP GRIDS FOR TODAY.
ACTIVITY IS EXPECTED TO WIND DOWN AFTER SUNSET...WITH CLEARING
SKIES. ON SUNDAY...MODELS ARE FORECASTING HEIGHTS TO CLIMB ACROSS
NORTHERN NEVADA...UNDER A LOW-MID SOUTHWEST FLOW. SOME MOISTURE
EXPECTED TO REMAIN OVER THE EASTERN HALF OF THE FORECAST AREA AND
HAVE CONTINUED WITH ISOLATED TO SCATTERED THUNDERSTORMS.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT FRIDAY. MODELS IN GOOD
AGREEMENT THROUGH THE LONG TERM. THE TROUGH THAT HAS BROUGHT THUNDERSTORMS
TO THE REGION WILL GRADUALLY MOVES EASTWARD AS THE RIDGE BUILDS BACK
OVER THE GREAT BASIN. WILL CONTINUE TO SEE ISOLATED THUNDERSTORMS
DEVELOP THROUGH TUESDAY AS INSTABILITY AND LIMITED MOISTURE WILL
REMAIN OVER EASTERN NEVADA. WEDNESDAY AND THURSDAY WILL DRY OUT AS
PW`S DROP TO .50" OR LESS AS SOUTHWESTERLY FLOW DOMINATES THE
REGION. ON FRIDAY THE MODELS ARE COMING INTO BETTER AGREEMENT WITH A
POTENTIAL SURGE OF MONSOON MOISTURE PUSHING INTO CENTRAL AND
NORTHEASTERN NEVADA WITH INCREASING CHANCES OF THUNDERSTORMS. WINDS
ARE EXPECTED TO INCREASE ACROSS CENTRAL AND EASTERN NEVADA ON
THURSDAY AND FRIDAY HOWEVER THERE IS UNCERTAINTY ON HOW DRY IT WILL
BE...SO THERE COULD BE SOME FIRE WEATHER CONCERNS THAT WILL NEED TO
BE CLOSELY WATCHED OVER THE COMING DAYS. EXPECT TEMPERATURES WILL
CONTINUE TO BE ABOVE NORMAL WITH TEMPERATURES IN THE 90S.
&&
.AVIATION...VFR CONDITIONS WITH ISOLATED THUNDERSTORMS EXPECTED TO
DEVELOP OVER THE EASTERN PARTS OF THE STATE. KELY WILL HAVE A 20 TO
25 PERCENT CHANCE OF THUNDERSTORMS. KEKO IS NOT EXPECTING
THUNDERSTORMS BUT A STORM OR TWO COULD DEVELOP NEARBY IN THE RUBY
MOUNTAINS.
&&
.FIRE WEATHER...EXPECT ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM ACTIVITY TO CONTINUE THIS AFTERNOON AND AGAIN SUNDAY.
THE MOST ACTIVITY WILL BE OVER ZONES 469...470...AND 455 IN THE
AFTERNOON AND EVENING HOURS. SOUTHWEST WINDS 10-15 MPH WITH GUSTS
TO 25 MPH WILL BE POSSIBLE ESPECIALLY IN THE SOUTHERN ZONES OF 454
AND 455.
DRIER WEATHER IS IN STORE MONDAY AFTERNOON WITH ISOLATED DRY
THUNDERSTORMS POSSIBLE IN FIRE ZONES 455...469...AND 470. COVERAGE
IS EXPECTED TO KEEP LAL`S TO 2. HEIGHTS BUILD DURING THE
WEEK...WHICH MEANS TEMPERATURES HEADING BACK UP TO THE MID TO
UPPER 90S FOR MANY VALLEY LOCATIONS. LOOK FOR POSSIBLE BREEZY
CONDITIONS THURSDAY AND FRIDAY.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
86/90/90/86
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1121 PM EDT SUN JUL 7 2013
.SYNOPSIS...
AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL SLIDE EAST ACROSS OUR
REGION OVERNIGHT AND MONDAY. THIS WILL RESULT IN MORE CHANCES OF
SHOWERS AND THUNDERSTORMS CONTINUING THROUGH MID-WEEK. DRIER AIR
FINALLY ARRIVES BY THE END OF THE WEEK AS HIGH PRESSURE BUILDS INTO
THE GREAT LAKES.
&&
.NEAR TERM /THROUGH MONDAY/...
UPPER LEVEL LOW IS SHIFTING ACROSS OHIO LATE THIS EVENING TOWARD
WESTERN PA. REGIONAL RADARS ARE SHOWING THE MAIN AREAS OF CONVECTION
LOCATED BELOW THIS UPPER LOW AND ACROSS EASTERN NY WITHIN THE
DIFFLUENT FLOW EAST OF THE UPPER LOW. IN BETWEEN THESE TWO AREAS OUR
KBUF RADAR IS SHOWING SOME QUICKLY WEAKENING SHOWERS SHIFTING ACROSS
WESTERN LAKE ONTARIO TOWARD NIAGARA COUNTY. THIS PRECIP HAS
DEVELOPED WITHIN THE MOIST AIRMASS OVER SOUTHERN CANADA WHERE RAP
MODEL ANALYSIS OF 500MB HEIGHTS SHOW A SHORTWAVE/INVERTED TROUGH
EXTENDING FROM THE CENTER OF THE UPPER LOW NORTH ACROSS SOUTHWEST
ONTARIO CANADA.
RECENT HRRR MODEL RUNS HAVE SHOWN THESE SHOWERS QUICKLY ENDING OVER
THE NIAGARA FRONTIER THROUGH THE EVENING WHICH IS ROUGHLY WHAT IS
ONGOING NOW. OUTSIDE OF THIS...SOME SHOWERS LOOK TO BE DRIFTING
OVER SOUTHERN OSWEGO AND LEWIS COUNTIES ASSOCIATED WITH CONVECTION
EAST OF SYRACUSE. ALSO THERE ARE A FEW WIDELY SCATTERED SHOWERS
DRIFTING EAST NEAR THE NY/PA STATE LINE. AS THE UPPER LEVEL LOW LIFT
NORTH TOWARD WESTERN NY THE HRRR SHOWS SOME MORE SHOWERS MAY BE
TRIGGERED MAINLY SOUTH OF BUFFALO LATER TONIGHT SO KEPT A CHANCE OF
SHOWERS IN THE FORECAST OVERNIGHT. OTHERWISE...SOME PATCHY FOG IS
POSSIBLE IN THE SOUTHERN TIER VALLEYS...AND EAST OF LAKE ONTARIO.
LOWS SHOULD RANGE FROM THE MID 60S TO AROUND 70.
ON MONDAY...THE CLOSED UPPER LEVEL LOW WILL GRADUALLY OPEN AS IT
SLIDES TO THE EAST. THIS FEATURE WILL RESULT IN A CONTINUED THREAT
FOR SHOWERS DURING THE DAY MONDAY...AS DAYTIME INSTABILITY ENHANCES
SHOWER ACTIVITY. SLIGHTLY COOLER TEMPERATURES ALOFT SHOULD ALLOW
STORMS TO DEVELOP LIGHTNING A BIT MORE QUICKLY THAN THE PAST COUPLE
DAYS. AS THE OPENING TROF EXITS TO THE EAST...EXPECT DRYING WITH THE
SUBSTANCE ASSOCIATED WITH THE EXITING FEATURE. AS A RESULT...SHOWERS
AND THUNDERSTORMS SHOULD TAPER OFF FROM WEST TO EAST DURING THE
AFTERNOON HOURS. TEMPERATURES WILL BE A TAD COOLER...WITH HIGHS INT
HE UPPER 70S TO LOWER 80S. IT WILL CONTINUE TO BE MOIST RESULTING IN
CONTINUED MUGGY CONDITIONS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS THE AXIS OF THE UPPER TROUGH WILL HAVE PASSED TO THE EAST OF
THE FORECAST AREA...EXPECT A SHARP DROP OFF IN POPS FOR MONDAY
NIGHT. WARM ADVECTION THROUGHOUT THE BOUNDARY LAYER WILL ARRIVE IN
WESTERN AND SOUTHERN NY ON TUESDAY WITH INCREASING BUT STILL LOW
CHANCE OF THUNDERSTORMS ACROSS THE SOUTHERN TIER...MAINLY DURING
TUESDAY AFTERNOON. TEMPS MONDAY NIGHT WILL BE IN THE LOWER TO MID
60S ACROSS THE SOUTHERN TIER AND TUG HILL...AND MID 60S TO NEAR 70
FOR THE LAKE PLAINS AND URBAN AREAS. HIGHS ON TUESDAY WILL RISE A
NOTCH TO THE LOWER TO MID 80S.
A TROUGH MOVING ACROSS ONTARIO PROVINCE WILL SPAWN A SURFACE LOW
OVER THE UPPER MID WEST ON TUESDAY TO SOUTH OF JAMES BAY ON
WEDNESDAY. 35 TO 40 KNOT WINDS AT 850MB ACROSS THE CENTRAL GREAT
LAKES WILL FORM A WARM FRONT ASSOCIATED WITH THE SURFACE LOW.
INCREASING MOISTURE AHEAD OF THE WARM FRONT...PRECIPITABLE WATER
RISING BACK TO NEAR 2 INCHES...AND ADDED LIFT IN THE VICINITY OF THE
SHORT WAVE TROUGH WILL BRING A GOOD CHANCE FOR SHOWERS AND
THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY. UNSETTLED WEATHER WILL
CONTINUE WEDNESDAY NIGHT AS A COLD FRONT...TRAILING SOUTH OF LOW
PRESSURE NEAR JAMES BAY...PUSHES EAST ACROSS THE STATE. TEMPS
TUESDAY NIGHT WILL RANGE FROM THE MID 60S ACROSS THE SOUTHERN TIER
AND TUG HILL...TO LOWER 70S FOR THE LAKE PLAINS AND URBAN AREAS.
HIGHS ON WEDNESDAY WILL BE SIMILAR TO TUESDAY...LOWER TO MID
80S...EVEN WITH THICKER CLOUD AND OCCURRENCE OF PRECIP.
DRIER AND MARGINALLY COOLER AIR WILL ARRIVE IN THE POSTFRONTAL
AIRMASS ON THURSDAY WITH LOWER CHANCE POPS AND PARTIAL CLEARING.
EXPECT HIGHS IN THE MID TO UPPER 70S ON THURSDAY AND LOWS THURSDAY
NIGHT IN THE UPPER 50S TO LOWER 60S AS SKIES CLEAR FURTHER.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THE UPPER TROUGH ACROSS ONTARIO WILL STALL AND DIG FARTHER
SOUTH...DEVELOPING A CUTOFF LOW ACROSS THE EASTERN U.S. THIS LOW
WILL DROP FARTHER TO THE SOUTH ON THE WEEKEND AND BLOCK THE WARMER
AIR FROM THE NATION`S MIDSECTION...ALSO TAPPING INTO MOISTURE FROM
THE WESTERN ATLANTIC. FRIDAY AND FRIDAY NIGHT SHOULD REMAIN DRY
AND QUITE COOLER WITH HIGHS IN THE 70S AND LOWS IN THE UPPER 50S
TO LOW 60S. HIGHER CHANCE FOR SHOWERS AND THUNDERSTORMS WILL
ARRIVE DURING SATURDAY AND SUNDAY AS THE SOUTHEASTERLY LOW LEVEL
FLOW FROM THE MID ATLANTIC INTERACTS WITH THE MID AND UPPER LEVEL
TROUGH. HIGH TEMPS FOR THE WEEKEND WILL BE IN THE MID TO UPPER 70S
ON SATURDAY AND THE UPPER 70S TO LOWER 80S ON SUNDAY.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
SCATTERED TO ISOLATED SHOWERS ARE POSSIBLE OVERNIGHT AS AN UPPER LOW OVER
OHIO MOVES CLOSER TO WESTERN NEW YORK. THERE CONTINUED TO BE QUITE A
BIT OF LOW LEVEL MOISTURE IN PLACE...BUT AS LONG AS WINDS PERSIST
AND THE MID AND HIGH CLOUDS REMAIN...EXPECT CIGS TO REMAIN MAINLY IN
THE VFR RANGE. THIS SAID...ANY PROLONGED CLEARING WOULD LIKELY
RESULT IN LOW CLOUDS AND FOG...WITH THE BEST CHANCE FOR THIS AT
JHW/ART.
THERE WILL BE A CONTINUED THREAT FOR SHOWERS AND POSSIBLY A
THUNDERSTORM ON MONDAY AS THE UPPER LEVEL LOW SHIFTS ACROSS NEW
YORK. EXPECT MAINLY VFR CONDITIONS EXCEPT IN STORMS WHERE HEAVY
RAINS COULD LOWER VSBY TO 2SM OR LESS.
OUTLOOK...
MONDAY NIGHT THROUGH WEDNESDAY...MAINLY VFR WITH SCATTERED
SHOWERS AND THUNDERSTORMS AND ASSOCIATED BRIEF MVFR/IFR
CONDITIONS.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
LIGHT TO MODERATE SOUTHWEST WINDS WILL CONTINUE THROUGH MONDAY WITH
CHOPPY WAVE ACTION AT TIMES ON BOTH LAKES...BUT CONDITIONS SHOULD
REMAIN BELOW SMALL CRAFT CRITERIA. AN AREA OF LOW PRESSURE WILL
SHIFT TOWARD THE LOWER LAKES TOWARD MID-WEEK WITH AN INCREASE IN
WINDS AND WAVES ON WEDNESDAY. SMALL CRAFT CONDITIONS MAY BE
EXPERIENCED MAINLY OVER THE NORTHEASTERN NEARSHORE WATERS OF THE LAKES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...SMITH/TMA
MARINE...SMITH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
825 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A PERSISTENT TROUGH OF LOW PRESSURE WILL GRADUALLY SLIDE EASTWARD
ACROSS THE REGION EARLY NEXT WEEK. THIS WILL RESULT IN CONTINUED
UNSETTLED WEATHER THROUGH MID-WEEK BEFORE DRIER AIR FINALLY
ARRIVES BY THE END OF THE WEEK AS HIGH PRESSURE BUILDS INTO THE
GREAT LAKES.
&&
.NEAR TERM /THROUGH MONDAY/...
AN UPPER LEVEL TROUGH IS CENTERED OVER OHIO THIS EVENING WITH THE
MAIN AREAS OF CONVECTION LOCATED BELOW THIS UPPER LOW AND ACROSS
THE TRI-STATE AREA WITHIN THE DIFFLUENT FLOW EAST OF THE UPPER
LOW. FOR THE MOST PART WESTERN AND NORTH CENTRAL NEW YORK REMAIN
RAIN-FREE WITH THE EXCEPTION OF A FEW WIDELY SCATTERED SHOWERS
WHICH MAY HAVE BEEN TRIGGERED ON REMNANT LAKE BREEZE BOUNDARIES
FROM TODAY.
FOCUS FOR THE REST OF THE EVENING IS ON A CLUSTER OF SHOWERS WITH
EMBEDDED MAINLY CLOUD-TO-CLOUD LIGHTNING MOVING SOUTHEAST ACROSS
THE WESTERN HALF OF LAKE ONTARIO. THIS PRECIP HAS DEVELOPED WITHIN
THE MOIST AIRMASS OVER SOUTHERN CANADA WHERE RAP MODEL ANALYSIS OF
500MB HEIGHTS SHOW SOME BROAD TROUGHINESS DIGGING ACROSS
SOUTHEASTERN ONTARIO CANADA. 22Z HRRR MODEL ROUGHLY SHOWS THIS
FEATURE WHICH IT FORECASTS TO SLOWLY SHIFT EAST-SOUTHEAST OVER THE
LAKE AND MOVE ACROSS THE NIAGARA FRONTIER. ITS PLACEMENT SEEMS TOO
FAR SOUTH COMPARED TO CURRENT RADAR SO UPDATED THE FORECAST GRIDS TO
SHOW AN EARLIER CHANCE OF SCATTED SHOWERS AND A CHANCE OF THUNDER
FOR MAINLY THE SOUTHERN LAKE ONTARIO LAKE SHORE THIS EVENING. THEN
KEPT THE PREVIOUS FORECAST WITH CHANCE OF SHOWERS OVERNIGHT AS SOME
OUT FLOW FROM THE CURRENT LAKE ONTARIO ACTIVITY MAY TRIGGER NEW
SHOWERS FURTHER SOUTH AND EAST ACROSS WESTERN NEW YORK OVERNIGHT.
AS HAS BEEN THE CASE...SOME PATCHY FOG IS POSSIBLE IN THE SOUTHERN
TIER VALLEYS...AND EAST OF LAKE ONTARIO. LOWS SHOULD RANGE FROM THE
MID 60S TO AROUND 70.
ON MONDAY...THE CLOSED UPPER LEVEL LOW WILL GRADUALLY OPEN AS IT
SLIDES TO THE EAST. THIS FEATURE WILL RESULT IN A CONTINUED THREAT
FOR SHOWERS DURING THE DAY MONDAY...AS DAYTIME INSTABILITY ENHANCES
SHOWER ACTIVITY. SLIGHTLY COOLER TEMPERATURES ALOFT SHOULD ALLOW
STORMS TO DEVELOP LIGHTNING A BIT MORE QUICKLY THAN THE PAST COUPLE
DAYS. AS THE OPENING TROF EXITS TO THE EAST...EXPECT DRYING WITH THE
SUBSTANCE ASSOCIATED WITH THE EXITING FEATURE. AS A RESULT...SHOWERS
AND THUNDERSTORMS SHOULD TAPER OFF FROM WEST TO EAST DURING THE
AFTERNOON HOURS. TEMPERATURES WILL BE A TAD COOLER...WITH HIGHS INT
HE UPPER 70S TO LOWER 80S. IT WILL CONTINUE TO BE MOIST RESULTING IN
CONTINUED MUGGY CONDITIONS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS THE AXIS OF THE UPPER TROUGH WILL HAVE PASSED TO THE EAST OF
THE FORECAST AREA...EXPECT A SHARP DROP OFF IN POPS FOR MONDAY
NIGHT. WARM ADVECTION THROUGHOUT THE BOUNDARY LAYER WILL ARRIVE IN
WESTERN AND SOUTHERN NY ON TUESDAY WITH INCREASING BUT STILL LOW
CHANCE OF THUNDERSTORMS ACROSS THE SOUTHERN TIER...MAINLY DURING
TUESDAY AFTERNOON. TEMPS MONDAY NIGHT WILL BE IN THE LOWER TO MID
60S ACROSS THE SOUTHERN TIER AND TUG HILL...AND MID 60S TO NEAR 70
FOR THE LAKE PLAINS AND URBAN AREAS. HIGHS ON TUESDAY WILL RISE A
NOTCH TO THE LOWER TO MID 80S.
A TROUGH MOVING ACROSS ONTARIO PROVINCE WILL SPAWN A SURFACE LOW
OVER THE UPPER MID WEST ON TUESDAY TO SOUTH OF JAMES BAY ON
WEDNESDAY. 35 TO 40 KNOT WINDS AT 850MB ACROSS THE CENTRAL GREAT
LAKES WILL FORM A WARM FRONT ASSOCIATED WITH THE SURFACE LOW.
INCREASING MOISTURE AHEAD OF THE WARM FRONT...PRECIPITABLE WATER
RISING BACK TO NEAR 2 INCHES...AND ADDED LIFT IN THE VICINITY OF THE
SHORT WAVE TROUGH WILL BRING A GOOD CHANCE FOR SHOWERS AND
THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY. UNSETTLED WEATHER WILL
CONTINUE WEDNESDAY NIGHT AS A COLD FRONT...TRAILING SOUTH OF LOW
PRESSURE NEAR JAMES BAY...PUSHES EAST ACROSS THE STATE. TEMPS
TUESDAY NIGHT WILL RANGE FROM THE MID 60S ACROSS THE SOUTHERN TIER
AND TUG HILL...TO LOWER 70S FOR THE LAKE PLAINS AND URBAN AREAS.
HIGHS ON WEDNESDAY WILL BE SIMILAR TO TUESDAY...LOWER TO MID
80S...EVEN WITH THICKER CLOUD AND OCCURRENCE OF PRECIP.
DRIER AND MARGINALLY COOLER AIR WILL ARRIVE IN THE POSTFRONTAL
AIRMASS ON THURSDAY WITH LOWER CHANCE POPS AND PARTIAL CLEARING.
EXPECT HIGHS IN THE MID TO UPPER 70S ON THURSDAY AND LOWS THURSDAY
NIGHT IN THE UPPER 50S TO LOWER 60S AS SKIES CLEAR FURTHER.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THE UPPER TROUGH ACROSS ONTARIO WILL STALL AND DIG FARTHER
SOUTH...DEVELOPING A CUTOFF LOW ACROSS THE EASTERN U.S. THIS LOW
WILL DROP FARTHER TO THE SOUTH ON THE WEEKEND AND BLOCK THE WARMER
AIR FROM THE NATION`S MIDSECTION...ALSO TAPPING INTO MOISTURE FROM
THE WESTERN ATLANTIC. FRIDAY AND FRIDAY NIGHT SHOULD REMAIN DRY
AND QUITE COOLER WITH HIGHS IN THE 70S AND LOWS IN THE UPPER 50S
TO LOW 60S. HIGHER CHANCE FOR SHOWERS AND THUNDERSTORMS WILL
ARRIVE DURING SATURDAY AND SUNDAY AS THE SOUTHEASTERLY LOW LEVEL
FLOW FROM THE MID ATLANTIC INTERACTS WITH THE MID AND UPPER LEVEL
TROUGH. HIGH TEMPS FOR THE WEEKEND WILL BE IN THE MID TO UPPER 70S
ON SATURDAY AND THE UPPER 70S TO LOWER 80S ON SUNDAY.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
EXPECT VFR CONDITIONS FOR THE REMAINDER OF THIS EVENING. THERE
MAY BE A FEW SHOWERS...BUT THESE WILL HAVE LITTLE IF ANY IMPACT ON
AREA TERMINALS.
FOR THE OVERNIGHT HOURS...EXPECT SCATTERED SHOWERS AS THE UPPER
LOW OVER OHIO MOVES CLOSER TO THE REGION. THERE WILL BE QUITE A
BIT OF LOW LEVEL MOISTURE IN PLACE...BUT AS LONG AS WINDS PERSIST
AND THE MID AND HIGH CLOUDS REMAIN...EXPECT CIGS TO REMAIN MAINLY
IN THE VFR RANGE. THIS SAID...ANY PROLONGED CLEARING WOULD LIKELY
RESULT IN LOW CLOUDS AND FOG...WITH THE BEST CHANCE FOR THIS AT
JHW/ART.
THERE WILL BE A CONTINUED THREAT FOR SHOWERS AND POSSIBLY A
THUNDERSTORM ON MONDAY. EXPECT MAINLY VFR CONDITIONS EXCEPT IN
STORMS WHERE HEAVY RAINS COULD LOWER VSBY TO 2SM OR LESS.
OUTLOOK...
MONDAY NIGHT THROUGH WEDNESDAY...MAINLY VFR WITH SCATTERED
SHOWERS AND THUNDERSTORMS AND ASSOCIATED BRIEF MVFR/IFR
CONDITIONS.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
SOUTH TO SOUTHWEST WINDS REMAIN BREEZY ON LAKE ERIE AND WESTERN LAKE
ONTARIO. THERE MAY BE A DECENT CHOP ON THE WATERS...DUE TO SW GUSTS
NEAR THE IMMEDIATE SHORELINE...BUT WAVES SHOULD REMAIN WELL BELOW 4
FT. SOME SHOWERS AND THUNDERSTORMS ARE DROPPING SOUTH ACROSS THE
WESTERN HALF OF LAKE ONTARIO AND MAY BRING LOCALIZED GUSTY WINDS AND
HIGHER WAVES.
LIGHT TO MODERATE SOUTHWEST WINDS WILL CONTINUE THROUGH MONDAY WITH
CHOPPY WAVE ACTION AT TIMES ON BOTH LAKE...BUT CONDITIONS SHOULD
REMAIN BELOW SMALL CRAFT CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL/SMITH
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...APFFEL/TMA
MARINE...SMITH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
810 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A WARM AND HUMID AIR MASS WILL PERSIST ACROSS THE REGION THROUGH
MUCH OF THE WEEK WITH NEAR DAILY CHANCES OF SHOWERS AND
THUNDERSTORMS EXPECTED. THE HIGHEST CONCENTRATION OF SHOWERS AND
STORMS WILL OCCUR ON MONDAY AND AGAIN ON WEDNESDAY WHEN LOCALLY
HEAVY RAINFALL IS POSSIBLE. TEMPERATURES WILL REMAIN ON THE WARM
SIDE...WITH HIGHS IN THE 80S AND OVERNIGHT LOWS GENERALLY IN THE
60S.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 809 PM EDT SUNDAY...LATEST GUIDANCE SHOWING BEST
INSTABILITY ACROSS CENTRAL AND SOUTHERN VERMONT AT THIS TIME...AS
WELL AS SOUTHERN ESSEX COUNTY IN NEW YORK STATE. THUS...WILL KEEP
IN A CHANCE FOR THUNDERSTORMS IN THESE AREAS. FURTHER
NORTH...CONDITIONS ARE MORE STABLE...SO HAVE DROPPED THE MENTION
OF THUNDERSTORMS ACROSS THE NORTH PORTION OF THE FORECAST AREA
OVERNIGHT AND JUST KEPT IN A CHANCE OF SHOWERS. MADE SOME MINOR
ADJUSTMENTS TO MIN TEMPERATURES OVERNIGHT.
PREVIOUS DISCUSSION FROM 435 PM EDT SUNDAY...A WARM AND HUMID
NIGHT EXPECTED ACROSS THE AREA AS DEEPER SUBTROPICAL FLOW HAS
PUSHED BACK NORTH AND EAST INTO THE AREA AS EXPECTED. SCATTERED
SHOWERS ALSO EXPECTED ON AND OFF THROUGH THE EVENING AND NIGHTTIME
HOURS AS HI- RES MODELS AND THIS AFTERNOON`S RAP ANALYSIS SHOWING
A WEAK SHORTWAVE MOVING THROUGH THE FLOW ACROSS OUR AREA. MID-
LEVEL MOISTURE CONVERGENCE ALSO EVIDENT AS WEAK SURFACE FRONT SAGS
SOUTH TO NEAR THE INTL BORDER OVERNIGHT AND STALLS. WITH SUCH WEAK
FEATURES QUITE DIFFICULT TO TIME AREAL PLACEMENT AND INTENSITY OF
PCPN...BUT PER LATEST LAPS/RUC PROGS WILL ADVERTISE HIGH CHANCE
POPS AND CONFINE HIGHER THREAT OF THUNDER AND LOCALLY HEAVY
RAINFALL TO OUR SOUTHERN COUNTIES WHERE BEST MLCAPE PROFILES
EXIST. AGAIN...A MUGGY NIGHT EXPECTED AS SURFACE DEWPOINTS HOLD IN
THE 60S TO AROUND 70. WINDS LIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 435 PM EDT SUNDAY...BY MONDAY STILL LOOKING AT SCATTERED TO
WIDESPREAD SHOWERS AND THUNDER ACROSS MUCH OF THE AREA WITH WARM
AND MOIST AIRMASS IN PLACE ON THE WESTERN PERIPHERY OF STRONG
BERMUDA HIGH PRESSURE. WE`LL ALSO HAVE SOME ADDED IMPETUS FROM A
WEAKENING MID-LEVEL SHORTWAVE TROUGH LIFTING OUT OF THE LOWER
GREAT LAKES/OHIO VALLEY STATES THROUGH THE DAY. THIS COMBINED WITH
LIGHTLY VEERED PBL FLOW...LOWER NCAPE AND DEEP WCD VALUES IN
EXCESS OF 11 KFT ALL SUPPORT CONTINUED MENTION OF LOCALLY HEAVY
RAINFALL IN THE MORE ROBUST CELLS WHERE EFFICIENT PRECIPITATION
LOADING WILL BE LIKELY. WHILE I CAN`T COMPLETELY RULE OUT AN
ISOLATED SEVERE CELL...WITH SUCH HIGH WBZ VALUES I`M REALLY NOT
EXPECTING ANYTHING OTHER THAN SOME BRIEF GUSTY WINDS AND POSSIBLE
SMALL HAIL IN THE STRONGER CORES. HIGHS ON THE SEASONABLY WARM
SIDE...76 TO 84 OR CLOSE TO BLENDED BIAS-CORRECTED GUIDANCE.
EVENING SHOWERS AND STORMS THEN SLOWLY WANE IN AREAL COVERAGE AND
INTENSITY AS WE PROGRESS INTO MONDAY NIGHT AS SHORTWAVE EXITS EAST
AND WEAK RIDGING ALONG WITH LAYER OF DRIER MID-LEVEL AIR ADVECTS
INTO THE REGION. NO AIRMASS CHANGE...BUT ENOUGH DRYING SUCH THAT
MANY AREAS SHOULD TREND DRY BY TUESDAY MORNING. LOWS MAINLY IN THE
60S.
THEN MORE UNCERTAINTY AS WE HEAD INTO TUESDAY. FEELING IS TUESDAY
SHOULD BE MORE DRY THAN WET GIVEN MID-LEVEL DRY AIR AND WEAK
SUBSIDENCE ADVECTING ACROSS THE REGION...BUT EVIDENCE THAT SOME SORT
OF LOWER LEVEL MOISTURE BOUNDARY MAY LINGER ACROSS OUR EASTERN
COUNTIES. ECMWF MORE ROBUST WITH CHANCES PCPN THAN OTHER SHORT TERM
MODELS...BUT WILL DOWNPLAY AT THIS POINT OFFERING JUST SLIGHT TO
LOWER CHANCE POPS THROUGH THE DAY AND MAINLY ACROSS VT WHERE SOME
WIDELY SCATTERED ACTIVITY MAY OCCUR. HIGHS IN THE LOWER TO MID 80S.
BY TUESDAY NIGHT WARM AND HUMID CONDITIONS CONTINUE BUT MAINLY DRY
WITH LOSS OF INSOLATION. LOWS TO HOLD ON THE MILD SIDE AND MAINLY IN
THE 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...ACTIVE WEATHER DAY EXPECTED WEDS/THURS
AS POTENT TROF DEVELOPS ACRS THE NORTHERN GREAT LAKES AND SFC COLD
FRNT MOVES ACRS OUR CWA. THIS FRNT WL INTERACT WITH MODEST INSTABILITY
WITH LIS AROUND -4C AND CAPE VALUES BTWN 1500 TO 2000 J/KG.
ALSO...NOTED A RIBBON OF ENHANCED MID LVL WINDS...CREATING DEEP
LAYER SHEAR VALUES BTWN 30 AND 40 KNOTS...ESPECIALLY ACRS OUR
NORTHERN CWA ON WEDS AFTN. THE AREAL COVERAGE/INTENSITY OF STORMS
WL HIGHLY DEPEND UPON AMOUNT OF INSTABILITY/CLRING AND EXACT TRACK OF S/W
ENERGY. GIVEN...THE GOOD AGREEMENT IN MODELS WITH SYNOPTIC
FEATURES WL CONT TO MENTION HIGH CHC/LOW LIKELY POPS WEDS INTO
WEDS NIGHT...STILL A MINOR TIMING DIFFERENCE BTWN THE FASTER GFS
AND SLOWER ECMWF. WEAK SUBSIDENCE AND HIGH PRES TRIES TO BUILD
ACRS OUR CWA LATE THURS INTO FRIDAY...WITH A BRIEF DRY SPELL
POSSIBLE. LOTS OF UNCERTAINTY ASSOCIATED WITH NEXT SYSTEM FRIDAY
INTO NEXT WEEKEND...WITH GFS SHOWING MID/UPPER CLOSED CIRCULATION
ACRS THE GREAT LAKES RETROGRADING SW TWD TEXAS BY SUNDAY...WHILE
THE ECMWF SPLITS THE SYSTEM INTO TWO DISTINCT CLOSED CIRCULATIONS
WITH GREATER IMPACT ACRS OUR FA. GIVEN THE UNCERTAINTY IN THE
EVOLUTION OF THIS COMPLEX SYNOPTIC PATTERN...WL MENTION CHC POPS
NEXT WEEKEND. IF THE ULVL PATTERN VERIFIES ON THE ECMWF AND DEEP
TROPICAL MOISTURE IS ADVECTED BACK INTO THE NE CONUS...HYDRO WL
NEED TO BE WATCHED CLOSELY...FOR THE POTENTIAL FOR HEAVY RAINFALL.
PROGGED 85H TEMPS AHEAD OF BOUNDARY RANGE BTWN 14-16C ON
WEDS/THURS...BEFORE COOLING BACK BTWN 10-12C ON
FRIDAY...SUPPORTING HIGHS MID/UPPER 80S MID WEEK TO M70S TO L80S
BY NEXT FRIDAY. LOWS WL BE MAINLY IN THE U50S MTNS TO M60S
VALLEYS.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
THROUGH 00Z TUESDAY...RADAR SHOWS PERSISTENT TS IN THE RUTLAND
AREA AND THIS WILL LIKELY CONTINUE NEXT SEVERAL HOURS AS WEAK
BOUNDRY REMAINS IN THE AREA. THIS COULD PRODUCE BRIEF IFR
CONDITIONS MAINLY DUE TO VIS AT KRUT NEXT SEVERAL HOURS. ANOTHER
COMPLEX OF STORMS AND HEAVY RAIN WILL MOVE VERY NEAR TO KRUT AGAIN
AFTER 05Z AND TAF REFLECTS MVFR CONDITION BUT COULD BE LOWER IF
STORMS HOLD TOGETHER. ELSEWHERE MUCH MORE BENIGN WITH MAINLY VFR
EXPECTED OVERNIGHT. A BOUNDARY LIES JUST NORTH OF THE CANADIAN
BORDER AND THIS KEEP VCSH NEAR KMSS THROUGH 06Z. EXPECT NE WINDS
TO DEVELOP AT KMSS SOON AND CONTINUE UNTIL THE BOUNDARY PUSHES
SOUTH. A FEW ISOLATED SHOWERS POSSIBLE AT THE OTHER SITES NEXT FEW
HOURS...THEN QUIET OVERNIGHT.
OUTLOOK OOZ TUESDAY THROUGH FRIDAY...SCATTERED SHOWERS AND
THUNDERSTORMS WL BE POSSIBLE MONDAY AND AGAIN ON WEDS/THURS. THIS
ACTIVITY WL HAVE THE POTENTIAL TO PRODUCE BRIEF PERIODS OF MVFR
CONDITIONS ALONG WITH LOCALIZED GUSTY WINDS IN AND NEAR STORMS.
ALSO...LOOK FOR SOME BR/FOG TO DEVELOP IF SKIES CAN
CLR...ESPECIALLY AT MPV/SLK BTWN 07-11Z...WITH GENERALLY SOUTH TO
SOUTHWEST WINDS THRU THE PERIOD.
&&
.HYDROLOGY...
AS OF 435 PM EDT SUNDAY... LOCALLY HEAVY RAINFALL WILL REMAIN
POSSIBLE ACROSS THE SOUTHERN PORTIONS OF THE FORECAST AREA THIS
EVENING...AND ACROSS THE ENTIRE AREA ON MONDAY. WHILE WIDESPREAD
OR ORGANIZED AREAS OF FLASH FLOODING ARE NOT EXPECTED...WCD VALUES
WILL REMAIN QUITE HIGH ALONG WITH HIGH COLUMNAR MOISTURE PROFILES.
THUS POINT TOTALS IN EXCESS OF ONE INCH IN AN HOUR OR LESS WILL BE
POSSIBLE...WHICH CHOULD LEAD TO LOCALIZED HYDROLOGICAL
CONCERNS...ESPECIALLY ON MONDAY WHEN BOUNDARY LAYER FLOW WILL BE
QUITE LIGHT BELOW 850 MB.
&&
.EQUIPMENT...
AS OF 415 AM EDT SUNDAY...THE KTYX RADAR IS DOWN UNTIL FURTHER
NOTICE. TECHS HAVE ORDERED PARTS...WHICH SHOULD ARRIVE ON MONDAY
AND THE RADAR SHOULD BE RETURNED TO SERVICE BY TUESDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/WGH
SHORT TERM...JMG
LONG TERM...TABER
AVIATION...TABER/NF
HYDROLOGY...WFO BTV
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
740 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A WARM AND HUMID AIRMASS WILL PERSIST ACROSS THE REGION THROUGH MUCH
OF THE WEEK WITH NEAR DAILY CHANCES OF SHOWERS AND THUNDERSTORMS
EXPECTED. THE HIGHEST CONCENTRATION OF SHOWERS AND STORMS WILL OCCUR
ON MONDAY AND AGAIN ON WEDNESDAY WHEN LOCALLY HEAVY RAINFALL IS
POSSIBLE. TEMPERATURES WILL REMAIN ON THE WARM SIDE...WITH HIGHS IN
THE 80S AND OVERNIGHT LOWS GENERALLY IN THE 60S.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 435 PM EDT SUNDAY...A WARM AND HUMID NIGHT EXPECTED ACROSS
THE AREA AS DEEPER SUBTROPICAL FLOW HAS PUSHED BACK NORTH AND EAST
INTO THE AREA AS EXPECTED. SCATTERED SHOWERS ALSO EXPECTED ON AND
OFF THROUGH THE EVENING AND NIGHTTIME HOURS AS HI-RES MODELS AND
THIS AFTERNOON`S RAP ANALYSIS SHOWING A WEAK SHORTWAVE MOVING
THROUGH THE FLOW ACROSS OUR AREA. MID-LEVEL MOISTURE CONVERGENCE
ALSO EVIDENT AS WEAK SURFACE FRONT SAGS SOUTH TO NEAR THE INTL
BORDER OVERNIGHT AND STALLS. WITH SUCH WEAK FEATURES QUITE
DIFFICULT TO TIME AREAL PLACEMENT AND INTENSITY OF PCPN...BUT PER
LATEST LAPS/RUC PROGS WILL ADVERTISE HIGH CHANCE POPS AND CONFINE
HIGHER THREAT OF THUNDER AND LOCALLY HEAVY RAINFALL TO OUR
SOUTHERN COUNTIES WHERE BEST MLCAPE PROFILES EXIST. AGAIN...A
MUGGY NIGHT EXPECTED AS SURFACE DEWPOINTS HOLD IN THE 60S TO
AROUND 70. WINDS LIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 435 PM EDT SUNDAY...BY MONDAY STILL LOOKING AT SCATTERED TO
WIDESPREAD SHOWERS AND THUNDER ACROSS MUCH OF THE AREA WITH WARM
AND MOIST AIRMASS IN PLACE ON THE WESTERN PERIPHERY OF STRONG
BERMUDA HIGH PRESSURE. WE`LL ALSO HAVE SOME ADDED IMPETUS FROM A
WEAKENING MID-LEVEL SHORTWAVE TROUGH LIFTING OUT OF THE LOWER
GREAT LAKES/OHIO VALLEY STATES THROUGH THE DAY. THIS COMBINED WITH
LIGHTLY VEERED PBL FLOW...LOWER NCAPE AND DEEP WCD VALUES IN
EXCESS OF 11 KFT ALL SUPPORT CONTINUED MENTION OF LOCALLY HEAVY
RAINFALL IN THE MORE ROBUST CELLS WHERE EFFICIENT PRECIPITATION
LOADING WILL BE LIKELY. WHILE I CAN`T COMPLETELY RULE OUT AN
ISOLATED SEVERE CELL...WITH SUCH HIGH WBZ VALUES I`M REALLY NOT
EXPECTING ANYTHING OTHER THAN SOME BRIEF GUSTY WINDS AND POSSIBLE
SMALL HAIL IN THE STRONGER CORES. HIGHS ON THE SEASONABLY WARM
SIDE...76 TO 84 OR CLOSE TO BLENDED BIAS-CORRECTED GUIDANCE.
EVENING SHOWERS AND STORMS THEN SLOWLY WANE IN AREAL COVERAGE AND
INTENSITY AS WE PROGRESS INTO MONDAY NIGHT AS SHORTWAVE EXITS EAST
AND WEAK RIDGING ALONG WITH LAYER OF DRIER MID-LEVEL AIR ADVECTS
INTO THE REGION. NO AIRMASS CHANGE...BUT ENOUGH DRYING SUCH THAT
MANY AREAS SHOULD TREND DRY BY TUESDAY MORNING. LOWS MAINLY IN THE
60S.
THEN MORE UNCERTAINTY AS WE HEAD INTO TUESDAY. FEELING IS TUESDAY
SHOULD BE MORE DRY THAN WET GIVEN MID-LEVEL DRY AIR AND WEAK
SUBSIDENCE ADVECTING ACROSS THE REGION...BUT EVIDENCE THAT SOME SORT
OF LOWER LEVEL MOISTURE BOUNDARY MAY LINGER ACROSS OUR EASTERN
COUNTIES. ECMWF MORE ROBUST WITH CHANCES PCPN THAN OTHER SHORT TERM
MODELS...BUT WILL DOWNPLAY AT THIS POINT OFFERING JUST SLIGHT TO
LOWER CHANCE POPS THROUGH THE DAY AND MAINLY ACROSS VT WHERE SOME
WIDELY SCATTERED ACTIVITY MAY OCCUR. HIGHS IN THE LOWER TO MID 80S.
BY TUESDAY NIGHT WARM AND HUMID CONDITIONS CONTINUE BUT MAINLY DRY
WITH LOSS OF INSOLATION. LOWS TO HOLD ON THE MILD SIDE AND MAINLY IN
THE 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...ACTIVE WEATHER DAY EXPECTED WEDS/THURS
AS POTENT TROF DEVELOPS ACRS THE NORTHERN GREAT LAKES AND SFC COLD
FRNT MOVES ACRS OUR CWA. THIS FRNT WL INTERACT WITH MODEST INSTABILITY
WITH LIS AROUND -4C AND CAPE VALUES BTWN 1500 TO 2000 J/KG.
ALSO...NOTED A RIBBON OF ENHANCED MID LVL WINDS...CREATING DEEP
LAYER SHEAR VALUES BTWN 30 AND 40 KNOTS...ESPECIALLY ACRS OUR
NORTHERN CWA ON WEDS AFTN. THE AREAL COVERAGE/INTENSITY OF STORMS
WL HIGHLY DEPEND UPON AMOUNT OF INSTABILITY/CLRING AND EXACT TRACK OF S/W
ENERGY. GIVEN...THE GOOD AGREEMENT IN MODELS WITH SYNOPTIC
FEATURES WL CONT TO MENTION HIGH CHC/LOW LIKELY POPS WEDS INTO
WEDS NIGHT...STILL A MINOR TIMING DIFFERENCE BTWN THE FASTER GFS
AND SLOWER ECMWF. WEAK SUBSIDENCE AND HIGH PRES TRIES TO BUILD
ACRS OUR CWA LATE THURS INTO FRIDAY...WITH A BRIEF DRY SPELL
POSSIBLE. LOTS OF UNCERTAINTY ASSOCIATED WITH NEXT SYSTEM FRIDAY
INTO NEXT WEEKEND...WITH GFS SHOWING MID/UPPER CLOSED CIRCULATION
ACRS THE GREAT LAKES RETROGRADING SW TWD TEXAS BY SUNDAY...WHILE
THE ECMWF SPLITS THE SYSTEM INTO TWO DISTINCT CLOSED CIRCULATIONS
WITH GREATER IMPACT ACRS OUR FA. GIVEN THE UNCERTAINTY IN THE
EVOLUTION OF THIS COMPLEX SYNOPTIC PATTERN...WL MENTION CHC POPS
NEXT WEEKEND. IF THE ULVL PATTERN VERIFIES ON THE ECMWF AND DEEP
TROPICAL MOISTURE IS ADVECTED BACK INTO THE NE CONUS...HYDRO WL
NEED TO BE WATCHED CLOSELY...FOR THE POTENTIAL FOR HEAVY RAINFALL.
PROGGED 85H TEMPS AHEAD OF BOUNDARY RANGE BTWN 14-16C ON
WEDS/THURS...BEFORE COOLING BACK BTWN 10-12C ON
FRIDAY...SUPPORTING HIGHS MID/UPPER 80S MID WEEK TO M70S TO L80S
BY NEXT FRIDAY. LOWS WL BE MAINLY IN THE U50S MTNS TO M60S
VALLEYS.
&&
.AVIATION /00Z TUESDAY THROUGH FRIDAY/
...THROUGH 00Z TUESDAY...RADAR SHOWS PERSISTENT TS IN THE RUTLAND
AREA AND THIS WILL LIKELY CONTINUE NEXT SEVERAL HOURS AS WEAK
BOUNDRY REMAINS IN THE AREA. THIS COULD PRODUCE BRIEF IFR
CONDITIONS MAINLY DUE TO VIS AT KRUT NEXT SEVERAL HOURS. ANOTHER
COMPLEX OF STORMS AND HEAVY RAIN WILL MOVE VERY NEAR TO KRUT AGAIN
AFTER 05Z AND TAF REFLECTS MVFR CONDITION BUT COULD BE LOWER IF
STORMS HOLD TOGETHER. ELSEWHERE MUCH MORE BENIGN WITH MAINLY VFR
EXPECTED OVERNIGHT. A BOUNDARY LIES JUST NORTH OF THE CANADIAN
BORDER AND THIS KEEP VCSH NEAR KMSS THROUGH 06Z. EXPECT NE WINDS
TO DEVELOP AT KMSS SOON AND CONTINUE UNTIL THE BOUNDARY PUSHES
SOUTH. A FEW ISOLATED SHOWERS POSSIBLE AT THE OTHER SITES NEXT FEW
HOURS...THEN QUIET OVERNIGHT.
OUTLOOK OOZ TUESDAY THROUGH FRIDAY...SCATTERED SHOWERS AND
THUNDERSTORMS WL BE POSSIBLE MONDAY AND AGAIN ON WEDS/THURS. THIS
ACTIVITY WL HAVE THE POTENTIAL TO PRODUCE BRIEF PERIODS OF MVFR
CONDITIONS ALONG WITH LOCALIZED GUSTY WINDS IN AND NEAR STORMS.
ALSO...LOOK FOR SOME BR/FOG TO DEVELOP IF SKIES CAN
CLR...ESPECIALLY AT MPV/SLK BTWN 07-11Z...WITH GENERALLY SOUTH TO
SOUTHWEST WINDS THRU THE PERIOD.
&&
.HYDROLOGY...
AS OF 435 PM EDT SUNDAY... LOCALLY HEAVY RAINFALL WILL REMAIN
POSSIBLE ACROSS THE SOUTHERN PORTIONS OF THE FORECAST AREA THIS
EVENING...AND ACROSS THE ENTIRE AREA ON MONDAY. WHILE WIDESPREAD
OR ORGANIZED AREAS OF FLASH FLOODING ARE NOT EXPECTED...WCD VALUES
WILL REMAIN QUITE HIGH ALONG WITH HIGH COLUMNAR MOISTURE PROFILES.
THUS POINT TOTALS IN EXCESS OF ONE INCH IN AN HOUR OR LESS WILL BE
POSSIBLE...WHICH CHOULD LEAD TO LOCALIZED HYDROLOGICAL
CONCERNS...ESPECIALLY ON MONDAY WHEN BOUNDARY LAYER FLOW WILL BE
QUITE LIGHT BELOW 850 MB.
&&
.EQUIPMENT...
AS OF 415 AM EDT SUNDAY...THE KTYX RADAR IS DOWN UNTIL FURTHER
NOTICE. TECHS HAVE ORDERED PARTS...WHICH SHOULD ARRIVE ON MONDAY
AND THE RADAR SHOULD BE RETURNED TO SERVICE BY TUESDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...TABER
AVIATION...TABER/NF
HYDROLOGY...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BUFFALO NY
728 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A PERSISTENT TROUGH OF LOW PRESSURE WILL GRADUALLY SLIDE EASTWARD
ACROSS THE REGION EARLY NEXT WEEK. THIS WILL RESULT IN CONTINUED
UNSETTLED WEATHER THROUGH MID-WEEK BEFORE DRIER AIR FINALLY
ARRIVES BY THE END OF THE WEEK AS HIGH PRESSURE BUILDS INTO THE
GREAT LAKES.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF MID-AFTERNOON...RADAR SHOWS MOST OF WESTERN NEW YORK IS
SHOWER-FREE...WITH JUST A FEW SHOWERS STARTING TO DEVELOP ACROSS
WESTERN PORTIONS OF THE SOUTHERN TIER. MEANWHILE...THE MOST
NOTEWORTHY FEATURE IS CONVECTION DEVELOPING ACROSS CENTRAL
PENNSYLVANIA. BOTH THE GFS/HRRR HANDLED AN INITIAL WAVE OF
CONVECTION EARLY THIS MORNING...AND IT APPEARS THESE MODELS ALSO
HAVE A GOOD HANDLE ON THE NEXT WAVE AS WELL. USING THIS
GUIDANCE...EXPECT THAT ORGANIZED CONVECTION WILL TRACK TO OUR
SOUTHEAST THROUGH EARLY EVENING. THIS LEAVES ONLY SUBTLE SURFACE
BOUNDARIES TO PROVIDE THE FOCUS NEEDED FOR SHOWERS AND THUNDERSTORMS
LATE THIS AFTERNOON. THERE WILL BE LAKE BREEZES BOTH EAST OF LAKE
ERIE...AND SOUTH AND EAST OF THE EASTERN HALF OF LAKE ONTARIO. IN
EACH CASE...EXPECT ANY SHOWERS TO BE SCATTERED IN NATURE...WITH A
FEW THUNDERSTORMS ALSO POSSIBLE. NE OF LAKE ONTARIO AND LAKE
ERIE...EXPECT THE WELL DEVELOPED SW FLOW TO STABILIZE THE BOUNDARY
LAYER...AND KEEP THE BUFFALO METRO AREA DRY THIS AFTERNOON...EVEN IF HIGH
CLOUDS FROM UPSTREAM LIMIT SUNSHINE.
FOR THIS EVENING...CONVECTION ACROSS PENNSYLVANIA SHOULD REMAIN TO
THE SOUTH...WITH MOST OF THE DIURNALLY DRIVEN SHOWERS LIKELY TO
TAPER OFF. HOWEVER...THERE IS SOME INDICATION THAT SHOWERS
MAY DEVELOP ACROSS CENTRAL NEW YORK IF AN OUTFLOW FROM THE
CONVECTION TO THE SOUTH INTERACTS WITH LINGERING INSTABILITY IN THE
REGION. THIS AREA WILL ALSO BE UNDERNEATH A DIFFLUENT FLOW ALOFT
AHEAD OF AN APPROACHING UPPER LOW...WHICH WOULD ENHANCE THE
CONVECTIVE POTENTIAL. THIS POSSIBILITY IS SHOWN BY THE HRRR AND 12Z
RGEM...AND TO A LESSER EXTENT 12Z GFS/NAM. IT IS MOST LIKELY TO STAY
SE OF OUR CWA...BUT MAY REACH INTO THE FINGER LAKES REGION. THIS
FEATURE BEARS WATCHING GIVING THE CONTINUED MOIST ENVIRONMENT WITH
PRECIPITABLE WATER VALUES STILL IN THE 1.75 INCH RANGE. SLOW MOVING
THUNDERSTORMS COULD PRODUCE LOCALLY HEAVY RAINFALL AND FLOODING.
OTHERWISE...AN UPPER LEVEL TROF IS FORECAST TO SLOWLY LIFT ACROSS
WESTERN PENNSYLVANIA OVERNIGHT. THIS WILL BRING A CHANCE OF MORE
GENERAL SHOWER ACTIVITY...HOWEVER IT SHOULD BE SOMEWHAT SPOTTY IN
NATURE. AS HAS BEEN THE CASE...SOME PATCHY FOG IS POSSIBLE IN THE
SOUTHERN TIER VALLEYS...AND EAST OF LAKE ONTARIO. LOWS SHOULD
RANGE FROM THE MID 60S TO AROUND 70.
ON MONDAY...THE CLOSED UPPER LEVEL LOW WILL GRADUALLY OPEN AS IT
SLIDES TO THE EAST. THIS FEATURE WILL RESULT IN A CONTINUED THREAT
FOR SHOWERS DURING THE DAY MONDAY...AS DAYTIME INSTABILITY ENHANCES
SHOWER ACTIVITY. SLIGHTLY COOLER TEMPERATURES ALOFT SHOULD ALLOW
STORMS TO DEVELOP LIGHTNING A BIT MORE QUICKLY THAN THE PAST COUPLE
DAYS. AS THE OPENING TROF EXITS TO THE EAST...EXPECT DRYING WITH THE
SUBSTANCE ASSOCIATED WITH THE EXITING FEATURE. AS A RESULT...SHOWERS
AND THUNDERSTORMS SHOULD TAPER OFF FROM WEST TO EAST DURING THE
AFTERNOON HOURS. TEMPERATURES WILL BE A TAD COOLER...WITH HIGHS INT
HE UPPER 70S TO LOWER 80S. IT WILL CONTINUE TO BE MOIST RESULTING IN
CONTINUED MUGGY CONDITIONS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS THE AXIS OF THE UPPER TROUGH WILL HAVE PASSED TO THE EAST OF
THE FORECAST AREA...EXPECT A SHARP DROP OFF IN POPS FOR MONDAY
NIGHT. WARM ADVECTION THROUGHOUT THE BOUNDARY LAYER WILL ARRIVE IN
WESTERN AND SOUTHERN NY ON TUESDAY WITH INCREASING BUT STILL LOW
CHANCE OF THUNDERSTORMS ACROSS THE SOUTHERN TIER...MAINLY DURING
TUESDAY AFTERNOON. TEMPS MONDAY NIGHT WILL BE IN THE LOWER TO MID
60S ACROSS THE SOUTHERN TIER AND TUG HILL...AND MID 60S TO NEAR 70
FOR THE LAKE PLAINS AND URBAN AREAS. HIGHS ON TUESDAY WILL RISE A
NOTCH TO THE LOWER TO MID 80S.
A TROUGH MOVING ACROSS ONTARIO PROVINCE WILL SPAWN A SURFACE LOW
OVER THE UPPER MID WEST ON TUESDAY TO SOUTH OF JAMES BAY ON
WEDNESDAY. 35 TO 40 KNOT WINDS AT 850MB ACROSS THE CENTRAL GREAT
LAKES WILL FORM A WARM FRONT ASSOCIATED WITH THE SURFACE LOW.
INCREASING MOISTURE AHEAD OF THE WARM FRONT...PRECIPITABLE WATER
RISING BACK TO NEAR 2 INCHES...AND ADDED LIFT IN THE VICINITY OF THE
SHORT WAVE TROUGH WILL BRING A GOOD CHANCE FOR SHOWERS AND
THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY. UNSETTLED WEATHER WILL
CONTINUE WEDNESDAY NIGHT AS A COLD FRONT...TRAILING SOUTH OF LOW
PRESSURE NEAR JAMES BAY...PUSHES EAST ACROSS THE STATE. TEMPS
TUESDAY NIGHT WILL RANGE FROM THE MID 60S ACROSS THE SOUTHERN TIER
AND TUG HILL...TO LOWER 70S FOR THE LAKE PLAINS AND URBAN AREAS.
HIGHS ON WEDNESDAY WILL BE SIMILAR TO TUESDAY...LOWER TO MID
80S...EVEN WITH THICKER CLOUD AND OCCURRENCE OF PRECIP.
DRIER AND MARGINALLY COOLER AIR WILL ARRIVE IN THE POSTFRONTAL
AIRMASS ON THURSDAY WITH LOWER CHANCE POPS AND PARTIAL CLEARING.
EXPECT HIGHS IN THE MID TO UPPER 70S ON THURSDAY AND LOWS THURSDAY
NIGHT IN THE UPPER 50S TO LOWER 60S AS SKIES CLEAR FURTHER.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THE UPPER TROUGH ACROSS ONTARIO WILL STALL AND DIG FARTHER
SOUTH...DEVELOPING A CUTOFF LOW ACROSS THE EASTERN U.S. THIS LOW
WILL DROP FARTHER TO THE SOUTH ON THE WEEKEND AND BLOCK THE WARMER
AIR FROM THE NATION`S MIDSECTION...ALSO TAPPING INTO MOISTURE FROM
THE WESTERN ATLANTIC. FRIDAY AND FRIDAY NIGHT SHOULD REMAIN DRY
AND QUITE COOLER WITH HIGHS IN THE 70S AND LOWS IN THE UPPER 50S
TO LOW 60S. HIGHER CHANCE FOR SHOWERS AND THUNDERSTORMS WILL
ARRIVE DURING SATURDAY AND SUNDAY AS THE SOUTHEASTERLY LOW LEVEL
FLOW FROM THE MID ATLANTIC INTERACTS WITH THE MID AND UPPER LEVEL
TROUGH. HIGH TEMPS FOR THE WEEKEND WILL BE IN THE MID TO UPPER 70S
ON SATURDAY AND THE UPPER 70S TO LOWER 80S ON SUNDAY.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
EXPECT VFR CONDITIONS FOR THE REMAINDER OF THIS EVENING. THERE
MAY BE A FEW SHOWERS...BUT THESE WILL HAVE LITTLE IF ANY IMPACT ON
AREA TERMINALS.
FOR THE OVERNIGHT HOURS...EXPECT SCATTERED SHOWERS AS THE UPPER
LOW OVER OHIO MOVES CLOSER TO THE REGION. THERE WILL BE QUITE A
BIT OF LOW LEVEL MOISTURE IN PLACE...BUT AS LONG AS WINDS PERSIST
AND THE MID AND HIGH CLOUDS REMAIN...EXPECT CIGS TO REMAIN MAINLY
IN THE VFR RANGE. THIS SAID...ANY PROLONGED CLEARING WOULD LIKELY
RESULT IN LOW CLOUDS AND FOG...WITH THE BEST CHANCE FOR THIS AT
JHW/ART.
THERE WILL BE A CONTINUED THREAT FOR SHOWERS AND POSSIBLY A
THUNDERSTORM ON MONDAY. EXPECT MAINLY VFR CONDITIONS EXCEPT IN
STORMS WHERE HEAVY RAINS COULD LOWER VSBY TO 2SM OR LESS.
OUTLOOK...
MONDAY NIGHT THROUGH WEDNESDAY...MAINLY VFR WITH SCATTERED
SHOWERS AND THUNDERSTORMS AND ASSOCIATED BRIEF MVFR/IFR
CONDITIONS.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
SOUTHWEST WINDS HAVE INCREASED ON LAKE ERIE AND WESTERN LAKE
ONTARIO...HOWEVER THE STRONGEST WINDS ARE ON LAND WHERE WINDS
ALOFT CAN MIX MORE READILY. WEBCAMS AND OBS SHOW ONLY MODEST WAVES
WITH NO WHITE CAPS ALONG THE NEARSHORES OF LAKE ERIE. THERE MAY BE
A DECENT CHOP ON WESTERN LAKE ONTARIO...DUE TO SW GUSTS NEAR THE
IMMEDIATE SHORELINE...BUT WAVES SHOULD REMAIN WELL BELOW 4 FT
SINCE WINDS WILL DIMINISH OFFSHORE.
LIGHT TO MODERATE SOUTHWEST WINDS WILL CONTINUE TONIGHT THROUGH
MONDAY WITH CHOPPY WAVE ACTION AT TIMES ON BOTH LAKE...BUT
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...APFFEL/TMA
MARINE...APFFEL/WCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
346 PM EDT SAT JUL 6 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EAST COAST COMBINED WITH A MID LEVEL
LOW OVER THE MIDWEST WILL KEEP A SOUTHERLY FLOW OF WARM AND MOIST
AIR THROUGH THE REMAINDER OF THE WEEKEND WITH SCATTERED SHOWERS AND
THUNDERSTORMS...ESPECIALLY INLAND FROM THE LAKES. THE UNSETTLED
WEATHER WILL CONTINUE THROUGH THE MIDDLE OF NEXT WEEK BEFORE DRIER
AIR FINALLY ARRIVES BY THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
WATER VAPOR IMAGERY SHOWS OUR REGION REMAINS IN A MOIST SOUTHERLY
FLOW...WITH HIGH PRESSURE OFF THE MID-ATLANTIC COAST AND LOW PRESSURE
ACROSS EASTERN MISSOURI. SHOWERS AND POSSIBLY A THUNDERSTORM SHOULD
DEVELOP INLAND OF THE LAKE-BREEZE ACROSS THE SOUTHERN TIER...HOWEVER
SLIGHTLY DRIER AIR SHOULD LIMIT THE AREAL COVERAGE OF THIS
ACTIVITY...MAKING IT MORE SCATTERED IN NATURE.
ANY DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS WILL GRADUALLY TAPER
OFF DURING THE EVENING HOURS...HOWEVER A LARGER AREA OF SHOWERS AND
THUNDERSTORMS DEVELOPING ACROSS WESTERN OHIO IS FORECAST TO MOVE
INTO OUR REGION AS IT WEAKENS TONIGHT. ALTHOUGH THERE ARE SOME MODEL
DIFFERENCES...IT APPEARS THESE SHOWERS WILL EVENTUALLY MOVE INTO
OUR REGION WITH THE NOSE OF AN INCREASING 700 MB FLOW. THE GFS/RGEM
HINT AT THIS...THE PAST TWO RUNS OF THE HRRR A BIT LATER IN TIMING
WHICH APPEARS MORE REALISTIC GIVEN THE SLOW MOTION OF THE FEATURE.
EXPECT ASSOCIATED SHOWERS AND THUNDERSTORMS TO MOVE FROM W-E LATE
THIS EVENING...WITH THESE LIKELY TO WEAKEN AS THEY MOVE FURTHER
NORTH FROM THE UPPER LEVEL SUPPORT LATER TONIGHT.
THE 12Z BUFFALO SOUNDING HAD A PRECIPITABLE WATER VALUE OF 1.50
INCHES...HOWEVER SOUNDINGS JUST UPSTREAM IN PITTSBURGH AND
CINCINNATI ARE APPROACHING 2 INCHES. THE RESULT WILL BE A
CONTINUED THREAT FOR LOCALLY HEAVY RAINFALL IN ANY STORMS WHICH DO
DEVELOP. 700 MB WINDS ARE FORECAST TO INCREASE TO AROUND 30 KNOTS
LATER TONIGHT...WHICH SHOULD AT LEAST PROVIDE SOME STORM MOTION TO
MITIGATE THE RISK FOR FLOODING. LARGE AREAS OR TRAINING CELLS
WOULD STILL HAVE THE POTENTIAL TO PRODUCE FLOODING...WITH
CONTINUED MENTION IN THE HWO STILL JUSTIFIED.
ON SUNDAY...THE PERSISTENT CUT-OFF LOW WILL FINALLY START TO LIFT
NORTHWARD. MODEL GUIDANCE DIFFERS ON EXACTLY HOW FAR IT WILL LIFT.
REGARDLESS OF THE EXACT TRACK...IT APPEARS LIKELY THAT IT WILL LIFT
A DECENT SLUG OF MOISTURE WITH IT. ITS CLOSER PROXIMITY WILL ALSO
ENHANCE UPPER LEVEL DIFFLUENCE AS THE 500 MB FLOW FANS OUT. BOTH OF
THESE FACTORS SHOULD LEAD TO MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS ON SUNDAY...WITH LAKE BREEZE BOUNDARIES PROVIDING AN
ADDITIONAL FOCUS. BECAUSE OF THIS...WILL CARRY A FAIRLY LARGE AREA
OF LIKELY POPS...WITH AN AREA OF CHANCE POPS DUE TO LAKE SHADOWING
NE OF THE LAKES. WITH PRECIPITABLE WATER VALUES NEAR 2 INCHES...THE
THREAT FOR LOCALLY HEAVY RAINS WILL PERSIST. HOWEVER...700 MB WINDS
SHOULD BE STRONGER THAN THEY HAVE BEEN...RESULTING IN SOME STORM
MOTION...WITH TRAINING THE MORE LIKELY THREAT. ITS ALSO WORTH NOTING
THAT WITH A SLIGHTLY MORE SHEARED WIND PROFILE...SOME STRONG TO
POSSIBLY SEVERE THUNDERSTORMS ARE POSSIBLE.
OTHERWISE...IT WILL BE ANOTHER WARM NIGHT...WITH MOISTURE AND A
MODEST FLOW LIKELY TO KEEP TEMPERATURES IN THE UPPER 60S TO LOWER
70S. SOME LIGHT FOG IS ALSO POSSIBLE...HOWEVER A MODEST FLOW SHOULD
LIMIT DEVELOPMENT. HIGHS ON SUNDAY SHOULD BE JUST A TAD COOLER IN
MOST LOCATIONS...DUE TO THE MORE WIDESPREAD SHOWERS. HOWEVER...THE
STRONGER SW FLOW WILL LEAD TO WARMER TEMPERATURES ALONG THE SOUTH
SHORES OF LAKE ONTARIO.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
THE UPPER TROUGH AND CUTOFF LOW WHICH HAVE BEEN IN PLACE OVER THE
MIDWESTERN STATES WILL BE ACROSS THE NORTH OF THE MID OHIO VALLEY
EARLY SUNDAY NIGHT...MOVING TO SOUTHWESTERN PA BY EARLY MONDAY.
COOLER TEMPERATURES ALOFT ASSOCIATED WITH PASSING UPPER LEVEL TROUGH
WILL ENHANCE INSTABILITY ON SUNDAY NIGHT AND MONDAY AND GENERATE A
FEW MORE SHOWERS AND THUNDERSTORMS.
PRECIPITABLE WATER VALUES THROUGH THE PERIOD WILL RANGE FROM 1.5
INCH TO 1.75 INCH...THUS ANY CONVECTION MAY PRODUCE DOWNPOURS OF
RAIN BUT THERE SHOULD BE SUFFICIENT DIRECTIONAL SHEAR TO KEEP CELLS
FROM TRAINING OVER THE SAME SMALL AREAS ALONG THE STORM TRACKS...
LIMITING THE FLOOD THREAT.
AS THE UPPER TROUGH MOVES TO THE EAST OF THE AREA ON TUESDAY...THERE
WILL BE WEAK RIDGING WHICH SHOULD SUPPRESS THE DEVELOPMENT OF PRECIP
DURING THE EARLY TO MID PARTS OF THE DAY. THERE MAY BE LATE DAY AND
EVENING STORMS MOVING FROM THE WEST AS A SHORT WAVE AND MODEST 30
KNOT 850MB JET ARRIVE FROM THE MIDWESTERN STATES...MAXIMIZING THE
CONVECTIVE CHANCE TUESDAY NIGHT.
TEMPERATURES DURING MONDAY WILL BE CLOSER TO SEASONAL NORMALS...
MAYBE A DEGREE OR TWO BELOW NORMAL IN SPOTS...AS THE UPPER TROUGH
CROSSES THE AREA. WARMER AIR RETURNS FOR TUESDAY WITH ABUNDANT
SUNSHINE AND HIGHS IN THE LOWER TO MIDDLE 80S. LOWS EACH NIGHT WILL
BE IN THE LOWER TO MID 60S ACROSS THE SOUTHERN TIER AND HIGHER
TERRAIN OF THE TUG HILL...AND THE MID TO UPPER 60S ELSEWHERE...EVEN
TO LOW 70S FOR THE URBAN CENTERS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A GENERAL ZONAL FLOW ALOFT AT THE START OF THIS PERIOD WILL
TRANSITION TO A HIGHER AMPLITUDE PATTERN...CHARACTERIZED BY A
DIGGING TROUGH OVER THE GREAT LAKES WHILE A RIDGE BUILDS OUT WEST.
THIS PATTERN SHIFT WILL RESULT IN A TREND TOWARD SLIGHTLY COOLER
TEMPERATURES AND LOWER HUMIDITY AS THE WEEK PROGRESSES.
BY WEDNESDAY...THE GFS AND ECMWF REMAIN CONSISTENT IN BRINGING A
STRONGER NORTHERN STREAM SHORTWAVE AND ASSOCIATED SURFACE LOW INTO
THE GREAT LAKES REGION. THIS WILL MAINTAIN A LIKELIHOOD OF SHOWERS
AND THUNDERSTORMS. THIS SYSTEM WILL PUSH EAST OF THE AREA BY
THURSDAY WITH A LOWERING RAIN CHANCE AS THE DAY AND EVENING
PROGRESS. AS THE AFOREMENTIONED UPPER LEVEL TROUGH SHIFTS EAST
ACROSS QUEBEC AND THE LOWER LAKES ON FRIDAY...TEMPERATURES MAY DROP
TO SLIGHTLY BELOW AVERAGE LEVELS. WHILE THE TROUGH MAY ENHANCE
INSTABILITY...THE LATEST GUIDANCE SUGGESTS THAT THIS SYSTEM WILL BE
STARVED FOR MOISTURE SO WILL HAVE ONLY LOW CHANCE OR SLIGHT CHANCE
POPS FOR FRIDAY AND SATURDAY. MOST OF THE RESULTANT RAIN FROM THIS
WILL BE ASSOCIATED WITH AN OFFSHORE COASTAL SYSTEM AND SURFACE HIGH
PRESSURE WILL DOMINATE THE EASTERN GREAT LAKES TO OHIO VALLEY.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AT 18Z...CONDITIONS WERE MAINLY VFR ACROSS THE REGION...WITH
SHOWER ACTIVITY QUITE SPARSE SO FAR. SHOWERS AND A FEW
THUNDERSTORMS ARE EXPECTED TO EXPAND DURING THE LATE AFTERNOON
HOURS...BUT WILL MAINLY ONLY IMPACT JHW...AS DRIER AIR IS IN PLACE
AT OTHER TAF LOCATIONS.
ANOTHER AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS MAY APPROACH
THE REGION TONIGHT...THOUGH CONFIDENCE IN TIMING AND LOCATION IS
LOW. SOME LIGHT FOG IS POSSIBLE AT EASTERN TAF SITES WHERE WINDS
WILL BE LESS...WITH IFR CIGS POSSIBLE AT JHW. CHANCES FOR
THUNDERSTORMS WILL INCREASE DURING THE DAY SUNDAY...DUE TO DIURNAL
CYCLES.
AS HAS BEEN THE CASE...HEAVY RAIN FROM SHOWERS AND THUNDERSTORMS
WILL BE ABLE TO BRIEFLY LOWER VSBY TO 2SM OR LESS.
OUTLOOK... SUNDAY NIGHT THROUGH THURSDAY...MAINLY VFR WITH
SCATTERED SHOWERS AND THUNDERSTORMS WITH PERIODS OF MVFR/IFR
CONDITIONS.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT OVER THE LOWER LAKES WILL KEEP
WIND AND WAVES RELATIVELY LOW THROUGH THE REMAINDER OF THE WEEKEND
AND INTO EARLY NEXT WEEK. EXPECT WINDS TO BE SOUTHWEST MOST OF THE
TIME WITH SOME LOCAL LAKE BREEZES ON LAKE ONTARIO TURNING WINDS
ONSHORE DURING THE AFTERNOONS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...APFFEL
MARINE...APFFEL/WCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1100 AM EDT SAT JUL 6 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EAST COAST COMBINED WITH A MID LEVEL
LOW OVER THE MIDWEST WILL KEEP A SOUTHERLY FLOW OF WARM AND MOIST
AIR GOING THROUGH THE WEEKEND WITH DAILY CHANCES OF SCATTERED
SHOWERS AND THUNDERSTORMS...ESPECIALLY INLAND FROM THE LAKES. THE
UNSETTLED WEATHER WILL CONTINUE THROUGH THE MIDDLE OF NEXT WEEK
BEFORE DRIER AIR FINALLY ARRIVES BY THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGERY THROUGH MID-MORNING SHOWS THE ENTIRE CWA DRY.
MEANWHILE...VISIBLE SATELLITE IMAGERY SHOWS SIGNIFICANT BREAKS IN
CLOUD COVER...WITH PERSISTENT STRATUS STILL LINGERING ACROSS THE
SOUTHERN TIER AND EAST OF LAKE ONTARIO.
FOR THIS AFTERNOON...THE MID LEVEL CUTOFF LOW OVER THE MIDWEST WILL
MOVE SLOWLY EAST...WITH A DOWNSTREAM RIDGE BUILDING A LITTLE OVER
THE LOWER LAKES. THIS WILL PROVIDE NEGLIGIBLE SYNOPTIC SCALE SUPPORT
FOR ANY RAIN TODAY...WITH MAIN ATTENTION FOCUSED ON THE MESOSCALE
FOR ANY TRIGGERS. THE AIRMASS WILL BECOME MODERATELY UNSTABLE AGAIN
INLAND FROM LAKE INFLUENCES GIVEN UPPER 60S DEWPOINTS AND TEMPS
CLIMBING WELL INTO THE 80S.
WITH A SOUTHWEST FLOW REGIME IN PLACE...CLIMATOLOGY TELLS US A BAND
OF CONVERGENCE WILL DEVELOP THIS AFTERNOON ALONG THE SOUTHERN FLANK
OF THE SOUTHWEST FLOW THAT FUNNELS UP LAKE ERIE. THIS BOUNDARY
TYPICALLY SETS UP FROM NEAR ERIE PA ACROSS THE SOUTHERN TIER IN A
SW/NE ORIENTATION AND INTO THE WESTERN FINGER LAKES. MESOSCALE MODEL
GUIDANCE SUCH AS OUR 6KM WORKSTATION WRF...4KM EXPERIMENTAL SPC
WRF...AND THE HOURLY UPDATED HRRR RUNS FOCUS MOST OF THE
CONVECTIVE DEVELOPMENT ALONG THIS BOUNDARY DURING THE AFTERNOON. A
SECOND LOW LEVEL CONVERGENCE ZONE WILL ALSO DEVELOP ALONG THE
SOUTH SHORE OF LAKE ONTARIO FROM NEAR ROCHESTER EAST INTO CENTRAL
NY AS A LAKE ONTARIO LAKE BREEZE DEVELOPS AND PUSHES INLAND DURING
THE AFTERNOON. THIS MAY ALSO PROVIDE SOME FOCUS FOR THUNDERSTORM
DEVELOPMENT...ALTHOUGH COVERAGE MAY BE A LITTLE MORE SPARSE ALONG
THIS BOUNDARY.
GIVEN THE AGREEMENT AMONGST VARIOUS MESOSCALE MODELS...WILL INDICATE
A STRIP OF LIKELY POPS FROM THE WESTERN SOUTHERN TIER INTO THE
WESTERN FINGER LAKES DURING THE AFTERNOON AND EVENING...WITH CHANCE
POPS SURROUNDING THIS AREA EXTENDING TO JUST SOUTH OF THE SOUTH
SHORE OF LAKE ONTARIO. A SOUTHWEST FLOW OFF LAKE ERIE SHOULD
STABILIZE THE BOUNDARY LAYER ENOUGH TO KEEP THE BUFFALO AREA DRY.
ACROSS THE NORTH COUNTRY...A PUSH OF MID LEVEL DRY AIR MOVING
SOUTHEAST FROM ONTARIO AND QUEBEC WILL STABILIZE THE AIRMASS AND
KEEP THAT AREA DRY AS WELL.
PWAT VALUES REMAIN AROUND 1.8 INCHES OR SO TODAY...WHICH IS 2-3
STANDARD DEVIATIONS ABOVE AVERAGE. NEEDLESS TO SAY...ANY STORMS
WHICH DEVELOP WILL PRODUCE TORRENTIAL DOWNPOURS IN THIS ENVIRONMENT.
STORM MOTION SHOULD BE AROUND 20 KNOTS OR SO WHICH SHOULD KEEP ANY
FLOOD RISK MINOR...UNLESS TRAINING DEVELOPS ALONG ANY OF THE
BOUNDARIES NOTED ABOVE. SIMILAR TO YESTERDAY...NO SIGNIFICANT SEVERE
WEATHER IS EXPECTED...BUT ONE OR TWO STORMS WHICH LATCH ONTO
BOUNDARIES MAY INTENSIFY ENOUGH TO PRODUCE MARGINAL HAIL OR A WET
MICROBURST.
THE DIURNALLY DRIVEN SHOWERS AND STORMS WILL SLOWLY DIMINISH THROUGH
THE EVENING HOURS WITH THE LOSS OF DAYTIME HEATING...AND SHOULD BE
DONE BY AROUND MIDNIGHT. AFTER THAT...WARM ADVECTION WILL INCREASE
ALOFT AHEAD OF THE CLOSED LOW WHICH WILL PROGRESS INTO THE OHIO
VALLEY OVERNIGHT. 850MB-700MB FLOW IS FORECAST TO INCREASE INTO THE
25-30 KNOT RANGE...WHICH WILL AID IN INCREASING CONVERGENCE AND
MOISTURE TRANSPORT INTO THE LOWER LAKES. THIS MAY SUPPORT A FEW
SCATTERED SHOWERS LATE TONIGHT INTO SUNDAY MORNING. IT WILL BE
ANOTHER WARM AND SULTRY NIGHT WITH LOWS AROUND 70 ON THE LAKE PLAINS
AND MID TO UPPER 60S ACROSS THE INTERIOR SOUTHERN TIER AND EAST OF
LAKE ONTARIO.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
THE UPPER TROUGH AND CUTOFF LOW WHICH HAVE BEEN IN PLACE OVER THE
MIDWESTERN STATES WILL SHIFT EAST INTO THE TENNESSEE AND LOWER OHIO
VALLEYS ON SUNDAY. THE MODELS ALSO SHOW A VARIETY OF WEAK...AND
DIFFICULT TO TIME...IMPULSES LIFTING OUT AHEAD OF THE MAIN UPPER
LEVEL TROUGH AND ROUNDING THE TOP OF THE WEAKENING UPPER LEVEL RIDGE
STILL ANCHORED OFF THE ATLANTIC COAST. INCREASING UPPER LEVEL
DIVERGENCE AHEAD OF THE APPROACHING TROUGH...COMBINED WITH DAYTIME
HEATING...WILL RESULT IN ANOTHER ROUND OF SCATTERED SHOWERS AND
THUNDERSTORMS...WITH THE GREATEST COVERAGE EXPECTED ACROSS THE
SOUTHERN TIER...UPPER GENESEE VALLEY AND FINGER LAKES.
THE MID LEVEL CUTOFF LOW IS FORECAST TO MOVE EAST INTO WESTERN
PA/SOUTHERN NEW YORK STATE SUNDAY NIGHT...THEN SHIFT EAST INTO
SOUTHERN NEW YORK STATE AND NEW ENGLAND ON MONDAY. THE INCREASE IN
LARGE SCALE ASCENT MAY KEEP A FEW SHOWERS GOING INTO THE NIGHT
DESPITE THE LOSS OF DAYTIME HEATING.
COOLER TEMPERATURES ASSOCIATED WITH PASSING UPPER LEVEL TROUGH WILL
ENHANCE INSTABILITY ON MONDAY AND GENERATE A FEW MORE SHOWERS AND
THUNDERSTORMS.
PWAT THROUGH THE PERIOD WILL RUN CLOSE TO 2 INCHES AT TIMES. THIS
WILL CONTINUE TO SUPPORT A RISK FOR TORRENTIAL DOWNPOURS AND
ASSOCIATED ISOLATED FLOOD RISK FROM ANY THUNDERSTORM WHICH
DEVELOPS...ESPECIALLY IF TRAINING OCCURS ALONG ANY OF THE LOW LEVEL
BOUNDARIES.
A COLD FRONT THAT WILL BE ASSOCIATED WITH A DEEP TROUGH OVER
NORTHERN QUEBEC IS FORECAST TO STAY JUST NORTH OF LAKE ONTARIO
DURING THIS PERIOD. AS A RESULT...IT WILL REMAIN MUGGY WITH
WARM OVERNIGHT LOWS AND HIGHS JUST SLIGHTLY ABOVE AVERAGE. THERE IS
A POSSIBILITY THAT LOW LEVEL MOISTURE MAY POOL SOUTH OF THIS FRONT
AND ENHANCE PCPN ACROSS OUR AREA ON MONDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
A GENERAL ZONAL FLOW ALOFT AT THE START OF THIS PERIOD WILL
TRANSITION TO A HIGHER AMPLITUDE PATTERN...CHARACTERIZED BY A
DIGGING TROUGH OVER THE GREAT LAKES WHILE A RIDGE BUILDS OUT WEST.
THIS PATTERN SHIFT WILL RESULT IN A TREND TOWARD SLIGHTLY COOLER
TEMPERATURES AND LOWER HUMIDITY AS THE WEEK PROGRESSES.
AT THE SURFACE...LOW PRESSURE TRACKING NORTH OF LAKE ONTARIO ON
TUESDAY WILL BRING A CHANCE FOR A FEW SHOWERS OR THUNDERSTORMS.
HUMIDITY WILL REMAIN HIGH ON TUESDAY...WHILE TEMPERATURES GENERALLY
RANGE IN THE LOWER TO MID 80S.
BY WEDNESDAY...THE GFS AND ECMWF REMAIN CONSISTENT IN BRINGING A
STRONGER NORTHERN STREAM SHORTWAVE AND ASSOCIATED SURFACE LOW INTO
THE GREAT LAKES REGION. THIS WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS. THIS SYSTEM WILL PUSH EAST OF THE AREA BY THURSDAY
WITH A LOWERING RAIN CHANCE AS THE DAY AND EVENING PROGRESS.
AS THE AFOREMENTIONED UPPER LEVEL TROUGH SHIFTS EAST ACROSS QUEBEC
AND THE LOWER LAKES ON FRIDAY...TEMPERATURES MAY DROP TO SLIGHTLY
BELOW AVERAGE LEVELS. WHILE THE TROUGH MAY ENHANCE INSTABILITY...THE
LATEST GUIDANCE SUGGESTS THAT THIS SYSTEM WILL BE STARVED FOR
MOISTURE. THEREFORE...WILL NOT MENTION ANY SHOWERS FOR FRIDAY.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
MAINLY VFR CONDITIONS WILL PREVAIL FOR THE 12Z TAF CYCLE WITH A FEW
EXCEPTIONS. LINGERING AREAS OF STRATUS ACROSS THE HIGHER TERRAIN
OF THE SOUTHERN TIER AND EAST OF LAKE ONTARIO SHOULD CONTINUE TO
BURN OFF THROUGH LATE MORNING...HOWEVER THIS COULD BE FOLLOWED BY
A MVFR STRATO-CU CLOUD DECK ONCE SURFACE TEMPERATURES RISE. BY
MID-LATE AFTERNOON EXPECT VFR CONDITIONS OUTSIDE OF SHOWERS AND TSTMS.
WE DO EXPECT ANOTHER ROUND OF SCATTERED SHOWERS AND TSTMS TO
DEVELOP WITH DAYTIME HEATING. THE MAIN FOCUS FOR THIS TODAY SHOULD
BE THE SOUTHERN EDGE OF THE BREEZE OFF LAKE ERIE WITH THE BEST
CONVECTIVE COVERAGE ACROSS THE WESTERN SOUTHERN TIER INTO THE
FINGER LAKES. A LAKE BREEZE OFF LAKE ONTARIO MAY PROVIDE A
SECONDARY LESSER FOCUS FROM NEAR KROC INTO CENTRAL NY. ANY OF
THESE SHOWERS WILL PRODUCE BRIEF PERIODS OF IFR...BUT THE BULK OF
THE TIME WILL BE VFR.
THE SHOWERS AND STORMS WILL DIMINISH THIS EVENING WITH THE LOSS OF
DAYTIME HEATING. THIS WILL LEAVE MAINLY VFR OVERNIGHT WITH PERIODS
OF MID LEVEL CLOUD CROSSING THE AREA. A FEW SCATTERED SHOWERS ARE
POSSIBLE AGAIN LATE SATURDAY NIGHT AS A MID LEVEL DISTURBANCE AND
THE NEXT PUSH OF DEEPER MOISTURE MOVES INTO THE LOWER LAKES REGION.
OUTLOOK...
SUNDAY THROUGH WEDNESDAY...MAINLY VFR WITH SCATTERED SHOWERS AND
THUNDERSTORMS AND ASSOCIATED BRIEF MVFR/IFR.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT OVER THE LOWER LAKES WILL KEEP
WIND AND WAVES RELATIVELY LOW THROUGH THE WEEKEND AND INTO EARLY
NEXT WEEK. EXPECT WINDS TO BE SOUTHWEST MOST OF THE TIME WITH SOME
LOCAL LAKE BREEZES ON LAKE ONTARIO TURNING WINDS ONSHORE DURING THE
AFTERNOONS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...TJP
LONG TERM...TJP/WCH
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1037 AM EDT SAT JUL 6 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EAST COAST COMBINED WITH A MID LEVEL
LOW OVER THE MIDWEST WILL KEEP A SOUTHERLY FLOW OF WARM AND MOIST
AIR GOING THROUGH THE WEEKEND WITH DAILY CHANCES OF SCATTERED
SHOWERS AND THUNDERSTORMS...ESPECIALLY INLAND FROM THE LAKES. THE
UNSETTLED WEATHER WILL CONTINUE THROUGH THE MIDDLE OF NEXT WEEK
BEFORE DRIER AIR FINALLY ARRIVES BY THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGERY THROUGH MID-MORNING SHOWS THE ENTIRE CWA DRY.
MEANWHILE...VISIBLE SATELLITE IMAGERY SHOWS SIGNIFICANT BREAKS IN
CLOUD COVER...WITH PERSISTENT STRATUS STILL LINGERING ACROSS THE
SOUTHERN TIER AND EAST OF LAKE ONTARIO.
FOR THIS AFTERNOON...THE MID LEVEL CUTOFF LOW OVER THE MIDWEST WILL
MOVE SLOWLY EAST...WITH A DOWNSTREAM RIDGE BUILDING A LITTLE OVER
THE LOWER LAKES. THIS WILL PROVIDE NEGLIGIBLE SYNOPTIC SCALE SUPPORT
FOR ANY RAIN TODAY...WITH MAIN ATTENTION FOCUSED ON THE MESOSCALE
FOR ANY TRIGGERS. THE AIRMASS WILL BECOME MODERATELY UNSTABLE AGAIN
INLAND FROM LAKE INFLUENCES GIVEN UPPER 60S DEWPOINTS AND TEMPS
CLIMBING WELL INTO THE 80S.
WITH A SOUTHWEST FLOW REGIME IN PLACE...CLIMATOLOGY TELLS US A BAND
OF CONVERGENCE WILL DEVELOP THIS AFTERNOON ALONG THE SOUTHERN FLANK
OF THE SOUTHWEST FLOW THAT FUNNELS UP LAKE ERIE. THIS BOUNDARY
TYPICALLY SETS UP FROM NEAR ERIE PA ACROSS THE SOUTHERN TIER IN A
SW/NE ORIENTATION AND INTO THE WESTERN FINGER LAKES. MESOSCALE MODEL
GUIDANCE SUCH AS OUR 6KM WORKSTATION WRF...4KM EXPERIMENTAL SPC
WRF...AND THE HOURLY UPDATED HRRR RUNS FOCUS MOST OF THE
CONVECTIVE DEVELOPMENT ALONG THIS BOUNDARY DURING THE AFTERNOON. A
SECOND LOW LEVEL CONVERGENCE ZONE WILL ALSO DEVELOP ALONG THE
SOUTH SHORE OF LAKE ONTARIO FROM NEAR ROCHESTER EAST INTO CENTRAL
NY AS A LAKE ONTARIO LAKE BREEZE DEVELOPS AND PUSHES INLAND DURING
THE AFTERNOON. THIS MAY ALSO PROVIDE SOME FOCUS FOR THUNDERSTORM
DEVELOPMENT...ALTHOUGH COVERAGE MAY BE A LITTLE MORE SPARSE ALONG
THIS BOUNDARY.
GIVEN THE AGREEMENT AMONGST VARIOUS MESOSCALE MODELS...WILL INDICATE
A STRIP OF LIKELY POPS FROM THE WESTERN SOUTHERN TIER INTO THE
WESTERN FINGER LAKES DURING THE AFTERNOON AND EVENING...WITH CHANCE
POPS SURROUNDING THIS AREA EXTENDING TO JUST SOUTH OF THE SOUTH
SHORE OF LAKE ONTARIO. A SOUTHWEST FLOW OFF LAKE ERIE SHOULD
STABILIZE THE BOUNDARY LAYER ENOUGH TO KEEP THE BUFFALO AREA DRY.
ACROSS THE NORTH COUNTRY...A PUSH OF MID LEVEL DRY AIR MOVING
SOUTHEAST FROM ONTARIO AND QUEBEC WILL STABILIZE THE AIRMASS AND
KEEP THAT AREA DRY AS WELL.
PWAT VALUES REMAIN AROUND 1.8 INCHES OR SO TODAY...WHICH IS 2-3
STANDARD DEVIATIONS ABOVE AVERAGE. NEEDLESS TO SAY...ANY STORMS
WHICH DEVELOP WILL PRODUCE TORRENTIAL DOWNPOURS IN THIS ENVIRONMENT.
STORM MOTION SHOULD BE AROUND 20 KNOTS OR SO WHICH SHOULD KEEP ANY
FLOOD RISK MINOR...UNLESS TRAINING DEVELOPS ALONG ANY OF THE
BOUNDARIES NOTED ABOVE. SIMILAR TO YESTERDAY...NO SIGNIFICANT SEVERE
WEATHER IS EXPECTED...BUT ONE OR TWO STORMS WHICH LATCH ONTO
BOUNDARIES MAY INTENSIFY ENOUGH TO PRODUCE MARGINAL HAIL OR A WET
MICROBURST.
THE DIURNALLY DRIVEN SHOWERS AND STORMS WILL SLOWLY DIMINISH THROUGH
THE EVENING HOURS WITH THE LOSS OF DAYTIME HEATING...AND SHOULD BE
DONE BY AROUND MIDNIGHT. AFTER THAT...WARM ADVECTION WILL INCREASE
ALOFT AHEAD OF THE CLOSED LOW WHICH WILL PROGRESS INTO THE OHIO
VALLEY OVERNIGHT. 850MB-700MB FLOW IS FORECAST TO INCREASE INTO THE
25-30 KNOT RANGE...WHICH WILL AID IN INCREASING CONVERGENCE AND
MOISTURE TRANSPORT INTO THE LOWER LAKES. THIS MAY SUPPORT A FEW
SCATTERED SHOWERS LATE TONIGHT INTO SUNDAY MORNING. IT WILL BE
ANOTHER WARM AND SULTRY NIGHT WITH LOWS AROUND 70 ON THE LAKE PLAINS
AND MID TO UPPER 60S ACROSS THE INTERIOR SOUTHERN TIER AND EAST OF
LAKE ONTARIO.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
THE UPPER TROUGH AND CUTOFF LOW WHICH HAVE BEEN IN PLACE OVER THE
MIDWESTERN STATES WILL SHIFT EAST INTO THE TENNESSEE AND LOWER OHIO
VALLEYS ON SUNDAY. THE MODELS ALSO SHOW A VARIETY OF WEAK...AND
DIFFICULT TO TIME...IMPULSES LIFTING OUT AHEAD OF THE MAIN UPPER
LEVEL TROUGH AND ROUNDING THE TOP OF THE WEAKENING UPPER LEVEL RIDGE
STILL ANCHORED OFF THE ATLANTIC COAST. INCREASING UPPER LEVEL
DIVERGENCE AHEAD OF THE APPROACHING TROUGH...COMBINED WITH DAYTIME
HEATING...WILL RESULT IN ANOTHER ROUND OF SCATTERED SHOWERS AND
THUNDERSTORMS...WITH THE GREATEST COVERAGE EXPECTED ACROSS THE
SOUTHERN TIER...UPPER GENESEE VALLEY AND FINGER LAKES.
THE MID LEVEL CUTOFF LOW IS FORECAST TO MOVE EAST INTO WESTERN
PA/SOUTHERN NEW YORK STATE SUNDAY NIGHT...THEN SHIFT EAST INTO
SOUTHERN NEW YORK STATE AND NEW ENGLAND ON MONDAY. THE INCREASE IN
LARGE SCALE ASCENT MAY KEEP A FEW SHOWERS GOING INTO THE NIGHT
DESPITE THE LOSS OF DAYTIME HEATING.
COOLER TEMPERATURES ASSOCIATED WITH PASSING UPPER LEVEL TROUGH WILL
ENHANCE INSTABILITY ON MONDAY AND GENERATE A FEW MORE SHOWERS AND
THUNDERSTORMS.
PWAT THROUGH THE PERIOD WILL RUN CLOSE TO 2 INCHES AT TIMES. THIS
WILL CONTINUE TO SUPPORT A RISK FOR TORRENTIAL DOWNPOURS AND
ASSOCIATED ISOLATED FLOOD RISK FROM ANY THUNDERSTORM WHICH
DEVELOPS...ESPECIALLY IF TRAINING OCCURS ALONG ANY OF THE LOW LEVEL
BOUNDARIES.
A COLD FRONT THAT WILL BE ASSOCIATED WITH A DEEP TROUGH OVER
NORTHERN QUEBEC IS FORECAST TO STAY JUST NORTH OF LAKE ONTARIO
DURING THIS PERIOD. AS A RESULT...IT WILL REMAIN MUGGY WITH
WARM OVERNIGHT LOWS AND HIGHS JUST SLIGHTLY ABOVE AVERAGE. THERE IS
A POSSIBILITY THAT LOW LEVEL MOISTURE MAY POOL SOUTH OF THIS FRONT
AND ENHANCE PCPN ACROSS OUR AREA ON MONDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
A GENERAL ZONAL FLOW ALOFT AT THE START OF THIS PERIOD WILL
TRANSITION TO A HIGHER AMPLITUDE PATTERN...CHARACTERIZED BY A
DIGGING TROUGH OVER THE GREAT LAKES WHILE A RIDGE BUILDS OUT WEST.
THIS PATTERN SHIFT WILL RESULT IN A TREND TOWARD SLIGHTLY COOLER
TEMPERATURES AND LOWER HUMIDITY AS THE WEEK PROGRESSES.
AT THE SURFACE...LOW PRESSURE TRACKING NORTH OF LAKE ONTARIO ON
TUESDAY WILL BRING A CHANCE FOR A FEW SHOWERS OR THUNDERSTORMS.
HUMIDITY WILL REMAIN HIGH ON TUESDAY...WHILE TEMPERATURES GENERALLY
RANGE IN THE LOWER TO MID 80S.
BY WEDNESDAY...THE GFS AND ECMWF REMAIN CONSISTENT IN BRINGING A
STRONGER NORTHERN STREAM SHORTWAVE AND ASSOCIATED SURFACE LOW INTO
THE GREAT LAKES REGION. THIS WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS. THIS SYSTEM WILL PUSH EAST OF THE AREA BY THURSDAY
WITH A LOWERING RAIN CHANCE AS THE DAY AND EVENING PROGRESS.
AS THE AFOREMENTIONED UPPER LEVEL TROUGH SHIFTS EAST ACROSS QUEBEC
AND THE LOWER LAKES ON FRIDAY...TEMPERATURES MAY DROP TO SLIGHTLY
BELOW AVERAGE LEVELS. WHILE THE TROUGH MAY ENHANCE INSTABILITY...THE
LATEST GUIDANCE SUGGESTS THAT THIS SYSTEM WILL BE STARVED FOR
MOISTURE. THEREFORE...WILL NOT MENTION ANY SHOWERS FOR FRIDAY.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
MAINLY VFR CONDITIONS WILL PREVAIL FOR THE 12Z TAF CYCLE WITH A FEW
EXCEPTIONS. AREAS OF LOW STRATUS WITH IFR CIGS ACROSS THE HIGHER
TERRAIN OF THE SOUTHERN TIER SHOULD BURN OFF BY MID TO LATE MORNING
WITH A RETURN TO MAINLY VFR. AN AREA OF MVFR TO IFR STRATUS EAST OF
LAKE ONTARIO SHOULD ADVECT EAST OF THE AREA AND BURN OFF BY MID TO
LATE MORNING AS WELL. FOR THE REST OF THE AREA EXTENSIVE MID LEVEL
CLOUD WILL CONTINUE TO CROSS THE REGION THIS MORNING.
THIS AFTERNOON EXPECT ANOTHER ROUND OF SCATTERED SHOWERS AND STORMS
TO DEVELOP WITH DAYTIME HEATING. THE MAIN FOCUS FOR THIS TODAY
SHOULD BE THE SOUTHERN EDGE OF THE BREEZE OFF LAKE ERIE WITH THE
BEST CONVECTIVE COVERAGE ACROSS THE WESTERN SOUTHERN TIER INTO THE
FINGER LAKES. A LAKE BREEZE OFF LAKE ONTARIO MAY PROVIDE A SECONDARY
LESSER FOCUS FROM NEAR KROC INTO CENTRAL NY. ANY OF THESE SHOWERS
WILL PRODUCE BRIEF PERIODS OF IFR...BUT THE BULK OF THE TIME WILL BE
VFR.
THE SHOWERS AND STORMS WILL DIMINISH THIS EVENING WITH THE LOSS OF
DAYTIME HEATING. THIS WILL LEAVE MAINLY VFR OVERNIGHT WITH PERIODS
OF MID LEVEL CLOUD CROSSING THE AREA. A FEW SCATTERED SHOWERS ARE
POSSIBLE AGAIN LATE SATURDAY NIGHT AS A MID LEVEL DISTURBANCE AND
THE NEXT PUSH OF DEEPER MOISTURE MOVES INTO THE LOWER LAKES REGION.
OUTLOOK...
SUNDAY THROUGH WEDNESDAY...MAINLY VFR WITH SCATTERED SHOWERS AND
THUNDERSTORMS AND ASSOCIATED BRIEF MVFR/IFR.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT OVER THE LOWER LAKES WILL KEEP
WIND AND WAVES RELATIVELY LOW THROUGH THE WEEKEND AND INTO EARLY
NEXT WEEK. EXPECT WINDS TO BE SOUTHWEST MOST OF THE TIME WITH SOME
LOCAL LAKE BREEZES ON LAKE ONTARIO TURNING WINDS ONSHORE DURING THE
AFTERNOONS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...TJP
LONG TERM...TJP/WCH
AVIATION...HITCHCOCK
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
330 AM EDT SAT JUL 6 2013
.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL PERSIST OVER THE REGION THROUGH
THE WEEKEND. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH
DAY WITH THE MOST WIDESPREAD COVERAGE OCCURRING DURING THE
AFTERNOON AND EVENING HOURS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1245 AM UPDATE...
SHRA/TSRA STILL DVLPNG AT THIS TIME. SPC MESOANALYSIS CONTS TO
INDICATE 500-1000 JOULES OF SBCAPE UNINHIBITED ACRS FINGER LKS,
THO SOME CIN DOWN ACRS NEPA WITH STORMS FORMING IN THE GRADIENT OF
CAPE. HV UPDATED GRIDS TO KEEP CHC POPS IN FOR THE NEXT 1-2 HRS
BFR FINALLY DIMINISHING. HIRES MODELS CONT TO INDICATE ECHOES
WINDING DOWN BY 06Z. HRRR DOES SHOW TSTMS CONTNG ACRS NEPA INTO
SULLIVAN CNTY NY THRU 08Z, THO IT DOES START OFF ABOUT AN HR BHND
WITH CURRENT LOCATION SO HV ADDED ISOLD THUNDER INTO THIS AREA
THRU THIS TIME.
10 PM UPDATE...
THUNDERSTORMS WITH HEAVY RAIN STILL ONGOING. SOME TRAINING
OCCURRED FROM CAYUGA AND SENECA TO MADISON AND ONEIDA COUNTIES.
FLASH FLOODING AGAIN HAPPENING IN MADISON COUNTY. SHOWERS THERE
SHOULD END BY MIDNIGHT. MESO MODELS HAVE THE STORMS DIMINISHING
IN THE NEXT 3 HOURS. NOTHING CLOSE TO SEVERE IN A FEW HOURS...BUT
TSTMS SLOW TO DIMINISH IN HEIGHT. ROTATION ALSO BEING
SHOWN...BUT NOT BRIGHT AND TIGHT RECENTLY.
ADJUSTMENTS TO THE QPF AND POPS TO CURRENT. EXTENDED SHOWERS AND
TSTMS INTO THE OVERNIGHT. LOW TEMPS AND WINDS LOOK GOOD.
AT 3 PM...WIDESPREAD SHOWERS/THUNDERSTORMS WERE OCCURRING FROM THE
NRN FINGER LAKES REGION EAST ACROSS THE SYR AREA TO THE WESTERN
MOHAWK VALLEY. THIS ACTIVITY IS BEING ENHANCED BY A MID LEVEL
SHORT WAVE THAT WILL MOVE EAST OF THE REGION BY LATE AFTERNOON.
CAPE VALUES RANGING FROM 1500-2000 J/KG ALONG WITH MODERATE DEEP
LAYER SHEAR COULD SUPPORT A FEW SVR THUNDERSTORMS WITH THE
PRIMARY THREAT DAMAGING WINDS. FURTHER SOUTH ACTIVITY REMAINS
ONLY ISOLATED TO SCATTERED AND IS EXPECTED TO REMAIN SO WITH LESS
FORCING. BY EARLY EVENING WITH LOSS OF DIURNAL HEATING CONVECTION
WILL DIMINISH WITH DRY CONDITIONS EXPECTED.
OVERNIGHT LOWS WILL RANGE FROM THE MID 60S TO LOWER 70S UNDER
PARTLY CLOUDY SKIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
SATURDAY...STRONG UPPER LEVEL RIDGE WILL REMAIN OVER THE NORTHEAST
WITH SFC HIGH PRES OFF THE MID ATLANTIC COAST BRINGING A
CONTINUATION OF WARM AND MUGGY CONDITIONS. MODELS INDICATE ANOTHER
SHORT WAVE MAY TRACK OVER THE RIDGE DURING THE AFTERNOON PRIMARILY
NORTH OF THE FA. MODEL SOUNDINGS INDICATE CAPE VALUES AROUND 1500
J/KG BUT WITH WEAKER FORCING AND LESS BULK SHEAR, CONVECTION IS
EXPECTED TO BE JUST ISOLATED TO SCATTERED WITH THE BEST COVERAGE
ACROSS CENTRAL NY. MAX TEMPS WILL RANGE FROM THE MID 80S TO LOWER
90S.
SATURDAY NIGHT...ONCE DAYTIME HEATING SUBSIDES CONVECTION WILL
QUICKLY WEAKEN AGAIN DURING THE EARLY EVENING HOURS WITH MUCH OF
THE OVERNIGHT PERIOD DRY. ANOTHER MUGGY/MILD NIGHT.
SUNDAY THROUGH MONDAY...UPPER LEVEL RIDGE WILL FLATTEN DURING THIS
PERIOD AS MID WEST TROF MOVES EAST WITH H5 LOW SOMEWHERE BETWEEN
THE MID ATLANTIC REGION TO CENTRAL PA BY MONDAY. THE NAM POSITIONS THIS
FEATURE FARTHER SOUTH WITH THE GFS/ECMWF NORTH. AS THIS OCCUR THE
UPPER LEVEL FLOW ACROSS THE NORTHEAST BECOMES MORE ZONAL.
SCATTERED CONVECTION IS EXPECTED EACH AFTERNOON/EVENING WITH
ISOLATED ACTIVITY CONTINUING THROUGH THE SUNDAY NIGHT PERIOD AS
UPPER LEVEL SUPPORT MAY KEEP ACTIVITY GOING. PWATS WILL REMAIN
HIGH THROUGH THE PERIOD SO ANY CONVECTIVE ACTIVITY WILL BE
ASSOCIATED WITH HEAVY DOWNPOURS.
MAX TEMPS BOTH SUNDAY/MONDAY WILL RANGE IN THE MID 80S TO AROUND 90.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
320 AM UPDATE...
LIMITED CHANGES REQUIRED THIS MORNING AS PREVIOUS FCST REMAINS IN
GREAT SHAPE. AS ALLUDED TO BELOW...REGION WILL SLOWLY TRANSITION
TO A MORE ZONAL PATTERN BY MIDWEEK AS CENTRAL US UPPER LOW FINALLY
EXITS STAGE RIGHT. UNFORTUNATELY DAILY SHWRS/STORMS WILL REMAIN
POSSIBLE UNTIL AT LEAST THU BEFORE A STRONG COLD FRONT ASSOCIATED
WITH A SLOW MOVING CANADIAN UPPER LOW SWINGS THROUGH THE AREA THU
AFTERNOON. BEYOND THIS...DRIER AIR WILL FINALLY ENTER THE REGION
WHICH WILL FINALLY MEAN AN END TO THE WARM AND HUMID CONDITIONS
THAT HAVE PREVAILED ACROSS THE REGION FOR THE PAST WEEK OR SO. IN
GENERAL...ABOVE AVERAGE CONFIDENCE THIS PERIOD AS BOTH GFS AND
ECMWF REMAIN IN GOOD AGREEMENT ON TIMING OF LARGE SCALE SYNOPTIC
FEATURES.
PREVIOUS NEAR TERM DISCUSSION...
PTRN WILL BE TRANSITIONING TO A MORE ZONAL REGIME IN THE MED RNG.
REMNANTS OF THE UPR LOW CRNTLY OVER THE CNTRL U.S. XPCTD TO BE
OVER PA ON MON...MOVG OFF THE CST TUE NGT. ZONAL FLOW FOLLOWING
THIS FEATURE WITH MULTIPLE EMBEDDED S/WV`S. POTNL FOR A FEW ROUNDS
OF CONVECTION IN THIS PTRN (PSBLY NON-DIURNAL) UNTIL FROPA ON
THU...WITH HI PRES XPCTD TO BUILD IN FROM THE GTLAKES LATE IN THE
WEEK. MAXES GNRLY L/M80S WITH 65-70 FOR LOWS...A BIT COOLER
(MAYBE) FOR FRI.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
BRIEF MVFR CONDITIONS WILL BE POSSIBLE THIS MORNING AT MOST SITES
AS MOIST LOW-LEVEL CONDITIONS PREVAIL ACROSS THE AREA. FOR
NOW...EXPECT DEVELOPING MVFR CIGS AT RME AFTER 09Z...WITH MVFR
VSBYS POSSIBLE AT ELM ALSO POSSIBLE AFTER 09Z. AT
BGM/ITH/SYR...BRIEF MVFR CONDITIONS WILL BE POSSIBLE AFTER THE 12Z
TIME FRAME AS DAYTIME MIXING COMMENCES AND LOW-LEVEL MOISTURE
REMAINS TRAPPED BELOW A DECAYING NOCTURNAL INVERSION.
BEYOND 15Z...ATTENTION THEN FOCUSES ON POSSIBLE CONVECTION AS A
WEAK SFC TROUGH ADVANCES SOUTH ACROSS THE REGION. FCST MODELS SHOW
THIS FEATURE POSSIBLY JOINING FORCES WITH A LAKE BREEZE BOUNDARY
TO RESULT IN CONVECTION FROM THE FINGER LAKES SOUTH THROUGH THE
NORTHERN TIER OF PA. FOR NOW...HAVE INCLUDED PROB30 MENTIONS AT
ITH/ELM/BGM BETWEEN 19 AND 23Z...WITH ACTIVITY QUICKLY COMING TO AN
END THIS EVENING WITH LOSS OF DAYTIME HEATING. SOUTHWEST WINDS
THIS MORNING WILL GRADUALLY SHIFT TO THE WEST TROUGH THE DAY AS
AFOREMENTIONED BOUNDARY SINKS SOUTH. EXPECT SPEEDS GENERALLY IN
THE 5-10 KT RANGE.
.OUTLOOK...
SUNDAY THROUGH WEDNESDAY... SCT SHRA/TSRA ARE ANTICIPATED EACH
AFTN/EVE...WITH BRIEF RESTRICTIONS PSBL. MVFR RESTRICTIONS ALSO
PSBL IN EARLY MRNG STRATUS/FOG. OTRW VFR PREVAILS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...PVN/RRM/TAC
SHORT TERM...RRM
LONG TERM...CMG
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
159 AM EDT SAT JUL 6 2013
.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL PERSIST OVER THE REGION THROUGH
THE WEEKEND. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH
DAY WITH THE MOST WIDESPREAD COVERAGE OCCURRING DURING THE
AFTERNOON AND EVENING HOURS.
&&
.NEAR TERM /THROUGH TODAY/...
1245 AM UPDATE...
SHRA/TSRA STILL DVLPNG AT THIS TIME. SPC MESOANALYSIS CONTS TO
INDICATE 500-1000 JOULES OF SBCAPE UNINHIBITED ACRS FINGER LKS,
THO SOME CIN DOWN ACRS NEPA WITH STORMS FORMING IN THE GRADIENT OF
CAPE. HV UPDATED GRIDS TO KEEP CHC POPS IN FOR THE NEXT 1-2 HRS
BFR FINALLY DIMINISHING. HIRES MODELS CONT TO INDICATE ECHOES
WINDING DOWN BY 06Z. HRRR DOES SHOW TSTMS CONTNG ACRS NEPA INTO
SULLIVAN CNTY NY THRU 08Z, THO IT DOES START OFF ABOUT AN HR BHND
WITH CURRENT LOCATION SO HV ADDED ISOLD THUNDER INTO THIS AREA
THRU THIS TIME.
10 PM UPDATE...
THUNDERSTORMS WITH HEAVY RAIN STILL ONGOING. SOME TRAINING
OCCURRED FROM CAYUGA AND SENECA TO MADISON AND ONEIDA COUNTIES.
FLASH FLOODING AGAIN HAPPENING IN MADISON COUNTY. SHOWERS THERE
SHOULD END BY MIDNIGHT. MESO MODELS HAVE THE STORMS DIMINISHING
IN THE NEXT 3 HOURS. NOTHING CLOSE TO SEVERE IN A FEW HOURS...BUT
TSTMS SLOW TO DIMINISH IN HEIGHT. ROTATION ALSO BEING
SHOWN...BUT NOT BRIGHT AND TIGHT RECENTLY.
ADJUSTMENTS TO THE QPF AND POPS TO CURRENT. EXTENDED SHOWERS AND
TSTMS INTO THE OVERNIGHT. LOW TEMPS AND WINDS LOOK GOOD.
AT 3 PM...WIDESPREAD SHOWERS/THUNDERSTORMS WERE OCCURRING FROM THE
NRN FINGER LAKES REGION EAST ACROSS THE SYR AREA TO THE WESTERN
MOHAWK VALLEY. THIS ACTIVITY IS BEING ENHANCED BY A MID LEVEL
SHORT WAVE THAT WILL MOVE EAST OF THE REGION BY LATE AFTERNOON.
CAPE VALUES RANGING FROM 1500-2000 J/KG ALONG WITH MODERATE DEEP
LAYER SHEAR COULD SUPPORT A FEW SVR THUNDERSTORMS WITH THE
PRIMARY THREAT DAMAGING WINDS. FURTHER SOUTH ACTIVITY REMAINS
ONLY ISOLATED TO SCATTERED AND IS EXPECTED TO REMAIN SO WITH LESS
FORCING. BY EARLY EVENING WITH LOSS OF DIURNAL HEATING CONVECTION
WILL DIMINISH WITH DRY CONDITIONS EXPECTED.
OVERNIGHT LOWS WILL RANGE FROM THE MID 60S TO LOWER 70S UNDER
PARTLY CLOUDY SKIES.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
SATURDAY...STRONG UPPER LEVEL RIDGE WILL REMAIN OVER THE NORTHEAST
WITH SFC HIGH PRES OFF THE MID ATLANTIC COAST BRINGING A
CONTINUATION OF WARM AND MUGGY CONDITIONS. MODELS INDICATE ANOTHER
SHORT WAVE MAY TRACK OVER THE RIDGE DURING THE AFTERNOON PRIMARILY
NORTH OF THE FA. MODEL SOUNDINGS INDICATE CAPE VALUES AROUND 1500
J/KG BUT WITH WEAKER FORCING AND LESS BULK SHEAR, CONVECTION IS
EXPECTED TO BE JUST ISOLATED TO SCATTERED WITH THE BEST COVERAGE
ACROSS CENTRAL NY. MAX TEMPS WILL RANGE FROM THE MID 80S TO LOWER
90S.
SATURDAY NIGHT...ONCE DAYTIME HEATING SUBSIDES CONVECTION WILL
QUICKLY WEAKEN AGAIN DURING THE EARLY EVENING HOURS WITH MUCH OF
THE OVERNIGHT PERIOD DRY. ANOTHER MUGGY/MILD NIGHT.
SUNDAY THROUGH MONDAY...UPPER LEVEL RIDGE WILL FLATTEN DURING THIS
PERIOD AS MID WEST TROF MOVES EAST WITH H5 LOW SOMEWHERE BETWEEN
THE MID ATLANTIC REGION TO CENTRAL PA BY MONDAY. THE NAM POSITIONS THIS
FEATURE FARTHER SOUTH WITH THE GFS/ECMWF NORTH. AS THIS OCCUR THE
UPPER LEVEL FLOW ACROSS THE NORTHEAST BECOMES MORE ZONAL.
SCATTERED CONVECTION IS EXPECTED EACH AFTERNOON/EVENING WITH
ISOLATED ACTIVITY CONTINUING THROUGH THE SUNDAY NIGHT PERIOD AS
UPPER LEVEL SUPPORT MAY KEEP ACTIVITY GOING. PWATS WILL REMAIN
HIGH THROUGH THE PERIOD SO ANY CONVECTIVE ACTIVITY WILL BE
ASSOCIATED WITH HEAVY DOWNPOURS.
MAX TEMPS BOTH SUNDAY/MONDAY WILL RANGE IN THE MID 80S TO AROUND 90.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
PTRN WILL BE TRANSITIONING TO A MORE ZONAL REGIME IN THE MED RNG.
REMNANTS OF THE UPR LOW CRNTLY OVER THE CNTRL U.S. XPCTD TO BE
OVER PA ON MON...MOVG OFF THE CST TUE NGT. ZONAL FLOW FOLLOWING
THIS FEATURE WITH MULTIPLE EMBEDDED S/WV`S. POTNL FOR A FEW ROUNDS
OF CONVECTION IN THIS PTRN (PSBLY NON-DIURNAL) UNTIL FROPA ON
THU...WITH HI PRES XPCTD TO BUILD IN FROM THE GTLAKES LATE IN THE
WEEK. MAXES GNRLY L/M80S WITH 65-70 FOR LOWS...A BIT COOLER
(MAYBE) FOR FRI.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
BRIEF MVFR CONDITIONS WILL BE POSSIBLE THIS MORNING AT MOST SITES
AS MOIST LOW-LEVEL CONDITIONS PREVAIL ACROSS THE AREA. FOR
NOW...EXPECT DEVELOPING MVFR CIGS AT RME AFTER 09Z...WITH MVFR
VSBYS POSSIBLE AT ELM ALSO POSSIBLE AFTER 09Z. AT
BGM/ITH/SYR...BRIEF MVFR CONDITIONS WILL BE POSSIBLE AFTER THE 12Z
TIME FRAME AS DAYTIME MIXING COMMENCES AND LOW-LEVEL MOISTURE
REMAINS TRAPPED BELOW A DECAYING NOCTURNAL INVERSION.
BEYOND 15Z...ATTENTION THEN FOCUSES ON POSSIBLE CONVECTION AS A
WEAK SFC TROUGH ADVANCES SOUTH ACROSS THE REGION. FCST MODELS SHOW
THIS FEATURE POSSIBLY JOINING FORCES WITH A LAKE BREEZE BOUNDARY
TO RESULT IN CONVECTION FROM THE FINGER LAKES SOUTH THROUGH THE
NORTHERN TIER OF PA. FOR NOW...HAVE INCLUDED PROB30 MENTIONS AT
ITH/ELM/BGM BETWEEN 19 AND 23Z...WITH ACTIVITY QUICKLY COMING TO AN
END THIS EVENING WITH LOSS OF DAYTIME HEATING. SOUTHWEST WINDS
THIS MORNING WILL GRADUALLY SHIFT TO THE WEST TROUGH THE DAY AS
AFOREMENTIONED BOUNDARY SINKS SOUTH. EXPECT SPEEDS GENERALLY IN
THE 5-10 KT RANGE.
.OUTLOOK...
SUNDAY THROUGH WEDNESDAY... SCT SHRA/TSRA ARE ANTICIPATED EACH
AFTN/EVE...WITH BRIEF RESTRICTIONS PSBL. MVFR RESTRICTIONS ALSO
PSBL IN EARLY MRNG STRATUS/FOG. OTRW VFR PREVAILS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...PVN/RRM/TAC
SHORT TERM...RRM
LONG TERM...
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1250 AM EDT SAT JUL 6 2013
.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL PERSIST OVER THE REGION THROUGH
THE WEEKEND. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH
DAY WITH THE MOST WIDESPREAD COVERAGE OCCURRING DURING THE
AFTERNOON AND EVENING HOURS.
&&
.NEAR TERM /THROUGH TODAY/...
1245 AM UPDATE...
SHRA/TSRA STILL DVLPNG AT THIS TIME. SPC MESOANALYSIS CONTS TO
INDICATE 500-1000 JOULES OF SBCAPE UNINHIBITED ACRS FINGER LKS,
THO SOME CIN DOWN ACRS NEPA WITH STORMS FORMING IN THE GRADIENT OF
CAPE. HV UPDATED GRIDS TO KEEP CHC POPS IN FOR THE NEXT 1-2 HRS
BFR FINALLY DIMINISHING. HIRES MODELS CONT TO INDICATE ECHOES
WINDING DOWN BY 06Z. HRRR DOES SHOW TSTMS CONTNG ACRS NEPA INTO
SULLIVAN CNTY NY THRU 08Z, THO IT DOES START OFF ABOUT AN HR BHND
WITH CURRENT LOCATION SO HV ADDED ISOLD THUNDER INTO THIS AREA
THRU THIS TIME.
10 PM UPDATE...
THUNDERSTORMS WITH HEAVY RAIN STILL ONGOING. SOME TRAINING
OCCURRED FROM CAYUGA AND SENECA TO MADISON AND ONEIDA COUNTIES.
FLASH FLOODING AGAIN HAPPENING IN MADISON COUNTY. SHOWERS THERE
SHOULD END BY MIDNIGHT. MESO MODELS HAVE THE STORMS DIMINISHING
IN THE NEXT 3 HOURS. NOTHING CLOSE TO SEVERE IN A FEW HOURS...BUT
TSTMS SLOW TO DIMINISH IN HEIGHT. ROTATION ALSO BEING
SHOWN...BUT NOT BRIGHT AND TIGHT RECENTLY.
ADJUSTMENTS TO THE QPF AND POPS TO CURRENT. EXTENDED SHOWERS AND
TSTMS INTO THE OVERNIGHT. LOW TEMPS AND WINDS LOOK GOOD.
AT 3 PM...WIDESPREAD SHOWERS/THUNDERSTORMS WERE OCCURRING FROM THE
NRN FINGER LAKES REGION EAST ACROSS THE SYR AREA TO THE WESTERN
MOHAWK VALLEY. THIS ACTIVITY IS BEING ENHANCED BY A MID LEVEL
SHORT WAVE THAT WILL MOVE EAST OF THE REGION BY LATE AFTERNOON.
CAPE VALUES RANGING FROM 1500-2000 J/KG ALONG WITH MODERATE DEEP
LAYER SHEAR COULD SUPPORT A FEW SVR THUNDERSTORMS WITH THE
PRIMARY THREAT DAMAGING WINDS. FURTHER SOUTH ACTIVITY REMAINS
ONLY ISOLATED TO SCATTERED AND IS EXPECTED TO REMAIN SO WITH LESS
FORCING. BY EARLY EVENING WITH LOSS OF DIURNAL HEATING CONVECTION
WILL DIMINISH WITH DRY CONDITIONS EXPECTED.
OVERNIGHT LOWS WILL RANGE FROM THE MID 60S TO LOWER 70S UNDER
PARTLY CLOUDY SKIES.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
SATURDAY...STRONG UPPER LEVEL RIDGE WILL REMAIN OVER THE NORTHEAST
WITH SFC HIGH PRES OFF THE MID ATLANTIC COAST BRINGING A
CONTINUATION OF WARM AND MUGGY CONDITIONS. MODELS INDICATE ANOTHER
SHORT WAVE MAY TRACK OVER THE RIDGE DURING THE AFTERNOON PRIMARILY
NORTH OF THE FA. MODEL SOUNDINGS INDICATE CAPE VALUES AROUND 1500
J/KG BUT WITH WEAKER FORCING AND LESS BULK SHEAR, CONVECTION IS
EXPECTED TO BE JUST ISOLATED TO SCATTERED WITH THE BEST COVERAGE
ACROSS CENTRAL NY. MAX TEMPS WILL RANGE FROM THE MID 80S TO LOWER
90S.
SATURDAY NIGHT...ONCE DAYTIME HEATING SUBSIDES CONVECTION WILL
QUICKLY WEAKEN AGAIN DURING THE EARLY EVENING HOURS WITH MUCH OF
THE OVERNIGHT PERIOD DRY. ANOTHER MUGGY/MILD NIGHT.
SUNDAY THROUGH MONDAY...UPPER LEVEL RIDGE WILL FLATTEN DURING THIS
PERIOD AS MID WEST TROF MOVES EAST WITH H5 LOW SOMEWHERE BETWEEN
THE MID ATLANTIC REGION TO CENTRAL PA BY MONDAY. THE NAM POSITIONS THIS
FEATURE FARTHER SOUTH WITH THE GFS/ECMWF NORTH. AS THIS OCCUR THE
UPPER LEVEL FLOW ACROSS THE NORTHEAST BECOMES MORE ZONAL.
SCATTERED CONVECTION IS EXPECTED EACH AFTERNOON/EVENING WITH
ISOLATED ACTIVITY CONTINUING THROUGH THE SUNDAY NIGHT PERIOD AS
UPPER LEVEL SUPPORT MAY KEEP ACTIVITY GOING. PWATS WILL REMAIN
HIGH THROUGH THE PERIOD SO ANY CONVECTIVE ACTIVITY WILL BE
ASSOCIATED WITH HEAVY DOWNPOURS.
MAX TEMPS BOTH SUNDAY/MONDAY WILL RANGE IN THE MID 80S TO AROUND 90.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
PTRN WILL BE TRANSITIONING TO A MORE ZONAL REGIME IN THE MED RNG.
REMNANTS OF THE UPR LOW CRNTLY OVER THE CNTRL U.S. XPCTD TO BE
OVER PA ON MON...MOVG OFF THE CST TUE NGT. ZONAL FLOW FOLLOWING
THIS FEATURE WITH MULTIPLE EMBEDDED S/WV`S. POTNL FOR A FEW ROUNDS
OF CONVECTION IN THIS PTRN (PSBLY NON-DIURNAL) UNTIL FROPA ON
THU...WITH HI PRES XPCTD TO BUILD IN FROM THE GTLAKES LATE IN THE
WEEK. MAXES GNRLY L/M80S WITH 65-70 FOR LOWS...A BIT COOLER
(MAYBE) FOR FRI.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
800 PM EDT UPDATE...
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE ACROSS THE FINGER
LAKES/LAKE PLAIN AND WESTERN MOHAWK VALLEY THIS EVENING. THESE
STORMS ARE MOVING TO THE E/NE. SHOWERS ARE EXPECTED TO AFFECT
KRME AND KSYR FOR THE NEXT COUPLE OF HOURS. ISOLATED MVFR WILL BE
EMBEDDED WITHIN THESE SHOWERS. AS THE SUN SETS...THIS ACTIVITY
SHOULD START TO DIMINISH AND VFR CONDITIONS ARE EXPECTED TO
PREVAIL. WINDS WILL REMAIN LIGHT AND SOUTHERLY THROUGH THE
OVERNIGHT HOURS AND TRANSITION TO THE WEST SATURDAY MORNING AS THE
SURFACE HIGH OFF THE EASTERN COAST MOVES SOUTHWARD. EARLY SATURDAY
MORNING BROKEN MVFR CIGS WILL DEVELOP ACROSS MUCH OF THE AREA AND
LIFT TO VFR BY LATE MORNING. ANOTHER ROUND OF THUNDERSTORMS ARE
EXPECTED SATURDAY AFTERNOON. CONFIDENCE IS NOT HIGH ON LOCATION OR
TIMING THUS LEFT OUT OF TAF FOR THE TIME BEING.
.OUTLOOK...
SUNDAY THROUGH WEDNESDAY... SCT SHRA/TSRA ARE ANTICIPATED EACH
AFTN/EVE...WITH BRIEF RESTRICTIONS PSBL. MVFR RESTRICTIONS ALSO
PSBL IN EARLY MRNG STRATUS/FOG. OTRW VFR PREVAILS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...PVN/RRM/TAC
SHORT TERM...RRM
LONG TERM...
AVIATION...KAH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
809 PM EDT SUN JUL 7 2013
.SYNOPSIS...
THE BERMUDA HIGH WILL CONTINUE TO AFFECT THE LOCAL WEATHER THRU
OUT THE UPCOMING WEEK...HOWEVER ITS POSITIONING WILL SLIDE
SLIGHTLY FURTHER OFFSHORE DURING THE WEEK. THIS WILL ALLOW A COLD
FRONT TO SLOWLY APPROACH FROM THE NORTHWEST BY THE NEXT UPCOMING
WEEKEND. TYPICAL SUMMERTIME WEATHER WITH DAILY AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS WILL OCCUR EACH DAY...INCREASING
IN COVERAGE AS WE APPROACH NEXT WEEKEND.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 300 PM SUNDAY...HIGH PRESSURE RIDGING INTO COASTAL CAROLINAS
FROM THE ATLANTIC WILL SHIFT SLIGHTLY EAST THROUGH TODAY. THIS
WILL ALLOW THE WINDS TO SHIFT TO MORE OF A SOUTH DIRECTION INLAND
WITH MORE OF A SOUTHEAST FLOW ALONG THE COAST...ENHANCED WITH AFTN
SEA BREEZE. STILL SEEING PLENTY OF DRY AIR THROUGH THE MID TO
UPPER LEVELS THROUGH TODAY WITH MOISTURE CONFINED TO LOW LEVELS
BELOW 5K FT. FLOW HAS VEERED SLIGHTLY THROUGH THE LOW LEVELS
COMING AROUND TO SOUTHWEST ABOVE THE SURFACE UP THROUGH H85. THIS
HAS KEPT BEST CONVERGENCE AROUND THE RIDGE CLOSER TO THE COAST
WHICH IN TURN HAS KEPT CLOUDS AND SHOWERS FROM PUSHING WELL
INLAND. CONTINUE TO EXPECT GOOD DEAL OF SUNSHINE ACROSS MUCH OF
THE AREA WITH ONLY ISOLATED SHWRS/TSTMS MAINLY ALONG SEA BREEZE
BOUNDARY AND FURTHER INLAND ASSOCIATED WITH CONVERGENCE AROUND
HIGH. HRRR SHOWING QUITE A FEW SHOWERS OVER SC THIS
AFTERNOON...REMAINING MAINLY WEST OF I95. DRIER AIR WILL CONTINUE
TO PUSH INLAND WITH PROGRESSION OF SEA BREEZE. MODELS SHOW PCP
WATER VALUES UP CLOSE TO 1.7 INCHES INLAND THIS AFTN DROPPING DOWN
TO 1.2 INCHES BY LATE THIS EVENING. THEREFORE CLOUDS AND ISOLATED
SHOWERS THAT DEVELOP ALONG THIS BOUNDARY AS IT PROGRESSES
INLAND...WILL LEAVE MOST OF THE COAST CLEAR BY THIS AFTERNOON AND
INLAND AREAS BY LATE THIS EVENING.
TEMPS BETWEEN 85 AND 90 MOST PLACES WILL DROP SLOWLY THROUGH THE
EVENING. EXPECT OVERNIGHT LOWS TO BE BETWEEN 70 AN 75 WITH
SLIGHTLY WARMER TEMPS RIGHT ALONG THE COAST WHERE WARMER OCEAN
WATERS WILL KEEP THEM HIGHER. MOISTURE PROFILES SHOW SOME UPPER
LEVEL MOISTURE INCREASING TONIGHT AS THE UPPER TROUGH CURRENTLY
OVER SOUTHERN ILLINOIS LIFTS NORTHEAST PRODUCING A MORE NW FLOW IN
THE UPPER ATMOSPHERE. THIS WILL PRODUCE SOME CIRRUS BY MORNING BUT
OVERALL EXPECT MAINLY CLEAR SKIES. HAVE INCLUDED MENTION OF PATCHY
FOG BUT LEFT OUT ANY SHOWERS...ALTHOUGH CAN NOT RULE OUT AN
ISOLATED SHOWER OR TWO MOVING ON SHORE.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...THE WESTERN ATLANTIC RIDGING BOTH SFC AND
ALOFT AND HAVING PROVIDED THE TROPICAL WX TYPE CONDITIONS DURING
THIS EXTENDED JULY 4TH WEEKEND...WILL WEAKEN ACROSS THE AREA
MONDAY INTO TUESDAY. THIS A RESULT OF THE SLIGHT PROGRESSION OF WX
FEATURES BOTH ALOFT AND AT THE SFC. THE UPPER RIDGE AXIS AND THE
CENTER OF THE ASSOCIATED WESTERN ATLANTIC SFC HIGH...AKA BERMUDA
HIGH...IS PROGGED BY THE MODELS TO SLIDE FURTHER OFFSHORE FROM
THE CAROLINA COASTS. THE ORIENTED LOWER TO MID MISSISSIPPI AND
OHIO RIVER UPPER TROF IS PROGGED TO FLATTEN SOME AS THE MAIN VORT
FINALLY PROGRESSES NE TO E...STAYING WELL NORTH OF THE FA DURING
THIS SHORT TERM PERIOD. WHAT FINALLY ENDS UP IS A LOW AMPLITUDE
UPPER TROUGHINESS ALONG THE SPINE OF THE APPALACHIANS FROM VA
SOUTHWESTWARD...AND LEE SIDE SFC TROFFINESS ACROSS THE CAROLINAS.
THE SFC RIDGE AXIS EXTENDING SW-W FROM THE OFFSHORE BERMUDA HIGH
WILL EVENTUALLY DROP SOUTH OF THE ILM CWA. THE TRUE ATLANTIC
TROPICAL ATM REGIME OF THE PAST SEVERAL DAYS WILL FINALLY COME
PARTIALLY TO AN END. WITH THE ADDITION OF CONVECTIVE FOCUS
MECHANISMS BESIDES THE SEA BREEZE FOR MON AND TUE AS WELL AS
BETTER INSTABILITY...POPS WILL SLOWLY INCREASE BUT REMAIN CAPPED
IN THE CHANCE CATEGORY. POPS WILL PEAK DURING THE AFTN/EARLY
EVENING AIDED BY THE DAYS HEATING. THE NOCTURNAL TROPICAL REGIME
TYPE CONVECTION OVER THE ATL WATERS OF THE PAST SEVERAL DAYS WILL
NO LONGER HAVE A STRAIGHT LINE SHOT TO THE IMMEDIATE COAST DURING
PRE-DAWN TUE...AND PRE-DAWN WED. HOWEVER BY PRE-DAWN WED...A SFC
TROF WILL HAVE REACHED THE ATLANTIC WATERS OFF THE SE U.S.
COAST...WHICH IS A REFLECTION FROM AN UPPER LOW THAT TRAVERSES THE
BAHAMAS MON AND PARTIALLY ACROSS FLORIDA TUE. MOISTURE ASSOCIATED
WITH THIS FEATURE COULD REACH THE ATL WATERS AND PUSH PARTIALLY ON
SHORE LATE ON THE PRE-DAWN WED HOURS. THIS WILL NEED TO BE
MONITORED. FOR MAX TEMPS MON AND TUE...GUIDANCE REMAINS RATHER
CLUSTERED WITH MID 80S ALONG THE IMMEDIATE COAST...UPPER 80S TO
AROUND 90 FROM THE COAST TO THE I-95 CORRIDOR...AND LOWER 90S WEST
OF THE I-95 CORRIDOR. FOR MIN TEMPS BOTH MORNINGS...A 70 TO 75
RANGE...THE EXCEPTION WILL BE THE IMMEDIATE COAST WHERE MID 70S TO
RULE BOTH DAYS.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...WHILE THE BEGINNING OF THE PERIOD WILL
CONTINUE WITH WARM SUMMER CONDITIONS AND ONLY ISOLATED
CONVECTION...A PATTERN REGIME CHANGE WILL OCCUR BY THE END OF THE
WEEK...AND A RENEWED WET PERIOD IS BECOMING MORE LIKELY FOR THE WKND.
BERMUDA HIGH AT THE SURFACE AND FLAT RIDGING ALOFT WILL CREATE ONE
LAST DAY OF TEMPS AT TO ABOVE CLIMO WITH A LOT OF SUNSHINE AND
LITTLE CONVECTION. THEREAFTER...UPPER TROUGHING BEGINS TO BUILD DOWN
FROM THE NORTHWEST AND ACROSS THE EASTERN CONUS. WHILE THE COLD
FRONT ASSOCIATED WITH THIS UPPER TROUGH WILL LIKELY GET HELD UP AND
WASH OUT JUST NORTH OF THE LOCAL AREA...DECREASING HEIGHTS ALOFT
WILL STEEPEN LAPSE RATES...LEADING TO INCREASING CONVECTIVE
POTENTIAL. AT THE SAME TIME...TROPICAL WAVE WHICH HAS BEEN PROGGED
TO MOVE BENEATH THE BERMUDA HIGH AND INTO FLORIDA WILL FEED SOME OF
ITS MOISTURE INTO THE CAROLINAS BEGINNING FRIDAY. THIS ENHANCED
MOISTURE...PWATS RISING TO OVER 2 INCHES...COMBINED WITH THE STEEPER
LR`S IN THE MID-LEVELS WILL SUPPORT EVEN MORE SIGNIFICANT CONVECTION
ON FRIDAY. DO NOT ANTICIPATE A SEVERE THREAT ATTM...BUT HEAVY RAIN
WILL BE POSSIBLE. MAX TEMPS WILL REMAIN AROUND CLIMO THROUGH THE END
OF THE WEEK...WITH LOWS HOVERING A FEW DEGREES ABOVE.
WEATHER COULD DETERIORATE MORE CONSIDERABLY FOR NEXT WEEKEND. 5H
TROUGH CLOSES OFF IN RESPONSE TO STRONG AMPLIFICATION OF THE
FLOW...AND BLOCKING RIDGE ACROSS THE WESTERN ATLANTIC. THIS FORCES
THE CLOSED LOW TO RETROGRADE TO THE WEST...WITH DEEP SOUTHERLY FLOW
ONCE AGAIN DEVELOPING ACROSS THE SOUTHEAST. IN A PATTERN EERILY
REMINISCENT OF THE END OF JUNE...CLOSED LOW ACROSS THE TN VLY WITH
BLOCKING HIGH OVER THE OCEAN WILL DRIVE TROPICAL MOISTURE INTO THE
REGION AND A WET PERIOD AGAIN LOOKS TO BE IN STORE. FORTUNATELY...AT
LEAST FOR D6/D7...IT DOES NOT LOOK QUITE AS ROBUST AS THE PATTERN WE
SAW TO CLOSE OUT JUNE...BUT AN EXTENDED PERIOD OF UNSETTLED
WEATHER LOOKS LIKELY FOR NEXT WKND.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...EXPECT VFR THROUGH THE PERIOD WITH THE EXCEPTION OF
SLIGHT POSSIBILITY OF PATCHY FOG INLAND...THOUGH CONFIDENCE IS LOW.
VFR PREVAILS ACROSS THE AREA THIS EVENING WITH GENERALLY SOUTH
WINDS AOB 8 KTS AND SCT/BKN MID LEVEL CLOUDS. EXPECT TREND TO
CONTINUE THROUGH THE OVERNIGHT HOURS...WITH WINDS DROPPING OFF
SLIGHTLY. THERE DOES NOT SEEM TO BE A GOOD AGREEMENT BETWEEN THE
MODELS AS TO WHETHER OR NOT AREAS OF FOG WILL DEVELOP OVERNIGHT.
HOWEVER...SUSTAINED WINDS SEEMS TO BE SLIGHTLY LESS THAN WHAT THEY
WERE PROJECTED EARLIER TODAY...WHICH WITH SOME AVAILABLE LOW LEVEL
MOISTURE AND SOME RADIATIONAL COOLING COULD LEAD TO AREAS OF PATCHY
FOG INLAND. FOR NOW HAVE INTRODUCED TEMPO MVFR AT KFLO/KLBT...BUT
CONFIDENCE IS LOW AND FEEL THE POTENTIAL IS BORDERLINE POSSIBLE. FOR
MONDAY...IF ANY FOG DEVELOPED...IT WILL QUICKLY DISSIPATE GIVING WAY
TO VFR THROUGH THE REMAINDER OF THE VALID PERIOD. EXPECT FEW/SCT MID
LEVEL CLOUDS AND SCT/BKN CIRRUS FOR THE DAY WITH SOUTHWESTERLY WINDS
AOB 12 KTS.
EXTENDED OUTLOOK...EARLY MORNING IFR/MVFR CIGS/VSBYS POSSIBLE
THROUGH THE EXTENDED PERIOD. INCREASING CHANCES FOR SHOWERS AND
THUNDERSTORMS THURSDAY AND FRIDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM SUNDAY...SOUTHERLY RETURN FLOW 10 TO 15 KTS WILL
PERSIST ACROSS THE WATERS AROUND THE PERIPHERY OF BERMUDA HIGH
PRESSURE. THE WINDS WILL ACTUALLY VEER EVER SO SLIGHTLY FROM S-SE
TO S-SW BY MORNING REMAINING AROUND 10 KTS FOR THE MOST PART. AN 8
SECOND SE SWELL WILL CONTINUE TO MIX WITH LOCALLY GENERATED WIND
WAVES TO PRODUCE TOTAL SEAS OF 2 TO 3 FT.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...THE WESTERN ATLANTIC HIGH...AKA BERMUDA
HIGH...WILL REMAIN THE PRIMARY INFLUENCE OF THE WINDS ACROSS THE
LOCAL WATERS. THE DEVELOPMENT OF THE LEE-SIDE TROF ACROSS THE
WESTERN AND CENTRAL CAROLINAS...AND THE SFC RIDGE AXIS THAT
EXTENDS SW-W FROM THE CENTER OF THE BERMUDA HIGH OFFSHORE...IS
PROGGED TO DROP SOUTH OF THE LOCAL WATERS THIS TIME PERIOD.
THEREFORE...A SW WIND DIRECTION WILL EVENTUALLY BECOME THE
DOMINANT WIND DIRECTION. THE DAILY SEA BREEZE WILL TEMPORARILY
BACK WINDS TO A MORE SOUTHERLY DIRECTION EACH AFTN/EVENING. WITH
THE CENTER OF THE HIGH FURTHER AWAY AND OFFSHORE FROM THE ILM
WATERS...THE SFC PG WILL SLIGHTLY TIGHTEN. BASICALLY LOOKING AT
WIND SPEEDS IN THE 10 TO 15 KT RANGE...WITH THE SEA BREEZE ADDING
5 KT OF SPEED NEARSHORE EACH AFTN AND EVENING...THUS REACHING 15
TO POSSIBLY 20 KT. SIGNIFICANT SEAS WILL HOVER AROUND THE 3 FOOT
HEIGHT THRU-OUT THE SHORT TERM.
THERE WILL BE LESS OF AN INFLUENCE FROM THE 6 TO 8 SECOND PERIOD
SE SWELL DUE TO FETCH LIMITATIONS...BUT AN INCREASED INFLUENCE
FROM THE 3 TO 5 SECOND PERIOD WIND DRIVEN WAVES. THIS WILL FINALLY
BEGIN TO LOWER THE RIP CURRENT RISK...RELATIVELY SPEAKING. IN
ADDITION...BOATERS NAVIGATING TO AND FROM THE ATL THRU AREA INLETS
WILL ALSO IMPROVE...SOME ESPECIALLY WHEN TRAVERSING THESE WATERS
DURING AN OUT-GOING TIDE.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...BERMUDA HIGH OFFSHORE PERSISTS DURING THE
EXTENDED...KEEPING SW WINDS ONGOING ACROSS THE WATERS. WHILE THE
GRADIENT ON THE WESTERN SIDE OF THIS RIDGE REMAINS RELATIVELY
WEAK...IT DOES SLOWLY STRENGTHEN LATE IN THE WEEK IN RESPONSE TO A
COLD FRONT DRIFTING SLOWLY TOWARDS THE AREA. WHILE THIS FRONT WILL
LIKELY NOT MAKE IT TO THE WATERS...AND INSTEAD WASH OUT ACROSS THE
CENTRAL CAROLINAS FRIDAY...THE PINCHING GRADIENT WILL HELP WINDS
INCREASE FROM 10-15 KTS WEDNESDAY TO 15-20 KTS THURSDAY AND
FRIDAY. THE SE SWELL WILL SLOWLY DECAY THROUGH THE PERIOD...BUT SW
WIND WAVES WILL GRADUALLY INCREASE IN AMPLITUDE. SEAS WILL BUILD
FROM 2-3 FT WEDNESDAY...TO AS MUCH AS 4-5 FT LATE THURSDAY INTO
FRIDAY...AND A SCEC MAY BE REQUIRED FOR A PORTION OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DCH
NEAR TERM...RGZ
SHORT TERM...DCH
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
750 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A WEAKENING UPPER LEVEL LOW WILL PROGRESS EAST ACROSS THE MID-
ATLANTIC TONIGHT. CYCLONIC FLOW ALOFT WILL PREVAIL OVER THE EASTERN
UNITED STATES THROUGH MID WEEK...WITH AN UNSEASONABLY DEEP UPPER
LEVEL TROUGH DIGGING SOUTHEAST IN THE MID-ATLANTIC BY FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 PM SUNDAY...
SOME VERY LIGHT SHOWERS REMAIN IN THE NORTHEAST PIEDMONT...BUT THE
STRONGER STORMS AND BETTER COVERAGE REMAINS JUST WEST OF THE TRIAD.
AS WITH YESTERDAY...THE HRRR HIGH RES CAM IS DOING THE BEST AT
SIMULATING THE CURRENT SHOWER ACTIVITY...ALTHOUGH THE TIMING MAY BE
A BIT OFF. HIGH PRESSURE REMAINS OFF THE CAROLINA COAST...WITH THE
LOW WEST OF THE APPALACHIANS OVER IL/IN. LOW LEVEL MOISTURE IS
ADVECTING INTO WESTERN NC OFF THE GULF AHEAD OF THE LOW PRESSURE
SYSTEM. AS THE UPPER LEVEL LOW CONTINUES TO MOVE EASTWARD INTO PA
TONIGHT...SMALL AMPLITUDE SHORTWAVES WILL TRACK NORTHEAST ACROSS
WESTERN NC/VA. IN ADDITION TO THE SHORTWAVES...MOISTURE CONVERGENCE
ALONG THE PIEDMONT TROUGH ARE THE LIKELY DRIVING MECHANISMS FOR THE
CONVECTION MOVING INTO THE TRIAD. CURRENT ANALYZED MLCAPE VALUES
RANGE FROM 1500-2000 J/KC ACROSS CENTRAL NC...WITH THE BEST CAPE
DISPLACED FROM THE BEST SHEAR (OVER THE MTNS). BEST CHANCES FOR
SHOWERS/STORMS WILL REMAIN IN THE WEST THROUGH TONIGHT. THERE IS THE
POTENTIAL FOR SOME STORMS TO PRODUCE DAMAGING WINDS THIS AFT/EVE...
MAINLY IN AND AROUND THE TRIAD WHERE THE DCAPE IS ANALYZED AROUND
1000 J/KG AND 0-6 KM SHEAR VALUES AROUND 30 KTS. LOWS TONIGHT
SIMILAR TO PREVIOUS NIGHTS IN THE LOWER 70S.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 240 PM SUNDAY...
AS THE UPPER LEVEL LOW MAKES ITS WAY ACROSS PA AND INTO NEW ENGLAND
MONDAY AND MONDAY NIGHT...THE ASSOCIATED TROUGH WILL MOVE INTO
CENTRAL NC...THUS DAMPENING THE HIGH AND PUSHING THE RIDGE AXIS
SOUTH AND EAST. THE MAIN SHOWER ACTIVITY WILL SHIFT SLOWLY EASTWARD
THROUGH THE DAY AND INTO THE EVENING MONDAY AS ADDITIONAL SHORTWAVE
DISTURBANCES MOVE OVER THE AREA. HIGHEST PRECIP CHANCES COINCIDE
WITH PEAK HEATING...AND WILL DECREASE SUBSTANTIALLY AFTER SUNSET.
HIGH TEMPS WILL BE SIMILAR TO TODAY...MID 80S NW INCREASING TO NEAR
90 IN THE EAST. OVERNIGHT LOWS WILL AGAIN BE SIMILAR TO PREVIOUS
NIGHTS...MAINLY IN THE LOW 70S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 230 PM SUNDAY...
FOR TUESDAY/TUESDAY NIGHT: VERY WEAK MID LEVEL TROUGH AXIS HOLDS
OVER THE EAST COAST WHILE A SUBTLE SURFACE TROUGH HOLDS OVER THE NC
PIEDMONT. ABOVE-NORMAL DEEP MOISTURE PERSISTS ESPECIALLY SOUTH AND
EAST OF THE TROUGH WITH PW VALUES RANGING FROM 1.7-2.0 INCHES FROM
NW TO SE OVER CENTRAL NC. THE WEAK WIND FIELD (PROJECTED WINDS NO
GREATER THAN 15 KTS BELOW 400 MB) THROUGHOUT THE MOIST COLUMN
COMBINED WITH DAYTIME DESTABILIZATION (MLCAPE PEAKING AT 1200-2000
J/KG) SUGGEST SCATTERED STORMS DEVELOPING IN THE AFTERNOON WITH SLOW
MOVEMENT AND THE POTENTIAL TO DUMP SOME HEAVY RAIN... GIVEN THE
LCL-TO-0C LAYER DEPTH APPROACHING 3.8-4 KM. THE GFS/NAM/ECMWF
GENERALLY FAVOR BETTER COVERAGE OVER THE SOUTHEAST CWA IN
CONJUNCTION WITH THE GREATEST MOISTURE AND INSTABILITY... SO WILL
EDGE POPS HIGHER THERE THAN IN THE REST OF THE CWA. SHOWERS/STORMS
SHOULD FOLLOW A TYPICAL DIURNAL PATTERN OF TAPERING DOWN AFTER
NIGHTFALL... ALTHOUGH WITH ANOMALOUSLY HIGH MOISTURE CONTINUING TO
POOL OVER CENTRAL NC... A FEW MEANDERING SHOWERS AND ISOLATED STORMS
MAY PERSIST OVERNIGHT. HIGHS 86-90. LOWS 70-73.
FOR WEDNESDAY/WEDNESDAY NIGHT: THIS LOOKS TO BE THE TIME FRAME WITH
A RELATIVE MINIMUM IN RAIN CHANCES... BUT CERTAINLY NOT ZERO
CONSIDERING THE STILL-HIGH PW VALUES NEAR 2.0 INCHES. THE WESTERLIES
TAKE A DIP INTO THE GREAT LAKES AS THE TROUGH BEGINS TO DIG TO OUR
NORTHWEST... RESULTING A SLIGHT DOWNSTREAM REBOUNDING IN HEIGHTS
OVER NC. GFS FORECAST SOUNDINGS SHOW A PERIOD OF MID LEVEL DRYING
BETWEEN 800 AND 500 MB MAINLY IN THE EASTERN CWA... WHERE BOTH THE
GFS AND ECMWF SHOW FAIRLY LOW QPF. WILL LEAVE IN CHANCE POPS...
SKEWED HIGHER IN THE TRIAD AND LOWER IN THE SOUTHEAST... FOCUSED ON
THE AFTERNOON/EVENING. HIGHS 87-91 AS THICKNESSES STAY NEAR
CLIMATOLOGY. THE DEEPENING MID LEVEL TROUGH TO OUR WEST RESULTS IN
AN UPTICK IN MID LEVEL WINDS OVER NW NC WEDNESDAY NIGHT... AND WITH
MOISTURE REMAINING HIGH OR EVEN INCREASING A BIT OVER OUR NW CWA
OVERNIGHT... WILL HOLD ONTO CHANCE POPS HERE WITH JUST A SLIGHT
CHANCE ELSEWHERE. LOWS 70-74.
FOR THURSDAY THROUGH SUNDAY: CONFIDENCE IS IMPROVING THAT THIS WILL
BE A FAIRLY WET PERIOD. THE LONGWAVE TROUGH DIGS FURTHER THROUGH THE
EASTERN GREAT LAKES AND OH VALLEY ON THURSDAY AS THE SURFACE COLD
FRONT MOVES IN FROM THE NW... AND THE INCREASING DYNAMICS AND DEEP
MOISTURE FLUX OVER NC WILL BRING INCREASING SHOWER/STORM COVERAGE
FROM NW TO SE AS WE HEAD THROUGH THURSDAY AFTERNOON/NIGHT. THE
MODELS CLOSE OFF A LOW TO OUR NORTHWEST... OVER WV/ERN KY/ERN TN...
ON FRIDAY BEFORE DROPPING IT DOWN TO NRN GA/AL/MS OVER THE WEEKEND.
SUCH A CLOSED LOW THAT FAR SOUTH IS HIGHLY UNUSUAL FOR THIS TIME OF
YEAR (GEFS FORECAST 500 MB HEIGHTS OVER 2 STANDARD DEVIATIONS BELOW
NORMAL OVER THE SOUTHEAST STATES)... SO IT IS SURPRISING HOW GOOD
THE AGREEMENT IS BETWEEN THE OP GFS (12Z/07) AND ECMWF (00Z/07).
WITH THE LOSS OF EASTWARD PUSH... THE SURFACE FRONT IS LIKELY TO
STALL OUT OVER CENTRAL NC... AND WITH A STRENGTHENING AND DEEPENING
SOUTHERLY FLOW ALLOWING 2.0+ INCH PW VALUES TO STREAK OVER CENTRAL
NC FROM THURSDAY NIGHT THROUGH AT LEAST SATURDAY... WITH SOME DRYING
POSSIBLE SUNDAY AS A LARGE AND STRONG MID LEVEL CYCLONE BUILDS FROM
OFF THE CANADIAN MARITIMES SOUTHWESTWARD INTO NC. WILL KEEP HIGH
RAIN CHANCES FOR THURSDAY NIGHT THROUGH SATURDAY... A BIT HIGHER IN
THE AFTERNOON/EVENING BUT NOT YIELDING MUCH AT NIGHT... DROPPING
BACK TOWARD CLIMATOLOGICAL POPS ON SUNDAY. EXPECT QUITE A BIT OF
CLOUDINESS THROUGH THIS PERIOD WITH HUMID CONDITIONS REDUCING THE
DIURNAL TEMP RANGE. LOWS AROUND 70-75 AND HIGHS IN THE LOW-MID 80S.
-GIH
&&
.AVIATION /00Z MONDAY THROUGH THURSDAY/...
AS OF 750 PM SUNDAY...
SCATTERED SHOWERS AND A FEW STORMS OVER THE WESTERN PIEDMONT WILL
SLOWLY TRANSLATE EAST THIS EVENING AS A TROUGH OF LOW PRESSURE MOVES
INTO THE AREA. THIS WILL BRING A CHANCE OF A BRIEF DOWNPOUR AND
STRONG WIND GUSTS TO KGSO/KINT THROUGH 06Z...AND POSSIBLY AS FAR
EAST AS KRDU THROUGH 09Z. MEANWHILE...MOISTURE POOLING ALONG THIS
TROUGH WILL LIKELY CAUSE SOME AREAS OF STRATUS TO DEVELOP BY
09Z...THOUGH CONFIDENCE IN WIDESPREAD MVFR/IFR CEILINGS IS LOW.
MOSTLY VFR CONDITIONS SHOULD REDEVELOP BY MID MORNING...AROUND
14Z...AND PERSIST INTO THE AFTERNOON HOURS. SHOWERS AND STORMS ARE
LIKELY AGAIN MONDAY AFTERNOON...WITH GREATER COVERAGE NEAR
KRDU/KRWI/KFAY.
OUTLOOK...
THE WEATHER PATTERN WILL BE FAIRLY PERSISTENT THROUGH MUCH OF THE
UPCOMING WEEK...WITH A PERIOD OF STRATUS/FOG POSSIBLE EACH MORNING
AND SCATTERED SHOWERS AND STORMS DURING THE AFTERNOON.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC
SHORT TERM...KC
LONG TERM...HARTFIELD
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
241 PM EDT SAT JUL 6 2013
.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL EXTEND WESTWARD INTO THE CAROLINAS
THROUGH THE WEEKEND. A WEAKENING UPPER LEVEL LOW CURRENTLY STALLED
OVER THE CENTRAL MISSISSIPPI RIVER VALLEY WILL TRACK SLOWLY EAST
ACROSS THE MID-ATLANTIC ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 PM SATURDAY...
ISOLATED SHOWERS CONTINUE ACROSS THE AREA THIS AFTERNOON...MOST
LIKELY DRIVEN BY A WEAK SURFACE WAVE OVER CENTRAL NC...AND SHOWERS
ALONG THE SEA BREEZE APPROACHING FROM THE SE WILL CONTINUE TO DRIFT
NORTHWARD THROUGH SUNSET. SO FAR THE HRRR HAS HAD THE BEST HANDLE ON
SHOWER ACTIVITY TODAY...SO WILL CONTINUE TO RELY ON THAT FORECAST
FOR PRECIP THROUGH TONIGHT. WINDS CONTINUE TO BE MAINLY SOUTHERLY OR
SSW AND SHOULD BECOME LIGHT OVERNIGHT. WITH LITTLE CHANGE IN THE
OVERALL PATTERN FROM THE LAST DAY OR SO...EXPECT LOWS TONIGHT
SIMILAR TO PREVIOUS DAYS...IN THE LOWER 70S.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 240 PM SATURDAY...
THE UPPER LEVEL LOW OVER THE MISSISSIPPI RIVER VALLEY WILL SLOWLY
MOVE ENE TOWARD THE NE US THROUGH SUNDAY NIGHT...DAMPENING THE HIGH
OVER CENTRAL NC AS THE TROUGH MOVES INTO THE AREA. WHILE THE SURFACE
HIGH SHOULD REMAIN IN PLACE...EXPECT A REFLECTION OF THE TROUGH TO
SHOW UP...AND WINDS TO BECOME MORE SOUTHWEST. SHOWER DEVELOPMENT
WILL CONTINUE TO BE DIURNALLY DRIVEN...WITH BEST CHANCES FOR RAIN
ACROSS THE WEST WHERE THE STRONGEST SW FLOW AND MOISTURE ADVECTION
SHOULD BE. HIGHS SUNDAY SIMILAR TO TODAY...MID 80S TO AROUND 90...
ALTHOUGH DEPENDING ON SHOWER DEVELOPMENT/COVERAGE...COULD BE A BIT
LOWER IN THE WEST. OVERNIGHT LOWS SIMILAR TO PREVIOUS NIGHTS...IN
THE LOW 70S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 225 PM SATURDAY...
FOR MONDAY/MONDAY NIGHT: THE CORE OF THE SHORTWAVE TROUGH THAT
PASSES OVER THE OH VALLEY SUNDAY IS EXPECTED TO BE LOCATED OVER NRN
WV AT 12Z MONDAY... FOLLOWING THE TIMING OF THE NAM/ECMWF/EC ENS
MEAN. (THE GFS HAS DEAMPLIFIED AND SPED UP IN RECENT RUNS...
ALTHOUGH IT DOES HAVE SUPPORT FROM THE CANADIAN MODEL... AND THUS
THE FORECAST CONFIDENCE IS LOWER THAN USUAL.) THE SHORTWAVE THEN
DAMPENS AS IT TRACKS TO THE ENE ACROSS THE NORTHEAST STATES AND JUST
OFF NEW ENGLAND BY DAYBREAK TUESDAY... LEAVING BEHIND A BAGGY WEAK
POSITIVELY TILTED TROUGH BACK ACROSS THE SRN APPALACHIANS. DEEP
LAYER BULK SHEAR REMAINS FAVORABLE (25-30 KTS) IN THE NORTHERN FOR
ORGANIZED CONVECTION EARLY IN THE DAY... WITH HIGHER VALUES OF
K-INDEX/LOW LEVEL MOISTURE FLUX/PW (1.8-2.0 IN.) STREAKING ACROSS
THE WRN AND NRN CWA DURING THE MORNING... ALONG THE LOW LEVEL TROUGH
AND ATTENDING WEAKENING DPVA ALOFT. WILL PLACE GOOD CHANCE POPS
ACROSS MUCH OF THE PIEDMONT AND SANDHILLS WITH LOWER POPS IN THE SE
WHERE DEEP MID LEVEL DRY AIR WILL HANG ON. THE DEEP LAYER SHEAR
WANES DURING THE AFTERNOON AS THE WAVE LIFTS OUT... BUT WITH BOTH PW
AND MOISTURE FLUX REMAINING ELEVATED WHILE MLCAPE PEAKS AT 1000-1600
J/KG... SUPPORT PERSISTS FOR AT LEAST SCATTERED SHOWERS AND STORMS
THROUGH THE DAY WITH THE BEST COVERAGE EASING EASTWARD ACROSS
CENTRAL NC FOLLOWING THE DRIFT OF THE WEAK TRAILING TROUGH AXIS.
WILL TAPER POPS DOWN TO A LOW CHANCE OF SHOWERS OVERNIGHT AS WE KEEP
THE SOMEWHAT MOIST COLUMN BUT LOSE THE INSTABILITY AND DYNAMICS.
MOSTLY CLOUDY SKIES SHOULD SHAVE A FEW DEGREES OFF FULL-SUN DAYTIME
TEMPS... AND EXPECT HIGHS OF 84 NW TO NEAR 90 SE. LOWS 70-73.
FOR TUESDAY/TUESDAY NIGHT: A WEAK SURFACE TROUGH AND VERY SUBTLE MID
LEVEL TROUGH AXIS HOLD OVER NC... AS THE MEAN LONGWAVE TROUGH STARTS
TO DIG OVER THE UPPER MIDWEST. FAIRLY DEEP MOISTURE PERSISTS OVER
CENTRAL NC... ALTHOUGH MODELS DIFFER QUITE A BIT WITH THE NAM
SHOWING PW VALUES AROUND 1.75 INCHES (WITH DRIER MID LEVEL AIR)
WHILE THE GFS DEPICTS A PW AXIS AROUND 2.1 INCHES. THIS LEADS TO A
WETTER TUESDAY ON THE GFS THAN THE NAM... ALTHOUGH BOTH MODELS ALONG
WITH THE ECMWF AND SREF MEAN SUGGEST GREATER PRECIP COVERAGE OVER
THE WRN HALF OF NC COMPARED TO THE EAST. PROJECTED MLCAPE RISING
WITH HEATING TO 1500-2000 J/KG AND AVAILABLE MOISTURE SHOULD SUPPORT
AT LEAST SCATTERED CONVECTION WITH HEATING... ALTHOUGH THE LACK OF
GOOD KINEMATICS AND LARGE SCALE FORCING FOR ASCENT WILL LIMIT
COVERAGE AND INTENSITY. WILL ONCE AGAIN HAVE POPS TAPERING DOWN TO
SLIGHT CHANCE AFTER SUNSET AND THROUGH THE OVERNIGHT HOURS. HIGHS
87-90 WITH THICKNESSES CLOSE TO SEASONAL NORMALS. LOWS 70-73.
FOR WEDNESDAY THROUGH SATURDAY: RIDGING HOLDS FIRM OVER NM HEADING
INTO LATE WEEK WHILE LONGWAVE TROUGHING DEEPENS OVER THE GREAT LAKES
THEN OVER THE EASTERN US. THE GFS/ECMWF DEVELOP SCATTERED CONVECTION
MAINLY OVER ERN TN AND SRN APPALACHIANS INTO THE WRN CWA WEDNESDAY
AFTERNOON... WITH THE MORE ORGANIZED ACTIVITY WELL TO THE NW OVER
THE OH VALLEY AHEAD OF THE INCOMING COLD FRONT. WILL KEEP POPS AS
CHANCE OVER CENTRAL NC... HIGHER WEST THAN EAST. THEN AS THE COLD
FRONT APPROACHES WITH THE DEEPENING TROUGH... EXPECT AN EXPANSION OF
THE BETTER CHANCE OF SHOWERS/STORMS TO THE ESE INTO NC... PEAKING
THURSDAY NIGHT INTO FRIDAY OVER CENTRAL NC ACCORDING TO THE ECMWF
AND EC ENS MEAN... AND SHIFTING INTO THE COASTAL PLAIN AND COAST ON
SATURDAY AS THE FRONT PUSHES THROUGH THE AREA. MODELS HAVE COME INTO
SUFFICIENTLY CLOSE AGREEMENT SUCH THAT CONFIDENCE IS JUST HIGH
ENOUGH TO GO WITH POPS RANGING FROM 40% SE TO 60% NW ON THURSDAY...
LOWERING A BIT TO CHANCE THURSDAY NIGHT... THEN 50-60% ON FRIDAY...
HIGHER EAST THAN WEST AS THE MID LEVEL TROUGH AXIS PUSHES OVER THE
MOUNTAINS. THE GFS/ECMWF TAKE THE SURFACE COLD FRONT INTO ERN NC BY
SATURDAY BUT WITH GROWING UNCERTAINTY THAT FAR OUT IN THE
FORECAST... WILL RETAIN A CHANCE OF SHOWERS/STORMS MAINLY IN THE
EAST AS THE MID LEVEL TROUGH IS LIKELY TO STALL OUT OVER THE REGION.
WILL STAY WITH PERSISTENCE WITH HIGHS IN THE UPPER 80S TO AROUND
90... SLIPPING ABOUT A CATEGORY BY LATE WEEK AS THICKNESSES TREND
DOWN BELOW NORMAL. NIGHTLY LOWS IN THE UPPER 60S TO LOWER 70S. -GIH
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
AS OF 140 PM SATURDAY...
24-HR TAF PERIOD:
SCATTERED SHOWERS CONTINUE OVER PORTIONS OF CENTRAL NC...WITH BEST
CHANCES EARLY AT KRDU AND KFAY AND POTENTIAL DEVELOPMENT AT KINT AND
KGSO LATER THIS AFTERNOON. PREDOMINANTLY VFR CONDITIONS EXPECTED AT
ALL TERMINALS THROUGH THIS EVENING. WITH THE SAME OVERALL PATTERN
EXPECTED...SUB-VFR CONDITIONS SIMILAR TO THIS MORNING ARE LIKELY...
WITH A PERIOD OF MAINLY IFR STRATUS ACROSS THE AREA BETWEEN 08Z AND
13Z SUNDAY. -KC
LOOKING AHEAD:
AVIATION CONDITIONS THROUGH THE MIDDLE OF NEXT WEEK WILL LARGELY BE
CONSISTENT WITH THE PREVIOUS FEW DAYS...CONSISTING OF IFR/LIFR FOG
OR STRATUS BETWEEN 07-14Z EACH MORNING AND A NEAR CLIMATOLOGICAL
CHANCE OF AFTERNOON/EVENING (16-00Z) CONVECTION. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC
SHORT TERM...KC
LONG TERM...HARTFIELD
AVIATION...KC/VINCENT
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1024 AM CDT SAT JUL 6 2013
.UPDATE...
ISSUED AT 1015 AM CDT SAT JUL 6 2013
MUCH UNCERTAINITY IN HOW THINGS WILL PLAY OUT STORM WISE LATER
TODAY-THIS EVE. CURRENTLY HAVE AREA OF SHOWERS AND A FEW STORMS IN
NW MN....WITH A PERSISTANT AREAO F SHOWERS DTL-FAR BACK INTO
SOUTHERN BARNES COUNTY CLOSER A WEAK SFC BOUNDARY CONVERGENCE
ZONE AS WINDS NORTH OF THIS AREA MORE NORTHERLY AND WINDS SOUTH OF
THIS REGION MORE SOUTHERLY. ALSO HAVE STORMS IN SE SK WITH
WEAKENING SHOWERS INTO TURTLE MOUNTAINS. THIS AREA FROM SASK INTO
NORTH CENTRAL ND MORE ASSOC WITH UPPER LOW AND STRONGER SFC NR
REGINA. THIS WILL LIFT NORTHEAST TODAY STRONGEST FORCING INTO
MANITOBA AND FAR NRN ND.
OTHER AREA IS THAT SFC BOUNDARY IN SE ND AND RUC KEEPS IT THERE
THRU LATE TODAY AND THIS COULD BE A FOCUS FOR ADDITIONAL STORM
DEVELOPMENT TODAY. SOME CLEARING NOTED INTO CNTRL INTO ERN ND
OUTSIDE OF STORM AREAS AND THUS WILL SEE AREAS OF SFC HEATING AND
CAPES WITH DEW PTS IN THE HIGH 60S WILL REACH 2-3K J/KG. THUS
WOULD EXPECT SOME RE-DEVELOPMENT IN WRN FCST AREA THIS AFTN AND
MOVE EAST LATE THIS AFTN/EVE. A BIT HIGHER THREAT FOR SVR MIGHT BE
IN SE ND ALONG BOUNDARY.
UPDATE ISSUED AT 654 AM CDT SAT JUL 6 2013
MAIN CHANGE WAS TO ADJUST POPS FOR ONGOING RADAR TRENDS. SHOWERS
AND A FEW STORMS ARE CONCENTRATED IN THE NORTHEAST AND SOUTHERN
PORTIONS OF THE CWA THIS MORNING. THIS ACTIVITY WILL MOVE OUT OF
THE AREA IN A FEW HOURS...BUT SHORT RANGE MODELS ARE IN DECENT
AGREEMENT ON CONVECTION REDEVELOPING BY AFTERNOON. CONTINUED TREND
OF POPS FILLING IN BY LATE IN THE DAY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 311 AM CDT SAT JUL 6 2013
WV LOOP SHOWS A WEAK LEAD SHORTWAVE COMING OUT INTO THE
PLAINS...WHICH HAS SET OFF SOME SHOWERS AND STORMS OVER OUR
WESTERN FORECAST AREA ALTHOUGH ACTIVITY HAS WEAKENED AS STORMS
OVER SD HAVE INCREASED ALONG THE NOSE OF THE LOW LEVEL JET. THE
MAIN SHORTWAVE IS STILL OUT OVER MT...AND WHAT IT PRODUCES AS IT
MOVES OUT LATER TODAY WILL DEPEND MUCH ON HOW THINGS PLAY OUT THIS
MORNING.
NONE OF THE SHORT RANGE MODELS ARE DOING A PARTICULARLY STELLAR JOB
HANDLING CURRENT CONVECTION. MOST OF THE SHOWERS HAVE BEEN
DISSIPATING AS THEY HAVE MOVED NORTHEASTWARD. WILL HAVE TO MAKE
SOME LAST MINUTE ADJUSTMENTS TO POPS BEFORE SENDING EVERYTHING
OUT...BUT THINK THAT WIDELY SCATTERED REMNANTS OF SHOWERS WILL
CONTINUE TO MOVE EAST NORTHEASTWARD THIS MORNING. THINK THERE
SHOULD BE A BREAK AND WE SHOULD BEGIN TO SCATTER OUT AND
DESTABILIZE OVER AT LEAST PART OF THE AREA THIS AFTERNOON...WITH
AROUND 2000 J/KG NOT OUT OF THE QUESTION. A WARM FRONT WILL ALSO
BE PUSHING INTO OUR SOUTHERN COUNTIES AT SOME POINT THIS
AFTERNOON...ALTHOUGH THERE IS SOME VARIATION AS TO EXACTLY WHERE.
DEEP LAYER BULK SHEAR IS ONLY AROUND 30 KTS OR SO...BUT WITH THE
WARM FRONT IN THE VICINITY THE LOW LEVEL HELICITY WILL BE FAIRLY
HIGH. WILL HAVE TO KEEP AN EYE OUT FOR SOME POSSIBLY SEVERE
CONVECTION LATE THIS AFTERNOON INTO THE EVENING.
THE CONVECTIVE ACTIVITY WILL MOVE OFF TO THE EAST TONIGHT AS THE
SHORTWAVE AND MAIN SFC LOW HEAD IN THAT DIRECTION...SO KEPT POPS
MAINLY EAST OF THE RED RIVER. NEAR ZONAL FLOW WILL CONTINUE
THROUGH SATURDAY NIGHT AND SUNDAY WITH A WEAK COLD FRONT MOVING
INTO THE CWA AND THEN WASHING OUT. HAVE SOME LOW POPS LINGERING IN
THE EAST THROUGH SUNDAY MORNING BUT OVERALL AFTER TONIGHT THERE
SHOULD BE A DRY TREND THROUGH THE REST OF THE WEEKEND.
AS FOR TEMPERATURES...HIGHS TODAY SHOULD AGAIN REACH THE 80S
ACROSS MUCH OF THE REGION. WINDS AND LINGERING CLOUDS/PRECIP WILL
KEEP LOWS TONIGHT IN THE 60S. THE WEAK FRONT WILL KNOCK BACK TEMPS
ONLY A FEW DEGREES FOR SUNDAY WITH HIGHS IN THE UPPER 70S TO MID
80S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 311 AM CDT SAT JUL 6 2013
NEAR ZONAL FLOW CONTINUES AND MODELS ARE STRUGGLING A BIT WITH THE
TIMING OF MINOR SHORTWAVES THROUGH MOVING THROUGH SUNDAY NIGHT AND
MONDAY. THE VARIOUS MODELS SHOW DIFFERENT TIMING OF WEAK
SHORTWAVES AND CONVECTION. FOR NOW KEPT POPS PRETTY LOW. MODELS
ARE IN BETTER AGREEMENT WITH A STRONGER SHORTWAVE TROUGH DIGGING
INTO SASK/MT MONDAY NIGHT SO WENT WITH HIGHER POPS FOR THAT TIME
PERIOD. TEMPS SHOULD BE FAIRLY SEASONABLE.
TUESDAY-FRIDAY...THE UPPER SHORTWAVE TROUGH WILL PROPAGATE EASTWARD
ALONG THE INTERNATIONAL BORDER ON TUESDAY...REACHING THE UPPER GREAT
LAKES BY WEDNESDAY MORNING. THUNDERSTORM ACTIVITY WILL BE GREATEST
TUESDAY INTO TUESDAY EVENING AS THE ASSOCIATED FRONT CROSSES THE
AREA. HIGHS ON TUESDAY LOOK TO BE IN THE 70S OVER THE NORTH TO THE
80S SOUTH.
SFC HIGH PRESSURE WILL BUILD ACROSS THE GREAT PLAINS WEDNESDAY AND
THURSDAY...AS UPPER RIDGING BEGINS TO AMPLIFY ACROSS THE ROCKIES AND
HIGH PLAINS. THE GFS CONTINUES TO LINGER SOME PRECIP OVER THE
NORTHEAST INTO WEDNESDAY...SO KEPT LOW POPS. HOWEVER...WED/THU LOOK
MOSTLY DRY...WITH LOWER HUMIDITY AND PLEASANT HIGH TEMPS IN THE 70S
TO LOW 80S AND LOWS IN THE 50S TO LOW 60S.
MODEL DIFFERENCES INCREASE BY LATE WEEK. GENERALLY...IT APPEARS THE
UPPER RIDGE WILL SPREAD EASTWARD AND FLATTEN WITH MORE ZONAL FLOW
ACROSS THE NORTHERN PLAINS. BOTH THE 00Z GFS/ECMWF SUGGEST THE
POTENTIAL FOR MCS ACTIVITY LATE IN THE WEEK...WITH CONVECTION FIRING
ACROSS THE HIGH PLAINS IN ASSOCIATION WITH WEAK UPPER LEVEL
IMPULSES...AND RIDING THE THICKNESS GRADIENT SOUTH AND EAST ALONG
THE EDGE OF THE DOME OF HOT AIR. DO MENTION SOME LOW POPS THURSDAY
NIGHT/FRIDAY MAINLY SOUTH AND WEST...BUT CONFIDENCE IS VERY LOW WITH
THIS SORT OF PATTERN IN TIMING INDIVIDUAL WAVES AND CONVECTIVE
CHANCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 654 AM CDT SAT JUL 6 2013
SHOWERS AND VFR CEILINGS WILL CONTINUE OVER PORTIONS OF THE
FORECAST AREA THIS MORNING THROUGH THE NEXT FEW HOURS. THERE WILL
BE A BREAK IN PRECIP FROM MID MORNING INTO THE AFTERNOON BEFORE
THUNDERSTORMS REDEVELOP. COVERAGE WILL BE SCATTERED SO JUST KEPT
MENTION AT VCTS FOR NOW. CONDITIIONS WILL REMAIN VFR EXCEPT FOR
SOME BRIEF DROPS TO MVFR UNDER THE HEAVIER CELLS. CONVECTION WILL
END OVER ALL BUT AROUND KBJI BY AROUND 06Z OR SO.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
639 AM CDT SAT JUL 6 2013
.UPDATE...
ISSUED AT 629 AM CDT SAT JUL 6 2013
LOCAL DOT CAMERAS SHOW DENSE FOG NEAR MARMARTH...AND BAKER MT ALSO
HAS DENSE FOG. ADDED SOME FOG TO THE SOUTHWEST FRO THE MORNING.
LATEST RUC MODEL HAS A SHORT WAVE TROUGH TRACKING ACROSS THE
NORTHWEST AT THIS TIME. SEEING SCT CONVECTION BREAKING OUT OVER
THE NORTH CENTRAL IN RESPONSE. FOCUSED ON THIS AREA FOR THE NEXT
FEW HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT SAT JUL 6 2013
MAIN FORECAST CHALLENGES ARE AGAIN CONVECTIVE COVERAGE...TIMING
AND SEVERE WEATHER POTENTIAL FOR TODAY. WV IMAGERY SHOWS W/NW FLOW
IN PLACE ACROSS NORTHERN PLAINS. ONE DISTURBANCE EMBEDDED IN THE
FLOW CURRENTLY LOCATED ACROSS CENTRAL MONTANA ASSOCIATED WITH WEAK
SURFACE LOW AND AREA OF THUNDERSTORMS JUST SOUTH OF GLASGOW. IF
THIS HOLDS TOGETHER IT COULD AFFECT PORTIONS OF WESTERN ND EARLY
THIS MORNING. NAM APPEARED TO INITIALIZE IT AND WEAKENS IT AS IT
APPROACHES OUR CWA. OTHERWISE...MODELS ARE IN GENERAL AGREEMENT
WITH PROGRESSION OF WEAK COLD FRONT ACROSS ND TODAY. BY 18Z MODELS
HAVE N/S ORIENTED FRONT LOCATED OVER CENTRAL ND. SURFACE BASED
CAPE IN WARM SECTOR AHEAD OF COLD FRONT APPROACHES 2000 J/KG WITH
30-40 KTS OF 0-6KM SHEAR IN PLACE. BY 00Z FRONT IS ALMOST OUT OF
OUR CWA SO ANY SEVERE RISK SHOULD END BY EARLY EVENING. SPC
CONTINUES TO DEPICT SLIGHT RISK AREA FOR SOUTHEAST QUARTER OF CWA WITH
LARGE HAIL AND DAMAGING WINDS THE BIGGEST THREAT...THOUGH THEY DO
ALSO HAVE A SMALL 5 PCT AREA FOR TORNADOES ACROSS FAR SOUTHEAST
CWA.
FOR TONIGHT...CONTINUED TO TAPER POPS DOWNWARD AS SURFACE HIGH
BUILDS IN BEHIND LOW PRESSURE. MODELS IN AGREEMENT WITH CONTINUING
ZONAL FLOW ALOFT WITH ANOTHER DISTURBANCE APPROACHING SW ND LATE
TONIGHT. THEREFORE...HAVE CONTINUED TO CARRY A SMALL AREA OF LOW
POPS OVER EXTREME SW ND LATE TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 400 AM CDT SAT JUL 6 2013
EXTENDED PERIOD CONTINUES TO BE ACTIVE THOUGH MID WEEK THEN STRONG
MID LEVEL RIDGING CUTS OFF THE THUNDERSTORM POTENTIAL FOR AWHILE
BEGINNING WEDNESDAY. MAIN FEATURES IN THE EXTENDED INCLUDE A LARGE
H500 RIDGE ACROSS THE SOUTHERN TIER OF STATES WITH SEVERAL
SHORTWAVES FORECAST TO MOVE ACROSS THE NORTHWEST AND INTO
THE NORTHERN PLAINS ON A BELT OF MODERATELY STRONG WESTERLY WINDS.
BOTH GFS AND ECMWF APPEAR CONSISTENT ALTHOUGH THE GFS CONTINUES TO
GENERATE HIGH AMOUNTS OF PRECIPITATION PROBABLY FROM CONVECTIVE
FEEDBACK. THE FIRST SHORTWAVE WILL TRACK ACROSS SOUTHERN CANADA AND
LIKELY WILL BRING A CHANCE OF THUNDERSTORMS SUNDAY AND SUNDAY NIGHT.
BUT A BETTER AND MORE SHARPLY DEFINED SHORTWAVE WILL BRING A
SECOND ROUND OF THUNDERSTORMS...WITH MODERATE RAINFALL MONDAY
NIGHT INTO TUESDAY. SPC ALSO HAS SEVERE WEATHER IN THE OUTLOOK FOR
THIS TIME PERIOD AS WELL.
BY WEDNESDAY THE SHORTWAVE TROUGH IS EXITING THE REGION AND THERE
SHOULD BE SEVERAL DAYS OF DRY WEATHER...WEDNESDAY AND THURSDAY...WITH
A RETURN TO SCATTERED THUNDERSTORMS BY FRIDAY. NO MAJOR CHANGES TO
TEMPERATURES...LOOKING AT MAINLY 80S FOR HIGHS AND 60S FOR LOWS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 629 AM CDT SAT JUL 6 2013
WITH SHORTWAVE TROUGH ENTERING THE NORTHWEST THIS
MORNING...BELIEVE THE MORNING HOURS WILL BE MORE ACTIVE...AND
UTILIZED VCTS AT KMOT. THEN SEE KBIS-KJMS BEING THE FOCUS FOR THE
AFTERNOON FOR THUNDERSTORMS. STILL USED VCTS FOR TIMING
UNCERTAINTY. OTHERWISE VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...JNS
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
509 PM EDT SAT JUL 6 2013
.SYNOPSIS...
AN UPPER LEVEL LOW OVER THE MISSISSIPPI VALLEY WILL MOVE NORTHEAST
AND CROSS THE AREA LATE SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
DID A QUICK LATE AFTERNOON UPDATE JUST TO EXPAND THE FORECAST
"LIKELY" AREA FOR SHOWERS/STORMS AND TO MENTION HEAVY RAIN WITH
SOME OF THE STORMS.
NOT SURE HOW FAR EAST THE CLUSTERS OF SHOWERS/STORMS WILL MAKE
IT OVERNIGHT...WE HAVE SOME SOME SUPPORT AS THE UPPER LOW DRIFTS
ENE. THE HISTORY IS FOR MOST OF THE ACTIVITY TO DIMINISH AFTER
DARK BUT WEAK/MODERATE DIVERGENCE ALOFT IS PROGGED TO CONTINUE
OVERNIGHT WITH A MARGINAL LOW LEVEL JET IN PLACE. I SUSPECT WE
WILL SEE SOME ACTIVITY PERSIST OR REDEVELOP DURING THE EARLY
MORNING HOURS.
MID AFTERNOON ISSUANCE...
RADAR RETURNS HAVE STARTED TO INCREASE IN WESTERN OHIO THIS
AFTERNOON. LATEST GUIDANCE INCLUDING THE HRRR SPREADS THIS
ACTIVITY EASTWARD ACROSS THE REMAINDER OF THE AREA. DO NOT THINK
COVERAGE WILL EVER GET ANY MORE THAN SCATTERED SO WILL GO WITH NO
HIGHER THAN 50 POPS MOST AREAS. PRECIPITABLE WATER VALUES HAVE
CLIMBED TO AROUND 2 INCHES SO ANY OF THE STRONGER STORMS WILL BE
PROLIFIC PRECIP MAKERS. FORTUNATELY IT APPEARS THE STORMS WILL BE
MOVING ALONG AT A GOOD CLIP. EXPECT TO SEE A DECREASE IN STORM
COVERAGE AFTER MIDNIGHT. SURFACE DEWPOINTS REMAIN IN THE UPPER 60S
TO LOWER 70S WHICH IS PRETTY CLOSE TO WHAT EXPECTED LOWS ARE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/...
NOT A WHOLE TO WRITE ABOUT TODAY. MORE OF THE SAME IS EXPECTED.
WAS UNABLE TO FIND A PERIOD TO GO DRY. HAVE GONE ABOVE GUIDANCE
POPS ON SUNDAY WITH THE NICE SHORT WAVE MOVING THROUGH. MODELS
SHOWING PRETTY GOOD SYNOPTIC LIFT AHEAD OF THIS TROUGH AND WITH
THE DEEP MOISTURE IN PLACE THINK LIKELY POPS ARE APPROPRIATE.
ANOTHER WAVE WILL MOVE ACROSS THE AREA ON MONDAY. WILL GO NO
HIGHER THAN CHANCE POPS FOR NOW BUT EXPECTED LATER SHIFTS WILL
HAVE TO BUMP PRECIP CHANCES TO LIKELY FOR A COUPLE OF PERIODS.
WILL MENTION THUNDER ALL PERIODS. IT APPEAR THAT TEMPS WILL SLOWLY
WARM DURING THE PERIOD UNDER THE PERSISTENT S TO SW FLOW REGIME.
HAVE GONE WARMER THAN GUIDANCE MOST PERIODS FOR LOWS AND SIMILAR
TO GUIDANCE FOR HIGHS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
COULD STILL BE SOME LINGERING SHRA THU MORNING IN THE
EAST...OTHERWISE THE COLD FRONT SHOULD HAVE CLEARED THINGS OUT BY
THU. THE NEXT SLOW MOVING UPPER TROUGH DIGS INTO THE EASTERN LAKES
LATE THU THRU SAT AND EVEN SHOWS SOME INDICATIONS THAT IT MAY TRY
AND CUT OFF JUST EAST OF THE AREA. CONCERNED THAT UPPER TROFFING MAY
ALLOW FOR SOME INSTABILITY SHRA TO DEVELOP WITH DAYTIME HEATING BUT
HIGH PRESSURE GENERALLY PREVAILING AT THE SURFACE SO PLAN TO KEEP
POPS MOSTLY UNDER 15%.
TEMPS WILL BE A LITTLE COOLER FOR FRI AND SAT BUT MORE NOTICEABLE
WILL BE THE REDUCED DEWPOINTS (HUMIDITY).
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
NEXT 24 HOURS SHOULD BE A REPEAT OF PREVIOUS 24 HOURS. SHRA AND TSRA
WILL DEVELOP THIS AFTERNOON INTO EVENING THEN SETTLE DOWN AFTER
SUNSET TO JUST SCT SHRA. THE BETTER THREAT IS EXPECTED TO BE OVER
THE WEST HALF OF THE AREA BUT CONVECTION WILL BE SCT SO IT WILL BE
HARD TO PINPOINT WHERE ANY GIVEN CELL BE BE AT ANY GIVEN TIME. WILL
USE TEMPO GROUPS WHERE ACTIVITY LOOKS IMMINENT OVER NEXT 2 TO 3
HOURS.
PATCHES OF LOWER CONDITIONS...POSSIBLY IFR WILL DEVELOP LATER
TONIGHT AS FOG DEVELOPS BUT HIGHER CLOUDS SHOULD KEEP THE FOG FROM
GETTING BELOW 2SM FOR MOST OF THE AREA. WITH SUNRISE...SHOULD SEE
CIGS FROM 500 FT TO 800 FT DEVELOP AGAIN FOR MOST TAF SITES. THE
LOWER CIGS WILL RISE TO HIGH END MVFR OR VFR CIGS BY 18Z SUN WITH
DAYTIME HEATING. NEW CONVECTION WILL ALSO START TO OCCUR BY 18Z.
.OUTLOOK...NON-VFR IN SHOWERS/THUNDERSTORMS AS WELL AS EARLY
MORNING FOG THROUGH TUESDAY.
&&
.MARINE...
LIGHT SOUTH FLOW WILL GRADUALLY VEER TO SW THRU SUN. A LOW WILL MOVE
ACROSS THE NORTHERN PART OF THE LAKES WED AND THU AND DRAG A COLD
FRONT ACROSS LAKE ERIE. THE SW FLOW SHOULD INCREASE TO 10 TO 20
KNOTS WED THEN VEER TO WEST FOR THU. MARGINAL SCA CONDITIONS COULD
DEVELOP FOR THU.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KOSARIK/KUBINA
NEAR TERM...KOSARIK/KUBINA
SHORT TERM...KUBINA
LONG TERM...ADAMS
AVIATION...ADAMS
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
321 PM EDT SAT JUL 6 2013
.SYNOPSIS...
AN UPPER LEVEL LOW OVER THE MISSISSIPPI VALLEY WILL MOVE EAST OVER
THE LOCAL AREA LATE SUNDAY AND SUNDAY NIGHT. ANOTHER UPPER LEVEL
FEATURE WILL CROSS THE REGION LATE MONDAY AND MONDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
RADAR RETURNS HAVE STARTED TO INCREASE IN WESTERN OHIO THIS
AFTERNOON. LATEST GUIDANCE INCLUDING THE HRRR SPREADS THIS
ACTIVITY EASTWARD ACROSS THE REMAINDER OF THE AREA. DO NOT THINK
COVERAGE WILL EVER GET ANY MORE THAN SCATTERED SO WILL GO WITH NO
HIGHER THAN 50 POPS MOST AREAS. PRECIPITABLE WATER VALUES HAVE CLIMBED TO
AROUND 2 INCHES SO ANY OF THE STRONGER STORMS WILL BE PROLIFIC
PRECIP MAKERS. FORTUNATELY IT APPEARS THE STORMS WILL BE MOVING
ALONG AT A GOOD CLIP. EXPECT TO SEE A DECREASE IN STORM COVERAGE
AFTER MIDNIGHT. SURFACE DEWPOINTS REMAIN IN THE UPPER 60S TO LOWER
70S WHICH IS PRETTY CLOSE TO WHAT EXPECTED LOWS ARE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH WEDNESDAY NIGHT/...
NOT A WHOLE TO WRITE ABOUT TODAY. MORE OF THE SAME IS EXPECTED.
WAS UNABLE TO FIND A PERIOD TO GO DRY. HAVE GONE ABOVE GUIDANCE
POPS ON SUNDAY WITH THE NICE SHORT WAVE MOVING THROUGH. MODELS
SHOWING PRETTY GOOD SYNOPTIC LIFT AHEAD OF THIS TROUGH AND WITH
THE DEEP MOISTURE IN PLACE THINK LIKELY POPS ARE APPROPRIATE.
ANOTHER WAVE WILL MOVE ACROSS THE AREA ON MONDAY. WILL GO NO
HIGHER THAN CHANCE POPS FOR NOW BUT EXPECTED LATER SHIFTS WILL
HAVE TO BUMP PRECIP CHANCES TO LIKELY FOR A COUPLE OF PERIODS.
WILL MENTION THUNDER ALL PERIODS. IT APPEAR THAT TEMPS WILL SLOWLY
WARM DURING THE PERIOD UNDER THE PERSISTENT S TO SW FLOW REGIME.
HAVE GONE WARMER THAN GUIDANCE MOST PERIODS FOR LOWS AND SIMILAR
TO GUIDANCE FOR HIGHS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
COULD STILL BE SOME LINGERING SHRA THU MORNING IN THE
EAST...OTHERWISE THE COLD FRONT SHOULD HAVE CLEARED THINGS OUT BY
THU. THE NEXT SLOW MOVING UPPER TROUGH DIGS INTO THE EASTERN LAKES
LATE THU THRU SAT AND EVEN SHOWS SOME INDICATIONS THAT IT MAY TRY
AND CUT OFF JUST EAST OF THE AREA. CONCERNED THAT UPPER TROFFING MAY
ALLOW FOR SOME INSTABILITY SHRA TO DEVELOP WITH DAYTIME HEATING BUT
HIGH PRESSURE GENERALLY PREVAILING AT THE SURFACE SO PLAN TO KEEP
POPS MOSTLY UNDER 15%.
TEMPS WILL BE A LITTLE COOLER FOR FRI AND SAT BUT MORE NOTICEABLE
WILL BE THE REDUCED DEWPOINTS (HUMIDITY).
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
NEXT 24 HOURS SHOULD BE A REPEAT OF PREVIOUS 24 HOURS. SHRA AND TSRA
WILL DEVELOP THIS AFTERNOON INTO EVENING THEN SETTLE DOWN AFTER
SUNSET TO JUST SCT SHRA. THE BETTER THREAT IS EXPECTED TO BE OVER
THE WEST HALF OF THE AREA BUT CONVECTION WILL BE SCT SO IT WILL BE
HARD TO PINPOINT WHERE ANY GIVEN CELL BE BE AT ANY GIVEN TIME. WILL
USE TEMPO GROUPS WHERE ACTIVITY LOOKS IMMINENT OVER NEXT 2 TO 3
HOURS.
PATCHES OF LOWER CONDITIONS...POSSIBLY IFR WILL DEVELOP LATER
TONIGHT AS FOG DEVELOPS BUT HIGHER CLOUDS SHOULD KEEP THE FOG FROM
GETTING BELOW 2SM FOR MOST OF THE AREA. WITH SUNRISE...SHOULD SEE
CIGS FROM 500 FT TO 800 FT DEVELOP AGAIN FOR MOST TAF SITES. THE
LOWER CIGS WILL RISE TO HIGH END MVFR OR VFR CIGS BY 18Z SUN WITH
DAYTIME HEATING. NEW CONVECTION WILL ALSO START TO OCCUR BY 18Z.
.OUTLOOK...NON-VFR IN SHOWERS/THUNDERSTORMS AS WELL AS EARLY
MORNING FOG THROUGH TUESDAY.
&&
.MARINE...
LIGHT SOUTH FLOW WILL GRADUALLY VEER TO SW THRU SUN. A LOW WILL MOVE
ACROSS THE NORTHERN PART OF THE LAKES WED AND THU AND DRAG A COLD
FRONT ACROSS LAKE ERIE. THE SW FLOW SHOULD INCREASE TO 10 TO 20
KNOTS WED THEN VEER TO WEST FOR THU. MARGINAL SCA CONDITIONS COULD
DEVELOP FOR THU.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...KUBINA
SHORT TERM...KUBINA
LONG TERM...ADAMS
AVIATION...ADAMS
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS NORMAN OK
1248 PM CDT SAT JUL 6 2013
.AVIATION...
VFR CONDITIONS ARE EXPECTED WITH GUSTY SOUTHWEST WIND IN THE DAYS
AND LIGTHER SOUTH WIND AT NIGHT.
&&
.PREV DISCUSSION... /ISSUED 1243 PM CDT SAT JUL 6 2013/
UPDATE...
UPDATING AGAIN TO EXTEND THE MENTION OF AT LEAST SPRINKLES INTO
THE AFTERNOON... AND TO LOWER FORECAST TEMPERATURES A TOUCH IN THE
NORTHWEST WHERE CLOUDS ARE LINGERING. THE RADAR ECHOES PERSIST
EARLY THIS AFTERNOON... ALTHOUGH IT IS MOSTLY VIRGA. NO MESONETS
HAVE MEASURED ANY PRECIPITATION WITHIN THE LAST COUPLE OF
HOURS... AND THERE HAS BEEN NO CLOUD-TO-GROUND LIGHTNING DETECTED
FOR OVER 3 HOURS. AFTER THE LAST COUPLE OF DAYS... CONFIDENCE IS
NOT TOO HIGH ABOUT THE EVOLUTION OF THESE ECHOES... ALTHOUGH ANY
IMPACT WILL BE MINOR. HRRR CONTINUES WIDESPREAD ECHOES AND LOCAL
WRF IS NOW ALSO BEGINNING TO KEEP FORECAST RADAR ECHOES. STILL
EXPECT MUCH OF IT TO BE VIRGA EVEN IF IT DOES PERSIST... SO WILL
LOWER POPS TO LESS THAN 20 PERCENT THIS AFTERNOON BUT KEEP THE
MENTION OF SPRINKLES IN THE FORECAST.
PREV DISCUSSION... /ISSUED 635 AM CDT SAT JUL 6 2013/
AVIATION... VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. A FEW
SHOWERS AND POSSIBLY ISOLATED TSRA THIS MORNING...MAINLY IN WESTERN
OK WILL CONTINUE THROUGH THE EARLY MORNING. THIS ACTIVITY IS
EXPECTED TO DIMINISH BY EARLY AFTERNOON. BRISK SOUTH WINDS AGAIN
EXPECTED TODAY...ESP IN WESTERN SECTIONS.
PREV DISCUSSION... /ISSUED 359 AM CDT SAT JUL 6 2013/
DISCUSSION...A FEW HIGH BASED SHOWERS/TSTMS HAVE DEVELOPED AGAIN
OVERNIGHT...MAINLY IN NW OK. THIS ACTIVITY MAY PERSIST THROUGH THE
MORNING BEFORE AGAIN DIMINISHING LATER TODAY.
UPPER RIDGE WILL CONTINUE TO EXPAND EASTWARD OVER THE AREA INTO
THE EARLY PART OF THE COMING WEEK RESULTING IN A CONTINUED WARMING
TREND WITH LITTLE CHANCE FOR PRECIP. MODELS ARE CONSISTENT WITH
S/W TROUGH TOPPING THE RIDGE THEN DROPPING SEWD THROUGH THE
NRN/CNTRL PLAINS AROUND MIDWEEK. ASSOCIATED FRONT WILL MOVE SWD
INTO OR NEAR NRN PARTS OF THE FA AND WILL CONTINUE WITH LOW POPS
THERE. DRY AND HOT WEATHER EXPECTED FOR THE LATTER PART OF THE
WEEK AS UPPER RIDGE BEGINS TO STRENGTHEN AND BECOME MORE EXPANSIVE
OVER THE CENTRAL PART OF THE COUNTRY.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 70 95 71 97 / 0 0 0 0
HOBART OK 70 99 71 100 / 0 0 0 0
WICHITA FALLS TX 71 99 73 100 / 0 0 0 0
GAGE OK 69 97 69 99 / 10 0 10 10
PONCA CITY OK 72 96 74 97 / 0 0 0 0
DURANT OK 70 95 73 94 / 0 0 0 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
26/09/09
AREA FORECAST DISCUSSION
NWS NORMAN OK
1243 PM CDT SAT JUL 6 2013
.UPDATE...
UPDATING AGAIN TO EXTEND THE MENTION OF AT LEAST SPRINKLES INTO
THE AFTERNOON... AND TO LOWER FORECAST TEMPERATURES A TOUCH IN THE
NORTHWEST WHERE CLOUDS ARE LINGERING. THE RADAR ECHOES PERSIST
EARLY THIS AFTERNOON... ALTHOUGH IT IS MOSTLY VIRGA. NO MESONETS
HAVE MEASURED ANY PRECIPITATION WITHIN THE LAST COUPLE OF
HOURS... AND THERE HAS BEEN NO CLOUD-TO-GROUND LIGHTNING DETECTED
FOR OVER 3 HOURS. AFTER THE LAST COUPLE OF DAYS... CONFIDENCE IS
NOT TOO HIGH ABOUT THE EVOLUTION OF THESE ECHOES... ALTHOUGH ANY
IMPACT WILL BE MINOR. HRRR CONTINUES WIDESPREAD ECHOES AND LOCAL
WRF IS NOW ALSO BEGINNING TO KEEP FORECAST RADAR ECHOES. STILL
EXPECT MUCH OF IT TO BE VIRGA EVEN IF IT DOES PERSIST... SO WILL
LOWER POPS TO LESS THAN 20 PERCENT THIS AFTERNOON BUT KEEP THE
MENTION OF SPRINKLES IN THE FORECAST.
&&
.PREV DISCUSSION... /ISSUED 635 AM CDT SAT JUL 6 2013/
AVIATION... VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. A FEW
SHOWERS AND POSSIBLY ISOLATED TSRA THIS MORNING...MAINLY IN WESTERN
OK WILL CONTINUE THROUGH THE EARLY MORNING. THIS ACTIVITY IS
EXPECTED TO DIMINISH BY EARLY AFTERNOON. BRISK SOUTH WINDS AGAIN
EXPECTED TODAY...ESP IN WESTERN SECTIONS.
PREV DISCUSSION... /ISSUED 359 AM CDT SAT JUL 6 2013/
DISCUSSION...A FEW HIGH BASED SHOWERS/TSTMS HAVE DEVELOPED AGAIN
OVERNIGHT...MAINLY IN NW OK. THIS ACTIVITY MAY PERSIST THROUGH THE
MORNING BEFORE AGAIN DIMINISHING LATER TODAY.
UPPER RIDGE WILL CONTINUE TO EXPAND EASTWARD OVER THE AREA INTO
THE EARLY PART OF THE COMING WEEK RESULTING IN A CONTINUED WARMING
TREND WITH LITTLE CHANCE FOR PRECIP. MODELS ARE CONSISTENT WITH
S/W TROUGH TOPPING THE RIDGE THEN DROPPING SEWD THROUGH THE
NRN/CNTRL PLAINS AROUND MIDWEEK. ASSOCIATED FRONT WILL MOVE SWD
INTO OR NEAR NRN PARTS OF THE FA AND WILL CONTINUE WITH LOW POPS
THERE. DRY AND HOT WEATHER EXPECTED FOR THE LATTER PART OF THE
WEEK AS UPPER RIDGE BEGINS TO STRENGTHEN AND BECOME MORE EXPANSIVE
OVER THE CENTRAL PART OF THE COUNTRY.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 93 70 95 71 / 10 0 0 0
HOBART OK 98 70 99 71 / 20 0 0 0
WICHITA FALLS TX 100 71 99 73 / 10 0 0 0
GAGE OK 95 69 97 69 / 20 10 0 10
PONCA CITY OK 94 72 96 74 / 20 0 0 0
DURANT OK 96 70 95 73 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1119 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS WILL
PERSIST INTO THE UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPPER LOW TRACKING EAST FROM CENTRAL OHIO OVERNIGHT WILL KEEP
SLGT/CHC POPS FOR SHWRS OVER CENTRAL PA OVERNIGHT. ANOTHER MUGGY
NIGHT IS IN STORE WITH AREAS OF RIVER VALLEY FOG MORE PREVALENT
THAT RECENT MORNINGS DUE TO WIDESPREAD NATURE OF THIS AFTERNOON`S
CONVECTION. MINS WILL RANGE FROM THE LOWER 60S NORTHWEST TO THE
LOWER 70S SOUTHEAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
ENSEMBLES AGREE IN SHUNTING THE AXIS OF HIGHEST PWATS EAST OF THE
AREA BY MONDAY NIGHT...AND MID LEVEL HEIGHT RISES AND WARM ADVECTION
SHOULD ALL COMBINE TO LIMIT OUR INSTABILITY. STILL LAPSE RATES
WILL BE FAVORABLE FOR SCT SHOWERS THROUGH THE DIURNAL MAXIMUM ON
MONDAY.
TEMPS FROM NEAR 80 IN THE NW...TO THE MID 80S IN THE SE WILL BE
VERY CLOSE TO NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
AFTER THE PASSAGE OF THE UPPER LOW...THE UPPER PATTERN WILL BECOME
QUASI-ZONAL FOR A TIME EARLY TO MID WEEK...WITH PA BEING ON THE
SOUTHERN EDGE OF THE WESTERLIES. THE MODELS ARE CONSISTENT WITH
PERSISTENT MOIST WESTERLY FLOW WHICH WILL LEAVE THE REGION
VULNERABLE TO CONVECTION AS WEAK DISTURBANCES RIPPLE EASTWARD OUT
OF THE MIDWEST AND GREAT LAKES.
A STRONGER TROUGH WILL DEEPEN OVER SOUTHERN CANADA AND OVER THE
GREAT LAKES REGION TOWARDS THE END OF THE WEEK. THIS SHOULD RESULT
IN A FAIRLY STRONG FRONTAL PASSAGE SOMETIME LATER WED OR THU AS
SLIGHTLY COOLER BUT MUCH DRIER AIR SLIDES OUT OF THE GR LAKES.
FROM THERE THE UPPER PATTERN ADVERTISED IN SOME LONGER RANGE
GUIDANCE TAKES ON A LOOK THAT IS EERILY FAMILIAR TO WHAT WE HAVE
JUST EXPERIENCED...WITH A NEW CUTOFF LOW FCST TO FORM OVER THE
EASTERN US...AND A RENEWED SURGE OF DEEP SOUTHERLY FLOW
EVENTUALLY EXPECTED TO DEVELOP ONCE AGAIN OVER THE EASTERN US. A
POTENTIAL COMPLICATING FACTOR IS A TROPICAL SYSTEM CURRENTLY WELL
OUT IN THE ATLANTIC THAT THE TROPICAL MODELS TRACK INTO THE
BAHAMAS BY LATE WEEK...MAKING A TANTALIZING FEATURE FOR THE
EASTERN US TROF TO PERHAPS INTERACT WITH.
WHAT HAS BEEN INTERESTING SO FAR THIS JULY HAS BEEN THE RATHER
HIGH LATITUDE THE BERMUDA RIDGE HAS OCCUPIED FOR SO EARLY IN THE
SEASON. THE LATEST PROGS ONCE AGAIN HAVE A STRONG CLOSED UPPER
HIGH AT UNUSUALLY HIGH LATITUDES BY NEXT WEEKEND. IF THE TROPICAL
SYSTEM CAN MANAGE TO HOLD TOGETHER...IT WOULD SUGGEST THE EASTERN
SEABOARD WOULD BE VULNERABLE IN ABOUT A WEEK`S TIME. STAY TUNED.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
A TROUGH OF LOW PRES APPROACHING FROM THE OHIO VALLEY WILL
PRODUCE A FEW -SHRA ACROSS THE REGION OVERNIGHT. HOWEVER...THE
BIG AVIATION CONCERN IS THE POTENTIAL OF LOW CIGS ALONG THE SPINE
OF THE APPALACHIANS FROM JST NORTH THRU BFD. LATE EVENING IR LOOP
ALREADY SHOWING SCT CLOUDS ACROSS THE W MTNS WITH BASES ARND 1500FT
AND AS BLYR COOLS/MOISTENS CIGS BLW 1KFT COULD DEVELOP. LATEST
SREF AND RAP OUTPUT BOTH SUPPORT THIS POTENTIAL OF IFR CONDS
ACROSS THE W MTNS...BUT NOT CERTAIN ENOUGH TO INCLUDE IN FCST YET.
FURTHER EAST...FOG IS CERTAINLY A POSSIBILITY...GIVEN THE WET
GROUND AND PARTIAL CLEARING EXPECTED LATE TONIGHT. HOWEVER...PRES
GRADIENT SUGGESTS THERE WILL BE ENOUGH OF A WIND TO PRECLUDE IFR
VSBYS. BELIEVE THE 800 FT CIG AT IPT AT 03Z IS A TEMPORARY
CONDITION AND ENOUGH OF A BREEZE WILL DEVELOP OVERNIGHT TO
PRECLUDE LOW CIGS THERE FOR THE BALANCE OF THE NIGHT.
ANY EARLY LOW CIGS/FOG SHOULD MIX OUT TO VFR CONDS ARND 12Z. FOR
THE REST OF MONDAY...EXPECT WIDESPREAD VFR CONDS. HOWEVER...PASSAGE
OF UPPER LVL TROUGH WILL BRING THE CHC OF A BRIEF SHRA/TSRA AND
ACCOMPANYING DROP IN VSBY.
OUTLOOK...
TUE...AM SHRA/LOW CIGS POSS W MTNS.
WED-THU...AM LOW CIGS POSS W MTNS. SCT TSRA IMPACTS POSS...MAINLY PM.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...DEVOIR/LA CORTE/RXR
SHORT TERM...LA CORTE
LONG TERM...LA CORTE/GARTNER
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1025 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS WILL
PERSIST INTO THE UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPPER LOW TRACKING EAST FROM CENTRAL OHIO OVERNIGHT WILL KEEP
SLGT/CHC POPS FOR SHWRS OVER CENTRAL PA OVERNIGHT. ANOTHER MUGGY
NIGHT IS IN STORE WITH AREAS OF RIVER VALLEY FOG MORE PREVALENT
THAT RECENT MORNINGS DUE TO WIDESPREAD NATURE OF THIS AFTERNOON`S
CONVECTION. MINS WILL RANGE FROM THE LOWER 60S NORTHWEST TO THE
LOWER 70S SOUTHEAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
ENSEMBLES AGREE IN SHUNTING THE AXIS OF HIGHEST PWATS EAST OF THE
AREA BY MONDAY NIGHT...AND MID LEVEL HEIGHT RISES AND WARM ADVECTION
SHOULD ALL COMBINE TO LIMIT OUR INSTABILITY. STILL LAPSE RATES
WILL BE FAVORABLE FOR SCT SHOWERS THROUGH THE DIURNAL MAXIMUM ON
MONDAY.
TEMPS FROM NEAR 80 IN THE NW...TO THE MID 80S IN THE SE WILL BE
VERY CLOSE TO NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
AFTER THE PASSAGE OF THE UPPER LOW...THE UPPER PATTERN WILL BECOME
QUASI-ZONAL FOR A TIME EARLY TO MID WEEK...WITH PA BEING ON THE
SOUTHERN EDGE OF THE WESTERLIES. THE MODELS ARE CONSISTENT WITH
PERSISTENT MOIST WESTERLY FLOW WHICH WILL LEAVE THE REGION
VULNERABLE TO CONVECTION AS WEAK DISTURBANCES RIPPLE EASTWARD OUT
OF THE MIDWEST AND GREAT LAKES.
A STRONGER TROUGH WILL DEEPEN OVER SOUTHERN CANADA AND OVER THE
GREAT LAKES REGION TOWARDS THE END OF THE WEEK. THIS SHOULD RESULT
IN A FAIRLY STRONG FRONTAL PASSAGE SOMETIME LATER WED OR THU AS
SLIGHTLY COOLER BUT MUCH DRIER AIR SLIDES OUT OF THE GR LAKES.
FROM THERE THE UPPER PATTERN ADVERTISED IN SOME LONGER RANGE
GUIDANCE TAKES ON A LOOK THAT IS EERILY FAMILIAR TO WHAT WE HAVE
JUST EXPERIENCED...WITH A NEW CUTOFF LOW FCST TO FORM OVER THE
EASTERN US...AND A RENEWED SURGE OF DEEP SOUTHERLY FLOW
EVENTUALLY EXPECTED TO DEVELOP ONCE AGAIN OVER THE EASTERN US. A
POTENTIAL COMPLICATING FACTOR IS A TROPICAL SYSTEM CURRENTLY WELL
OUT IN THE ATLANTIC THAT THE TROPICAL MODELS TRACK INTO THE
BAHAMAS BY LATE WEEK...MAKING A TANTALIZING FEATURE FOR THE
EASTERN US TROF TO PERHAPS INTERACT WITH.
WHAT HAS BEEN INTERESTING SO FAR THIS JULY HAS BEEN THE RATHER
HIGH LATITUDE THE BERMUDA RIDGE HAS OCCUPIED FOR SO EARLY IN THE
SEASON. THE LATEST PROGS ONCE AGAIN HAVE A STRONG CLOSED UPPER
HIGH AT UNUSUALLY HIGH LATITUDES BY NEXT WEEKEND. IF THE TROPICAL
SYSTEM CAN MANAGE TO HOLD TOGETHER...IT WOULD SUGGEST THE EASTERN
SEABOARD WOULD BE VULNERABLE IN ABOUT A WEEK`S TIME. STAY TUNED.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
WIDESPREAD VFR CONDS NOTED ACROSS CENTRAL PA AS OF 23Z. HOWEVER...SOME
DETERIORATION IN FLYING CONDS EXPECTED OVERNIGHT...MAINLY ACROSS
THE W MTNS. A TROUGH OF LOW PRES APPROACHING FROM THE OHIO VALLEY
WILL PRODUCE A FEW -SHRA ACROSS THE W MTNS EARLY THIS EVENING AND
FOR MUCH OF THE NIGHT ACROSS EASTERN PA. HOWEVER...THE BIG
AVIATION CONCERN IS THE POTENTIAL OF LOW CIGS ALONG THE SPINE OF
THE APPALACHIANS FROM JST NORTH THRU BFD. ABUNDANT LOW LVL
MOISTURE ASCENDING THE W MTNS COULD PRODUCE LOW CIGS ACROSS THE
LAUREL HIGHLANDS AS EARLY AS THIS EVENING /23Z OBS AT K2G4 ALREADY
SHOWING 100 PCT RH/. THE LOW CIG THREAT COULD SPREAD NORTH ALONG
THE ALLEGHENY MTNS TOWARD BFD LATE TONIGHT AS BLYR COOLS/MOISTENS.
LATEST SREF AND RAP OUTPUT BOTH SUPPORT THIS POTENTIAL OF IFR
CONDS ACROSS THE W MTNS...BUT NOT CERTAIN ENOUGH TO INCLUDE IN
FCST YET. FURTHER EAST...FOG IS CERTAINLY A POSSIBILITY...GIVEN
THE WET GROUND AND PARTIAL CLEARING EXPECTED LATE TONIGHT.
HOWEVER...PRES GRADIENT SUGGESTS THERE WILL BE ENOUGH OF A WIND TO
PRECLUDE IFR VSBYS.
ANY EARLY LOW CIGS/FOG SHOULD MIX OUT TO VFR CONDS ARND 12Z. FOR
THE REST OF MONDAY...EXPECT WIDESPREAD VFR CONDS. HOWEVER...PASSAGE
OF UPPER LVL TROUGH WILL BRING THE CHC OF A BRIEF SHRA/TSRA AND
ACCOMPANYING DROP IN VSBY.
OUTLOOK...
TUE...AM SHRA/LOW CIGS POSS W MTNS.
WED-THU...AM LOW CIGS POSS W MTNS. SCT TSRA IMPACTS POSS...MAINLY PM.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...DEVOIR/LA CORTE/RXR
SHORT TERM...LA CORTE
LONG TERM...LA CORTE/GARTNER
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
759 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS WILL
PERSIST INTO THE UPCOMING WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
SEVERE THREAT WINDING DOWN RAPIDLY ACROSS FAR EASTERN PORTIONS OF
MY CWA. MODERATE SHOWERS CONTINUE OVER EASTERN HALF IN THE COLD
POOL AND WILL TAKE A FEW MORE HOURS TO DISSIPATE AND PROPOGATE
EASTWARD. ISOLATED ACTIVITY WILL STILL BE POSSIBLE FROM LATE
EVENING OVERNIGHT. ANOTHER MUGGY NIGHT IS IN STORE WITH AREAS OF
RIVER VALLEY FOG MORE PREVALENT THAT RECENT MORNINGS DUE TO
WIDESPREAD NATURE OF THIS AFTERNOON`S CONVECTION. MINS WILL RANGE
FROM THE LOWER 60S NORTHWEST TO THE LOWER 70S SOUTHEAST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH 6 PM MONDAY/...
SHORT RANGE GUIDANCE AGREES IN TRACKING THE REMNANTS OF THE
AMAZINGLY PERSISTENT UPPER LOW/TROF THROUGH THE REGION OVERNIGHT
AND EARLY MONDAY. THIS SYSTEM HAS ACTED AS A MOISTURE PUMP INTO
THE NE US FOR OVER A WEEK AND ITS DEMISE WILL MARK A TRANSITION
TO MORE OF A ZONAL FLOW ALOFT TO START THE NEW WORK WEEK.
THE BEST FORCING WITH THE UPPER LOW IS EXPECTED TO PASS LATER
TONIGHT...DURING THE NORMAL DIURNAL LULL IN INSTABILITY. IT WILL
LIKELY KEEP A BETTER CHANCE OF SHOWERS GOING DEEPER INTO THE
OVERNIGHT THAN PREVIOUS NIGHTS WITH LOCALLY HEAVY RAIN LIKELY
BEING THE BIGGEST THREAT.
MONDAY WILL REMAIN WARM AND HUMID AND SCATTERED CONVECTION ONCE
AGAIN CANNOT BE RULED OUT...BUT CHANCES SHOULD BE LESS THAN RECENT
DAYS. ENSEMBLES AGREE IN SHUNTING THE AXIS OF HIGHEST PWATS EAST
OF THE AREA...AND MID LEVEL HEIGHT RISES AND WARM ADVECTION SHOULD
ALL COMBINE TO LIMIT OUR INSTABILITY.
TEMPS FROM NEAR 80 IN THE NW...TO THE MID 80S IN THE SE WILL BE
VERY CLOSE TO NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
AFTER THE PASSAGE OF THE UPPER LOW...THE UPPER PATTERN WILL BECOME
QUASI-ZONAL FOR A TIME EARLY TO MID WEEK...WITH PA BEING ON THE
SOUTHERN EDGE OF THE WESTERLIES. THE MODELS ARE CONSISTENT WITH
PERSISTENT MOIST WESTERLY FLOW WHICH WILL LEAVE THE REGION
VULNERABLE TO CONVECTION AS WEAK DISTURBANCES RIPPLE EASTWARD OUT
OF THE MIDWEST AND GREAT LAKES.
A STRONGER TROUGH WILL DEEPEN OVER SOUTHERN CANADA AND OVER THE
GREAT LAKES REGION TOWARDS THE END OF THE WEEK. THIS SHOULD RESULT
IN A FAIRLY STRONG FRONTAL PASSAGE SOMETIME LATER WED OR THU AS
SLIGHTLY COOLER BUT MUCH DRIER AIR SLIDES OUT OF THE GR LAKES.
FROM THERE THE UPPER PATTERN ADVERTISED IN SOME LONGER RANGE
GUIDANCE TAKES ON A LOOK THAT IS EERILY FAMILIAR TO WHAT WE HAVE
JUST EXPERIENCED...WITH A NEW CUTOFF LOW FCST TO FORM OVER THE
EASTERN US...AND A RENEWED SURGE OF DEEP SOUTHERLY FLOW
EVENTUALLY EXPECTED TO DEVELOP ONCE AGAIN OVER THE EASTERN US. A
POTENTIAL COMPLICATING FACTOR IS A TROPICAL SYSTEM CURRENTLY WELL
OUT IN THE ATLANTIC THAT THE TROPICAL MODELS TRACK INTO THE
BAHAMAS BY LATE WEEK...MAKING A TANTALIZING FEATURE FOR THE
EASTERN US TROF TO PERHAPS INTERACT WITH.
WHAT HAS BEEN INTERESTING SO FAR THIS JULY HAS BEEN THE RATHER
HIGH LATITUDE THE BERMUDA RIDGE HAS OCCUPIED FOR SO EARLY IN THE
SEASON. THE LATEST PROGS ONCE AGAIN HAVE A STRONG CLOSED UPPER
HIGH AT UNUSUALLY HIGH LATITUDES BY NEXT WEEKEND. IF THE TROPICAL
SYSTEM CAN MANAGE TO HOLD TOGETHER...IT WOULD SUGGEST THE EASTERN
SEABOARD WOULD BE VULNERABLE IN ABOUT A WEEK`S TIME. STAY TUNED.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
WIDESPREAD VFR CONDS NOTED ACROSS CENTRAL PA AS OF 23Z. HOWEVER...SOME
DETERIORATION IN FLYING CONDS EXPECTED OVERNIGHT...MAINLY ACROSS
THE W MTNS. A TROUGH OF LOW PRES APPROACHING FROM THE OHIO VALLEY
WILL PRODUCE A FEW -SHRA ACROSS THE W MTNS EARLY THIS EVENING AND
FOR MUCH OF THE NIGHT ACROSS EASTERN PA. HOWEVER...THE BIG
AVIATION CONCERN IS THE POTENTIAL OF LOW CIGS ALONG THE SPINE OF
THE APPALACHIANS FROM JST NORTH THRU BFD. ABUNDANT LOW LVL
MOISTURE ASCENDING THE W MTNS COULD PRODUCE LOW CIGS ACROSS THE
LAUREL HIGHLANDS AS EARLY AS THIS EVENING /23Z OBS AT K2G4 ALREADY
SHOWING 100 PCT RH/. THE LOW CIG THREAT COULD SPREAD NORTH ALONG
THE ALLEGHENY MTNS TOWARD BFD LATE TONIGHT AS BLYR COOLS/MOISTENS.
LATEST SREF AND RAP OUTPUT BOTH SUPPORT THIS POTENTIAL OF IFR
CONDS ACROSS THE W MTNS...BUT NOT CERTAIN ENOUGH TO INCLUDE IN
FCST YET. FURTHER EAST...FOG IS CERTAINLY A POSSIBILITY...GIVEN
THE WET GROUND AND PARTIAL CLEARING EXPECTED LATE TONIGHT.
HOWEVER...PRES GRADIENT SUGGESTS THERE WILL BE ENOUGH OF A WIND TO
PRECLUDE IFR VSBYS.
ANY EARLY LOW CIGS/FOG SHOULD MIX OUT TO VFR CONDS ARND 12Z. FOR
THE REST OF MONDAY...EXPECT WIDESPREAD VFR CONDS. HOWEVER...PASSAGE
OF UPPER LVL TROUGH WILL BRING THE CHC OF A BRIEF SHRA/TSRA AND
ACCOMPANYING DROP IN VSBY.
OUTLOOK...
TUE...AM SHRA/LOW CIGS POSS W MTNS.
WED-THU...AM LOW CIGS POSS W MTNS. SCT TSRA IMPACTS POSS...MAINLY PM.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...DEVOIR/LA CORTE/RXR
SHORT TERM...LA CORTE
LONG TERM...LA CORTE/GARTNER
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
625 PM CDT SUN JUL 7 2013
.AVIATION...
VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS.
JORDAN
&&
.PREV DISCUSSION... /ISSUED 344 PM CDT SUN JUL 7 2013/
SHORT TERM...
A FLATTENED AND QUASI-ZONAL UA RIDGE HAS SHIFTED TO THE SOUTHERN
PLAINS...WITH THE CENTER DRAPED FROM THE SOUTHERN PLAINS TO WRN NM.
A PLUME OF PACIFIC MOISTURE CONTINUED TO SPILL ACROSS THE CWA
RESULTING IN FEW-SCT HIGH LEVEL CLOUDINESS. MID-UPPER LEVEL
THICKNESS VALUES ARE SLIGHTER LOWER THAN YESTERDAY DURING THIS
TIME...BUT WARM TEMPS STILL PREVAILED WITH HIGHS IN THE UPPER 80S TO
LOWER 90S ON THE CAPROCK TO LOWER TO MID 90S OFF THE CAPROCK A SFC
TROUGH WAS LOCATED FROM SWRN KS TO SOUTH CENTRAL NM...THOUGH THE
PRESSURE GRADIENT WAS NOT AS STRONG AS PREVIOUS DAYS AND THUS SRLY
WIND SPEEDS WERE NOT OVERLY BREEZY LATE THIS AFTN /10-20 MPH/. THE
CO-EXISTENCE OF THE AFOREMENTIONED SFC TROUGH WITH THE BEST THETA-E
AXIS...IN ADDITION TO OROGRAPHIC INFLUENCES AND DAYTIME
DESTABILIZATION...CAUSED THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS ACROSS THE HIGHER MOUNTAINOUS TERRAIN OF ERN NM AND
SERN CO. WITH THE UA RIDGE TAKING UP RESIDENCE ACROSS THE SOUTHERN
PLAINS...STEERING FLOW IS RATHER WEAK WHICH WILL MAKE MOUNTAINOUS
AREA STORMS HARD PRESSED TO REACH THE FA /THIS HAS BEEN THE CASE THE
PAST FEW DAYS/. HOWEVER...A FEW ELEVATED LIGHT SHOWERS HAVE
DEVELOPED ACROSS THE FAR SWRN TEXAS PANHANDLE...COINCIDING WITH
ADEQUATE ALBEIT WEAK MID-LEVEL MOISTURE CONVERGENCE. THE RUC HAS
PICKED UP ON THIS SIGNAL WITH HINTS OF IT EXPANDING TO THE NWRN
ZONES LATER THIS AFTN...BEFORE WANING AOA SUNSET.
THE PLUME OF PACIFIC MOISTURE TRAPPED BENEATH THE RIDGE WILL ENSUE
TONIGHT...ALTHOUGH IT IS PROGGED TO THIN AND BE CONFINED TO THE WRN
PANHANDLES AND FAR NWRN ZONES. MID-LEVEL ASCENT ACROSS THE SAID
AREA ARE NOT THAT IMPRESSIVE...BUT MODELS DO EXHIBIT LIGHT QPF
SIGNALS NEAR THE TX/NM BORDER OR JUST WEST OF THE CWA. DUE TO RECENT
NIGHTS OF NOCTURNAL ACTIVITY...WILL GO AHEAD AND RAISE POPS TO
MENTIONABLE LEVELS ACROSS THE FAR NWRN ZONES. WEAKENED OVERNIGHT LLJ
EQUATES RELATIVELY LIGHT SERLY SFC WINDS...BUT MILD TEMPS ARE STILL
ANTICIPATED /MID 60S NW TO 70S EAST/. TOMORROW...UA RIDGING AND WARM
TEMPS WILL ENSUE /LOW TO MID 90S ON THE CAPROCK TO MID UPPER 90S OFF
THE CAPROCK/ THOUGH THE CENTER OF THE RIDGE WILL RETROGRADE TO AZ/NM
WHILST A GULF OF MEXICO WEAKNESS TREKS WNW ACROSS SRN TX. NOT
EXPECTING THIS WEAKNESS TO PROVIDE THE CWFA WITH ANY MAJOR CHANGES
WITH REGARD TO SENSIBLE WX...WITH THE EXCEPTION OF DEWPOINTS
INCREASING INTO THE LOW 60S AND NEARING MID-LEVEL CLOUDINESS FOR THE
FAR SERN ZONES. PLUME OF PACIFIC MOISTURE WILL ALSO SHIFT WEST TO
MORE SO ACROSS NM WHERE BEST PRECIP CHANCES WILL RESIDE. /29
LONG TERM...
FEW CHANGES ONCE AGAIN THIS FORECAST PACKAGE...AS THE LARGE UPPER
LEVEL HIGH PRESSURE RIDGE WILL DOMINATE OUR WEATHER THROUGH THE
WEEK AND LIKELY THE WEEKEND AS WELL. PRECIPITATION SIGNALS THIS
COMING WEEK ARE HARD TO COME BY...THOUGH ONE WE ARE SEEING
CONSISTENTLY IS IN THE LATE WEDNESDAY AND EARLY THURSDAY TIME-
FRAME AS A WAVE DIGS INTO THE NORTHERN GREAT LAKES WITH A
WEAKENING SURFACE FRONTAL BOUNDARY LURCHING SLOWLY SOUTHWARD. THE
LATEST RUNS DO NOT APPEAR TO WEAKEN THE RIDGE VERY MUCH AND
STEERING FLOW SHOULD REMAIN VERY WEAK. BUT SOLUTIONS HAVE BEEN
PAINTING THUNDER DEVELOPMENT NEAR THIS BOUNDARY ACROSS THE TEXAS
PANHANDLE INTO WESTERN OKLAHOMA...AND EVEN VERY NEAR THE RED RIVER
BY EARLY THURSDAY. BULK OF SOLUTIONS...HOWEVER...APPEAR TO BOUND
THE ACTIVITY JUST TO THE NORTH AND EAST OF THE NORTHERN ROLLING
PLAINS. WE WILL RETAIN THE JUST SUB-MENTIONABLE LEVEL OF
PRECIPITATION UNTIL WE SEE MORE SIGNALS WITHIN OUR AREA. FOLLOWING
THIS WAVE...THE UPPER RIDGE STILL APPEARS TO SPRING BACK TO THE
NORTH AND EAST...CENTERED JUST TO OUR NORTH FOR THE END OF THE
WEEK INTO THE EARLY WEEKEND. THIS STILL SHOULD ACCOUNT FOR
SLIGHTLY HOTTER TEMPERATURES AND WE HAVE BOOSTED HIGHS A DEGREE OR
TWO ABOVE THE PREVIOUS FORECAST. FINALLY...BY LATE IN THE WEEKEND
THE RIDGE IS EXPECTED TO RETROGRADE TO OUR WEST AS A SOUTHWESTWARD
MOVING UPPER LOW TRAVERSES THE DEEP SOUTH PERHAPS CROSSING WEST OF
THE MISSISSIPPI BY MONDAY. LOTS OF QUESTIONS ABOUT THIS PATTERN...
THOUGH SOME LEVEL OF COOLING ALONG WITH A MOISTURE INCREASE SEEM
FAIRLY CERTAIN. MOST OF THE REAL CHANGES... HOWEVER...WILL BE IN
DAY 8 AND BEYOND. STAY TUNED. RMCQUEEN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 66 93 67 95 67 / 20 10 10 10 10
TULIA 66 95 69 97 69 / 10 10 10 10 10
PLAINVIEW 67 93 69 96 69 / 10 10 10 10 10
LEVELLAND 67 94 68 94 68 / 10 10 10 10 10
LUBBOCK 68 95 70 96 70 / 10 10 10 10 10
DENVER CITY 68 94 67 93 67 / 10 10 10 10 10
BROWNFIELD 69 94 67 95 68 / 10 10 10 0 10
CHILDRESS 70 98 73 100 74 / 0 0 0 0 10
SPUR 70 97 71 97 71 / 0 0 0 0 10
ASPERMONT 71 98 72 100 73 / 0 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/99
AREA FORECAST DISCUSSION
NWS SPOKANE WA
229 PM PDT Sat Jul 6 2013
.SYNOPSIS...
Mainly clear skies and light winds are expected through Monday.
There will be a chance for thunderstorms over the North Cascades
this evening and once again on Sunday. Tuesday should be the
warmest day of the week with high temperatures in the upper 80s to
mid 90s. Wednesday will be locally breezy with the arrival of a
cold front. The front will knock temperatures back close to normal
for Thursday, Friday, and Saturday.
&&
.DISCUSSION...
Tonight: Isolated thunderstorms have been retained in the forecast
for this evening over the north Washington Cascades and for the
high terrain near Bonners Ferry...Clark Fork...and Priest Lake.
Showers have been slow to develop this afternoon. As of 2 PM, a
couple of weak cells were evident over far north Idaho, but
nothing resembling deep convection. The RUC surface based CAPE
analysis depicts more instability over the Cascade crest from
Snoqualmie Pass north into southern B.C. The NAM, GFS, SREF and
HRRR all produce at least a little convective precipitation over
the Cascades between 3 PM and 8 PM, so a 20 percent chance of
terrain based thunderstorms has been retained through early this
evening. For the remainder of north Idaho and east Washington,
mainly light winds and mostly clear skies will be the rule for
tonight. Great weather for the 4th of July weekend.
Sunday: Our main area of interest for Sunday will once again be
the north Washington Cascades. A more dynamic upper low (currently
off the coast of central B.C.) will dig over northwest Washington
on Sunday afternoon. Look for thunderstorms to initiate by early
to mid afternoon on Sunday from Stevens Pass and points north.
Instability and shear parameters resemble what we saw yesterday
over the Okanogan Highlands, so locally heavy rain, small hail,
and gusty winds will be possible. The mention of thunderstorms has
been added to the Hazardous Weather Outlook. The East Slopes of
the Cascades is a potentially high impact area. The 25-Mile
Wildfire on the north shore of Lake Chelan is susceptible to
erratic thunderstorm outflow. The 2012 burn scars around Wenatchee
and Chelan are also prone to mud slides and flash flooding. At
this time, the model consensus is for the most concentrated
thunderstorm activity to be north of Lake Chelan. The thunderstorm
threat will certainly be worth monitoring Sunday and Sunday
evening. East of the Cascades, the weather looks much more benign.
Mainly sunny skies and light winds are expected once again on
Sunday. /GKoch
Sunday night, Monday and Monday night: There will be a chance of
showers and thunderstorms across the northern mountains as an
upper level trough axis swings across the Inland NW. After the
diurnally driven convection wanes Sunday evening, upper level
dynamics will take over and keep the threat of showers with
embedded thunderstorms going from the far northern Cascades,
across the Okanogan Highlands and into the Northeast Mountains and
far north Idaho late Sunday night and into Monday morning. There
is also a smaller possibility of convection across the Blue
mountains and into the central ID panhandle where a wedge of mid
level instability develops. Meanwhile winds will be gusty in the
Cascade valleys Sunday night and spilling into the Columbia Basin.
The upper level disturbance will exit by Monday afternoon although
lingering low level instability will keep the mention of afternoon
and evening convection across northeast Washington and north
Idaho. Drier westerly flow will move into the region Monday night
as high pressure moves into the region. Temperatures will be
running slightly above normal. /rfox.
Tuesday through Thursday: A ridge of high pressure shifts east
and opens the door for the passage of two or three systems. The
main result looks to be, after peak heating on Tuesday, a slight
cool-down and locally breezy afternoon and/or evening conditions.
All models show lower afternoon relative humidity, especially
Wednesday. The critical winds may not sync with the lowest
humidity. Yet this will be monitored for possible impacts for fire
weather concerns. The passing systems suggest possible shower
chances. A weak impulse slips by the northern Cascades and
Canadian border Tuesday as the ridge axis is shifting east. While
models are not in total agreement on its timing, more than half
indicate some afternoon CAPE in the above locations. So I kept a
slight chance of showers and thunderstorms going here.
A second, deeper shortwave passes Wednesday afternoon into
Thursday morning and a third wave comes up from the southwest
Thursday afternoon. First during the day Wednesday the deeper wave
drops down the BC coast toward WA, while a jet streak comes up
through northern CA and OR. The BC shortwave pivots inland
sometime between late Wednesday afternoon and Wednesday night. The
deepest lift appears to remain north of the Canadian border. Yet a
cold front crossing eastern Washington into northern Idaho late
Wednesday into Thursday morning and jet streak coming up from
southwest will provide some lift. The third shortwave rides up
along the stalled front. Slower models bring this wave by
southeast Washington and northern Idaho; other keep it across
Oregon and central and southern Idaho.
The question is: will there be enough instability and/or moisture
when these features come through to generate any precipitation?
The continued disagreements in timing lessen forecaster
confidence. I kept shower and thunderstorms chance going across
the northern mountains, as well as near the Blues through central
Panhandle. But the overall best instability remains around but not
over eastern WA and northern ID, so the precipitation chances
remain low. /J. Cote`
Thursday Night through Saturday: Pattern for this period looks
rather active compared to what we have seen in the recent past.
Models are in decent agreement given this being quite a ways out.
Late Friday into Saturday will see a system pushing in from the NW
bringing some moisture with it. By the end of this time frame we
will have the upper level low continue to push to the east and
out of our area diminishing the threat for showers.
Examining the threat for showers we will see the system track
along the USA/BC border and increase the chances for showers in
these areas but overall the best chances look to be in NE WA and
the N Idaho Panhandle as that is where the models put the majority
of the QPF. Increased chances for showers and thunderstorms will be
present throughout the day on Saturday. Currently the mention of
showers is for the higher elevations as topography will likely play
a key role initiating the showers. The Euro brought the system to
the south much further than the previous run following what the
GFS had been showing. This brings higher confidence of the
event...the question will be whether t-storms are present or if it
is simply showers. Total totals would be supportive along with
shear and the upper level cold pool with the system...but very
limited CAPE and positive LIs would hinder storm development.
This will be something we watch in the upcoming days to see how
models bring this system in.
The other thing to keep an eye on will be the winds as they will
pick up with the passing of the system due to the tightened gradient.
Currently only breezy conditions are in the forecast...but if the
track of the system would change this could lead to increased
winds. As we progress closer to the event model agreement will
hopefully increase allowing for more confidence in this weekend
system. /Fliehman
&&
.AVIATION...
18Z TAFS: Mainly clear skies and light winds are anticipated for
the TAF sites of eastern Washington and north Idaho through 18z
Sunday. Isolated showers and thunderstorms may be encountered in
the 20z-03z time frame over the mountain peaks near Bonners Ferry
and over the high terrain north and west of the Methow Valley in
the north Washington Cascades. /GKoch
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 56 85 58 84 58 88 / 0 0 0 10 0 0
Coeur d`Alene 53 84 55 82 53 86 / 0 0 0 10 10 0
Pullman 46 83 51 83 49 87 / 0 0 10 10 0 0
Lewiston 57 92 61 91 60 95 / 0 0 10 10 0 0
Colville 50 88 53 87 53 91 / 10 10 20 20 10 10
Sandpoint 47 83 51 81 50 85 / 10 0 10 30 20 10
Kellogg 52 83 54 82 54 85 / 10 0 0 20 10 0
Moses Lake 56 91 59 91 58 94 / 0 0 10 0 0 0
Wenatchee 61 89 61 89 63 92 / 0 10 10 0 0 0
Omak 56 89 56 90 58 93 / 0 10 20 10 0 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
949 PM CDT SUN JUL 7 2013
.UPDATE...
ISSUED AT 949 PM CDT SUN JUL 7 2013
FORECAST STILL REMAINS PROBLEMATIC FOR TONIGHT. CONVECTION THAT
WENT UP ALONG THE SURFACE TROUGH CONTINUES TO PUSH TOWARDS THE
FORECAST AREA...IN PARTICULAR SOUTHEAST MINNESOTA. THIS IS DESPITE
MLCAPE VALUES THAT HAVE DROPPED TO 500-1000 J/KG AND MLCIN THAT
HAVE CLIMBED TO 100-150 J/KG. THE IMPACT OF THESE TWO VARIABLES
HAS DEFINITELY KNOCKED DOWN THE AMOUNT OF LIGHTNING...AND IT
APPEARS OUTFLOWS COMBINING WITH THE SURFACE TROUGH ARE WHAT IS
HELPING TO KEEP SOME SHOWER ACTIVITY GOING. NOT SURE IF THE
SHOWERS WILL LAST MORE THAN A FEW MORE HOURS...THOUGH...SINCE EACH
PASSING HOUR WILL MEAN LESS CAPE AND MORE CIN.
JUST TO OUR NORTH OVER NORTHERN WISCONSIN...NUMEROUS SHOWERS AND
SOME THUNDERSTORMS HAVE DEVELOPED THERE. THESE ARE ON THE NOSE OF
AN 850MB MOISTURE TRANSPORT CORE. THIS CORE LIFTS UP TOWARDS UPPER
MICHIGAN IN THE NEXT FEW HOURS...SO THINKING MUCH OF THE
CONVECTION MAY DO THE SAME...KEEPING TAYLOR/CLARK COUNTIES OUT OF
MUCH SHOWER ACTIVITY.
OVERNIGHT...LATEST 08.01Z RAP HAS ANOTHER 850MB MOISTURE TRANSPORT
SURGE COMING UP OUT OF CENTRAL IOWA...IGNITING CONVECTION BY 07Z
JUST EAST OF THE MS RIVER. HAVE LEFT THE 20-30 PERCENT CHANCES
GOING OVERNIGHT FOR THIS SCENARIO. CONFIDENCE IS STILL LOW ON WHAT
WILL HAPPEN OVERNIGHT...ESPECIALLY BECAUSE THE OVERALL LOW TO MID
LEVEL MOISTURE TRANSPORT IS VEERING MORE EASTERLY IN RESPONSE TO
THE 500MB FLOW TURNING ZONAL...AS WELL AS THAT SURFACE TROUGH
MOVING INTO THE FORECAST AREA.
UPDATE ISSUED AT 650 PM CDT SUN JUL 7 2013
CONVECTIVE THOUGHTS FOR TONIGHT...
AT 2330Z...CLUSTER OF UNORGANIZED SHOWERS AND THUNDERSTORMS
CONTINUES JUST NORTH AND WEST OF MINNEAPOLIS. THESE ARE ALONG A
LOW PRESSURE TROUGH STRETCHING FROM NORTHWEST WISCONSIN INTO
SOUTHWEST MN. TEMPERATURES IN THE UPPER 80S COMBINED WITH
DEWPOINTS POOLING TO NEAR 70F ALONG THE TROUGH RESULTING IN
MLCAPES 2000-2500 J/KG AND NO MLCIN. LACK OF 0-6 KM SHEAR HAS KEPT
THESE UNORGANIZED...WITH OUTFLOWS OCCASIONALLY POPPING UP STORMS. TO
THE WEST...ANOTHER CLUSTER OF SHOWERS AND THUNDERSTORMS BUT MUCH
MORE ORGANIZED HAS BEEN PROGRESSING ACROSS EASTERN SOUTH DAKOTA.
0-6KM SHEAR THERE IS AROUND 40 KT...COMPARED TO LESS THAN 30 OVER
CENTRAL MN. THE STORMS IN SOUTH DAKOTA ARE TAKING ON A
SOUTH/SOUTHEASTWARD MOTION...THOUGH...INTO THE HIGHER INSTABILITY
PRESENT IN EASTERN NEBRASKA WHERE UPWARDS OF 3500 J/KG OF MLCAPE IS
SUGGESTED BY THE RAP.
THE FORECAST TONIGHT IS VERY UNCERTAIN FOR PRECIPITATION BEING
OBSERVED OVER THE FORECAST AREA. STORMS OVER CENTRAL MINNESOTA ARE
SURFACE BASED INITIATED FROM DAYTIME HEATING...THUS ONCE
TEMPERATURES BEGIN TO COOL...THEY SHOULD ALL DIMINISH DURING THE
EVENING HOURS...PERHAPS BY 10 PM. ADDITIONALLY...RAP MLCAPE
ANALYSIS SHOWS AN AREA OF 50 TO 200 MLCIN ALREADY PRESENT FROM
NORTHEAST IOWA INTO SOUTHEAST MN...PROVIDING PROTECTION FROM
STORMS MOVING IN THERE. NOW SOME SURFACE BASED STORMS COULD GO UP
IN THE NEXT HOUR OR SO UP IN TAYLOR/CLARK COUNTIES IF THE LOW
PRESSURE TROUGH CAN SINK SOUTH INTO THAT AREA. TO THE WEST...THERE
WAS CONCERN FROM THE PREVIOUS FORECAST THE STORMS OVER SOUTH
DAKOTA COULD TRACK EAST INTO OUR AREA. HOWEVER...THESE AS NOTED
EARLIER ARE DROPPING MORE SOUTH. 07.22Z RAP 925-700MB MOISTURE
TRANSPORT FOR EARLY THIS EVENING IS FOCUSED MORE INTO
NEBRASKA...THEN VEERS EAST INTO IOWA AND FOCUSES JUST SOUTH OF THE
FORECAST AREA. THUS...IT IS ENTIRELY POSSIBLE THE FORECAST AREA
MOSTLY ENDS UP DRY TONIGHT. OVERALL PRECIPITATION CHANCES SEEM
REASONABLE FOR NOW...BUT MAY HAVE TO LOWER THEM OR DRY THEM OUT
ENTIRELY IN A FEW HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 305 PM CDT SUN JUL 7 2013
THE MAIN FOCUS GOING INTO TOMORROW IS WITH THE CHANCES FOR RAIN
SHOWERS/THUNDERSTORMS AS A COLD FRONT MOVES THROUGH THE REGION.
CURRENTLY...A HUMID AIR MASS IS IN PLACE AT THE SURFACE AS DEW
POINTS CONTINUE TO RISE IN RESPONSE TO AN INCREASE OF LOW LEVEL
MOISTURE TRANSPORT OUT OF THE GULF. SURFACE ANALYSIS SHOWS TWO
COLD FRONTS IN THE VICINITY OF WESTERN MINNESOTA. THE FIRST ONE
EXTENDS FROM NORTHERN WISCONSIN DOWN THROUGH SOUTH CENTRAL
MINNESOTA AND EASTERN NEBRASKA. THE SECOND COLD FRONT IS JUST TO
THE WEST OF THIS OTHER FRONT AND EXTENDS FROM A SURFACE LOW IN
SOUTHERN MANITOBA DOWN THROUGH WESTERN MINNESOTA AND EASTERN SOUTH
DAKOTA. WITH DEW POINTS IN THE LOW 70S BETWEEN THESE TWO
FRONTS...07.19Z RAP ANALYSIS SHOWS AN AXIS OF 3000 J/KG OF SURFACE
BASED CAPE. CONVECTION HAS INITIATED ALONG THE FIRST FRONT AND A
LAKE BREEZE BOUNDARY NORTHWEST OF THE TWIN CITES AND DOWN ALONG
THE FRONT. FURTHER ALOFT...MID LEVEL RIDGING EXTENDS FROM THE
SOUTHERN PLAINS THROUGH THE UPPER GREAT LAKES. A MID LEVEL SHORT
WAVE TROUGH IS CURRENT IN THE DAKOTAS AND WILL TRACK TO THE EAST
THROUGH TONIGHT AND IS TIED TO THE SECONDARY COLD FRONT.
THE ENVIRONMENT AHEAD OF THE COLD FRONTS APPEARS TO BE CAPPED
AROUND 800MB...SO AM NOT EXPECTING ANY DEVELOPMENT OUT IN THE WARM
SECTOR DESPITE THE HIGH CAPE ENVIRONMENT. THE MAIN CHANCES WILL
BE AS THE FRONT AND WEAKENING MID LEVEL TROUGH COME THROUGH THIS
EVENING AND OVERNIGHT. THE FRONT WILL THEN PUSH THROUGH AND STALL
TO THE SOUTH OF THE REGION IN IOWA ON MONDAY. HAVE DROPPED THE
PRECIPITATION CHANCES DOWN A LITTLE ON MONDAY AS IT LOOKS LIKE
SURFACE TO UPPER LEVEL RIDGING WILL SETTLE IN FOR A BRIEF PERIOD
AND KEEP THE REGION MORE ON THE DRY SIDE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 305 PM CDT SUN JUL 7 2013
THE MAIN FOCUS IN THE LONG TERM IS ON MONDAY NIGHT INTO TUESDAY
AND WITH WHERE A MESOSCALE CONVECTIVE SYSTEM WILL DEVELOP AND
TRACK THROUGH ON TUESDAY MORNING.
THE 07.12Z GUIDANCE CONTINUES TO GIVE SOME UNCERTAINTY WITH THE
TRAJECTORY OF THIS MCS. THE GFS/NAM TAKE A MORE SOUTHERLY ROUTE
ACROSS IOWA DUE TO THE LOW LEVEL JET/MOISTURE TRANSPORT ONLY
REACHING EASTERN NEBRASKA BY 6Z TUESDAY. THE PREFERRED GUIDANCE IS
FROM THE ECMWF/GEM SOLUTION WHICH PUSH THE LLJ NOSE INTO EASTERN
SOUTH DAKOTA BY THIS TIME...AND DESPITE THE GEM/ECMWF SHOWING THE
MAIN QPF STAYING WELL TO THE NORTH OF THE REGION TOWARD
DULUTH...AM CONCERNED THAT THE MCS WOULD DEVELOP IN WESTERN
MINNESOTA AND RUN EAST SOUTHEAST ALONG THE NOSE OF THE LOW LEVEL
JET AND INSTABILITY GRADIENT. THIS IDEA FOLLOWS WELL WITH FORECAST
CORFIDI VECTORS WHICH POINT TO THE SOUTHEAST TUESDAY
MORNING...WHICH WOULD TAKE IT STRAIGHT THROUGH THE MIDDLE OF THE
FORECAST AREA ALONG THE MINNESOTA/IOWA BORDER INTO WESTERN
WISCONSIN. GIVEN THE MODEL DIFFERENCES...HAVE NOT HIT THE
PRECIPITATION CHANCES TOO HIGH YET AND WILL HAVE TO SEE HOW THE
PATTERN EVOLVES INTO TOMORROW. WITH THE INCREASING MOISTURE
TRANSPORT AND POTENTIAL FOR HEAVY RAIN...FLASH FLOODING WILL BE A
THREAT DESPITE THE RECENT DRY SPELL. DETAILS ARE OUTLINED IN THE
HYDROLOGY AFD SECTION.
THIS MCS CAUSES SOME HAVOC GOING INTO THE AFTERNOON ON TUESDAY
AND WHAT THE SEVERE THUNDERSTORM CHANCES ARE AFTER ITS PASSAGE. IF
THE SYSTEM TRACKS TO THE SOUTH...THEN IT LIKELY KEEPS THE MAIN
WARM FRONT DOWN THERE AS WELL AND LIMITS THE SEVERE POTENTIAL. IF
IT TRACKS THROUGH THE HEART OF THE FORECAST AREA...AS WE THINK IT
MAY...THE QUESTION WILL BE HOW FAST DOES IT CLEAR AND ALLOW THE
ENVIRONMENT TO RECHARGE BY PEAK HEATING. IF THE SYSTEM WERE TO
CLEAR EARLY ENOUGH AND ALLOW FOR DESTABILIZATION BY LATE AFTERNOON
OUR SEVERE THREAT WOULD BE FAIRLY HIGH DUE TO A VEERING 0-6KM
SHEAR PROFILE...HIGH INSTABILITY...AND DEEP FORCING FROM A SURFACE
LOW AND MID LEVEL TROUGH. WITH A LINGERING OUTFLOW BOUNDARY/WARM
FRONT IN THE REGION...THE HAZARDS WOULD INCLUDE LARGE
HAIL...FLASH FLOODING...DAMAGING WINDS AND THE POSSIBILITY OF A
TORNADO OR TWO GIVEN THE HIGH 0-1KM SHEAR/HELICITY. THE THING
IS...CONFIDENCE IS JUST NOT THERE YET TO LEAN ONE WAY OR ANOTHER
UNTIL THERE IS BETTER CONSENSUS ON THE TRACK OF THE EARLY MORNING
MCS.
BEYOND THIS SYSTEM...IT LOOKS LIKE A DRY AND SEASONAL PERIOD
THROUGH THE REST OF THE WEEK AS UPPER LEVEL RIDGING SETS UP ACROSS
THE UPPER MISSISSIPPI RIVER VALLEY. A COLD FRONT WILL APPROACH THE
REGION FROM THE WEST BY NEXT WEEKEND AND COULD BRING THE NEXT SHOT
OF RAIN ALONG WITH IT. THERE ARE SOME TIMING DIFFERENCES BETWEEN
THE 07.12Z GFS AND ECMWF WITH THIS FEATURE THAT WILL BE RUNNING
INTO THE RIDGING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 650 PM CDT SUN JUL 7 2013
DRY LOW LEVEL AIR JUST ABOVE THE SURFACE AGAIN HELPING TO PROMOTE
VFR CONDITIONS AT BOTH TAF SITES EARLY THIS EVENING. THERE ARE
STORMS JUST TO THE NORTH AND WEST OF MINNEAPOLIS...BUT THESE ARE
HIGHLY TIED TO DAYTIME HEATING AND SHOULD DISSIPATE BEFORE THEY
CAN APPROACH RST OR LSE. OTHER STORMS ACROSS EASTERN SOUTH DAKOTA
ARE TRACKING MORE SOUTH VERSUS EAST...THUS ARE LIKELY TO MISS THE
TAF SITES AS WELL. SO ALTHOUGH A TROUGH OF LOW PRESSURE CURRENTLY
IN CENTRAL MINNESOTA IS FORECAST TO DROP THROUGH THE TAF SITES
LATE TONIGHT...HAVE KEPT THE TAF FORECASTS DRY. WITH THE CONCERN
NOW THAT NO PRECIPITATION WILL OCCUR AT EITHER TAF SITE...FOG
SHOULD NOT BE AS MUCH OF AN ISSUE GIVEN LACK OF RAINFALL RECENTLY.
HAVE RAISED VISIBILITIES TO 5 SM AT BOTH TAF SITES FOR
09-13Z...AND THIS MIGHT NEED TO BE RAISED HIGHER SINCE THERE MIGHT
BE CLOUDS TO DEAL WITH TO DISRUPT FOG FORMATION. VFR CONDITIONS
ARE LIKELY TO CONTINUE THROUGH THE DAY MONDAY AS LIGHT NORTHERLY
FLOW BEHIND THE TROUGH BRINGS IN SOME MORE DRIER AIR.
&&
.HYDROLOGY...TUESDAY
ISSUED AT 305 PM CDT SUN JUL 7 2013
THE MAIN HYDRO CONCERNS COME IN ON TUESDAY AS A COMPLEX OF
THUNDERSTORMS IS FORECAST TO TRACK THROUGH THE REGION. THE
QUESTION IS WHERE AND WHEN WILL IT COME THROUGH? MOST OF THE MODEL
GUIDANCE SUGGEST THAT THIS SYSTEM WILL FORM IN NORTHWEST NEBRASKA
AND RUN EAST ACROSS IOWA MONDAY NIGHT INTO TUESDAY MORNING. WITH
SHOWERS AND THUNDERSTORMS EXPECTED TO DEVELOP AHEAD OF THIS
COMPLEX NORTH OF A WARM FRONT...THE POTENTIAL IS THERE FOR SOME
HEAVY RAIN TO FALL. THANKFULLY...CONDITIONS HAVE BEEN DRY FOR THE
PAST WEEK...SO FLASH FLOOD GUIDANCE HAS COME UP CONSIDERABLY AND
THE SOIL SHOULD BE ABLE TO HANDLE THE EXCESS MOISTURE REASONABLY
WELL FOR A PERIOD. THAT SAID...INCREASING PRECIPITABLE WATER
VALUES AND LOW LEVEL MOISTURE TRANSPORT AIMING INTO THE
REGION...EXPECT THAT HEAVY RAIN AND FLASH FLOODING IS POSSIBLE
WITH SOME RENEWED RISES ON AREA RIVERS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...AJ
HYDROLOGY...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
650 PM CDT SUN JUL 7 2013
.UPDATE...
ISSUED AT 650 PM CDT SUN JUL 7 2013
CONVECTIVE THOUGHTS FOR TONIGHT...
AT 2330Z...CLUSTER OF UNORGANIZED SHOWERS AND THUNDERSTORMS
CONTINUES JUST NORTH AND WEST OF MINNEAPOLIS. THESE ARE ALONG A
LOW PRESSURE TROUGH STRETCHING FROM NORTHWEST WISCONSIN INTO
SOUTHWEST MN. TEMPERATURES IN THE UPPER 80S COMBINED WITH
DEWPOINTS POOLING TO NEAR 70F ALONG THE TROUGH RESULTING IN
MLCAPES 2000-2500 J/KG AND NO MLCIN. LACK OF 0-6 KM SHEAR HAS KEPT
THESE UNORGANIZED...WITH OUTFLOWS OCCASIONALLY POPPING UP STORMS. TO
THE WEST...ANOTHER CLUSTER OF SHOWERS AND THUNDERSTORMS BUT MUCH
MORE ORGANIZED HAS BEEN PROGRESSING ACROSS EASTERN SOUTH DAKOTA.
0-6KM SHEAR THERE IS AROUND 40 KT...COMPARED TO LESS THAN 30 OVER
CENTRAL MN. THE STORMS IN SOUTH DAKOTA ARE TAKING ON A
SOUTH/SOUTHEASTWARD MOTION...THOUGH...INTO THE HIGHER INSTABILITY
PRESENT IN EASTERN NEBRASKA WHERE UPWARDS OF 3500 J/KG OF MLCAPE IS
SUGGESTED BY THE RAP.
THE FORECAST TONIGHT IS VERY UNCERTAIN FOR PRECIPITATION BEING
OBSERVED OVER THE FORECAST AREA. STORMS OVER CENTRAL MINNESOTA ARE
SURFACE BASED INITIATED FROM DAYTIME HEATING...THUS ONCE
TEMPERATURES BEGIN TO COOL...THEY SHOULD ALL DIMINISH DURING THE
EVENING HOURS...PERHAPS BY 10 PM. ADDITIONALLY...RAP MLCAPE
ANALYSIS SHOWS AN AREA OF 50 TO 200 MLCIN ALREADY PRESENT FROM
NORTHEAST IOWA INTO SOUTHEAST MN...PROVIDING PROTECTION FROM
STORMS MOVING IN THERE. NOW SOME SURFACE BASED STORMS COULD GO UP
IN THE NEXT HOUR OR SO UP IN TAYLOR/CLARK COUNTIES IF THE LOW
PRESSURE TROUGH CAN SINK SOUTH INTO THAT AREA. TO THE WEST...THERE
WAS CONCERN FROM THE PREVIOUS FORECAST THE STORMS OVER SOUTH
DAKOTA COULD TRACK EAST INTO OUR AREA. HOWEVER...THESE AS NOTED
EARLIER ARE DROPPING MORE SOUTH. 07.22Z RAP 925-700MB MOISTURE
TRANSPORT FOR EARLY THIS EVENING IS FOCUSED MORE INTO
NEBRASKA...THEN VEERS EAST INTO IOWA AND FOCUSES JUST SOUTH OF THE
FORECAST AREA. THUS...IT IS ENTIRELY POSSIBLE THE FORECAST AREA
MOSTLY ENDS UP DRY TONIGHT. OVERALL PRECIPITATION CHANCES SEEM
REASONABLE FOR NOW...BUT MAY HAVE TO LOWER THEM OR DRY THEM OUT
ENTIRELY IN A FEW HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 305 PM CDT SUN JUL 7 2013
THE MAIN FOCUS GOING INTO TOMORROW IS WITH THE CHANCES FOR RAIN
SHOWERS/THUNDERSTORMS AS A COLD FRONT MOVES THROUGH THE REGION.
CURRENTLY...A HUMID AIR MASS IS IN PLACE AT THE SURFACE AS DEW
POINTS CONTINUE TO RISE IN RESPONSE TO AN INCREASE OF LOW LEVEL
MOISTURE TRANSPORT OUT OF THE GULF. SURFACE ANALYSIS SHOWS TWO
COLD FRONTS IN THE VICINITY OF WESTERN MINNESOTA. THE FIRST ONE
EXTENDS FROM NORTHERN WISCONSIN DOWN THROUGH SOUTH CENTRAL
MINNESOTA AND EASTERN NEBRASKA. THE SECOND COLD FRONT IS JUST TO
THE WEST OF THIS OTHER FRONT AND EXTENDS FROM A SURFACE LOW IN
SOUTHERN MANITOBA DOWN THROUGH WESTERN MINNESOTA AND EASTERN SOUTH
DAKOTA. WITH DEW POINTS IN THE LOW 70S BETWEEN THESE TWO
FRONTS...07.19Z RAP ANALYSIS SHOWS AN AXIS OF 3000 J/KG OF SURFACE
BASED CAPE. CONVECTION HAS INITIATED ALONG THE FIRST FRONT AND A
LAKE BREEZE BOUNDARY NORTHWEST OF THE TWIN CITES AND DOWN ALONG
THE FRONT. FURTHER ALOFT...MID LEVEL RIDGING EXTENDS FROM THE
SOUTHERN PLAINS THROUGH THE UPPER GREAT LAKES. A MID LEVEL SHORT
WAVE TROUGH IS CURRENT IN THE DAKOTAS AND WILL TRACK TO THE EAST
THROUGH TONIGHT AND IS TIED TO THE SECONDARY COLD FRONT.
THE ENVIRONMENT AHEAD OF THE COLD FRONTS APPEARS TO BE CAPPED
AROUND 800MB...SO AM NOT EXPECTING ANY DEVELOPMENT OUT IN THE WARM
SECTOR DESPITE THE HIGH CAPE ENVIRONMENT. THE MAIN CHANCES WILL
BE AS THE FRONT AND WEAKENING MID LEVEL TROUGH COME THROUGH THIS
EVENING AND OVERNIGHT. THE FRONT WILL THEN PUSH THROUGH AND STALL
TO THE SOUTH OF THE REGION IN IOWA ON MONDAY. HAVE DROPPED THE
PRECIPITATION CHANCES DOWN A LITTLE ON MONDAY AS IT LOOKS LIKE
SURFACE TO UPPER LEVEL RIDGING WILL SETTLE IN FOR A BRIEF PERIOD
AND KEEP THE REGION MORE ON THE DRY SIDE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 305 PM CDT SUN JUL 7 2013
THE MAIN FOCUS IN THE LONG TERM IS ON MONDAY NIGHT INTO TUESDAY
AND WITH WHERE A MESOSCALE CONVECTIVE SYSTEM WILL DEVELOP AND
TRACK THROUGH ON TUESDAY MORNING.
THE 07.12Z GUIDANCE CONTINUES TO GIVE SOME UNCERTAINTY WITH THE
TRAJECTORY OF THIS MCS. THE GFS/NAM TAKE A MORE SOUTHERLY ROUTE
ACROSS IOWA DUE TO THE LOW LEVEL JET/MOISTURE TRANSPORT ONLY
REACHING EASTERN NEBRASKA BY 6Z TUESDAY. THE PREFERRED GUIDANCE IS
FROM THE ECMWF/GEM SOLUTION WHICH PUSH THE LLJ NOSE INTO EASTERN
SOUTH DAKOTA BY THIS TIME...AND DESPITE THE GEM/ECMWF SHOWING THE
MAIN QPF STAYING WELL TO THE NORTH OF THE REGION TOWARD
DULUTH...AM CONCERNED THAT THE MCS WOULD DEVELOP IN WESTERN
MINNESOTA AND RUN EAST SOUTHEAST ALONG THE NOSE OF THE LOW LEVEL
JET AND INSTABILITY GRADIENT. THIS IDEA FOLLOWS WELL WITH FORECAST
CORFIDI VECTORS WHICH POINT TO THE SOUTHEAST TUESDAY
MORNING...WHICH WOULD TAKE IT STRAIGHT THROUGH THE MIDDLE OF THE
FORECAST AREA ALONG THE MINNESOTA/IOWA BORDER INTO WESTERN
WISCONSIN. GIVEN THE MODEL DIFFERENCES...HAVE NOT HIT THE
PRECIPITATION CHANCES TOO HIGH YET AND WILL HAVE TO SEE HOW THE
PATTERN EVOLVES INTO TOMORROW. WITH THE INCREASING MOISTURE
TRANSPORT AND POTENTIAL FOR HEAVY RAIN...FLASH FLOODING WILL BE A
THREAT DESPITE THE RECENT DRY SPELL. DETAILS ARE OUTLINED IN THE
HYDROLOGY AFD SECTION.
THIS MCS CAUSES SOME HAVOC GOING INTO THE AFTERNOON ON TUESDAY
AND WHAT THE SEVERE THUNDERSTORM CHANCES ARE AFTER ITS PASSAGE. IF
THE SYSTEM TRACKS TO THE SOUTH...THEN IT LIKELY KEEPS THE MAIN
WARM FRONT DOWN THERE AS WELL AND LIMITS THE SEVERE POTENTIAL. IF
IT TRACKS THROUGH THE HEART OF THE FORECAST AREA...AS WE THINK IT
MAY...THE QUESTION WILL BE HOW FAST DOES IT CLEAR AND ALLOW THE
ENVIRONMENT TO RECHARGE BY PEAK HEATING. IF THE SYSTEM WERE TO
CLEAR EARLY ENOUGH AND ALLOW FOR DESTABILIZATION BY LATE AFTERNOON
OUR SEVERE THREAT WOULD BE FAIRLY HIGH DUE TO A VEERING 0-6KM
SHEAR PROFILE...HIGH INSTABILITY...AND DEEP FORCING FROM A SURFACE
LOW AND MID LEVEL TROUGH. WITH A LINGERING OUTFLOW BOUNDARY/WARM
FRONT IN THE REGION...THE HAZARDS WOULD INCLUDE LARGE
HAIL...FLASH FLOODING...DAMAGING WINDS AND THE POSSIBILITY OF A
TORNADO OR TWO GIVEN THE HIGH 0-1KM SHEAR/HELICITY. THE THING
IS...CONFIDENCE IS JUST NOT THERE YET TO LEAN ONE WAY OR ANOTHER
UNTIL THERE IS BETTER CONSENSUS ON THE TRACK OF THE EARLY MORNING
MCS.
BEYOND THIS SYSTEM...IT LOOKS LIKE A DRY AND SEASONAL PERIOD
THROUGH THE REST OF THE WEEK AS UPPER LEVEL RIDGING SETS UP ACROSS
THE UPPER MISSISSIPPI RIVER VALLEY. A COLD FRONT WILL APPROACH THE
REGION FROM THE WEST BY NEXT WEEKEND AND COULD BRING THE NEXT SHOT
OF RAIN ALONG WITH IT. THERE ARE SOME TIMING DIFFERENCES BETWEEN
THE 07.12Z GFS AND ECMWF WITH THIS FEATURE THAT WILL BE RUNNING
INTO THE RIDGING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 650 PM CDT SUN JUL 7 2013
DRY LOW LEVEL AIR JUST ABOVE THE SURFACE AGAIN HELPING TO PROMOTE
VFR CONDITIONS AT BOTH TAF SITES EARLY THIS EVENING. THERE ARE
STORMS JUST TO THE NORTH AND WEST OF MINNEAPOLIS...BUT THESE ARE
HIGHLY TIED TO DAYTIME HEATING AND SHOULD DISSIPATE BEFORE THEY
CAN APPROACH RST OR LSE. OTHER STORMS ACROSS EASTERN SOUTH DAKOTA
ARE TRACKING MORE SOUTH VERSUS EAST...THUS ARE LIKELY TO MISS THE
TAF SITES AS WELL. SO ALTHOUGH A TROUGH OF LOW PRESSURE CURRENTLY
IN CENTRAL MINNESOTA IS FORECAST TO DROP THROUGH THE TAF SITES
LATE TONIGHT...HAVE KEPT THE TAF FORECASTS DRY. WITH THE CONCERN
NOW THAT NO PRECIPITATION WILL OCCUR AT EITHER TAF SITE...FOG
SHOULD NOT BE AS MUCH OF AN ISSUE GIVEN LACK OF RAINFALL RECENTLY.
HAVE RAISED VISIBILITIES TO 5 SM AT BOTH TAF SITES FOR
09-13Z...AND THIS MIGHT NEED TO BE RAISED HIGHER SINCE THERE MIGHT
BE CLOUDS TO DEAL WITH TO DISRUPT FOG FORMATION. VFR CONDITIONS
ARE LIKELY TO CONTINUE THROUGH THE DAY MONDAY AS LIGHT NORTHERLY
FLOW BEHIND THE TROUGH BRINGS IN SOME MORE DRIER AIR.
&&
.HYDROLOGY...TUESDAY
ISSUED AT 305 PM CDT SUN JUL 7 2013
THE MAIN HYDRO CONCERNS COME IN ON TUESDAY AS A COMPLEX OF
THUNDERSTORMS IS FORECAST TO TRACK THROUGH THE REGION. THE
QUESTION IS WHERE AND WHEN WILL IT COME THROUGH? MOST OF THE MODEL
GUIDANCE SUGGEST THAT THIS SYSTEM WILL FORM IN NORTHWEST NEBRASKA
AND RUN EAST ACROSS IOWA MONDAY NIGHT INTO TUESDAY MORNING. WITH
SHOWERS AND THUNDERSTORMS EXPECTED TO DEVELOP AHEAD OF THIS
COMPLEX NORTH OF A WARM FRONT...THE POTENTIAL IS THERE FOR SOME
HEAVY RAIN TO FALL. THANKFULLY...CONDITIONS HAVE BEEN DRY FOR THE
PAST WEEK...SO FLASH FLOOD GUIDANCE HAS COME UP CONSIDERABLY AND
THE SOIL SHOULD BE ABLE TO HANDLE THE EXCESS MOISTURE REASONABLY
WELL FOR A PERIOD. THAT SAID...INCREASING PRECIPITABLE WATER
VALUES AND LOW LEVEL MOISTURE TRANSPORT AIMING INTO THE
REGION...EXPECT THAT HEAVY RAIN AND FLASH FLOODING IS POSSIBLE
WITH SOME RENEWED RISES ON AREA RIVERS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...AJ
HYDROLOGY...HALBACH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
722 PM MDT SUN JUL 7 2013
.UPDATE...
ISSUED AT 721 PM MDT SUN JUL 7 2013
SHOWER AND TSTM ACTIVITY HAS BEEN QUITE SPARSE ACROSS THE CWA
OVER THE PAST SEVERAL HOURS...PROBABLY DUE TO WEAK SUBSIDENCE
BENEATH SHORTWAVE RIDGING IN PLACE ACROSS FAR EASTERN WY AND
THE WESTERN PANHANDLE. HIGHEST CONVECTIVE COVERAGE SHOULD BE
WEST OF THE LARAMIE RANGE THROUGH THE EVE HOURS WITH DYNAMIC
SUPPORT AHEAD OF A RESPECTABLE MIDLVL SHORTWAVE. SOME STORMS
HAVE ALSO TRIED TO DEVELOP ALONG AND JUST EAST OF THE LARAMIE
RANGE...IN ADVANCE OF A SERIES OF WEAKER IMPULSES MOVING INTO
SOUTHERN WY AT THIS HOUR. THIS ACTIVITY HAS REALLY STRUGGLED
THOUGH DESPITE SBCAPES NEAR 1000 J/KG AND FAVORABLE EFFECTIVE
VERTICAL SHEAR. ASIDE FROM THESE AREAS...HAVE RESTRICTED POPS
TO THE ISOLATED CATEGORY AS THE LATEST HRRR SHOWS VERY LITTLE
IN THE WAY OF EVENING ACTIVITY. ALSO REMOVED MENTION OF SEVERE
CONSIDERING CORES HAVE BEEN RATHER LOW EVEN IN THE STRONGEST
STORMS. FINALLY...INHERITED GRIDS HAD LITTLE IF ANY MENTION
OF PCPN DURING THE OVERNIGHT PERIOD. STILL LOOKS LIKE FORCED
ASCENT AND LLVL THETA-E ADVECTION IN ADVANCE OF THE NEXT WAVE
WILL BE SUFFICIENT FOR AT LEAST ISOLATED CONVECTION. ELEVATED
CAPES ARE PROGGED TO INCREASE TO NEAR 1000 J/KG AFTER 06Z WITH
0-6KM SHEAR REMAINING BETWEEN 30 AND 40 KTS...SO CANNOT RULE
OUT A FEW STRONGER STORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 200 PM MDT SUN JUL 7 2013
SIMILAR TO YESTERDAY...A BIT OF CONVECTION NOW DEVELOPING OVER FAR
SE WY. CONVECTION SO FAR LIKELY HINDERED BY LACK OF ANY REAL
FORCING AND SOME SUBSIDENCE BEHIND UPPER WAVE NOW MOVING OVER THE
PLAINS. WV LOOP HINTS AT ANOTHER WEAK IMPULSE OVER WESTERN
COLORADO WHICH SHOULD TREK ENE THROUGH THIS EVENING. SHOULD SEE
SOME INCREASE IN CONVECTION AS A RESULT. BETTER INSTABILITY OVER
THE PANHANDLE MAY ALLOW FOR SOME STRONG TO SEVERE STORMS TO OCCUR
BUT SHOULD BE ISOLATED. ACTIVITY WILL DIMINISH LATER IN THE
EVENING. ANOTHER ROUND SHOULD OCCUR MONDAY AFTERNOON AND EVENING
WITH THE PASSAGE OF ANOTHER UPPER IMPULSE OVER MODEST LOW LEVEL
UPSLOPE FLOW. ACTIVITY ON TUESDAY SHOULD BE MORE ISOLATED.
TEMPERATURES REMAINING QUITE WARM OTHERWISE.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 200 PM MDT SUN JUL 7 2013
PREDOMINANT FEATURE REMAINS UPPER SUBTROPICAL RIDGE THROUGH
THE FORECAST PERIOD. ON WED RIDGE AXIS FLATTENS WITH WEST
TO NORTHWEST FLOW ALOFT OVER THE CWA. SHORTWAVE ENERGY TO
NORTH WILL KEEP SFC FRONTAL BOUNDARY BISECTING WY AND NE
PANHANDLE WITH SE SFC USLOPE FLOW AND MOISTURE/INSTABILTY.
HAVE KEPT PCPN CHCS ACROSS THE AREA CONSISTENT EAST OF LARAMIE
RANGE. ON THU THE UPPER RIDGE AMPLIFIES ACROSS ERN WY WITH
GOOD SUBSIDENCE ALOFT. MAY BE CHC FOR AFTN ELEVATED CONVECTION
THU AFT 00Z BUT RATHER SLIGHT FOR NOW. MID LEVEL MOISTURE WILL
ADVECT INTO AREA LATE THU AS UPPER FLOW SHIFTS TO SW. THIS
WILL TEND TO INCREASE PCPN CHCS FOR AFTN CONVECTION ALONG
AND WEST OF LARAMIE RANGE/SNOWIES AND HAVE INCREASED POPS
IN THOSE AREAS. ON SAT THE COMBINATION OF SE SFC FLOW AND
SUBTROPICAL MOISTURE FEED ARE POSSIBLE FOR BEST CHC OF
AFTN CONVECTION ACROSS THE ENTIRE AREA. TEMPS WILL MAINTAIN
ABOVE NORMAL 5-10 DEGS WITH FRI WARMEST DAY UNDER THERMAL RIDGE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY AFTERNOON)
ISSUED AT 721 PM MDT SUN JUL 7 2013
MOSTLY BENIGN WEATHER ACROSS SOUTHEAST WYOMING AND THE NEBRASKA
PANHANDLE TONIGHT THROUGH MONDAY MORNING BUT THERE WILL BE A FEW
THUNDERSTORMS AROUND. THREAT FOR SEVERE THUNDERSTORMS IS LOW...BUT
GUSTY WIND AND SMALL HAIL POSSIBLE UNTIL LATE THIS EVENING. ALTHOUGH
ISOLATED SHOWERS AND THUNDERSTORMS MAY LINGER THROUGH TONIGHT THERE
WILL BE A HIGHER THREAT FOR THUNDERSTORMS MONDAY AFTERNOON AND
EVENING WITH THE POTENTIAL FOR SEVERE THUNDERSTORMS WITH LARGE HAIL
AND DAMAGING WIND. OUTSIDE OF SHOWERS AND THUNDERSTORMS...WINDS WILL
MAINLY BE ON THE LIGHT SIDE THROUGH MONDAY BUT GUSTS TO 20 KTS
POSSIBLE MAINLY WEST OF THE LARAMIE RANGE MONDAY AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 200 PM MDT SUN JUL 7 2013
CONCERNS WILL REMAIN MINIMAL THROUGH THE MID PART OF THE WEEK AS
GENERALLY NON-CRITICAL WEATHER CONDITIONS EXPECTED. AFTERNOON
TEMPERATURES WILL REMAIN QUITE WARM WITH LOW HUMIDITIES MAINLY
OVER WESTERN DISTRICTS...BUT DECENT OVERNIGHT RECOVERIES. WIDELY
SCATTERED MAINLY LATE DAY SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH TUESDAY...THEN BE SOMEWHAT MORE ISOLATED OTHERWISE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...HAMMER
SHORT TERM...RE
LONG TERM...SLA
AVIATION...LIEBL
FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1227 AM MDT SAT JUL 6 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 315 PM MDT FRI JUL 5 2013
SHORTWAVE TROUGH IS MOVING ACROSS WESTERN WYOMING EARLY THIS AFTERNOON
WITH PLENTIFUL MOISTURE MOVING OVERHEAD IN WESTERLY FLOW ALOFT.
SCATTERED TO WIDESPREAD SHOWERS AND THUNDERSTORMS HAVE DEVELOPING
MAINLY ALONG AND WEST OF THE LARAMIE RANGE WITHIN THIS MOISTURE
PLUME AND WEAKLY UNSTABLE ENVIRONMENT...WITH BLENDED AMSU-SSM/I
PWATS ANALYZED TO BE AROUND 1 INCH. WILL CONTINUE TO SEE THIS AND
NEW DEVELOPMENT TREK EASTWARD THROUGH THE AFTERNOON AS THE UPPER
WAVE CONTINUES TO MOVE OVERHEAD AND FURTHER HEATING DESTABILIZES
THE EASTERN PLAINS. MESOANALYSIS AT 20Z SHOWS WEAK DEEP LAYER
SHEAR OVER THE FORECAST AREA WITH RAP FORECAST MAINTAINING SHEAR
OF ABOUT 35 KT OR LESS THROUGH THIS AFTERNOON...SO STORMS WILL
LIKELY REMAIN MODERATE TO HEAVY RAIN PRODUCERS WITH A FEW PRODUCING
SMALL HAIL AND GUSTY WINDS. ALL IN ALL...SOME MUCH NEEDED RAINS
WILL FALL OVER MUCH OF THE FORECAST AREA TODAY AND THIS EVENING.
THE DEEPEST OF THE MOISTURE PLUME WILL SHIFT EAST TONIGHT AND
TOMORROW ALTHOUGH STILL LOOKING AT PWATS TO BE ONE HALF INCH TO ONE
INCH FROM WEST TO EAST BY TOMORROW AFTERNOON. A WEAK COOL FRONT WILL
MOVE SOUTH ACROSS THE EASTERN PLAINS LATE TOMORROW MORNING WITH
WINDS SHIFTING TO THE NORTH THEN EAST BEHIND THE FRONT AS IT STALLS
ALONG THE LARAMIE RANGE. SHOULD SEE WEAK SHOWERS WITH PERHAPS A CLAP
OF THUNDER DEVELOP ALONG THE FRONT IN THE MORNING. A BROADER
COVERAGE OF STORMS WILL DEVELOP IN THE HIGH TERRAIN IN THE AFTERNOON
AS ANOTHER SHORTWAVE APPROACHES FROM THE WEST IN ADDITION TO WITHIN
THE CONVERGENCE ALONG THE LARAMIE RANGE. BULK SHEAR WILL BE ABOUT 10
KT HIGHER TOMORROW THAN TODAY SO COULD SEE MORE ORGANIZED STORMS
PRODUCE STRONGER WINDS AND PERHAPS LARGER HAIL. STILL NOT EXPECTING
ANYTHING SEVERE HOWEVER WITH WEAK INSTABILITY FORECAST...MORESO
AGAIN THE MAIN THREAT WITH THIS ACTIVITY WILL REMAIN MODERATE TO
HEAVY RAIN.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 PM MDT FRI JUL 5 2013
A CONSENSUS OF THE LATEST MEDIUM RANGE MODEL GUIDANCE SUGGESTS
THAT THE UNSETTLED WEATHER PATTERN WILL CONTINUE INTO THE EARLY
PART OF THE WEEK. A BROAD UPPER RIDGE WILL DOMINATE THE SOUTHERN
HALF OF THE CONUS WITH THE FASTER WESTERLIES CONFINED TO THE
NORTHERN STATES. A ZONAL FLOW ALOFT WILL TRANSPORT PACIFIC MOISTURE
AS WELL AS SOME SHORTWAVE ENERGY ACROSS THE REGION DURING THIS
TIME. SCATTERED DEEP MOIST CONVECTION WILL DEVELOP SUNDAY AND
MONDAY...MAINLY DURING THE AFTERNOON AND EVENING. BEST INSTABILITY
AND 0-6KM SHEAR (SBCAPES 1000-1500 J/KG AND 30-40 KT RESPECTIVELY)
WILL BE ALONG AN AXIS FROM NORTHEAST WYOMING THROUGH THE BLACK
HILLS AND WESTERN NEBRASKA BOTH SUNDAY AND MONDAY. SO THE POTENTIAL
WILL EXIST FOR ISOLATED STRONG TO SEVERE TSTORMS PRODUCING STRONG
WINDS AND HAIL. THIS WOULD INCLUDE AREAS EAST OF A LINE FROM
DOUGLAS TO TORRINGTON TO KIMBALL. HIGH PRECIP WATER VALUES (0.75
TO 1.25 INCHES) WILL YIELD EFFICIENT RAIN-PRODUCING STORMS.
TUESDAY...THE AXIS OF GREATER INSTABILITY AND SHEAR WILL BE LOCATED
OVER CENTRAL SOUTH DAKOTA AND NEBRASKA. SOMEWHAT DRIER AIR WILL
SPREAD EAST ACROSS THE CWA AT THAT TIME...LIMITING THE CONVECTION
TO ISOLATED MAINLY ALONG AND EAST OF THE MOUNTAINS. WEDNESDAY...
HIGHER INSTABILITY TRIES TO ADVECT NORTHWESTWARD INTO THE EASTERN
PLAINS DURING THE AFTERNOON AND EVENING. HOWEVER...WARMER AIR ALOFT
WILL ONCE AGAIN KEEP CONVECTION ISOLATED. CANNOT RULE OUT A FEW
STRONG TSTORMS. THURSDAY LOOKS DRY WITH THE UPPER RIDGE AND MID
LEVEL CAP SUPPRESSING CONVECTION. THE RIDGE AXIS SHIFTS EAST INTO
THE HIGH PLAINS FRIDAY WITH THE FLOW ALOFT BECOMING SOUTHWEST.
THIS MAY ADVECT SOME PACIFIC MOISTURE INTO THE CWA FOR ISOLATED
AFTERNOON CONVECTION OVER THE HIGHER TERRAIN. TEMPERATURES DURING
THE EXTENDED FORECAST PERIOD WILL CONTINUE TO AVERAGE ABOVE SEASONAL
NORMALS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1220 AM MDT SAT JUL 6 2013
VFR CONDITIONS THROUGH THE TAF PERIOD. A LINE OF SHOWERS IS
CURRENTLY MOVING EASTWARD OVER ALBANY COUNTY...SO A BRIEF PERIOD
OF -SHRA WILL BE POSSIBLE AT KLAR AND KCYS IN THE NEXT FEW HOURS.
OTHERWISE...WEAK WINDS AND MIDLEVEL CLOUDS WILL PREVAIL OVERNIGHT.
ANOTHER ROUND OF SCATTERED SHOWERS AND TSTMS ARE EXPECTED TO
DEVELOP ON SATURDAY AFTERNOON IN A MOIST AND UNSTABLE AIRMASS.
&&
.FIRE WEATHER...
ISSUED AT 315 PM MDT FRI JUL 5 2013
THE FIRE WEATHER THREAT WILL REMAIN MARGINAL THROUGH THE WEEKEND AS
PLENTIFUL AVAILABLE MOISTURE WILL MAINTAIN GOOD CHANCES FOR WETTING
RAINS OVER MUCH OF THE DISTRICT. THUNDERSTORMS SHOULD DEVELOP ACROSS
THE FORECAST AREA EACH AFTERNOON AND WILL PRODUCE GUSTY WINDS
ESPECIALLY WEST OF THE LARAMIE RANGE...ALONG WITH MODERATE TO
LOCALLY HEAVY RAINFALL AT TIMES. OTHERWISE...GENERAL WINDS WILL
REMAIN RELATIVELY LIGHT WITH A FEW LOCATIONS IN THE WIND PRONE
AREAS SEEING SOUTHWEST WINDS GUSTING TO 30 MPH IN THE AFTERNOON.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...RJM
LONG TERM...MAJ
AVIATION...FINCH
FIRE WEATHER...RJM
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
350 AM EDT MON JUL 8 2013
.SHORT TERM /TODAY THROUGH TUESDAY/...
500MB ANALYSIS SHOWS AN UPPER LOW MOVING INTO THE WESTERN MIDDLE
ATLANTIC WITH A WEAK SHEAR AXIS EXTENDING INTO THE CENTRAL CWFA THIS
MORNING. WV STILL DEPICTS THE HIGH MOISTURE PLUME VERY WELL ACROSS
THE CENTRAL AND SOUTHERN CWFA...BUT ALSO SHOWS SOME DRIER AIR HAS
WORKED ITS WAY INTO THE NORTHERN CWFA. THE TROUGH/SHEAR AXIS IS
EXPECTED TO PUSH SOUTH TODAY.
FORECAST PROBLEM OF THE DAY WILL BE POPS. SUSPECT THE CURRENT
ACTIVITY ON THE REGIONAL RADAR LOOP HAS DEVELOP ALONG AND SOUTH OF
THE SHEAR AXIS. DO THINK THE SHEAR AXIS WILL HELP SUPPORT CONVECTIVE
DEVELOPMENT TODAY...ESPECIALLY ACROSS THE CENTRAL CWFA. THE LATEST
RUN OF THE HRRR DOES SHOW SOME EARLY DEVELOPMENT ACROSS THE NORTHERN
TIER OF ZONES THIS MORNING...AND THAT COULD BE ASSOCIATED WITH WEAK
SHORTWAVE DROPPING SOUTH IN THE FLOW. ALSO...ACROSS THE SOUTHERN
CWFA...CONVECTIVE DEVELOPMENT COULD BE ENHANCED BY ANY ACTIVITY THAT
DEVELOPS ALONG THE SEA BREEZE AND MOVES INLAND. THE BEST CHANCES FOR
THUNDER SHOULD BE IN THE CENTRAL AND SOUTHERN ZONES...WHERE MORE
BREAKS IN THE CLOUD COVER COULD OCCUR...SURFACE INSTABILITY WILL BE
A LITTLE HIGHER AND THE SEA BREEZE COULD AID WITH LIFT.
THE SHEAR AXIS SHOULD SET UP TO THE SOUTH TOMORROW...BUT BOTH THE
GFS AND NAM ARE PROGGING ANOTHER PIECE OF SHORTWAVE ENERGY TO DROP
SOUTH IN THE FLOW TOMORROW AFTERNOON. IN ADDITION...THE MOISTURE
PLUME SHOULD BE LOCATED FURTHER SOUTH THAN TODAY. SO...EXPECT
CONVECTION TO BE A LITTLE MORE DIURNAL IN NATURE. FOR NOW...LEFT
GENERAL SCT POPS.
WILL GO AHEAD AND LEAVE THE FLASH FLOOD WATCH IN EFFECT THROUGH
TODAY. EVEN THOUGH THE COVERAGE OF POPS MAY BE LOWER THAN IN
PREVIOUS DAYS ACROSS THE NORTH...ANY THUNDERSTORM COULD PRODUCE
LOCALLY HEAVY RAINFALL. PWATS WILL DROP TO AROUND AN INCH AND A HALF
IN THE NORTH...BUT A THUNDERSTORM COULD EASILY DROP A QUICK INCH OR
MORE. FFG VALUES ARE AROUND AN INCH ACROSS MUCH OF THE AREA...WITH
SOME AREAS LESS THAN A QUARTER OF AN INCH.
NLISTEMAA
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE EXTENDED BEGINS WITH THE SOUTHEAST IN A GENERAL WEAKNESS
PATTERN ALOFT...SANDWICHED BETWEEN THE TWO UPPER HIGHS /ONE IN
THE ATLANTIC AND ONE IN THE SOUTHWEST STATES/ AND TWO UPPER LOWS
OR TROUGHS /WEAK WAVE IN THE EASTERLIES OVER FLORIDA AND LONGWAVE
TROUGH IN CANADA/. WEAK SURFACE BOUNDARY REMAINS IN PLACE TUESDAY
NIGHT AND WEDNESDAY AND WHILE THERE IS VERY LITTLE FORCING...
THERE WILL BE ENOUGH MOISTURE AND INSTABILITY TO KEEP SLIGHT TO
LOW CHANCE POPS ACROSS THE AREA.
WEDNESDAY NIGHT INTO THURSDAY...THE LONGWAVE TROUGH DEEPENS IN
RESPONSE TO A SHORTWAVE RIDING DOWN THE NORTHWEST FLOW TOWARD THE
OHIO VALLEY. THIS PUSHES A REINFORCING FRONT THROUGH THE TENNESSEE
VALLEY AND INTO THE SOUTHEAST...WARRANTING HIGHER POPS FOR
THURSDAY AFTERNOON. KEPT TREND OF LIKELY POPS UP NORTH. AS THE
POSITIVELY TILTED TROUGH CONTINUES TO DEEPEN THE FRONT WILL PRETTY
MUCH STALL ACROSS THE SOUTHEAST...THOUGH THERE IS SOME QUESTION AS
TO HOW STRONG THE GREAT LAKES SURFACE HIGH WILL BE AND IF PORTIONS
OF THE STATE ARE ABLE TO CLEAR OUT LATE IN THE WEEK...AS PER THE
00Z GFS...OR IF SIGNIFICANT MOISTURE REMAINS OVER THE ENTIRE AREA
AS PER THE 00Z ECMWF. IF THE GFS IS TO BE BELIEVE...DRY AIR IS
ABLE TO PUSH IN FRIDAY INTO SATURDAY LEADING TO OVERNIGHT LOWS IN
THE 60S. ADD THIS TO TEMPS CONTINUING AT OR BELOW NORMAL...NOT BAD
AT ALL FOR THIS TIME OF YEAR.
BY SATURDAY MORNING THE GFS HAS ALREADY CUT OFF THE UPPER LOW
ACROSS GEORGIA WHILE THE ECMWF JUST HAS A VERY LONG AND SKINNY
TROUGH IN PLACE. THIS IS A PRETTY INTERESTING AND PERPLEXING CHANGE
FROM LAST NIGHT/S SOLUTIONS...WHERE THE GFS AND ECMWF WERE IN
REMARKABLE AGREEMENT WITH THE CUTOFF LOW. WITH TONIGHT/S RUNS...
WHILE THE SENSIBLE WEATHER RESULTS ARE NOT ALL THAT DIFFERENT...
THE MASS FIELDS ARE ACTUALLY QUITE A BIT DIFFERENT. IN EITHER CASE
THOUGH...ABOVE-NORMAL PWATS REMAIN OVER THE SOUTHEAST. ADD TO
THIS WHATEVER HAPPENS WITH CHANTAL...OR THE REMNANTS THEREOF.
ENSEMBLE GUIDANCE TAKE THE SYSTEM SOMEWHERE INTO THE SOUTHEAST
LATE IN THE PERIOD...GFS WITH A MORE NOTICEABLE CIRCULATION INTO
THE JACKSONVILLE FLORIDA AREA...BUT THE ECMWF WITH JUST A GENERAL
AREA OF MOISTURE INTO THE FLORIDA PENINSULA. SO ALL THAT SAID...
HAVE KEPT POPS JUST ABOVE CLIMO FOR THE WEEKEND ESPECIALLY SUNDAY.
TEMPS REMAIN AT OR BELOW NORMAL THROUGH THE WEEKEND.
TDP
&&
.AVIATION...
06Z UPDATE...
PERSISTENCE FORECAST ON TAP SINCE NO AIRMASS CHANGE. EXPECT IFR
CIGS AT MOST TERMINAL SITES THIS MORNING...WITH SOME LIFR AT MCN
AND CSG POSSIBLE. CIGS SHOULD START TO LIFT AROUND 12-14Z...BUT
WILL REMAIN BKN VFR FOR THE AFTERNOON. WINDS WILL BE LIGHT TODAY
AOB 10KT...BUT A SLIGHT SHIFT TO THE SW IS POSSIBLE THIS
AFTERNOON.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 71 87 72 / 60 40 40 30
ATLANTA 84 72 86 73 / 60 40 40 30
BLAIRSVILLE 81 64 81 67 / 60 40 40 30
CARTERSVILLE 85 70 86 72 / 50 40 40 30
COLUMBUS 86 73 90 74 / 60 40 40 20
GAINESVILLE 83 70 85 72 / 50 40 40 30
MACON 86 73 90 73 / 60 40 40 20
ROME 87 70 87 72 / 60 40 40 30
PEACHTREE CITY 84 70 87 72 / 60 40 40 30
VIDALIA 89 74 91 74 / 60 40 40 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES:
BANKS...BARROW...BARTOW...CARROLL...CATOOSA...CHATTOOGA...
CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...DADE...DAWSON...
DEKALB...DOUGLAS...FANNIN...FAYETTE...FLOYD...FORSYTH...GILMER...
GORDON...GREENE...GWINNETT...HALL...HARALSON...HEARD...HENRY...
JACKSON...LUMPKIN...MADISON...MORGAN...MURRAY...NEWTON...NORTH
FULTON...OCONEE...OGLETHORPE...PAULDING...PICKENS...POLK...
ROCKDALE...SOUTH FULTON...TALIAFERRO...TOWNS...UNION...WALKER...
WALTON...WHITE...WHITFIELD...WILKES.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....TDP
AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
439 AM CDT MON JUL 8 2013
.DISCUSSION...
330 AM CDT
THE FORECAST CHALLENGES ARE PRIMARILY WITHIN THE NEXT 48 HOURS AS
THE AREA HAS BEEN OVERTAKEN BY THE SOUPIEST AIR MASS OF THE
SEASON...IN FACT THE MOST PROLONGED HIGH DEW POINT EPISODE SINCE
THE HEAT WAVE JUST OVER ONE YEAR AGO /JUL 4-7/. WITH THIS COMES
SEVERE STORM AND HEAVY RAIN POTENTIAL...MORE SO ON TUESDAY. IN
ADDITION...THE HIGHEST HEAT INDICES OF THE SEASON ARE
FORECAST...AND WHILE NOT AT ADVISORY CRITERIA THESE LOOK TO
FLIRT WITH 100 DEGREES IN SOME SOUTHERN CWA LOCATIONS ON TUESDAY
AFTERNOON.
SYNOPSIS...THE UPPER LEVEL RIDGE ACROSS THE CENTRAL AND SOUTHERN
PLAINS IS EVOLVING EAST EARLY THIS MORNING WITH TURBULENT MOIST
FLOW AROUND ITS NORTHERN PERIPHERY. NUMEROUS AREAS OF CONVECTION
ARE PRESENT ASSOCIATED WITH SHORT WAVE ASCENT AND MOIST ADVECTION
ON THE LOW-LEVEL JET. A WEAK LOW-LEVEL TROUGH IS PRESENT FROM
NORTHERN WI TO NORTHERN KS. TO THE EAST AND SOUTH OF THIS
FEATURE...UPPER 60S TO MID 70S DEW POINTS PREVAIL ON MOST
OBSERVATIONS ALL THE WAY TO THE ATLANTIC AND GULF COASTS. THE
RIDGE WILL TRY TO EXPAND INTO THE AREA THIS AFTERNOON AND MORE SO
TONIGHT WITH CONTINUED SYNOPTIC SOUTHERLY SURFACE FLOW ACROSS THE
AREA. THE SURFACE TROUGH WILL WORK ITS WAY LIKELY INTO FAR
SOUTHERN WI BY LATE AFTERNOON. TWO SURFACE LOWS LOOK TO RIDE ALONG
THIS...ONE DURING THE DAY TUE ASSOCIATED WITH A STRONG SHORT WAVE
EXITING THE GREAT BASIN EARLY THIS MORNING...AND ANOTHER STRONGER
SURFACE LOW ASSOCIATED WITH AN UPPER TROUGH THAT WILL DEVELOP INTO
THE GREAT LAKES BY LATE TUE NIGHT. THIS SECOND WAVE WILL USHER A
COOL FRONT THROUGH THE AREA WED MORNING WITH THE SOMEWHAT
COOLER/DRIER AIR BEING REALIZED BY WED NIGHT.
THIS MORNING...IT APPEARS THERE ARE TWO IMMEDIATE UPSTREAM SHORT
WAVES...ONE BETTER DEFINED ONE PER WATER VAPOR AND RADAR MOSAIC
ACROSS NORTHEAST IA...AND ANOTHER ACROSS FAR SOUTHERN IA/NORTHERN
MO. TOGETHER THESE WILL MOVE EAST AND LOOK TO SLOWLY
WEAKEN LATER THIS MORNING ACROSS THE EASTERN FORECAST AREA WITH
THE MORE DOMINANT JET TO THE NORTH. PROFILER DATA INDICATES 35 KT
850-925MB FLOW INTO THE AREA WHICH LOOKS TO CONTINUE PAST
DAYBREAK. SO EXPECT THAT SHOWER AND EMBEDDED STORM ACTIVITY WILL
BE SUSTAINED AS FAR EAST AS CHICAGO BY MID-MORNING. THE HRRR SEEMS
TO HAVE A FIRM HANDLE ON THE ONGOING CONVECTION AND ITS EVOLUTION
MAKES SENSE AND HAVE FOLLOWED CLOSELY IN OUR FORECAST HOURLY POPS.
HAVE SEEN A COUPLE 20 KT PLUS GUSTS IN SW WI INDICATING THAT A
COLD POOL MAY BE TRYING TO DEVELOP. THIS AND ANY MCV DEVELOPMENT
WOULD ALSO AID IN SUSTAINING THE ACTIVITY EASTWARD. SEVERE
POTENTIAL IS MAINLY LOW WITH THIS THROUGH THE MORNING AND RADAR
TRENDS FROM ARX/DVN CONFIRM NOTHING POTENT IN THE STORM
BEHAVIORS...THOUGH CANT RULE OUT SMALL HAIL OR GUSTY WINDS. IN
ADDITION...STORMS WILL BE VERY EFFICIENT RAIN PRODUCERS GIVEN HIGH
ATMOSPHERIC MOISTURE CONTENT /PWATS AOA 1.65 INCHES AND 700MB TDS
AOA 4C/.
CONFIDENCE...HIGH.
THIS AFTERNOON AND TONIGHT...WITH THE PRIMARY SHORT WAVE IMPULSES
HAVING MOVED EAST...COVERAGE OF PRECIP SHOULD AT LEAST TEMPORARILY
DIMINISH IN THE EARLY AFTERNOON. OUTFLOW BOUNDARIES FROM THE
MORNING ACTIVITY...EVEN IF ELEVATED COULD CONTINUE FESTERING
CONVECTION THIS AFTERNOON GIVEN ATTAINABLE CONVECTIVE TEMPS. THIS
WOULD SEEM MOST FAVORED ALONG AND SOUTH OF I-80. THE SURFACE
BOUNDARY WILL BE NEAR THE IL/WI STATE LINE...AND SIMILAR TO PREV
FORECAST REASONING COULD SEE SOME SCATTERED DEVELOPMENT LATER THIS
AFTERNOON ALONG THAT AS WELL. AFTER WHAT WILL LIKELY BE A SLOW
TEMPERATURE CLIMB THIS MORNING...THIS AFTERNOON SHOULD SEE
RECOVERY INTO THE UPPER 80S AND MAYBE EVEN 90...ESPECIALLY ACROSS
THE WESTERN HALF OF THE FORECAST AREA. WITH SUCH HIGH DEW POINT
AIR...SURFACE BASED INSTABILITY OF 1500-2500 J/KG WOULD BE
SUPPORTED BY THESE FORECAST TEMPS AND DEW POINTS. MOST GUIDANCE
DOES HAVE A SPLOTCHY QPF PRODUCED OVER THE AREA. ANY SCATTERED
CONVECTION THAT CAN DEVELOP THIS AFTERNOON INTO THE EVE WOULD HAVE
SOME SEVERE WEATHER THREAT. THE HIGH PWAT AIR WILL SUPPORT HEAVY
RAIN ALONG WITH PRECIP LOADING CONCERNS TOWARDS ISOLATED DOWNBURSTS
IN ANY MORE ROBUST CELLS OR MULTI-CELL CLUSTERS...BUT OVERALL
THREAT COVERAGE IS LOW. AS WE HEAD TO AFTER SUNDOWN...HEIGHT
FALLS AND THE LLJ NOSE CONTINUE TO BE FOCUSED TO THE NORTHWEST OF
THE AREA /OVER MN AND NORTHERN IA/. THIS IS WHERE LIKELY MCS
DEVELOPMENT WILL OCCUR LATE. IN ADVANCE...BROAD WARM AND MOIST
ADVECTION ALOFT MAY ALLOW FOR ISOLATED TO SCATTERED CONVECTIVE
DEVELOPMENT OVER THE AREA. DEEP WARM CLOUD PROCESSES WILL BE AT
PLAY WITH PWATS CONTINUING TO INCH UP...MEANING HEAVY RAIN WILL BE
THE GREATEST THREAT. GIVEN A SOMEWHAT DIFFUSE 850MB BAROCLINIC
ZONE AND FORWARD PROPAGATION INDICATED...THE TRAINING SETUP IS
SOMEWHAT MARGINAL IN THE FORECAST AREA AT LEAST PRIOR TO DAYBREAK
TUE. SO NO FLASH FLOOD WATCH BEING ISSUED AT THIS TIME BUT THIS
WILL NEED TO BE MONITORED.
CONFIDENCE...MEDIUM.
TUESDAY AND TUESDAY NIGHT...THESE ARE THE PERIODS WITH THE GREATER
POTENTIAL FOR HIGHER IMPACT WEATHER. MANY MODELS IN THE SUITE OF
GUIDANCE CONTINUE TO ADVERTISE A PRIMARY MCS DEVELOPING BY TUE
MORNING AHEAD OF A STRONG IMPULSE. THERE ARE VARIANCES IN
LATITUDE ON THIS...BUT CERTAINLY THE PATTERN WOULD SUPPORT SUCH
EVOLUTION WITH AMPLE INSTABILITY AHEAD OF AN MCS EVEN IN THE
MORNING GIVEN THE HIGH ABSOLUTE MOISTURE. THE SPC HAS OUTLOOKED A
30 PERCENT AREA FOR THEIR DAY TWO OUTLOOK FOR THIS REASON AND THE
AREA THEY INDICATED IS WHAT HAS BEEN FAVORED IN OUR FORECAST. IT
IS INTERESTING TO NOTE THAT THE CIPS ANALOG GUIDANCE FOR MULTIPLE
DAYS HAS INDICATED MATCHES ON SEVERE WIND EVENTS FROM NORTHERN IA
INTO SOUTHERN WI AND FAR NORTHERN IL AND CONTINUES TO DO SUCH
BASED ON THE NAM FORECAST. SO THE MOST FAVORED AREA WOULD LIKELY
BE NORTH OF I-80...AND MAYBE EVEN NORTH OF I-88 FOR POTENTIALLY A
STRONG WIND COMPLEX ON TUE. SOME OF THE SLOWER GUIDANCE HAS THIS
EVEN HAPPENING IN THE AFTERNOON. CONFIDENCE ON EXACT DEVELOPMENT
BY AFTERNOON AND NIGHTTIME DROPS...ESPECIALLY IF ANYTHING CAN
SPARK OFF OUTFLOWS. CERTAINLY A SEVERE WEATHER POTENTIAL EXISTS
THROUGH THE REST OF THE DAY WITH GRADUALLY INCREASING DEEP LAYER
SHEAR AND PLENTY OF INSTABILITY. THE SOUTHERN FORECAST AREA COULD
WARM INTO THE LOWER TO MID 90S. RIGHT NOW HEAD INDICES ARE
FORECAST AROUND 100 FOR MULTIPLE AFTERNOON HOURS IN THE SOUTHERN
FORECAST AREA...WHILE AROUND THE MID 90S IN ROCKFORD AND CHICAGO
THOUGH CONFIDENCE THERE IS LOW BASED ON PROBABLE MORNING/EARLY
AFTERNOON CONVECTION. HAVE MENTIONED HEAVY RAIN IN THE FORECAST
FOR TUE AND TUE NIGHT GIVEN THE ATMOSPHERIC SETUP AND DO HAVE CHC
SEVERE MENTIONED IN FAR NORTHERN IL GIVEN THE CONSISTENT SIGNAL
AND PATTERN SUPPORT FOR AT THE LEAST A NEARBY MCS.
CONFIDENCE...OVERALL MEDIUM.
WEDNESDAY...THE COOL FRONT...OR AT LEAST THE WIND SHIFT IS MAINLY
AGREED ON BY GUIDANCE TO BE MOVING SOUTHEAST THROUGH THE AREA
EARLY WED. THE COOLER TEMPERATURES IN THE MIX DOWN LAYER LOOK TO
ARRIVE LATE IN THE AFTERNOON INTO THE EVE...SO HIGHS IN THE MID TO
UPPER 80S ARE STILL FORECAST. SOME ONGOING CONVECTION IS LIKELY
IN THE SOUTHEAST CWA AT LEAST ON WED MORNING...THOUGH COVERAGE IS
TOUGH TO TELL AT THIS POINT. DEW POINTS LOOK TO FALL BY WED EVE.
CONFIDENCE...HIGH.
EXTENDED...HAVE NOT MADE TOO MANY CHANGES FROM A SMART BLEND OF
GUIDANCE WITH GOING FORECAST. THIS PERIOD LOOKS MAINLY QUIET AS
THE PATTERN EVOLVES THROUGH THE WEEKEND TO ONCE AGAIN A BLOCKED
SETUP. SURFACE HIGH PRESSURE LOOKS TO PREVAIL WITH ONSHORE FLOW
INTO CHICAGOLAND AND NORTHWEST INDIANA. THIS SHOULD OFFER ONLY
MINIMAL COOLING THOUGH WITH BASICALLY TEMPERATURES AT OR JUST
BELOW SEASONAL NORMALS IN MOST PLACES.
CONFIDENCE...HIGH.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* WIDELY SCATTERED SHOWERS WITH ISOLATED TS EARLY THIS
MORNING...WITH LIMITED OR NO VIS RESTRICTION EXPECTED.
* SHOWERS AND TS ARRIVING LATER THIS MORNING AROUND 13-14Z...WITH
MVFR VIS POSSIBLE.
* CHANCES FOR SHOWERS AND POSSIBLE TS ONCE AGAIN LATER THIS
AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
AS SEVERAL MID LEVEL DISTURBANCES APPROACH FROM THE WEST...LATEST
RADAR IMAGERY SHOWING SCATTERED SHOWER DEVELOPMENT OCCURRING ACROSS
NORTHWEST ILLINOIS EARLY THIS MORNING. EXPECT THIS SCATTERED
DEVELOPMENT ALONG WITH ISOLATED TS TO PERSIST EARLY THIS
MORNING...BUT WITH LITTLE IMPACTS TO THE TERMINALS EXPECTED. AM
MONITORING SHOWER/TS DEVELOPMENT ACROSS NORTHERN/EASTERN IOWA AND
EXPECT THIS AREA OF PRECIP TO SHIFT EASTWARD THROUGH THE EARLY
MORNING HOURS AND MOVE ACROSS THE TERMINALS LATER THIS MORNING.
WITH FAVORABLE METEOROLOGICAL CONDITIONS AND LATEST SHORT TERM
GUIDANCE SHIFTING THIS PRECIP EAST THROUGH THE AREA...FELT
COMFORTABLE ADDING IN A PREVAILING GROUP FOR AT LEAST SHOWERS FOR
ALL OF THE TERMINALS THIS MORNING WHILE ALSO ADDING IN A TEMPO
GROUP FOR POSSIBLE THUNDER THROUGH MID MORNING. SHOULD THEN
OBSERVE THIS PRECIP EXIT TO THE EAST WITH A LULL IN THE
ACTIVITY...BEFORE REDEVELOPMENT OCCURS WITH AN APPROACHING FRONT
LATER THIS AFTERNOON. DO FEEL THAT SHOWERS/THUNDERSTORMS WILL
DEVELOP AROUND THE AREA LATER THIS AFTERNOON...BUT CONFIDENCE IS
LOWER WITH REGARDS TO TIMING/COVERAGE AND EVEN TS POTENTIAL. WILL
CONTINUE TO MONITOR THIS AFTERNOON ACTIVITY AND ADJUST AS NEEDED.
EXPECT SOUTHERLY WINDS THIS FORECAST PERIOD WITH A TREND MORE
TOWARDS THE WEST SOUTHWEST THROUGH MID DAY...WHILE SPEEDS INCREASE
AND SPORADIC GUSTS DEVELOP.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE WITH WIDELY SCATTERED SHOWERS/TS IN THE NEAR
TERM.
* HIGH CONFIDENCE WITH SHOWERS/TS LATER THIS MORNING.
* LOW MEDIUM CONFIDENCE WITH SHOWERS/TS COVERAGE AND TIMING LATER
THIS AFTERNOON.
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
* TUESDAY...TSRA LIKELY. MVFR/GUSTY WINDS POSSIBLE.
* WEDNESDAY...CHANCE OF TSRA.
* THURSDAY THROUGH SATURDAY...DRY/VFR.
&&
.MARINE...
425 AM CDT
AS AN AREA OF LOW PRESSURE OVER THE UPPER MISSISSIPPI VALLEY
SHIFTS EAST TOWARDS THE LAKE THIS MORNING...SOUTH TO SOUTHEAST
WINDS OF 10 TO 20 KT ARE BEING OBSERVED ACROSS THE LAKE. WITH THIS
LOW CONTINUING ACROSS THE LAKE TODAY...EXPECT FAIRLY DIFFERENT
CONDITIONS FROM THE NORTH HALF TO THE SOUTH HALF. WITH THIS LOW
MOVING THROUGH AND A BOUNDARY LEFT OVER THE LAKE...THE NORTHERN
HALF OF THE LAKE WILL OBSERVE WINDS SHIFTING TO THE NORTHEAST AND
EAST TODAY/TONIGHT WHILE THE SOUTHERN HALF REMAINS SOUTHWEST AND
WEST. AN EASTERLY COMPONENT TO THE WIND LATE TONIGHT INTO TUESDAY
WILL ONCE AGAIN TURN MORE SOUTHERLY AS NEW LOW PRESSURE DEVELOPS
TO THE WEST. SPEEDS WILL INCREASE TO 10 TO 20 KT ON TUESDAY BEFORE
TURNING TO THE SOUTHWEST AND WEST TUESDAY NIGHT...BEFORE A PERIOD
OF NORTHERLY WINDS SETTLES IN ON WEDNESDAY THROUGH THE REMAINDER
OF THE FORECAST PERIOD.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
416 AM CDT MON JUL 8 2013
.DISCUSSION...
330 AM CDT
THE FORECAST CHALLENGES ARE PRIMARILY WITHIN THE NEXT 48 HOURS AS
THE AREA HAS BEEN OVERTAKEN BY THE SOUPIEST AIR MASS OF THE
SEASON...IN FACT THE MOST PROLONGED HIGH DEW POINT EPISODE SINCE
THE HEAT WAVE JUST OVER ONE YEAR AGO /JUL 4-7/. WITH THIS COMES
SEVERE STORM AND HEAVY RAIN POTENTIAL...MORE SO ON TUESDAY. IN
ADDITION...THE HIGHEST HEAT INDICES OF THE SEASON ARE
FORECAST...AND WHILE NOT AT ADVISORY CRITERIA THESE LOOK TO
FLIRT WITH 100 DEGREES IN SOME SOUTHERN CWA LOCATIONS ON TUESDAY
AFTERNOON.
SYNOPSIS...THE UPPER LEVEL RIDGE ACROSS THE CENTRAL AND SOUTHERN
PLAINS IS EVOLVING EAST EARLY THIS MORNING WITH TURBULENT MOIST
FLOW AROUND ITS NORTHERN PERIPHERY. NUMEROUS AREAS OF CONVECTION
ARE PRESENT ASSOCIATED WITH SHORT WAVE ASCENT AND MOIST ADVECTION
ON THE LOW-LEVEL JET. A WEAK LOW-LEVEL TROUGH IS PRESENT FROM
NORTHERN WI TO NORTHERN KS. TO THE EAST AND SOUTH OF THIS
FEATURE...UPPER 60S TO MID 70S DEW POINTS PREVAIL ON MOST
OBSERVATIONS ALL THE WAY TO THE ATLANTIC AND GULF COASTS. THE
RIDGE WILL TRY TO EXPAND INTO THE AREA THIS AFTERNOON AND MORE SO
TONIGHT WITH CONTINUED SYNOPTIC SOUTHERLY SURFACE FLOW ACROSS THE
AREA. THE SURFACE TROUGH WILL WORK ITS WAY LIKELY INTO FAR
SOUTHERN WI BY LATE AFTERNOON. TWO SURFACE LOWS LOOK TO RIDE ALONG
THIS...ONE DURING THE DAY TUE ASSOCIATED WITH A STRONG SHORT WAVE
EXITING THE GREAT BASIN EARLY THIS MORNING...AND ANOTHER STRONGER
SURFACE LOW ASSOCIATED WITH AN UPPER TROUGH THAT WILL DEVELOP INTO
THE GREAT LAKES BY LATE TUE NIGHT. THIS SECOND WAVE WILL USHER A
COOL FRONT THROUGH THE AREA WED MORNING WITH THE SOMEWHAT
COOLER/DRIER AIR BEING REALIZED BY WED NIGHT.
THIS MORNING...IT APPEARS THERE ARE TWO IMMEDIATE UPSTREAM SHORT
WAVES...ONE BETTER DEFINED ONE PER WATER VAPOR AND RADAR MOSAIC
ACROSS NORTHEAST IA...AND ANOTHER ACROSS FAR SOUTHERN IA/NORTHERN
MO. TOGETHER THESE WILL MOVE EAST AND LOOK TO SLOWLY
WEAKEN LATER THIS MORNING ACROSS THE EASTERN FORECAST AREA WITH
THE MORE DOMINANT JET TO THE NORTH. PROFILER DATA INDICATES 35 KT
850-925MB FLOW INTO THE AREA WHICH LOOKS TO CONTINUE PAST
DAYBREAK. SO EXPECT THAT SHOWER AND EMBEDDED STORM ACTIVITY WILL
BE SUSTAINED AS FAR EAST AS CHICAGO BY MID-MORNING. THE HRRR SEEMS
TO HAVE A FIRM HANDLE ON THE ONGOING CONVECTION AND ITS EVOLUTION
MAKES SENSE AND HAVE FOLLOWED CLOSELY IN OUR FORECAST HOURLY POPS.
HAVE SEEN A COUPLE 20 KT PLUS GUSTS IN SW WI INDICATING THAT A
COLD POOL MAY BE TRYING TO DEVELOP. THIS AND ANY MCV DEVELOPMENT
WOULD ALSO AID IN SUSTAINING THE ACTIVITY EASTWARD. SEVERE
POTENTIAL IS MAINLY LOW WITH THIS THROUGH THE MORNING AND RADAR
TRENDS FROM ARX/DVN CONFIRM NOTHING POTENT IN THE STORM
BEHAVIORS...THOUGH CANT RULE OUT SMALL HAIL OR GUSTY WINDS. IN
ADDITION...STORMS WILL BE VERY EFFICIENT RAIN PRODUCERS GIVEN HIGH
ATMOSPHERIC MOISTURE CONTENT /PWATS AOA 1.65 INCHES AND 700MB TDS
AOA 4C/.
CONFIDENCE...HIGH.
THIS AFTERNOON AND TONIGHT...WITH THE PRIMARY SHORT WAVE IMPULSES
HAVING MOVED EAST...COVERAGE OF PRECIP SHOULD AT LEAST TEMPORARILY
DIMINISH IN THE EARLY AFTERNOON. OUTFLOW BOUNDARIES FROM THE
MORNING ACTIVITY...EVEN IF ELEVATED COULD CONTINUE FESTERING
CONVECTION THIS AFTERNOON GIVEN ATTAINABLE CONVECTIVE TEMPS. THIS
WOULD SEEM MOST FAVORED ALONG AND SOUTH OF I-80. THE SURFACE
BOUNDARY WILL BE NEAR THE IL/WI STATE LINE...AND SIMILAR TO PREV
FORECAST REASONING COULD SEE SOME SCATTERED DEVELOPMENT LATER THIS
AFTERNOON ALONG THAT AS WELL. AFTER WHAT WILL LIKELY BE A SLOW
TEMPERATURE CLIMB THIS MORNING...THIS AFTERNOON SHOULD SEE
RECOVERY INTO THE UPPER 80S AND MAYBE EVEN 90...ESPECIALLY ACROSS
THE WESTERN HALF OF THE FORECAST AREA. WITH SUCH HIGH DEW POINT
AIR...SURFACE BASED INSTABILITY OF 1500-2500 J/KG WOULD BE
SUPPORTED BY THESE FORECAST TEMPS AND DEW POINTS. MOST GUIDANCE
DOES HAVE A SPLOTCHY QPF PRODUCED OVER THE AREA. ANY SCATTERED
CONVECTION THAT CAN DEVELOP THIS AFTERNOON INTO THE EVE WOULD HAVE
SOME SEVERE WEATHER THREAT. THE HIGH PWAT AIR WILL SUPPORT HEAVY
RAIN ALONG WITH PRECIP LOADING CONCERNS TOWARDS ISOLATED DOWNBURSTS
IN ANY MORE ROBUST CELLS OR MULTI-CELL CLUSTERS...BUT OVERALL
THREAT COVERAGE IS LOW. AS WE HEAD TO AFTER SUNDOWN...HEIGHT
FALLS AND THE LLJ NOSE CONTINUE TO BE FOCUSED TO THE NORTHWEST OF
THE AREA /OVER MN AND NORTHERN IA/. THIS IS WHERE LIKELY MCS
DEVELOPMENT WILL OCCUR LATE. IN ADVANCE...BROAD WARM AND MOIST
ADVECTION ALOFT MAY ALLOW FOR ISOLATED TO SCATTERED CONVECTIVE
DEVELOPMENT OVER THE AREA. DEEP WARM CLOUD PROCESSES WILL BE AT
PLAY WITH PWATS CONTINUING TO INCH UP...MEANING HEAVY RAIN WILL BE
THE GREATEST THREAT. GIVEN A SOMEWHAT DIFFUSE 850MB BAROCLINIC
ZONE AND FORWARD PROPAGATION INDICATED...THE TRAINING SETUP IS
SOMEWHAT MARGINAL IN THE FORECAST AREA AT LEAST PRIOR TO DAYBREAK
TUE. SO NO FLASH FLOOD WATCH BEING ISSUED AT THIS TIME BUT THIS
WILL NEED TO BE MONITORED.
CONFIDENCE...MEDIUM.
TUESDAY AND TUESDAY NIGHT...THESE ARE THE PERIODS WITH THE GREATER
POTENTIAL FOR HIGHER IMPACT WEATHER. MANY MODELS IN THE SUITE OF
GUIDANCE CONTINUE TO ADVERTISE A PRIMARY MCS DEVELOPING BY TUE
MORNING AHEAD OF A STRONG IMPULSE. THERE ARE VARIANCES IN
LATITUDE ON THIS...BUT CERTAINLY THE PATTERN WOULD SUPPORT SUCH
EVOLUTION WITH AMPLE INSTABILITY AHEAD OF AN MCS EVEN IN THE
MORNING GIVEN THE HIGH ABSOLUTE MOISTURE. THE SPC HAS OUTLOOKED A
30 PERCENT AREA FOR THEIR DAY TWO OUTLOOK FOR THIS REASON AND THE
AREA THEY INDICATED IS WHAT HAS BEEN FAVORED IN OUR FORECAST. IT
IS INTERESTING TO NOTE THAT THE CIPS ANALOG GUIDANCE FOR MULTIPLE
DAYS HAS INDICATED MATCHES ON SEVERE WIND EVENTS FROM NORTHERN IA
INTO SOUTHERN WI AND FAR NORTHERN IL AND CONTINUES TO DO SUCH
BASED ON THE NAM FORECAST. SO THE MOST FAVORED AREA WOULD LIKELY
BE NORTH OF I-80...AND MAYBE EVEN NORTH OF I-88 FOR POTENTIALLY A
STRONG WIND COMPLEX ON TUE. SOME OF THE SLOWER GUIDANCE HAS THIS
EVEN HAPPENING IN THE AFTERNOON. CONFIDENCE ON EXACT DEVELOPMENT
BY AFTERNOON AND NIGHTTIME DROPS...ESPECIALLY IF ANYTHING CAN
SPARK OFF OUTFLOWS. CERTAINLY A SEVERE WEATHER POTENTIAL EXISTS
THROUGH THE REST OF THE DAY WITH GRADUALLY INCREASING DEEP LAYER
SHEAR AND PLENTY OF INSTABILITY. THE SOUTHERN FORECAST AREA COULD
WARM INTO THE LOWER TO MID 90S. RIGHT NOW HEAD INDICES ARE
FORECAST AROUND 100 FOR MULTIPLE AFTERNOON HOURS IN THE SOUTHERN
FORECAST AREA...WHILE AROUND THE MID 90S IN ROCKFORD AND CHICAGO
THOUGH CONFIDENCE THERE IS LOW BASED ON PROBABLE MORNING/EARLY
AFTERNOON CONVECTION. HAVE MENTIONED HEAVY RAIN IN THE FORECAST
FOR TUE AND TUE NIGHT GIVEN THE ATMOSPHERIC SETUP AND DO HAVE CHC
SEVERE MENTIONED IN FAR NORTHERN IL GIVEN THE CONSISTENT SIGNAL
AND PATTERN SUPPORT FOR AT THE LEAST A NEARBY MCS.
CONFIDENCE...OVERALL MEDIUM.
WEDNESDAY...THE COOL FRONT...OR AT LEAST THE WIND SHIFT IS MAINLY
AGREED ON BY GUIDANCE TO BE MOVING SOUTHEAST THROUGH THE AREA
EARLY WED. THE COOLER TEMPERATURES IN THE MIX DOWN LAYER LOOK TO
ARRIVE LATE IN THE AFTERNOON INTO THE EVE...SO HIGHS IN THE MID TO
UPPER 80S ARE STILL FORECAST. SOME ONGOING CONVECTION IS LIKELY
IN THE SOUTHEAST CWA AT LEAST ON WED MORNING...THOUGH COVERAGE IS
TOUGH TO TELL AT THIS POINT. DEW POINTS LOOK TO FALL BY WED EVE.
CONFIDENCE...HIGH.
EXTENDED...HAVE NOT MADE TOO MANY CHANGES FROM A SMART BLEND OF
GUIDANCE WITH GOING FORECAST. THIS PERIOD LOOKS MAINLY QUIET AS
THE PATTERN EVOLVES THROUGH THE WEEKEND TO ONCE AGAIN A BLOCKED
SETUP. SURFACE HIGH PRESSURE LOOKS TO PREVAIL WITH ONSHORE FLOW
INTO CHICAGOLAND AND NORTHWEST INDIANA. THIS SHOULD OFFER ONLY
MINIMAL COOLING THOUGH WITH BASICALLY TEMPERATURES AT OR JUST
BELOW SEASONAL NORMALS IN MOST PLACES.
CONFIDENCE...HIGH.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* WIDELY SCATTERED SHOWERS WITH ISOLATED TS EARLY THIS
MORNING...WITH LIMITED OR NO VIS RESTRICTION EXPECTED.
* SHOWERS AND TS ARRIVING LATER THIS MORNING AROUND 13-14Z...WITH
MVFR VIS POSSIBLE.
* CHANCES FOR SHOWERS AND POSSIBLE TS ONCE AGAIN LATER THIS
AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
AS SEVERAL MID LEVEL DISTURBANCES APPROACH FROM THE WEST...LATEST
RADAR IMAGERY SHOWING SCATTERED SHOWER DEVELOPMENT OCCURRING ACROSS
NORTHWEST ILLINOIS EARLY THIS MORNING. EXPECT THIS SCATTERED
DEVELOPMENT ALONG WITH ISOLATED TS TO PERSIST EARLY THIS
MORNING...BUT WITH LITTLE IMPACTS TO THE TERMINALS EXPECTED. AM
MONITORING SHOWER/TS DEVELOPMENT ACROSS NORTHERN/EASTERN IOWA AND
EXPECT THIS AREA OF PRECIP TO SHIFT EASTWARD THROUGH THE EARLY
MORNING HOURS AND MOVE ACROSS THE TERMINALS LATER THIS MORNING.
WITH FAVORABLE METEOROLOGICAL CONDITIONS AND LATEST SHORT TERM
GUIDANCE SHIFTING THIS PRECIP EAST THROUGH THE AREA...FELT
COMFORTABLE ADDING IN A PREVAILING GROUP FOR AT LEAST SHOWERS FOR
ALL OF THE TERMINALS THIS MORNING WHILE ALSO ADDING IN A TEMPO
GROUP FOR POSSIBLE THUNDER THROUGH MID MORNING. SHOULD THEN
OBSERVE THIS PRECIP EXIT TO THE EAST WITH A LULL IN THE
ACTIVITY...BEFORE REDEVELOPMENT OCCURS WITH AN APPROACHING FRONT
LATER THIS AFTERNOON. DO FEEL THAT SHOWERS/THUNDERSTORMS WILL
DEVELOP AROUND THE AREA LATER THIS AFTERNOON...BUT CONFIDENCE IS
LOWER WITH REGARDS TO TIMING/COVERAGE AND EVEN TS POTENTIAL. WILL
CONTINUE TO MONITOR THIS AFTERNOON ACTIVITY AND ADJUST AS NEEDED.
EXPECT SOUTHERLY WINDS THIS FORECAST PERIOD WITH A TREND MORE
TOWARDS THE WEST SOUTHWEST THROUGH MID DAY...WHILE SPEEDS INCREASE
AND SPORADIC GUSTS DEVELOP.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE WITH WIDELY SCATTERED SHOWERS/TS IN THE NEAR
TERM.
* HIGH CONFIDENCE WITH SHOWERS/TS LATER THIS MORNING.
* LOW MEDIUM CONFIDENCE WITH SHOWERS/TS COVERAGE AND TIMING LATER
THIS AFTERNOON.
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
* TUESDAY...TSRA LIKELY. MVFR/GUSTY WINDS POSSIBLE.
* WEDNESDAY...CHANCE OF TSRA.
* THURSDAY THROUGH SATURDAY...DRY/VFR.
&&
.MARINE...
232 PM CDT
HIGH PRESSURE OVER HUDSON BAY WILL MOVE NORTHEASTWARD TONIGHT WHILE
SEVERAL AREAS OF LOW PRESSURE STRETCHING FROM SOUTHERN MANITOBA INTO
THE UPPER MISSISSIPPI RIVER VALLEY AND BACK INTO THE SOUTHERN HIGH
PLAINS EVOLVES. THE STRONGEST LOW IS OVER LAKE MANITOBA THIS
AFTERNOON AND WILL MAKE ITS WAY TO DEVELOP NORTHWARD AS AN UPPER
TROUGH REACHES IT TONIGHT AND MONDAY. THE NEXT AREA OF LOW PRESSURE
IS MORE OF A TROUGH THAT EXTENDS FROM CENTRAL MINNESOTA TO THE U.P.
OF MICHIGAN AND EASTERN LAKE SUPERIOR. AS THE HIGH TO THE NORTHEAST
DEPARTS THIS LOW WILL MOVE NORTHEAST AND WEAKEN BUT WILL HAVE ENOUGH
ENERGY TO PUSH A FRONTAL BOUNDARY SOUTHWARD ACROSS NORTHERN LAKE
MICHIGAN TONIGHT. THE PRESSURE PATTERN WILL WEAKEN AS THE UPPER FLOW
FLATTENS. THE FRONT WILL CONTINUE SOUTHWARD BUT WEAKEN AS IT DOES SO
INTO TUESDAY LEAVING A LIGHT FLOW PATTERN OVER MUCH OF THE LAKE. IN
THE MEANTIME...INCREASINGLY WARM AND MOIST AIR WILL RETURN TO THE
LAKE LIKELY ALLOWING THE COVERAGE OF HAZE/FOG TO INCREASE INTO
MONDAY AND TUESDAY. AT THE MOMENT...THE LOWER VSBY SEEMS TO BE
CONFINED TO PORTIONS OF THE NORTHERN WISCONSIN SHORELINE. THE FRONT
DOES NOT BRING MUCH OF A PUSH OF DRIER OR COOLER AIR SO DESPITE ITS
PASSAGE ACROSS NORTHERN AND CENTRAL PARTS OF THE LAKE THE FOG DOES
LOOK TO TRY AN EXPAND. ANOTHER SERIES OF UPPER TROUGHS WILL MOVE
INTO THE WESTERN U.S. AND CANADA BY THIS TIME TRIGGERING NEW SURFACE
LOW PRESSURE DEVELOPMENT ACROSS THE CENTRAL AND NORTHERN HIGH PLAINS
WHICH THEN CROSSES OVER OR JUST NORTH OF THE LAKE INTO WEDNESDAY.
THIS WILL PUSH A COOL FRONT ACROSS THE LAKE WHICH WILL THEN BE
FOLLOWED BY A LARGE AREA OF HIGH PRESSURE. THIS WILL LEAD TO A
PERIOD OF NORTHERLY WINDS BEHIND THE FRONT WITH A TRANSITION TO
LIGHT AND VARIABLE WINDS AS THE HIGH MOVES CLOSER LATE IN THE WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
336 AM CDT MON JUL 8 2013
.DISCUSSION...
330 AM CDT
THE FORECAST CHALLENGES ARE PRIMARILY WITHIN THE NEXT 48 HOURS AS
THE AREA HAS BEEN OVERTAKEN BY THE SOUPIEST AIR MASS OF THE
SEASON...IN FACT THE MOST PROLONGED HIGH DEW POINT EPISODE SINCE
THE HEAT WAVE JUST OVER ONE YEAR AGO /JUL 4-7/. WITH THIS COMES
SEVERE STORM AND HEAVY RAIN POTENTIAL...MORE SO ON TUESDAY. IN
ADDITION...THE HIGHEST HEAT INDICES OF THE SEASON ARE
FORECAST...AND WHILE NOT AT ADVISORY CRITERIA THESE LOOK TO
FLIRT WITH 100 DEGREES IN SOME SOUTHERN CWA LOCATIONS ON TUESDAY
AFTERNOON.
SYNOPSIS...THE UPPER LEVEL RIDGE ACROSS THE CENTRAL AND SOUTHERN
PLAINS IS EVOLVING EAST EARLY THIS MORNING WITH TURBULENT MOIST
FLOW AROUND ITS NORTHERN PERIPHERY. NUMEROUS AREAS OF CONVECTION
ARE PRESENT ASSOCIATED WITH SHORT WAVE ASCENT AND MOIST ADVECTION
ON THE LOW-LEVEL JET. A WEAK LOW-LEVEL TROUGH IS PRESENT FROM
NORTHERN WI TO NORTHERN KS. TO THE EAST AND SOUTH OF THIS
FEATURE...UPPER 60S TO MID 70S DEW POINTS PREVAIL ON MOST
OBSERVATIONS ALL THE WAY TO THE ATLANTIC AND GULF COASTS. THE
RIDGE WILL TRY TO EXPAND INTO THE AREA THIS AFTERNOON AND MORE SO
TONIGHT WITH CONTINUED SYNOPTIC SOUTHERLY SURFACE FLOW ACROSS THE
AREA. THE SURFACE TROUGH WILL WORK ITS WAY LIKELY INTO FAR
SOUTHERN WI BY LATE AFTERNOON. TWO SURFACE LOWS LOOK TO RIDE ALONG
THIS...ONE DURING THE DAY TUE ASSOCIATED WITH A STRONG SHORT WAVE
EXITING THE GREAT BASIN EARLY THIS MORNING...AND ANOTHER STRONGER
SURFACE LOW ASSOCIATED WITH AN UPPER TROUGH THAT WILL DEVELOP INTO
THE GREAT LAKES BY LATE TUE NIGHT. THIS SECOND WAVE WILL USHER A
COOL FRONT THROUGH THE AREA WED MORNING WITH THE SOMEWHAT
COOLER/DRIER AIR BEING REALIZED BY WED NIGHT.
THIS MORNING...IT APPEARS THERE ARE TWO IMMEDIATE UPSTREAM SHORT
WAVES...ONE BETTER DEFINED ONE PER WATER VAPOR AND RADAR MOSAIC
ACROSS NORTHEAST IA...AND ANOTHER ACROSS FAR SOUTHERN IA/NORTHERN
MO. TOGETHER THESE WILL MOVE EAST AND LOOK TO SLOWLY
WEAKEN LATER THIS MORNING ACROSS THE EASTERN FORECAST AREA WITH
THE MORE DOMINANT JET TO THE NORTH. PROFILER DATA INDICATES 35 KT
850-925MB FLOW INTO THE AREA WHICH LOOKS TO CONTINUE PAST
DAYBREAK. SO EXPECT THAT SHOWER AND EMBEDDED STORM ACTIVITY WILL
BE SUSTAINED AS FAR EAST AS CHICAGO BY MID-MORNING. THE HRRR SEEMS
TO HAVE A FIRM HANDLE ON THE ONGOING CONVECTION AND ITS EVOLUTION
MAKES SENSE AND HAVE FOLLOWED CLOSELY IN OUR FORECAST HOURLY POPS.
HAVE SEEN A COUPLE 20 KT PLUS GUSTS IN SW WI INDICATING THAT A
COLD POOL MAY BE TRYING TO DEVELOP. THIS AND ANY MCV DEVELOPMENT
WOULD ALSO AID IN SUSTAINING THE ACTIVITY EASTWARD. SEVERE
POTENTIAL IS MAINLY LOW WITH THIS THROUGH THE MORNING AND RADAR
TRENDS FROM ARX/DVN CONFIRM NOTHING POTENT IN THE STORM
BEHAVIORS...THOUGH CANT RULE OUT SMALL HAIL OR GUSTY WINDS. IN
ADDITION...STORMS WILL BE VERY EFFICIENT RAIN PRODUCERS GIVEN HIGH
ATMOSPHERIC MOISTURE CONTENT /PWATS AOA 1.65 INCHES AND 700MB TDS
AOA 4C/.
CONFIDENCE...HIGH.
THIS AFTERNOON AND TONIGHT...WITH THE PRIMARY SHORT WAVE IMPULSES
HAVING MOVED EAST...COVERAGE OF PRECIP SHOULD AT LEAST TEMPORARILY
DIMINISH IN THE EARLY AFTERNOON. OUTFLOW BOUNDARIES FROM THE
MORNING ACTIVITY...EVEN IF ELEVATED COULD CONTINUE FESTERING
CONVECTION THIS AFTERNOON GIVEN ATTAINABLE CONVECTIVE TEMPS. THIS
WOULD SEEM MOST FAVORED ALONG AND SOUTH OF I-80. THE SURFACE
BOUNDARY WILL BE NEAR THE IL/WI STATE LINE...AND SIMILAR TO PREV
FORECAST REASONING COULD SEE SOME SCATTERED DEVELOPMENT LATER THIS
AFTERNOON ALONG THAT AS WELL. AFTER WHAT WILL LIKELY BE A SLOW
TEMPERATURE CLIMB THIS MORNING...THIS AFTERNOON SHOULD SEE
RECOVERY INTO THE UPPER 80S AND MAYBE EVEN 90...ESPECIALLY ACROSS
THE WESTERN HALF OF THE FORECAST AREA. WITH SUCH HIGH DEW POINT
AIR...SURFACE BASED INSTABILITY OF 1500-2500 J/KG WOULD BE
SUPPORTED BY THESE FORECAST TEMPS AND DEW POINTS. MOST GUIDANCE
DOES HAVE A SPLOTCHY QPF PRODUCED OVER THE AREA. ANY SCATTERED
CONVECTION THAT CAN DEVELOP THIS AFTERNOON INTO THE EVE WOULD HAVE
SOME SEVERE WEATHER THREAT. THE HIGH PWAT AIR WILL SUPPORT HEAVY
RAIN ALONG WITH PRECIP LOADING CONCERNS TOWARDS ISOLATED DOWNBURSTS
IN ANY MORE ROBUST CELLS OR MULTI-CELL CLUSTERS...BUT OVERALL
THREAT COVERAGE IS LOW. AS WE HEAD TO AFTER SUNDOWN...HEIGHT
FALLS AND THE LLJ NOSE CONTINUE TO BE FOCUSED TO THE NORTHWEST OF
THE AREA /OVER MN AND NORTHERN IA/. THIS IS WHERE LIKELY MCS
DEVELOPMENT WILL OCCUR LATE. IN ADVANCE...BROAD WARM AND MOIST
ADVECTION ALOFT MAY ALLOW FOR ISOLATED TO SCATTERED CONVECTIVE
DEVELOPMENT OVER THE AREA. DEEP WARM CLOUD PROCESSES WILL BE AT
PLAY WITH PWATS CONTINUING TO INCH UP...MEANING HEAVY RAIN WILL BE
THE GREATEST THREAT. GIVEN A SOMEWHAT DIFFUSE 850MB BAROCLINIC
ZONE AND FORWARD PROPAGATION INDICATED...THE TRAINING SETUP IS
SOMEWHAT MARGINAL IN THE FORECAST AREA AT LEAST PRIOR TO DAYBREAK
TUE. SO NO FLASH FLOOD WATCH BEING ISSUED AT THIS TIME BUT THIS
WILL NEED TO BE MONITORED.
CONFIDENCE...MEDIUM.
TUESDAY AND TUESDAY NIGHT...THESE ARE THE PERIODS WITH THE GREATER
POTENTIAL FOR HIGHER IMPACT WEATHER. MANY MODELS IN THE SUITE OF
GUIDANCE CONTINUE TO ADVERTISE A PRIMARY MCS DEVELOPING BY TUE
MORNING AHEAD OF A STRONG IMPULSE. THERE ARE VARIANCES IN
LATITUDE ON THIS...BUT CERTAINLY THE PATTERN WOULD SUPPORT SUCH
EVOLUTION WITH AMPLE INSTABILITY AHEAD OF AN MCS EVEN IN THE
MORNING GIVEN THE HIGH ABSOLUTE MOISTURE. THE SPC HAS OUTLOOKED A
30 PERCENT AREA FOR THEIR DAY TWO OUTLOOK FOR THIS REASON AND THE
AREA THEY INDICATED IS WHAT HAS BEEN FAVORED IN OUR FORECAST. IT
IS INTERESTING TO NOTE THAT THE CIPS ANALOG GUIDANCE FOR MULTIPLE
DAYS HAS INDICATED MATCHES ON SEVERE WIND EVENTS FROM NORTHERN IA
INTO SOUTHERN WI AND FAR NORTHERN IL AND CONTINUES TO DO SUCH
BASED ON THE NAM FORECAST. SO THE MOST FAVORED AREA WOULD LIKELY
BE NORTH OF I-80...AND MAYBE EVEN NORTH OF I-88 FOR POTENTIALLY A
STRONG WIND COMPLEX ON TUE. SOME OF THE SLOWER GUIDANCE HAS THIS
EVEN HAPPENING IN THE AFTERNOON. CONFIDENCE ON EXACT DEVELOPMENT
BY AFTERNOON AND NIGHTTIME DROPS...ESPECIALLY IF ANYTHING CAN
SPARK OFF OUTFLOWS. CERTAINLY A SEVERE WEATHER POTENTIAL EXISTS
THROUGH THE REST OF THE DAY WITH GRADUALLY INCREASING DEEP LAYER
SHEAR AND PLENTY OF INSTABILITY. THE SOUTHERN FORECAST AREA COULD
WARM INTO THE LOWER TO MID 90S. RIGHT NOW HEAD INDICES ARE
FORECAST AROUND 100 FOR MULTIPLE AFTERNOON HOURS IN THE SOUTHERN
FORECAST AREA...WHILE AROUND THE MID 90S IN ROCKFORD AND CHICAGO
THOUGH CONFIDENCE THERE IS LOW BASED ON PROBABLE MORNING/EARLY
AFTERNOON CONVECTION. HAVE MENTIONED HEAVY RAIN IN THE FORECAST
FOR TUE AND TUE NIGHT GIVEN THE ATMOSPHERIC SETUP AND DO HAVE CHC
SEVERE MENTIONED IN FAR NORTHERN IL GIVEN THE CONSISTENT SIGNAL
AND PATTERN SUPPORT FOR AT THE LEAST A NEARBY MCS.
CONFIDENCE...OVERALL MEDIUM.
WEDNESDAY...THE COOL FRONT...OR AT LEAST THE WIND SHIFT IS MAINLY
AGREED ON BY GUIDANCE TO BE MOVING SOUTHEAST THROUGH THE AREA
EARLY WED. THE COOLER TEMPERATURES IN THE MIX DOWN LAYER LOOK TO
ARRIVE LATE IN THE AFTERNOON INTO THE EVE...SO HIGHS IN THE MID TO
UPPER 80S ARE STILL FORECAST. SOME ONGOING CONVECTION IS LIKELY
IN THE SOUTHEAST CWA AT LEAST ON WED MORNING...THOUGH COVERAGE IS
TOUGH TO TELL AT THIS POINT. DEW POINTS LOOK TO FALL BY WED EVE.
CONFIDENCE...HIGH.
EXTENDED...HAVE NOT MADE TOO MANY CHANGES FROM A SMART BLEND OF
GUIDANCE WITH GOING FORECAST. THIS PERIOD LOOKS MAINLY QUIET AS
THE PATTERN EVOLVES THROUGH THE WEEKEND TO ONCE AGAIN A BLOCKED
SETUP. SURFACE HIGH PRESSURE LOOKS TO PREVAIL WITH ONSHORE FLOW
INTO CHICAGOLAND AND NORTHWEST INDIANA. THIS SHOULD OFFER ONLY
MINIMAL COOLING THOUGH WITH BASICALLY TEMPERATURES AT OR JUST
BELOW SEASONAL NORMALS IN MOST PLACES.
CONFIDENCE...HIGH.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WIDELY SCATTERED SHOWERS WITH ISOLATED TS EARLY THIS
MORNING...WITH LIMITED OR NO VIS RESTRICTION EXPECTED.
* BETTER CHANCES FOR SHOWERS AND TS ARRIVE LATER THIS MORNING
AROUND 13-14Z...WITH MVFR VIS POSSIBLE.
* CHANCES FOR SHOWERS AND POSSIBLE TS ONCE AGAIN LATER THIS
AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
AS SEVERAL MID LEVEL DISTURBANCES APPROACH FROM THE WEST...LATEST
RADAR IMAGERY SHOWING SCATTERED SHOWER DEVELOPMENT OCCURRING ACROSS
NORTHWEST ILLINOIS EARLY THIS MORNING. EXPECT THIS SCATTERED
DEVELOPMENT ALONG WITH ISOLATED TS TO PERSIST EARLY THIS
MORNING...BUT WITH LITTLE IMPACTS TO THE TERMINALS EXPECTED. AM
MONITORING SHOWER/TS DEVELOPMENT ACROSS NORTHERN/EASTERN IOWA AND
EXPECT THIS AREA OF PRECIP TO SHIFT EASTWARD THROUGH THE EARLY
MORNING HOURS AND MOVE ACROSS THE TERMINALS LATER THIS MORNING.
WITH FAVORABLE METEOROLOGICAL CONDITIONS AND LATEST SHORT TERM
GUIDANCE SHIFTING THIS PRECIP EAST THROUGH THE AREA...FELT
COMFORTABLE ADDING IN A PREVAILING GROUP FOR AT LEAST SHOWERS FOR
ALL OF THE TERMINALS THIS MORNING WHILE ALSO ADDING IN A TEMPO
GROUP FOR POSSIBLE THUNDER THROUGH MID MORNING. SHOULD THEN
OBSERVE THIS PRECIP EXIT TO THE EAST WITH A LULL IN THE
ACTIVITY...BEFORE REDEVELOPMENT OCCURS WITH AN APPROACHING FRONT
LATER THIS AFTERNOON. DO FEEL THAT SHOWERS/THUNDERSTORMS WILL
DEVELOP AROUND THE AREA LATER THIS AFTERNOON...BUT CONFIDENCE IS
LOWER WITH REGARDS TO TIMING/COVERAGE AND EVEN TS POTENTIAL. WILL
CONTINUE TO MONITOR THIS AFTERNOON ACTIVITY AND ADJUST AS NEEDED.
EXPECT SOUTHERLY WINDS THIS FORECAST PERIOD WITH A TREND MORE
TOWARDS THE WEST SOUTHWEST THROUGH MID DAY...WHILE SPEEDS INCREASE
AND SPORADIC GUSTS DEVELOP.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE WITH WIDELY SCATTERED SHOWERS/TS IN THE NEAR
TERM.
* MEDIUM CONFIDENCE WITH SHOWERS/TS LATER THIS MORNING.
* LOW MEDIUM CONFIDENCE WITH SHOWERS/TS COVERAGE AND TIMING LATER
THIS AFTERNOON.
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
* TUESDAY...TSRA LIKELY. MVFR/GUSTY WINDS POSSIBLE.
* WEDNESDAY...CHANCE OF TSRA.
* THURSDAY THROUGH SATURDAY...DRY/VFR.
&&
.MARINE...
232 PM CDT
HIGH PRESSURE OVER HUDSON BAY WILL MOVE NORTHEASTWARD TONIGHT WHILE
SEVERAL AREAS OF LOW PRESSURE STRETCHING FROM SOUTHERN MANITOBA INTO
THE UPPER MISSISSIPPI RIVER VALLEY AND BACK INTO THE SOUTHERN HIGH
PLAINS EVOLVES. THE STRONGEST LOW IS OVER LAKE MANITOBA THIS
AFTERNOON AND WILL MAKE ITS WAY TO DEVELOP NORTHWARD AS AN UPPER
TROUGH REACHES IT TONIGHT AND MONDAY. THE NEXT AREA OF LOW PRESSURE
IS MORE OF A TROUGH THAT EXTENDS FROM CENTRAL MINNESOTA TO THE U.P.
OF MICHIGAN AND EASTERN LAKE SUPERIOR. AS THE HIGH TO THE NORTHEAST
DEPARTS THIS LOW WILL MOVE NORTHEAST AND WEAKEN BUT WILL HAVE ENOUGH
ENERGY TO PUSH A FRONTAL BOUNDARY SOUTHWARD ACROSS NORTHERN LAKE
MICHIGAN TONIGHT. THE PRESSURE PATTERN WILL WEAKEN AS THE UPPER FLOW
FLATTENS. THE FRONT WILL CONTINUE SOUTHWARD BUT WEAKEN AS IT DOES SO
INTO TUESDAY LEAVING A LIGHT FLOW PATTERN OVER MUCH OF THE LAKE. IN
THE MEANTIME...INCREASINGLY WARM AND MOIST AIR WILL RETURN TO THE
LAKE LIKELY ALLOWING THE COVERAGE OF HAZE/FOG TO INCREASE INTO
MONDAY AND TUESDAY. AT THE MOMENT...THE LOWER VSBY SEEMS TO BE
CONFINED TO PORTIONS OF THE NORTHERN WISCONSIN SHORELINE. THE FRONT
DOES NOT BRING MUCH OF A PUSH OF DRIER OR COOLER AIR SO DESPITE ITS
PASSAGE ACROSS NORTHERN AND CENTRAL PARTS OF THE LAKE THE FOG DOES
LOOK TO TRY AN EXPAND. ANOTHER SERIES OF UPPER TROUGHS WILL MOVE
INTO THE WESTERN U.S. AND CANADA BY THIS TIME TRIGGERING NEW SURFACE
LOW PRESSURE DEVELOPMENT ACROSS THE CENTRAL AND NORTHERN HIGH PLAINS
WHICH THEN CROSSES OVER OR JUST NORTH OF THE LAKE INTO WEDNESDAY.
THIS WILL PUSH A COOL FRONT ACROSS THE LAKE WHICH WILL THEN BE
FOLLOWED BY A LARGE AREA OF HIGH PRESSURE. THIS WILL LEAD TO A
PERIOD OF NORTHERLY WINDS BEHIND THE FRONT WITH A TRANSITION TO
LIGHT AND VARIABLE WINDS AS THE HIGH MOVES CLOSER LATE IN THE WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
300 AM CDT MON JUL 8 2013
.DISCUSSION...
ISSUED 300 AM CDT MON JUL 8 2013
WARM AND HUMID CONDITIONS WITH PERIODIC CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL PREVAIL FOR THE NEXT COUPLE OF DAYS...BEFORE
COOLER AND DRIER WEATHER ARRIVES BY THE END OF THE WEEK.
07Z/2AM SURFACE ANALYSIS SHOWS LOW PRESSURE CENTERED OVER WESTERN
WISCONSIN...WITH NEARLY STATIONARY BOUNDARY EXTENDING SOUTHWESTWARD
INTO NEBRASKA. CONVECTION HAS DEVELOPED ALONG THIS BOUNDARY...AIDED
BY A SUBTLE 500MB SHORT-WAVE OVER MINNESOTA AND A 30-35KT 850MB
JET FROM THE SOUTHERN PLAINS INTO IOWA.
SHORT TERM...TODAY THROUGH WEDNESDAY
00Z MODELS ARE PERFORMING VERY POORLY THUS FAR...WITH NONE OF THEM
ADEQUATELY SHOWING THE CURRENT CONVECTION TO THE N/NW OF ILLINOIS.
ONLY THE 05Z HRRR HAS A REASONABLE HANDLE ON THE SITUATION...SO
WILL FOLLOW ITS SOLUTION CLOSELY FOR THE IMMEDIATE SHORT-TERM
FORECAST. HRRR SHOWS A LINE OF SHOWERS AND THUNDERSTORMS
DEVELOPING ACROSS EASTERN IOWA/FAR NORTHERN MISSOURI OVER THE NEXT
COUPLE OF HOURS...THEN PUSHES THE LINE INTO THE NORTHERN KILX CWA
AFTER 10Z. GIVEN 30KT LOW-LEVEL JET ORIENTED FROM KANSAS E/NE
INTO WESTERN ILLINOIS THIS MORNING...THINK THIS IS A PLAUSIBLE
SOLUTION. RADAR MOSAIC IS ALREADY SHOWING A BROKEN LINE OF
CONVECTION DEVELOPING ALONG/WEST OF THE MISSISSIPPI RIVER...SO
HAVE BUMPED POPS TO LIKELY ALONG AND NORTHWEST OF A RUSHVILLE TO
BLOOMINGTON-NORMAL LINE THIS MORNING. AS LOW-LEVEL JET WEAKENS AND
SHIFTS BACK WESTWARD...SHOWERS/THUNDER WILL TEND TO DISSIPATE
LATER THIS MORNING AS IT SAGS SOUTHEASTWARD TOWARD THE I-72
CORRIDOR. WILL CARRY CHANCE POPS AS FAR SOUTH AS A SPRINGFIELD TO
MATTOON LINE ACCORDINGLY...WITH ONLY SLIGHT CHANCES FOR ISOLATED
THUNDER ACROSS THE FAR SE CWA THIS AFTERNOON. WILL BE A VERY WARM
AND HUMID DAY...WITH HIGHS REACHING THE UPPER 80S AND LOWER 90S.
LOW PRESSURE WILL TRACK THROUGH THE GREAT LAKES TONIGHT...WITH
TRAILING FRONTAL BOUNDARY SINKING SLIGHTLY FURTHER SOUTHWARD TO
NEAR THE ILLINOIS/WISCONSIN BORDER. SCATTERED SHOWERS/THUNDER WILL
PERSIST NEAR THE BOUNDARY...RESULTING IN LOW CHANCE POPS FOR THE
NORTHERN TWO-THIRDS OF THE CWA TONIGHT. FURTHER SOUTH...LITTLE OR
NO PRECIP IS ANTICIPATED ALONG/SOUTH OF I-70. AS LOW-LEVEL JET
STRENGTHENS AND SHORT-WAVE CURRENTLY OVER UTAH TRACKS E/NE INTO
THE NORTHERN PLAINS...AN MCS WILL LIKELY DEVELOP OVER SOUTHERN
MINNESOTA/NORTHERN IOWA LATE TONIGHT. TRAJECTORIES TAKE THIS
SYSTEM MAINLY EASTWARD ACROSS WISCONSIN AND NORTHERN ILLINOIS
TUESDAY MORNING. THINK BULK OF THE CONVECTION WILL REMAIN JUST
NORTH OF CENTRAL ILLINOIS...PRIMARILY ALONG/NORTH OF I-80. WILL
FEATURE HIGHEST POPS ACROSS THE NORTHERN CWA ACCORDINGLY...WITH
ONLY LOW CHANCE TO SLIGHT CHANCE POPS ACROSS THE CENTRAL AND
SOUTHERN ZONES. MAIN STORY ON TUESDAY WILL BE THE HEAT AND
HUMIDITY. AFTERNOON HIGH TEMPERATURES IN THE LOWER 90S COMBINED
WITH DEWPOINTS IN THE LOWER TO MIDDLE 70S...WILL RESULT IN HEAT
INDEX VALUES APPROACHING 100 DEGREES.
BEST CHANCE FOR WIDESPREAD CONVECTION STILL ON TARGET FOR TUESDAY
NIGHT INTO WEDNESDAY...AS NORTHERN STREAM WAVE CURRENTLY OVER THE
PACIFIC NORTHWEST PUSHES COLD FRONT SOUTHWARD INTO CENTRAL
ILLINOIS. WITH FRONT INTERACTING WITH A VERY MOIST AIRMASS
CHARACTERIZED BY PRECIPITABLE WATER VALUES IN EXCESS OF 2
INCHES...WILL CONTINUE TO FEATURE LIKELY POPS WITH FROPA. SEVERE
WEATHER THREAT REMAINS UNCERTAIN...HOWEVER LOCALLY HEAVY RAINFALL
WILL BE A GOOD BET WITH THE STORMS LATE TUESDAY NIGHT INTO WEDNESDAY.
FRONT WILL DROP SOUTHWARD INTO THE OHIO RIVER VALLEY BY WEDNESDAY
EVENING...ENDING THE THREAT FOR RAIN FROM NORTH TO SOUTH ACROSS
THE AREA. WILL LINGER CHANCE POPS ALONG/SOUTH OF I-70 THROUGH
WEDNESDAY EVENING...THEN WILL GO DRY ACROSS THE BOARD AFTER MIDNIGHT.
LONG TERM...THURSDAY THROUGH SUNDAY
COOLER/DRIER WEATHER WILL PREVAIL THROUGH THE EXTENDED...AS HIGH
PRESSURE BUILDS INTO THE GREAT LAKES. HIGH TEMPERATURES WILL ONLY
REACH THE LOWER TO MIDDLE 80S...WHILE OVERNIGHT LOWS DROP INTO THE
LOWER TO MIDDLE 60S.
BARNES
&&
.AVIATION...
ISSUED 1152 PM CDT SUN JUL 7 2013
A FEW SPOTTY SHOWERS HAVE COME AS CLOSE AS NORTHWEST
ILLINOIS...AND MID/HIGH LEVEL CLOUDINESS IS ON THE INCREASE ACROSS
THE CENTRAL ILLINOIS TERMINALS. HOWEVER...THE BULK OF THE
SHOWERS/STORMS ARE STILL WELL TO THE NORTHWEST...ALONG A LINE
EXTENDING FROM NORTHERN WISCONSIN INTO WESTERN NEBRASKA. IF THE
MORE SOLID LINE HOLDS TOGETHER...IT MAY IMPACT KPIA AND KBMI A
LITTLE AFTER SUNRISE. EVEN IF THE STORMS DO NOT MAKE IT INTO THE
AREA BEFORE DRYING UP...THERE IS A CHANCE FOR AN OUTFLOW BOUNDARY
FROM THESE STORMS SERVING AS A FOCUS FOR STORMS WITH THE HEATING
OF THE DAY MONDAY. IN ANY EVENT...CONFIDENCE IN THE
TIMING/COVERAGE OF CONVECTION IS TOO LOW TO MENTION IN MOST
TERMINALS. HAVE CONTINUED WITH AN EARLY MORNING VCSH AT KPIA/KBMI
AS THIS AREA WILL BE CLOSEST TO THE NOCTURNAL STORMS THAT SHOULD
BE DECAYING AS THEY APPROACH. VFR CONDITIONS SHOULD PREVAIL THROUGH
THE PERIOD OUTSIDE OF ANY STORMS.
BAK
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
234 AM MDT MON JUL 8 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1254 PM MDT SUN JUL 7 2013
LATEST WV IMAGERY AND RAP ANALYSIS SHOW H5 RIDGE STILL IN PLACE
ACROSS SOUTHERN PLAINS WITH SERIES OF WEAK SHORTWAVE TROUGHS
ROTATING AROUND WESTERN AND NORTHERN EXTENT OF RIDGE THROUGH
WESTERLY FLOW. AT THE SURFACE A COLD FRONT HAS STALLED ALONG THE
KS/NE BORDER WITH A SURFACE TROUGH EXTENDING SOUTH ALONG THE KS/CO
BORDER.
A WEAK SHORTWAVE TROUGH EXPECTED TO DROP SOUTH OUT OF WESTERN
NEBRASKA LATE THIS AFTERNOON AND TONIGHT WILL COMBINE WITH THESE
SURFACE FEATURES TO INITIATE SCATTERED THUNDERSTORMS ACROSS THE CWA.
PRIMARY FOCUS SHOULD BE ALONG FRONT WHERE HIGH TD VALUES NORTH OF
THE FRONT HAVE RESULTED IN ML CAPE 1000-1500 J/KG AS OF THE LATEST
RAP ANALYSIS. BETTER DEEP SHEER IS EXPECTED TO BE IN PLACE NORTH OF
THE FRONT WHERE 0-6KM BULK SHEER AROUND 35KT BY 00Z COULD SUPPORT A
SEVERE WIND AND HAIL THREAT. THERE IS LESS INSTABILITY AND MORE CIN
TO OVERCOME FURTHER SOUTH ALONG THE SURFACE TROUGH...HOWEVER AS
DAYTIME HEATING CONTINUES AND THE SHORTWAVE TROUGH MOVES SOUTH WE
SHOULD BE ABLE TO SEE AT LEAST ISOLATED THUNDERSTORMS DEVELOPING
ALONG THE SURFACE TROUGH THIS AFTERNOON/EVENING. PWAT VALUES
1.2-1.3" REPRESENT AN ANOMALOUSLY WET ATMOSPHERE FOR THIS TIME OF
YEAR...AND AS WAS THE CASE YESTERDAY MANY OF THESE STORMS WILL BE
SLOW MOVERS...SO HEAVY RAIN WILL BE A CONCERN WHERE STORMS DEVELOP.
LEE TROUGH IS EXPECTED TO BEGIN TO DEEPEN LATE TONIGHT WITH LLJ
BUILDING ACROSS THE NE HALF OF THE CWA. WITH INCREASING ISENTROPIC
ASCENT AND H85 SUPPORT WE COULD SEE LINGERING THUNDERSTORMS IN
PROXIMITY OF THE FRONTAL ZONE ACROSS OUR NE CWA...SO I KEPT ISO
THUNDER MENTION MOST OF THE NIGHT FOR THOSE LOCATIONS. THERE IS
SOME INDICATION WITH VERY MOIST E-NE BL FLOW OF FOG DEVELOPING IN
SW NEBRASKA...HOWEVER WITH BL LIKELY MIXED WITH LLJ INCREASING AND
FRONT POSSIBLY SHIFTING NORTH I WAS NOT CONFIDENT ENOUGH TO ADD
MENTION.
DESPITE LARGE SCALE FORCING IN PLACE MONDAY IT DOES LOOK LIKE A
TROUGH AXIS/DRYLINE ALONG KS/CO BORDER COULD HELP INITIATE
THUNDERSTORMS BY THE AFTERNOON WITH INSTABILITY BUILDING ACROSS THE
EASTERN CWA. I WASNT CONFIDENT ENOUGH TO ADD MORE THAN SLIGHT CHANCE
MENTION AT THIS POINT. H85 TEMPS ARE ACTUALLY ADVERTISED TO BE 2-3C
WARMER THAN THE LAST FEW DAYS WHEN HIGHS HAVE BEEN AROUND 100F...SO
WE COULD BE LOOKING AT NEAR RECORD HIGH TEMPS ACROSS THE CWA MONDAY
WITH VALUES IN THE 100S ACROSS THE AREA.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 232 AM MDT MON JUL 8 2013
STRONG 500 MB HIGH PRESSURE WILL START OVER THE FOUR CORNERS REGION
FOR THURSDAY AND WILL SLOWLY PROPAGATE EASTWARD INTO THE HIGH PLAINS
REGION FOR FRIDAY AND SATURDAY. RIDGE AXIS WILL TAKE ON A MORE
NEGATIVE TILT AS UPPER LEVEL JET STREAM RETURNS TO A MORE ZONAL FLOW
FOR THE WEEKEND. THE JET WILL STILL REMAIN WELL TO THE NORTH OF THE
TRI STATE AREA...KEEPING WEATHER PATTERN STAGNANT FOR THE DURATION
OF THE EXTENDED FORECAST PERIOD. THE UPPER LEVEL RIDGE WILL TAKE A
MORE BROAD SHAPE ACROSS THE WESTERN AND CENTRAL PART OF THE CONUS
INTO EARLY NEXT WEEK. SURFACE LOW PRESSURE SYSTEM WILL REMAIN OVER
THE TRI STATE AREA FOR THE PERIOD WITH CHANCES OF ISOLATED
THUNDERSTORMS TO DEVELOP FOR THURSDAY AND FRIDAY. CHANCES INCREASE
FOR PRECIPITATION SUNDAY AND EARLY NEXT WEEK AS A POTENTIAL ALBERTA
CLIPPER SYSTEM DEVELOPS AND MOVES THROUGH THE HIGH PLAINS. HIGH
TEMPERATURES WILL REMAIN WARM INTO THE UPPER 90S AND LOWER 100S FOR
THE AREA UNTIL SUNDAY...WHERE TEMPERATURES WILL COOL SLIGHTLY AND
APPROACH NEAR NORMAL FOR THE TRI STATE AREA WITH HIGHS IN THE UPPER
80S AND LOWER 90S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1105 PM MDT SUN JUL 7 2013
VFR CONDITIONS EXPECTED AT KGLD AND KMCK. ERRATIC AND POSSIBLY
GUSTY WINDS STILL POSSIBLE FROM TAF ISSUANCE THROUGH 08Z AS
SHOWERS AND THUNDERSTORMS MOVE ACROSS THE TERMINALS. BETWEEN 08Z-
12Z WINDS SHOULD BECOME SOUTHERLY AT 10KTS OR SO WITH ONLY SOME
MID AND HIGH LEVEL CLOUDINESS. DURING THE MID TO LATE AFTERNOON
SOUTHERLY WINDS OF 13-15KTS WITH HIGHER GUSTS TO DEVELOP AND
CONTINUE THROUGH THE EARLY EVENING HOURS. DIURNAL LATE AFTERNOON
AND EVENING SHOWERS/THUNDERSTORMS POSSIBLE ONCE AGAIN FOR BOTH
TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DJR
LONG TERM...MK
AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1105 PM MDT SUN JUL 7 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1254 PM MDT SUN JUL 7 2013
LATEST WV IMAGERY AND RAP ANALYSIS SHOW H5 RIDGE STILL IN PLACE
ACROSS SOUTHERN PLAINS WITH SERIES OF WEAK SHORTWAVE TROUGHS
ROTATING AROUND WESTERN AND NORTHERN EXTENT OF RIDGE THROUGH
WESTERLY FLOW. AT THE SURFACE A COLD FRONT HAS STALLED ALONG THE
KS/NE BORDER WITH A SURFACE TROUGH EXTENDING SOUTH ALONG THE KS/CO
BORDER.
A WEAK SHORTWAVE TROUGH EXPECTED TO DROP SOUTH OUT OF WESTERN
NEBRASKA LATE THIS AFTERNOON AND TONIGHT WILL COMBINE WITH THESE
SURFACE FEATURES TO INITIATE SCATTERED THUNDERSTORMS ACROSS THE CWA.
PRIMARY FOCUS SHOULD BE ALONG FRONT WHERE HIGH TD VALUES NORTH OF
THE FRONT HAVE RESULTED IN ML CAPE 1000-1500 J/KG AS OF THE LATEST
RAP ANALYSIS. BETTER DEEP SHEER IS EXPECTED TO BE IN PLACE NORTH OF
THE FRONT WHERE 0-6KM BULK SHEER AROUND 35KT BY 00Z COULD SUPPORT A
SEVERE WIND AND HAIL THREAT. THERE IS LESS INSTABILITY AND MORE CIN
TO OVERCOME FURTHER SOUTH ALONG THE SURFACE TROUGH...HOWEVER AS
DAYTIME HEATING CONTINUES AND THE SHORTWAVE TROUGH MOVES SOUTH WE
SHOULD BE ABLE TO SEE AT LEAST ISOLATED THUNDERSTORMS DEVELOPING
ALONG THE SURFACE TROUGH THIS AFTERNOON/EVENING. PWAT VALUES
1.2-1.3" REPRESENT AN ANOMALOUSLY WET ATMOSPHERE FOR THIS TIME OF
YEAR...AND AS WAS THE CASE YESTERDAY MANY OF THESE STORMS WILL BE
SLOW MOVERS...SO HEAVY RAIN WILL BE A CONCERN WHERE STORMS DEVELOP.
LEE TROUGH IS EXPECTED TO BEGIN TO DEEPEN LATE TONIGHT WITH LLJ
BUILDING ACROSS THE NE HALF OF THE CWA. WITH INCREASING ISENTROPIC
ASCENT AND H85 SUPPORT WE COULD SEE LINGERING THUNDERSTORMS IN
PROXIMITY OF THE FRONTAL ZONE ACROSS OUR NE CWA...SO I KEPT ISO
THUNDER MENTION MOST OF THE NIGHT FOR THOSE LOCATIONS. THERE IS
SOME INDICATION WITH VERY MOIST E-NE BL FLOW OF FOG DEVELOPING IN
SW NEBRASKA...HOWEVER WITH BL LIKELY MIXED WITH LLJ INCREASING AND
FRONT POSSIBLY SHIFTING NORTH I WASNT CONFIDENT ENOUGH TO ADD
MENTION.
DESPITE LARGE SCALE FORCING IN PLACE MONDAY IT DOES LOOK LIKE A
TROUGH AXIS/DRYLINE ALONG KS/CO BORDER COULD HELP INITIATE
THUNDERSTORMS BY THE AFTERNOON WITH INSTABILITY BUILDING ACROSS THE
EASTERN CWA. I WASNT CONFIDENT ENOUGH TO ADD MORE THAN SLIGHT CHANCE
MENTION AT THIS POINT. H85 TEMPS ARE ACTUALLY ADVERTISED TO BE 2-3C
WARMER THAN THE LAST FEW DAYS WHEN HIGHS HAVE BEEN AROUND 100F...SO
WE COULD BE LOOKING AT NEAR RECORD HIGH TEMPS ACROSS THE CWA MONDAY
WITH VALUES IN THE 100S ACROSS THE AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 1251 PM MDT SUN JUL 7 2013
AN UPPER RIDGE CENTERED OVER THE SOUTHERN ROCKIES WILL BE THE
DOMINATING INFLUENCE THROUGH THE LONG TERM PERIOD. TEMPERATURES
WILL BE ABOVE NORMAL...ALTHOUGH A WEAK COLD FRONT ON TUESDAY WILL
KNOCK TEMPERATURES DOWN A FEW DEGREES THROUGH THURSDAY...THEY WILL
WARM AGAIN FOR THE LATE WEEK AND WEEKEND. POSITION OF THE RIDGE
EARLY IN THE PERIOD WILL BE CLOSER TO THE FOUR CORNERS AND ALLOW
SHORTWAVE TROUGHS ROTATING AROUND IT TO BRING A CHANCE FOR SCATTERED
THUNDERSTORMS. AS THE RIDGE BUILDS EASTWARD LATER IN THE
WEEK...THUNDERSTORM CHANCES WILL BECOME MORE ISOLATED. SEVERE
WEATHER IS NOT ANTICIPATED WITH THE WEAK FLOW ALOFT LIMITING UPDRAFT
ORGANIZATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1105 PM MDT SUN JUL 7 2013
VFR CONDITIONS EXPECTED AT KGLD AND KMCK. ERRATIC AND POSSIBLY
GUSTY WINDS STILL POSSIBLE FROM TAF ISSUANCE THROUGH 08Z AS
SHOWERS AND THUNDERSTORMS MOVE ACROSS THE TERMINALS. BETWEEN 08Z-
12Z WINDS SHOULD BECOME SOUTHERLY AT 10KTS OR SO WITH ONLY SOME
MID AND HIGH LEVEL CLOUDINESS. DURING THE MID TO LATE AFTERNOON
SOUTHERLY WINDS OF 13-15KTS WITH HIGHER GUSTS TO DEVELOP AND
CONTINUE THROUGH THE EARLY EVENING HOURS. DIURNAL LATE AFTERNOON
AND EVENING SHOWERS/THUNDERSTORMS POSSIBLE ONCE AGAIN FOR BOTH
TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DJR
LONG TERM...024
AVIATION...99
AREA FORECAST DISCUSSION
NWS PADUCAH KY
330 AM CDT MON JUL 8 2013
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 329 AM CDT MON JUL 8 2013
A LITTLE BIT OF A BALANCING ACT IN THE SHORT TERM. GIVEN THE
SLIGHTLY STRONGER SUBSIDENCE OF THE RIDGE MOVING INTO THE WFO PAH
FORECAST AREA FROM THE WEST ON SUNDAY...ANTICIPATE SLIGHTLY BETTER
SUBSIDENCE /WARMING/ TODAY...ESPECIALLY IN THE SOUTHERN 1/2 OF
SOUTHEAST MO.
THERE WILL BE A ZONE OF UNCERTAINTY FOR SHOWER/THUNDERSTORM
GENERATION THIS AFTERNOON...MAINLY ALONG AND NORTH OF ROUTE 13 IN
SOUTHERN IL...THEN NORTHEAST TO NORTH OF KEHR AND KOWB. LOOKING AT
THE LATEST GFS/NAM/RAP/SREF SOUNDINGS SUGGEST FOR ANYTHING TO GET
GOING THIS AFTERNOON...IT WOULD HAVE TO COME FROM AIR PARCELS MOVE
FROM AROUND 800 MB. EVEN THE MOST UNSTABLE SOUNDINGS STILL HAVE
SKINNY CAPE...LITTLE IN THE WAY OF SIGNIFICANT INSTABILITY/BUOYANCY/MOISTURE
TO SUPPORT PERSISTENT AND SUSTAINED UPDRAFTS.
FOR NOW...HAVE BLENDED WITH THE HRRR TO HIGHLIGHT ANY ISOLATED
THUNDERSTORM CHANCES FOR THIS AFTERNOON...ALBEIT SMALL. FROM A
COMPLIMENTARY STANDPOINT...ADJUSTED MAX TEMPERATURES UP SLIGHTLY.
FOR NOW...TEMPERATURES THIS AFTERNOON SHOULD KEEP HEAT INDEX
VALUES FROM CRITICAL LEVELS THIS AFTERNOON.
HOWEVER...FOR TUESDAY AND WEDNESDAY...OUTSIDE OF THE RAIN
AREAS...THE SIGNAL HAS BEEN CONSISTENT OVER SOUTHEAST MO AND PARTS
OF SOUTHERN IL AND THE PURCHASE AREA OF WEST KENTUCKY FOR MEETING
HEAT ADVISORY CRITERIA DURING THE AFTERNOON HOURS...MAINLY FROM
18Z TO 00Z /1 PM TO 7 PM CDT. PLAN ON MENTIONING THIS POTENTIAL IN
THE HWO...AS WELL HIGHLIGHTING IT IN A SPECIAL WEATHER STATEMENT.
OF COURSE...MOST OF THE POTENTIAL WILL BE OUTSIDE OF RAIN AREAS.
TUESDAYS CONVECTIVE ACTIVITY...GIVEN LESSER SHEAR ALOFT...WILL
LIKELY BECOME OUTFLOW DOMINATED AS IT DEVELOPS FURTHER
SOUTH...WITH A STRONG DIURNAL COMPONENT.
FOR WEDNESDAY...AM NOT SURPRISED WITH THE LOCATION OF THE SLIGHT
RISK AREA FROM SPC...GIVEN THE SHEAR AND FORCING IN PLACE. STILL
BELIEVE HEAVY RAIN WILL BE THE DOMINATE HAZARD. HAIL WILL
INITIALLY BE MARGINAL...BUT WIND GUSTS BETWEEN 45 AND 55 MPH MAY
BE POSSIBLE. THE SIGNAL FOR THE HIGHEST POPS/WEATHER ON WEDNESDAY
HAS BEEN CONSISTENT FOR NEARLY SEVEN DAYS NOW.
WITH RESPECT TO TEMPERATURES TUESDAY...WENT A LEAST ANOTHER
DEGREE HIGHER AS THE RIDGE STILL HAS SOME INFLUENCE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 329 AM CDT MON JUL 8 2013
THE COLD FRONT RESPONSIBLE FOR FOCUSING THE MID WEEK PRECIPITATION
EVENT WILL BE DRAPED ALONG OR JUST SOUTH OF THE OHIO RIVER THURSDAY
MORNING. A FEW SHOWERS AND THUNDERSTORMS MAY LINGER MAINLY SOUTH AND
EAST OF THE OHIO RIVER THURSDAY MORNING BEFORE THE FRONT COMPLETELY
SLIPS SOUTH OF THE AREA.
LATE IN THE WEEK...HIGH PRESSURE WILL BUILD SOUTH FROM CANADA...
BRINGING ANOTHER SPELL OF TEMPERATURES BELOW SEASONAL NORMS. GOOD
CONTINUITY AMONG THE RECENT OPERATIONAL AND ENSEMBLE DEPICTIONS FROM
THE GFS...ECMWF...AND GEM LENDS RELATIVELY HIGH CONFIDENCE TO THE
LATE WEEK FORECAST. ALONG WITH THE MILDER TEMPERATURES WILL COME
LESS HUMIDITY...AS DEW POINTS BOTTOM OUT IN THE UPPER 50S AND LOWER
60S FRIDAY AND SATURDAY.
IN THE UPPER LEVELS...A BUILDING RIDGE OVER THE CENTRAL U.S. WILL
SQUEEZE A TROUGH INTO THE EAST. THIS MAY EVENTUALLY LEAD TO THE
DEVELOPMENT OF A CUT-OFF LOW OVER THE SOUTHERN GULF STATES LATE IN
THE WEEKEND...BUT THIS IS WHERE FORECAST CONFIDENCE DECREASES
MARKEDLY. ENOUGH MOISTURE MAY CREEP NORTH AND WEST INTO THE FORECAST
AREA TO WARRANT A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS BY
SUNDAY. TEMPERATURES WILL GRADUALLY WARM OVER THE WEEKEND AS WELL...
BUT SHOULD REMAIN WITHIN SEASONAL RANGE.
&&
.AVIATION...
ISSUED AT 1238 AM CDT MON JUL 8 2013
DRY WEATHER WITH PRIMARILY VFR CONDITIONS WILL PREVAIL OVER THE NEXT
24 HOURS. A BRIEF PERIOD OF MVFR CONDITIONS IS POSSIBLE AROUND
DAYBREAK FROM THE FORMATION OF PATCHY LIGHT FOG. EXPECT SOME CU
DEVELOPMENT AGAIN BY LATE MONDAY MORNING. PREVAILING WIND WILL BE
SOUTHERLY AOB 10 KNOTS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...SMITH
LONG TERM...RJP
AVIATION...RJP
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
511 AM EDT MON JUL 8 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 508 AM EDT MON JUL 8 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE NRN CONUS AND SRN CANADA. AT THE SFC...A FRONTAL BOUNDARY
EXTENDED ACROSS NRN WI THROUGH SRN UPPER MI. A SHORTWAVE TROUGH FROM
NRN ONTARIO THROUGH WRN LAKE SUPERIOR INTO NW WI SUPPORTED A LARGE
AREA OF SHOWERS AND THUNDERSTORMS ACROSS CNTRL UPPER MI INTO NE WI
AND NRN LAKE MICHIGAN. EVEN THOUGH THE GREATER MUCAPE VALUES OF
500-1000 J/KG AND STRONGER TSRA WERE LOCATED ALONG AND SOUTH OF THE
FRONT...FORCING ASSOCIATED WITH THE SHRTWV WAS STRONG ENOUGH TO
SUPPORT TSRA OVER N CNTRL UPPER MI. MANY LOCATIONS FROM GOGEBIC
COUNTY THROUGH SRN UPPER MI HAVE RECEIVED RAINFALL AMOUNTS IN THE 1
TO 2 INCH RANGE...PER RADAR ESTIMATES.
TODAY...EXPECT THAT AS THE SHRTWV MOVES OFF TO THE EAST THIS
MORNING...THE SHRA/TSRA WILL ALSO SHIFT INTO THE ERN CWA. WITH SOME
CLEARING IN THE AFTERNOON...TEMPS COULD AGAIN REBOUND TO
THE LOWER 80S OVER THE SOUTH HALF OF UPPER MICHIGAN. EVEN THOUGH THIS
WOULD BOOST MLCAPE VALUES BACK INTO THE 1K-2K J/KG RANGE...WITH MID
LEVEL RIDGING AND WEAK QVECTOR DIV BUILDING INTO THE AREA IN THE WAKE
OF THE SHORTWAVE....PCPN CHANCES WILL BE MINIMAL. NEVERTHELESS...SOME
ISOLD SHRA/TSRA WILL STILL BE POSSIBLE...MAINLY OVER THE S CNTRL CWA
WHERE MODELS SUGGEST A WEAK SFC TROUGH AXIS WOULD MAXIMIZE LOW LEVEL
CONVERGENCE.
TONIGHT...WEAK MID-LEVEL RIDGING SHOULD AND LOSS OF DAYTIME HEATING
SHOULD BRING AN END TO ANY LINGERING PCPN. MID LEVEL DRYING AND A
DEVELOPING SUBSIDENCE INVERSION ABOVE LINGERING LOW-LEVEL MOISTURE
WILL FAVOR ANOTHER ROUND OF FOG ACROSS INTERIOR LOCATIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 508 AM EDT MON JUL 8 2013
THE MODELS CONTINUE TO AGREE ON THE GENERAL IDEA THAT AN MCS WILL BE
ONGOING AT THE START OF THE PERIOD NEAR THE NOSE OF THE 40-45KT LLJ
OVER THE UPPER MISSISSIPPI VALLEY. HOWEVER...THERE TENDS TO BE SOME
MODEL DISAGREEMENT ON THE EXACT PLACEMENT OF THE MCS...WHICH WILL
PROVE CRITICAL IN THE PRECIPITATION AND POP FORECAST ESPECIALLY
TUESDAY AFTERNOON INTO TUESDAY EVENING. IN GENERAL...THE MODELS HAVE
TRENDED NORTHWARD WITH THE NOSE OF THE LOW LEVEL JET. THE REGIONAL
GEM IS THE MOST AGGRESSIVE...WITH THE BEST LOW LEVEL JET ENERGY
FOCUSED WELL INTO NRN MN AND WESTERN LAKE SUPERIOR TUESDAY...WHILE
THE NAM AND GFS SUPPRESS IT FURTHER SOUTH INTO CENTRAL WI AND
SOUTH-CENTRAL UPPER MI RESPECTIVELY. DUE TO CONVECTIVE FEEDBACK FROM
BOTH THE MODELS...IT IS UNCLEAR WHERE THIS MCS WILL TRACK ON
TUESDAY...HOWEVER CLIMATOLOGY...PAST EXPERIENCE AND MODEL FORWARD
PROPAGATING CORFIDI VECTORS WOULD SUGGEST THAT ANY MCS OVER
SOUTHERN/CENTRAL MN TUE MORNING WOULD LIKELY STAY NEAR OR JUST SOUTH
OF THE WI/MI BORDER AND PERHAPS CLIP MENOMINEE COUNTY LATER TUESDAY
AFTERNOON. THIS SCENARIO WOULD POTENTIALLY LEAVE MUCH OF UPPER
MICHIGAN DRY ON TUESDAY OR JUST WITH RESIDUAL STRATIFORM RAIN AND
EMBEDDED THUNDER TUE AFTN INTO THE EVENING. IN ADDITION...THIS MCS
MAY HELP DISRUPT THE MOISTURE INFLOW INTO THE MAIN SYSTEM AND COLD
FRONT OVER THE NRN PLAINS/NW ONTARIO LATER TUESDAY INTO TUESDAY
NIGHT. RESIDUAL CLOUD COVER BLOWOFF FROM THE MCS MAY ALSO ALLOW FOR
DIMINISHED INSTABILITY ACROSS THE REGION AS THE COLD FRONT
APPROACHES FROM THE NORTHWEST TUESDAY NIGHT. AS SUCH...AS PREVIOUS
FORECASTS HAVE INDICATED...CONFIDENCE REMAINS RATHER LOW REGARDING
THE POP/QPF FORECAST TUESDAY AFTERNOON INTO TUESDAY NIGHT. FOR
NOW...HAVE MAINTAINED LIKELY POPS ACROSS THE SOUTH CENTRAL TUE AFTN
WITH CHANCE POPS ELSEWHERE. FOR TUESDAY NIGHT...HAVE OPTED TO GO
WITH LIKELY POPS NEAR LAKE MICHIGAN WITH CHANCE POPS ELSEWHERE AS
THE MAIN UPPER WAVE AND ASSOCIATED COLD FRONT PASS THROUGH.
MUCH LESS HUMID AND MORE SEASONABLE TEMPS ON WEDNESDAY BEHIND THE
COLD FRONT. CANNOT RULE OUT A PASSING SHOWER EARLY ACROSS THE
EASTERN HALF OF UPPER MI EARLY WED MORNING AS THE UPPER TROUGH AXIS
WILL HAVE YET TO PASS THROUGH. OTHERWISE...HIGH PRESSURE WILL BUILD
ACROSS THE AREA WED NIGHT-THURSDAY LEADING TO VERY SEASONABLE AND
DRY CONDITIONS. UPPER HEIGHTS BUILD ON FRIDAY ACROSS THE WESTERN
LAKES...GIVING SOME WARMER TEMPS BUT DRY CONDITIONS WILL CONTINUE.
ON SATURDAY...THE GFS AND 00Z ECMWF ARE IN BETTER AGREEMENT IN
SHOWING A WEAK DISTURBANCE MOVING OVER THE RIDGE AXIS. ALTHOUGH
MOISTURE WILL BE LACKING...CANNOT TOTALLY RULE OUT SHOWERS/STORMS
ACROSS THE WEST SAT AFTN AS AS SUCH HAVE ADDED A 30 PCT CHANCE ON
SATURDAY. NEXT SYSTEM MOVES INTO THE WESTERN LAKES LATE IN THE
WEEKEND OR EARLY MONDAY. STILL SOME TIMING ISSUES WITH THE ECMWF
BEING FASTER THAN THE GFS. WITH THIS IN MIND...HAVE KEPT ANY MENTION
OF PRECIPITATION OUT OF THE FORECAST FOR SUNDAY...BUT MAY NEED TO BE
INTRODUCED IN LATER FORECASTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 155 AM EDT MON JUL 8 2013
EXPECT LIFR/VLIFR CONDITIONS TO PERSIST AT CMX/SAW THRU SUNRISE WITH
ENE FLOW OF MOIST AIR OFF LK SUP IN THE PRESENCE OF NOCTURNAL
COOLING. THE FOG AND LO CLD HAS HAD A HARDER TIME MOVING INTO IWD...
BUT STILL EXPECT FOG/LIFR CONDITIONS TO DVLP THERE WITH THE ARRIVAL
OF DRIER AIR ALOFT EARLY THIS MRNG. WITH DAYTIME HEATING...THERE WL
BE SLOW IMPROVEMENT LATER THIS MRNG/EARLY AFTN. THE BEST CHC FOR
PERSISTENT LOWER CONDITIONS WL BE AT SAW WITH A MORE FAVORABLE
UPSLOPE NE WIND COMPONENT. MORE FOG/IFR CONDITIONS ARE ON TAP FOR
TNGT WITH LGT WINDS/NOCTURNAL COOLING UNDER DRY AIR ALOFT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 508 AM EDT MON JUL 8 2013
A DENSE FOG ADVISORY REMAINS TODAY FOR ALL OF LAKE SUPERIOR GIVEN SEVERAL
SHIP REPORTS OF NEAR ZERO VISIBILITY AND VERY HUMID AIR OVER
RELATIVELY CHILLY LAKE SUPERIOR WATERS. THE FOG MAY ALSO LINGER INTO
TONIGHT BEFORE DISSIPATING TUESDAY. A SURFACE FRONT MOVING ACROSS
LAKE SUPERIOR TUESDAY EVENING WILL ALLOW WINDS TO SHIFT TO THE
NORTHWEST AT 15 TO 25 KNOTS FOR A SHORT TIME LATE TUESDAY NIGHT INTO
WEDNESDAY. HIGH PRESSURE WILL SETTLE BACK OVER THE LAKE FOR THE
LATER HALF OF THE WEEK WITH WINDS LESS THAN 15 KNOTS EXPECTED INTO
NEXT WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
LSZ162-240>251-263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
1053 PM MDT SUN JUL 7 2013
.UPDATE...
ISSUED UPDATE TO ZONES TO REMOVE REMAINING SEVERE THUNDERSTORM
WATCH. ADJUSTED POPS FOR REMAINDER OF NIGHT AS WELL. BT
&&
.SHORT TERM...VALID FOR MON AND TUE...
MAIN FORECAST ISSUE IS SEVERE WX POTENTIAL THIS AFTERNOON/EVENING
AND AGAIN TOMORROW.
WATER VAPOR IMAGERY SHOWS WSW FLOW ALOFT WITH SHORTWAVE ENERGY
APPROACHING FROM THE GREAT BASIN. A STRONGER TROF CAN BE SEEN
ALONG THE PAC NW COAST...AND THIS FEATURE WILL BE A PLAYER FOR US
MONDAY AND MONDAY NIGHT. PWATS IN PLACE ARE QUITE HIGH AND IN THE
VICINITY OF AN INCH...PERHAPS A BIT HIGHER IN OUR EAST. LOW LEVEL
E-SE WINDS ARE INCREASING...PROVIDING GREATER SHEAR AND LOW LEVEL
MOISTURE THAN WE SAW ON SATURDAY...AND LATEST 850MB ANALYSIS
SUGGESTS NOSE OF 850MB DEWPTS TO +13C IN FAR SE MT. WE REMAIN
UNDER RRQ OF 60KT H3 JET TO OUR NORTH...THUS MODEST SYNOPTIC
ASCENT IS PRESENT. OVERALL INGREDIENTS ARE IN PLACE FOR SEVERE
WEATHER LATE THIS AFTN AND EVENING. RECENT HRRR RUNS AGREE WITH
THIS ASSESSMENT AND HAVE BEEN CONSISTENT.
CONVECTION BEGINNING TO INITIATE OVER OUR SW MTNS WITH A FEW
LIGHTNING STRIKES NOTED SOUTH OF LIVINGSTON. A LONE CELL HAS
EMERGED FROM THE CU FIELD SE OF BROADUS. WILL BE INTERESTING TO
SEE WHAT SERN CELL WILL DO OVER THE NEXT COUPLE HOURS...SFC TEMPS
NEAR THE MID 80S MAY BE ENOUGH TO BREAK CAP THAT HAS BEEN IN
PLACE. OTHERWISE FOCUS SHOULD BE IN OUR WEST AS ACTIVITY SPREADS
OFF THE HIGH TERRAIN...SHIFTING EAST OVER TIME.
GREATEST SEVERE POTENTIAL THIS AFTN AND EVENING WILL BE EAST OF
BILLINGS IN REGION OF GREATER INSTABILITY AND SHEAR...ESPECIALLY
AS LOW LEVEL JET KICKS IN THIS EVENING. FOR MONDAY...OUR ENTIRE
AREA WILL BE AT AN ELEVATED RISK FOR SEVERE STORMS DUE TO
COMBINATION OF ASCENT FROM PAC NW TROF AND SURFACE COLD FRONT.
LARGE HAIL AND DAMAGING WINDS MAIN THREATS. HEAVY RAIN WILL
CONTINUE TO BE A POSSIBILITY BOTH TODAY AND TOMORROW DUE TO THE
MOISTURE RICH AIRMASS IN PLACE.
PASSAGE OF TROF...SURGE OF DRIER AIR AND SHIFT TO NW FLOW ALOFT
WILL SIGNAL THE BEGINNINGS OF A PATTERN SHIFT ON TUESDAY...AS THE
MOIST AIRMASS FINALLY GETS CLEANED OUT. COULD BE SOME MORNING
SHOWERS ON TUESDAY ALONG PV MAX...BUT OTHERWISE EXPECT DRIER AND
MORE STABLE CONDITIONS AS COOLER SFC RIDGE BUILDS IN FROM THE NW.
HAVE LOWERED POPS TUESDAY AFTERNOON AND NIGHT.
AS FOR TEMPS...MONDAY WILL BE THE WARMER OF THE NEXT TWO DAYS...
WITH PREFRONTAL CONDITIONS PERHAPS ALLOWING FOR TEMPS NEAR 90F.
TUESDAY WILL BE POSTFRONTAL AND COOLER WITH UPPER 70S TO MID 80S
FOR HIGHS...OR A LITTLE BELOW NORMAL.
JKL
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
MINIMAL CHANGES TO THE EXTENDED PERIOD...DUE IN LARGE PART TO
MODEL INCONSISTENCY FOR LATTER PORTIONS OF THE PERIOD.
THE PERIOD BEGINS WED UNDER AN UPPER LEVEL RIDGE...SO EXPECT HOT
AND MAINLY DRY CONDITIONS. MODELS DO SHOW SOME SHORTWAVE ACTIVITY
ROUNDING THE RIDGE...WITH SE LOW LEVEL FLOW OVER SOUTHEAST MONTANA
LATE WED AFTN/EVE...SO I KEPT A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST ACROSS THE SE. RIDGING DOMINATES
THROUGH MUCH OF THE DAY THURS...SO HOT AND DRY CONDITIONS WILL
AGAIN BE THE RULE. A WEAK COLD FRONT...ALONG WITH SHORTWAVE
ACTIVITY...WILL MOVE ACROSS THE REGION THURS NIGHT...SO WE MAY SEE
SOME CONVECTIVE ACTIVITY THURS EVE/NIGHT OVER THE WESTERN
MOUNTAINS...AND OVER THE EAST...WHERE SHEAR IS BETTER AND THE
ATMOSPHERE IS LESS CAPPED. FRI LOOKS TO BE A TAD COOLER BEHIND THE
FRONT...BUT STILL QUITE WARM.
MODEL SOLUTIONS DIVERGE SAT AND SUN. THE ECMWF BRINGS ANOTHER
COLD FRONT THROUGH THE REGION SAT AND KEEP THE REGION UNDER THE
INFLUENCE OF A WEAK UPPER LEVEL TROF SUN. MEANWHILE...THE GFS
KEEPS THE AREA MAINLY UNDER THE INFLUENCE OF SOUTHWESTERLY FLOW
ALOFT AROUND AN UPPER LEVEL RIDGE. BECAUSE OF THE LARGE MODEL
DIFFERENCES...I LEFT THE FORECAST FROM SAT TO THE END OF THE
EXTENDED PRETTY MUCH AS I INHERITED IT.
TEMPS WED AND THURS LOOK TO BE IN THE MID 80S TO MID 90S...WITH
SLIGHTLY COOLER WEATHER FRI. NOT QUITE SURE WHAT TEMPS WILL BE SAT
AND SUN. IF THE GFS IS CORRECT...UPPER 80S TO 90S. IF THE ECMWF
IS CORRECT...UPPER 70S TO MID 80S. FOR NOW...KEPT SAT AND SUN
TEMPS IN THE MID 80S TO AROUND 90...SORT OF A BLEND OF THE GFS AND
ECMWF. STC
&&
.AVIATION...
CONVECTIVE ACTIVITY WILL DIMINISH THROUGH MIDNIGHT WITH JUST AN
ISOLATED SHOWER OR THUNDERSTORM AFTER MIDNIGHT IN MOST AREAS.
STRONG WIND GUSTS AND MVFR TO IFR CONDITIONS IN HEAVY RAIN ARE THE
MAIN THREATS FROM STORMS TONIGHT. OUTSIDE OF STORMS EXPECT VFR
CONDITIONS. LOCAL AREAS OF FOG ARE POSSIBLE EARLY MONDAY MORNING
IN AREAS THAT SAW HEAVY RAIN THIS EVENING...BUT SO FAR THIS
DOESN`T INCLUDE AREA TAF LOCATIONS. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 062/089 061/084 059/091 064/094 064/090 061/091 060/089
33/T 32/T 11/U 11/B 22/T 22/T 22/T
LVM 053/088 050/085 048/091 056/094 052/090 051/091 050/089
53/T 31/B 11/U 11/B 22/T 22/T 22/T
HDN 060/091 061/085 056/092 064/095 064/091 061/092 060/090
23/T 32/T 11/U 11/B 22/T 22/T 22/T
MLS 065/088 062/084 059/092 066/095 063/090 062/091 061/089
34/T 53/T 11/U 12/T 22/T 22/T 22/T
4BQ 061/090 060/084 056/090 062/093 063/089 061/090 060/088
33/T 43/T 11/U 12/T 22/T 22/T 33/T
BHK 060/084 060/079 055/086 061/089 063/085 062/086 061/084
44/T 54/T 12/T 22/T 22/T 22/T 33/T
SHR 056/090 056/083 052/089 059/093 058/089 056/090 055/088
23/T 32/T 11/U 11/U 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
334 AM CDT MON JUL 8 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 312 AM CDT MON JUL 8 2013
ANOTHER ACTIVE SEVERE WEATHER DAY IS EXPECTED BEGINNING THIS
AFTERNOON THROUGH THE OVERNIGHT HOURS TONIGHT. THE FOCUS FOR STORM
DEVELOPMENT REVOLVES AROUND A STRONG UPPER LEVEL DISTURBANCE MOVING
THROUGH THE DAKOTAS. A WEAKER DISTURBANCE WILL APPROACH SWRN NEB
LATE THIS AFTERNOON PERHAPS FOCUSING ANOTHER CLUSTER OF STRONG TO
SEVERE STORMS. THE DISTURBANCE MOVING THROUGH THE DAKOTAS IS
EXPECTED TO LIFT A 700 MB WARM FRONT THROUGH SWRN NEB...PERHAPS
CAPPING THE ATMOSPHERE THIS EVENING. IT WOULD APPEAR THERE IS A
WINDOW FOR SEVERE STORM DEVELOPMENT ACROSS SWRN NEB LATE THIS
AFTERNOON BEFORE THE ATMOSPHERE BECOMES CAPPED THIS EVENING. THERE
ARE NO HOLDS BARRED ACROSS NCNTL AND NW NEB LATE THIS AFTN AND
THIS EVENING WHERE THE CAP WILL BE WEAKER AND JUST AS UNSTABLE AS
THE SOUTHWEST.
THE RAP SUGGESTS STORMS COULD FIRE ACROSS NCNTL NEB LATE THIS AFTN
JUST AHEAD OF THE MID LEVEL WARM FRONT. AT THE SFC A WARM FRONT WILL
LIE ALONG INTERSTATE 80 PROVIDING AN OPPORTUNITY FOR STORM
DEVELOPMENT THERE. THUS THE FCST USES A MULTIMODEL BLEND FOR HIGHEST
POPS...40S...ACROSS THE NORTH AND ISOLATED POPS ACROSS SWRN NEB.
HIGHS TODAY SHOULD REACH WELL INTO THE 90S ALONG AND SOUTH OF THE
SFC FRONT NEAR INTERSTATE 80 AND 80S ACROSS NCNTL NEB. LOWS TONIGHT
FALL INTO THE 60S TO AROUND 70.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 312 AM CDT MON JUL 8 2013
A COLD FRONT WILL BE DRIVEN SOUTH THROUGH THE AREA TUESDAY...AS A
STRONG SHORT WAVE TROUGH SKIRTS EAST ACROSS THE NORTHERN PLAINS
AND SOUTHERN CANADA. THIS WILL BRING A TEMPORARY REST FROM T-STORM
ACTIVITY...AS THE BEST FOCUS WILL SHIFT SOUTH AND EAST OF THE AREA
ALONG THE FRONT. WEDNESDAY THE FRONT WILL BEGIN TO LIFT BACK NORTH
AS A WARM FRONT...WITH A WARM MOIST EASTERLY UPSLOPE FLOW LIKELY
TO IGNITE T-STORMS ACROSS THE PANHANDLE WEDNESDAY AFTERNOON. THESE
SHOULD MOVE EAST INTO CENTRAL/SOUTHWEST NEBRASKA WEDNESDAY
EVENING.
THE UPPER LEVEL RIDGE OF HIGH PRESSURE IS STILL EXPECTED TO BUILD
NORTH OVER THE AREA THURSDAY INTO FRIDAY. WARMING MID LEVEL
TEMPERATURES WILL LIKELY CAP THE ATMOSPHERE...AND T-STORM CHANCES
WILL DIMINISH. HOT WEATHER CAN ALSO BE ANTICIPATED AS THE RIDGE
BUILDS IN...WITH HIGHS IN THE MID 90S TO AROUND 100 DEGREES.
ANOTHER STRONG SHORTWAVE TROUGH WILL PUSH EAST ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA SATURDAY AND SUNDAY. THIS APPEARS TO
DRIVE ANOTHER COLD FRONT SOUTH INTO THE AREA...WITH RETURNING
CHANCES FOR T-STORMS AND SOMEWHAT COOLER TEMPERATURES BY SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 110 AM CDT MON JUL 8 2013
SCATTERED STRONG OR SEVERE THUNDERSTORMS ARE EXPECTED TO REDEVELOP
LATE MONDAY AFTERNOON OR EARLY EVENING ROUGHLY 23Z-02Z WITH
ACTIVITY CONTINUING WELL INTO THE EVENING HOURS.
THE ONGOING CONVECTION...LIGHT RAIN AND MVFR CIGS SHOULD EXIT
SWRN NEB BY 09Z. VFR IS EXPECTED ALL AREAS THEREAFTER UNTIL 22Z-
02Z. PRIME AREAS FOR STORM DEVELOPMENT ARE SWRN NEB AND NORTHWEST
NEB.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
326 AM CDT MON JUL 8 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT MON JUL 8 2013
THE MAIN CONCERN IN THE SHORT TERM WILL BE THE CHANCE OF
THUNDERSTORMS...SOME POSSIBLY SEVERE. EARLY MORNING RADAR MOSAIC
SHOWS THUNDERSTORMS MOVING ACROSS NORTHEAST MONTANA INTO NORTHWEST
NORTH DAKOTA. THE HRRR CAPTURES THIS ACTIVITY AND MOVES IT INTO
THE NORTH CENTRAL PART OF THE STATE LATER THIS MORNING. MUCAPE
FROM THE SPC MESOSCALE ANALYSIS PAGE SHOWS VALUES NEAR 1000 J/KG
THIS MORNING ACROSS NORTHWEST / NORTH CENTRAL NORTH DAKOTA...SO AN
ISOLATED STRONG STORM IS POSSIBLE.
ATTENTION THIS AFTERNOON SHIFTS TO A BOUNDARY THAT IS EXPECTED TO
BECOME ESTABLISHED FROM SOUTHWEST NORTH DAKOTA INTO THE NORTH
CENTRAL PART OF THE STATE. THE LATEST RAP SHOWS CONVECTION
DEVELOPING ALONG THE BOUNDARY BY EARLY AFTERNOON. THERE WILL BE
GOOD INSTABILITY IN PLACE WITH MLCAPE VALUES OF 1500-2500
J/KG...AND DEEP LAYER SHEAR OF 40 KTS SHOULD SUPPORT SUPERCELLS.
THE MAIN THREATS ARE EXPECTED TO BE LARGE HAIL AND DAMAGING
WINDS...THOUGH AN ISOLATED TORNADO IS ALSO POSSIBLE.
LATER TONIGHT...A STRONG H5 WAVE IS EXPECTED TO MOVE ACROSS MONTANA
INTO NORTH DAKOTA. THIS WILL HELP INCREASE THUNDERSTORM
COVERAGE...WITH THE POTENTIAL DEVELOPMENT OF AN EASTWARD
PROPAGATING MCS. THIS WILL GRADUALLY SHIFT THE PRIMARY
THUNDERSTORM THREATS TO DAMAGING WINDS AND HEAVY RAIN LATER
TONIGHT. SEE THE HYDRO SECTION BELOW WHICH DISCUSSES THE HEAVY
RAIN POTENTIAL.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT MON JUL 8 2013
THE CHALLENGE IN THE EXTENDED WILL BE ENDING THE PRECIPITATION
CHANCES TUESDAY AS THE SHORTWAVE EXITS THE REGION. BELIEVE RESIDUAL
SHOWERS AND THUNDERSTORMS WILL BE IN THE NORTH AND EAST TUESDAY
MORNING...WITH ONLY A SLIGHT CHANCE SOUTH. THE PRECIPITATION WILL
LIKELY BE EXITING THE REGION BY EARLY AFTERNOON...SO BY EVENING
TUESDAY IT SHOULD BE DRY ACROSS THE REGION. THIS WILL BE FOLLOWED BY
A RELATIVELY QUIET PERIOD WEDNESDAY AND THURSDAY AS AN H500 RIDGE
BUILDS INTO THE REGION. HOWEVER...MUCH WARMER TEMPERATURES
ASSOCIATED WITH THE RIDGE WILL ALSO ARRIVE IN THE WEST ON THURSDAY
AND CONTINUE INTO FRIDAY. BOTH GFS AND ECMWF MODELS SUPPORT THIS
SCENARIO. EXPECT HIGH TEMPERATURES WEDNESDAY INTO THE LOW TO MIDDLE
90S WEST...UPPER 80S TO AROUND 90 CENTRAL. AS THE RIDGE MOVES EAST
ON FRIDAY INTO THE WEEKEND...WILL BE PICKING UP MORE CHANCES FOR
THUNDERSTORMS AS SHORTWAVE ENERGY WILL AGAIN BE MOVING THROUGH THE
NORTHERN PLAINS. THAT BEING 5 TO 7 DAYS OUT...AND WITH MODELS
DIFFERING IN THE FLOW ALOFT...JUST MENTIONED SLIGHT CHANCE FOR
THUNDERSTORMS FRIDAY INTO WEEKEND. GFS HAS BUILDING HEIGHTS FOR THIS
PERIOD ALOFT WHILE THE EUROPEAN IS MORE ACTIVE WITH SHORTWAVE ENERGY
MOVING THROUGH....ALTHOUGH BOTH MODELS WOULD SUPPORT SOME
THUNDERSTORMS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 325 AM CDT MON JUL 8 2013
THE MAIN CONCERN FOR THE 06Z TAFS WILL BE THE CHANCE OF
THUNDERSTORMS. EARLY MORNING RADARS SHOW THUNDERSTORMS MOVING
ACROSS EASTERN MONTANA TOWARDS WESTERN NORTH DAKOTA. CONFIDENCE IN
ANY OF THIS INITIAL ACTIVITY REACHING A TERMINAL LOCATION IS NOT
HIGH...AND WILL ONLY CARRY VCTS AT KISN EARLY THIS MORNING.
THUNDERSTORM CHANCES INCREASE THIS AFTERNOON AND TONIGHT AT ALL
TERMINAL LOCATIONS. WILL START WITH VCTS / VCSH AT ALL SPOTS THIS
AFTERNOON...AND TREND TOWARDS A PROB30 THIS EVENING FOR ALL BUT
KBIS AND KJMS.
&&
.HYDROLOGY...
ISSUED AT 325 AM CDT MON JUL 8 2013
HEAVY RAIN IS POSSIBLE WITH MULTIPLE ROUNDS OF THUNDERSTORMS TODAY
INTO TONIGHT. PRECIPITABLE WATER VALUES AROUND 1.5 INCHES ARE
EXPECTED TONIGHT ACROSS MUCH OF THE FORECAST AREA. THE HEAVIEST
RAIN POTENTIAL APPEARS TO BE ALONG AND NORTH OF HIGHWAY
200...WHERE AN EASTWARD PROPAGATING MCS IS POSSIBLE. 1 HOUR FLASH
FLOOD GUIDANCE VALUES ARE AT LEAST 1.5 INCHES...AND 3 HOUR VALUES
ARE GENERALLY IN THE 1.5 - 3.0 INCH RANGE. DECIDED TO HOLD OFF ON
ANY FLASH FLOOD WATCHES FOR NOW DUE TO THE RELATIVELY HIGH FLASH
FLOOD GUIDANCE VALUES AND EXPECTED PROGRESSIVE STORM MOTIONS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CK
LONG TERM...WAA
AVIATION...CK
HYDROLOGY...CK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
538 AM EDT MON JUL 8 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS WILL
PERSIST UNTIL A COLD FRONT PASSES THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE UPPER LOW SHOWS UP WELL ON SATELLITE AND RUC ANALYSIS OVER
WESTERN PA. REGIONAL RADAR MOSAIC SHOWS SCATTERED CONVECTION
PINWHEELING AROUND THIS FEATURE FROM OHIO TO THE MID ATL COAST.
SOME SHOWERS LOOK TO BE AIMING AT FAR SERN PA FOR THE NEXT FEW
HOURS...OTHERWISE THE REGION IS DRY.
HIGH PRESSURE WILL REMAIN IN CONTROL FOR THE MOST PART TODAY IN
THE WAKE OF THE UPPER TROF/LOW. WITH THE UPPER SYSTEM PRETTY MUCH
OVERHEAD TO START THE DAY...LARGE SCALE ASCENT AND SOME MODEST
INSTABILITY WILL HELP TRIGGER SOME SCATTERED SHOWERS. TIMING OF
THE UPPER TROF/LOW SUGGESTS THAT MOST SHOWERS WILL BE FROM LATE
MORNING THROUGH MID AFTERNOON...WITH EXPECTED RISING HEIGHTS AND
MID LEVEL WARMING HELPING TO PUT A LID ON THINGS LATER IN THE DAY.
THE CLOUDS AND SCATTERED SHOWERS WILL HELP LIMIT TODAY`S MAX TEMPS
WITH HIGHS RANGING FROM THE MID 70S TO MID 80S FROM NW TO SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
IN THE WAKE OF OUR DEPARTING LOW...WE WILL BEGIN TO SEE THE UPPER
FLOW BECOMING MORE WESTERLY WITH THE LOCAL AREA BEING CLOSE TO THE
SOUTHERN EDGE OF THIS WESTERLY FLOW. FOR THE OVERNIGHT THERE IS
SOME MEASURE OF AGREEMENT THAT CONVECTION CURRENTLY OVER THE
WESTERN GR LAKES WILL SPILL DOWN AND COME THROUGH THE AREA LATER AT
NIGHT AS AN MCS. THE SREF AND GEFS BOTH LATCH ONTO THIS...WITH
SLIGHT PLACEMENT DIFFERENCES. I USED THIS TO BRING HIGHER POPS
INTO THE AREA AFTER MIDNIGHT AND INTO TUESDAY MORNING. THE MODELS
DIMINISH THE INSTABILITY AFTER SUNSET SO AM NOT TOO CONCERNED
ABOUT LATE NIGHT SEVERE WEATHER...BUT SOME NOCTURNAL ELEVATED
THUNDER LOOKS LIKE A REASONABLE POSSIBILITY.
ONCE THE CONVECTION PASSES...PROBABLY BY MID TO LATE MORNING
TUESDAY...THE AFTERNOON SHOULD BE RELATIVELY QUIET WITH
TEMPERATURES REBOUNDING WELL INTO THE 80S REGION-WIDE...WITH THE
HUMIDITY HANGING IN TOUGH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD OF NEARLY ZONAL FLOW ALOFT WILL BE RELATIVELY SHORT-LIVED
AS THE ROCKIES RIDGE IS EXPECTED TO EXPERIENCE A
RESURGENCE...RESULTING IN THE DOWNSTREAM TROUGH DIGGING OVER THE
EASTERN US.
YESTERDAY`S MODEL RUNS SHOWED THE DEVELOPMENT OF A PATTERN THAT
LOOKED MUCH LIKE WHAT WE WERE RECENTLY SADDLED WITH FOR OVER A
WEEK WITH A DEEP LOW OVER THE TN/OH VALLEY AND A STRONG BERMUDA
RIDGE NOSING INTO THE EASTERN SEABOARD KEEPING A DEEP SOUTHERLY
FLOW OF TROPICAL AIR LOCKED IN OVER THE EASTERN US. THE LATEST
RUNS DO CREATE AN UPPER LOW/TROUGH BUT TONIGHT THE GUIDANCE
IS FASTER AND DOESN`T STALL THE LOW. INDICATIONS ARE THAT WHATEVER
FORMS BETWEEN THE BERMUDA RIDGE AND THE RIDGE IN THE ROCKIES WILL
BE RELATIVELY WEAK AND EITHER SETTLE SOUTH INTO THE GULF OR BECOME
LOST AS A GENERAL WEAKNESS BETWEEN WHAT THE GEFS SHOWS AS A HUGE
AREA OF ANOMALOUSLY HIGH HEIGHTS ASSOCIATED WITH THE SUBTROPICAL
RIDGE FROM THE CENTRAL ATLANTIC ALL THE WAY WEST TO THE ROCKY
MOUNTAINS BY NEXT WEEKEND.
THIS IS INTERESTING FOR THE EVENTUAL DEVELOPMENTS ASSOCIATED WITH
CHANTAL. WHILE THE STORM IS EXPECTED TO ENCOUNTER LAND AS WELL AS
INCREASING WIND SHEAR...AND THERE IS SOME QUESTION THAT IT WILL
EVEN SURVIVE AS IT TREKS WESTWARD TOWARD THE CARIBBEAN OR
BAHAMAS...IF IT DOES SURVIVE...THE EVENTUAL PATH SEEMS PAVED FOR
A TRACK INTO THE SERN US OR THE EAST COAST AS THE SUBTROPICAL
RIDGE LOOKS ABNORMALLY MIGHTY FOR THIS TIME OF YEAR. STILL THE
BETTER PART OF A WEEK BEFORE THAT HAPPENS.
IN THE MEAN TIME A DECENT LOOKING COLD FRONT IS EXPECTED TO PASS
THROUGH THE REGION ALONG ABOUT THURSDAY ASSOCIATED WITH THE UPPER
TROUGH THAT IS EXPECTED TO DEVELOP OVER THE EASTERN US. IT SHOULD
USHER IN SOME DRIER AIR FOR THE WEEK`S END THAT COULD LAST A DAY
OR TWO BEFORE THE RIDGE REASSERTS ITSELF LOCALLY. OVERALL IT LOOKS
LIKE ANOTHER VERY SUMMERY WEEK...PRETTY TYPICAL FOR EARLY JULY.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
EXPECT A WIDE RANGE OF CONDITIONS OVERNIGHT. SOME SITES WILL
BE VFR...WHILE OTHERS WILL HAVE FOG AND LOWER CIGS...IFR AT
TIMES.
A TROUGH OF LOW PRES APPROACHING FROM THE OHIO VALLEY WILL
PRODUCE A FEW -SHRA ACROSS THE REGION OVERNIGHT. HOWEVER...
UNLIKE LAST FEW NIGHTS...MAINLY ISOLATED WITHOUT WITH HEAVY
RAIN AND THUNDER.
ANY EARLY LOW CIGS/FOG SHOULD MIX OUT TO VFR CONDS BY 14Z.
FOR THE REST OF MONDAY...EXPECT WIDESPREAD VFR CONDS.
HOWEVER...PASSAGE OF UPPER LVL TROUGH WILL BRING A CHC OF
A BRIEF SHRA/TSRA AND ACCOMPANYING DROP IN VSBY. AS THE
UPPER LVL TROUGH IS FURTHER EAST TODAY...WOULD NOT EXPECT
THE WIDESPREAD SHOWERS AND STORMS THAT WE HAD ON SUNDAY.
OUTLOOK...
TUE...AM SHRA/LOW CIGS POSS W MTNS.
WED-THU...AM LOW CIGS POSS W MTNS. SCT TSRA IMPACTS POSS...MAINLY PM.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
206 AM EDT MON JUL 8 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS WILL
PERSIST INTO THE UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPPER LOW SHOWS UP WELL ON SATELLITE AND RUC ANALYSIS OVER EASTERN
OHIO. CANNOT RULE OUT THE CHANCE OF A SHOWER OR SPRINKLE OVERNIGHT
AS THIS FEATURE SWINGS THROUGH...BUT HAVE DOWNPLAYED POPS OVERALL.
IT`S STILL QUITE MUGGY OUT...BUT MOST PLACES ARE 5-10 COOLER
TONIGHT THAN LAST NIGHT...COURTESY OF MORE CLOUDS AND SHOWERS
SUNDAY THAN PREVIOUS DAYS. THIS WILL ALSO CONTRIBUTE TO MORE
WIDESPREAD LOW CLOUDS AND FOG TOWARD MORNING.
MINS WILL RANGE FROM THE LOWER 60S NORTHWEST TO THE UPPER 60S
SOUTHEAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
ENSEMBLES AGREE IN SHUNTING THE AXIS OF HIGHEST PWATS EAST OF THE
AREA BY MONDAY NIGHT...AND MID LEVEL HEIGHT RISES AND WARM ADVECTION
SHOULD ALL COMBINE TO LIMIT OUR INSTABILITY. STILL LAPSE RATES
WILL BE FAVORABLE FOR SCT SHOWERS THROUGH THE DIURNAL MAXIMUM ON
MONDAY.
TEMPS FROM NEAR 80 IN THE NW...TO THE MID 80S IN THE SE WILL BE
VERY CLOSE TO NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
AFTER THE PASSAGE OF THE UPPER LOW...THE UPPER PATTERN WILL BECOME
QUASI-ZONAL FOR A TIME EARLY TO MID WEEK...WITH PA BEING ON THE
SOUTHERN EDGE OF THE WESTERLIES. THE MODELS ARE CONSISTENT WITH
PERSISTENT MOIST WESTERLY FLOW WHICH WILL LEAVE THE REGION
VULNERABLE TO CONVECTION AS WEAK DISTURBANCES RIPPLE EASTWARD OUT
OF THE MIDWEST AND GREAT LAKES.
A STRONGER TROUGH WILL DEEPEN OVER SOUTHERN CANADA AND OVER THE
GREAT LAKES REGION TOWARDS THE END OF THE WEEK. THIS SHOULD RESULT
IN A FAIRLY STRONG FRONTAL PASSAGE SOMETIME LATER WED OR THU AS
SLIGHTLY COOLER BUT MUCH DRIER AIR SLIDES OUT OF THE GR LAKES.
FROM THERE THE UPPER PATTERN ADVERTISED IN SOME LONGER RANGE
GUIDANCE TAKES ON A LOOK THAT IS EERILY FAMILIAR TO WHAT WE HAVE
JUST EXPERIENCED...WITH A NEW CUTOFF LOW FCST TO FORM OVER THE
EASTERN US...AND A RENEWED SURGE OF DEEP SOUTHERLY FLOW
EVENTUALLY EXPECTED TO DEVELOP ONCE AGAIN OVER THE EASTERN US. A
POTENTIAL COMPLICATING FACTOR IS A TROPICAL SYSTEM CURRENTLY WELL
OUT IN THE ATLANTIC THAT THE TROPICAL MODELS TRACK INTO THE
BAHAMAS BY LATE WEEK...MAKING A TANTALIZING FEATURE FOR THE
EASTERN US TROF TO PERHAPS INTERACT WITH.
WHAT HAS BEEN INTERESTING SO FAR THIS JULY HAS BEEN THE RATHER
HIGH LATITUDE THE BERMUDA RIDGE HAS OCCUPIED FOR SO EARLY IN THE
SEASON. THE LATEST PROGS ONCE AGAIN HAVE A STRONG CLOSED UPPER
HIGH AT UNUSUALLY HIGH LATITUDES BY NEXT WEEKEND. IF THE TROPICAL
SYSTEM CAN MANAGE TO HOLD TOGETHER...IT WOULD SUGGEST THE EASTERN
SEABOARD WOULD BE VULNERABLE IN ABOUT A WEEK`S TIME. STAY TUNED.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
EXPECT A WIDE RANGE OF CONDITIONS OVERNIGHT. SOME SITES WILL
BE VFR...WHILE OTHERS WILL HAVE FOG AND LOWER CIGS...IFR AT
TIMES.
A TROUGH OF LOW PRES APPROACHING FROM THE OHIO VALLEY WILL
PRODUCE A FEW -SHRA ACROSS THE REGION OVERNIGHT. HOWEVER...
UNLIKE LAST FEW NIGHTS...MAINLY ISOLATED WITHOUT WITH HEAVY
RAIN AND THUNDER.
ANY EARLY LOW CIGS/FOG SHOULD MIX OUT TO VFR CONDS BY 14Z.
FOR THE REST OF MONDAY...EXPECT WIDESPREAD VFR CONDS.
HOWEVER...PASSAGE OF UPPER LVL TROUGH WILL BRING A CHC OF
A BRIEF SHRA/TSRA AND ACCOMPANYING DROP IN VSBY. AS THE
UPPER LVL TROUGH IS FURTHER EAST TODAY...WOULD NOT EXPECT
THE WIDESPREAD SHOWERS AND STORMS THAT WE HAD ON SUNDAY.
OUTLOOK...
TUE...AM SHRA/LOW CIGS POSS W MTNS.
WED-THU...AM LOW CIGS POSS W MTNS. SCT TSRA IMPACTS POSS...MAINLY PM.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...DEVOIR/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE/GARTNER
AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
136 AM EDT MON JUL 8 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS WILL
PERSIST INTO THE UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPPER LOW SHOWS UP WELL ON SATELLITE AND RUC ANALYSIS OVER EASTERN
OHIO. CANNOT RULE OUT THE CHANCE OF A SHOWER OR SPRINKLE OVERNIGHT
AS THIS FEATURE SWINGS THROUGH...BUT HAVE DOWNPLAYED POPS OVERALL.
IT`S STILL QUITE MUGGY OUT...BUT MOST PLACES ARE 5-10 COOLER
TONIGHT THAN LAST NIGHT...COURTESY OF MORE CLOUDS AND SHOWERS
SUNDAY THAN PREVIOUS DAYS. THIS WILL ALSO CONTRIBUTE TO MORE
WIDESPREAD LOW CLOUDS AND FOG TOWARD MORNING.
MINS WILL RANGE FROM THE LOWER 60S NORTHWEST TO THE UPPER 60S
SOUTHEAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
ENSEMBLES AGREE IN SHUNTING THE AXIS OF HIGHEST PWATS EAST OF THE
AREA BY MONDAY NIGHT...AND MID LEVEL HEIGHT RISES AND WARM ADVECTION
SHOULD ALL COMBINE TO LIMIT OUR INSTABILITY. STILL LAPSE RATES
WILL BE FAVORABLE FOR SCT SHOWERS THROUGH THE DIURNAL MAXIMUM ON
MONDAY.
TEMPS FROM NEAR 80 IN THE NW...TO THE MID 80S IN THE SE WILL BE
VERY CLOSE TO NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
AFTER THE PASSAGE OF THE UPPER LOW...THE UPPER PATTERN WILL BECOME
QUASI-ZONAL FOR A TIME EARLY TO MID WEEK...WITH PA BEING ON THE
SOUTHERN EDGE OF THE WESTERLIES. THE MODELS ARE CONSISTENT WITH
PERSISTENT MOIST WESTERLY FLOW WHICH WILL LEAVE THE REGION
VULNERABLE TO CONVECTION AS WEAK DISTURBANCES RIPPLE EASTWARD OUT
OF THE MIDWEST AND GREAT LAKES.
A STRONGER TROUGH WILL DEEPEN OVER SOUTHERN CANADA AND OVER THE
GREAT LAKES REGION TOWARDS THE END OF THE WEEK. THIS SHOULD RESULT
IN A FAIRLY STRONG FRONTAL PASSAGE SOMETIME LATER WED OR THU AS
SLIGHTLY COOLER BUT MUCH DRIER AIR SLIDES OUT OF THE GR LAKES.
FROM THERE THE UPPER PATTERN ADVERTISED IN SOME LONGER RANGE
GUIDANCE TAKES ON A LOOK THAT IS EERILY FAMILIAR TO WHAT WE HAVE
JUST EXPERIENCED...WITH A NEW CUTOFF LOW FCST TO FORM OVER THE
EASTERN US...AND A RENEWED SURGE OF DEEP SOUTHERLY FLOW
EVENTUALLY EXPECTED TO DEVELOP ONCE AGAIN OVER THE EASTERN US. A
POTENTIAL COMPLICATING FACTOR IS A TROPICAL SYSTEM CURRENTLY WELL
OUT IN THE ATLANTIC THAT THE TROPICAL MODELS TRACK INTO THE
BAHAMAS BY LATE WEEK...MAKING A TANTALIZING FEATURE FOR THE
EASTERN US TROF TO PERHAPS INTERACT WITH.
WHAT HAS BEEN INTERESTING SO FAR THIS JULY HAS BEEN THE RATHER
HIGH LATITUDE THE BERMUDA RIDGE HAS OCCUPIED FOR SO EARLY IN THE
SEASON. THE LATEST PROGS ONCE AGAIN HAVE A STRONG CLOSED UPPER
HIGH AT UNUSUALLY HIGH LATITUDES BY NEXT WEEKEND. IF THE TROPICAL
SYSTEM CAN MANAGE TO HOLD TOGETHER...IT WOULD SUGGEST THE EASTERN
SEABOARD WOULD BE VULNERABLE IN ABOUT A WEEK`S TIME. STAY TUNED.
&&
.AVIATION /05Z MONDAY THROUGH FRIDAY/...
A TROUGH OF LOW PRES APPROACHING FROM THE OHIO VALLEY WILL
PRODUCE A FEW -SHRA ACROSS THE REGION OVERNIGHT. HOWEVER...THE
BIG AVIATION CONCERN IS THE POTENTIAL OF LOW CIGS ALONG THE SPINE
OF THE APPALACHIANS FROM JST NORTH THRU BFD. LATE EVENING IR LOOP
ALREADY SHOWING SCT CLOUDS ACROSS THE W MTNS WITH BASES ARND 1500FT
AND AS BLYR COOLS/MOISTENS CIGS BLW 1KFT COULD DEVELOP. LATEST
SREF AND RAP OUTPUT BOTH SUPPORT THIS POTENTIAL OF IFR CONDS
ACROSS THE W MTNS...BUT NOT CERTAIN ENOUGH TO INCLUDE IN FCST YET.
FURTHER EAST...FOG IS CERTAINLY A POSSIBILITY...GIVEN THE WET
GROUND AND PARTIAL CLEARING EXPECTED LATE TONIGHT. HOWEVER...PRES
GRADIENT SUGGESTS THERE WILL BE ENOUGH OF A WIND TO PRECLUDE IFR
VSBYS. BELIEVE THE 800 FT CIG AT IPT AT 03Z IS A TEMPORARY
CONDITION AND ENOUGH OF A BREEZE WILL DEVELOP OVERNIGHT TO
PRECLUDE LOW CIGS THERE FOR THE BALANCE OF THE NIGHT.
ANY EARLY LOW CIGS/FOG SHOULD MIX OUT TO VFR CONDS ARND 12Z. FOR
THE REST OF MONDAY...EXPECT WIDESPREAD VFR CONDS. HOWEVER...PASSAGE
OF UPPER LVL TROUGH WILL BRING THE CHC OF A BRIEF SHRA/TSRA AND
ACCOMPANYING DROP IN VSBY.
OUTLOOK...
TUE...AM SHRA/LOW CIGS POSS W MTNS.
WED-THU...AM LOW CIGS POSS W MTNS. SCT TSRA IMPACTS POSS...MAINLY PM.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...DEVOIR/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE/GARTNER
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
430 AM CDT MON JUL 8 2013
.DISCUSSION...
THE FORECAST HAS BEEN FRUSTRATING THE LAST 24 HOURS GIVEN THE
PROSPECTS OF RAIN CHANCES FOR YESTERDAY. GOES SOUNDER PRECIP WATER
AND 00Z SOUNDINGS FROM CRP AND LCH SHOW THAT A TROPICAL AIRMASS
WITH PW AROUND 2.2 INCHES HAS MOVED OVER SE TX. DESPITE THAT THERE
HAS BEEN VERY LITTLE SIGNIFICANT RAINFALL ACROSS THE AREA. IT
SEEMS THAT THE UPPER LEVEL PATTERN HAS NOT BEEN SUPPORTIVE OF
CONVECTION IN HIND SIGHT. THE LAST COUPLE OF DAYS HAVE FEATURED A
SHEAR AXIS OVER THE AREA WITH AN UPPER LEVEL RIDGE EXPANDING INTO
THE PLAINS AS AN UPPER LOW EXITS THE REGION TOWARDS THE GREAT
LAKES. SEEMS LIKE THE SHEAR AXIS DID NOT WEAKEN AS MUCH AS THE
MODELS SUGGESTED AND WHEN IT DID...SUBSIDENCE FROM THE RIDGE WAS
APPARENTLY STRONG ENOUGH TO LIMIT CONVECTION.
GOING FORWARD TO TODAY...THINK WE WILL SEE MUCH OF THE SAME.
UPPER AIR ANALYSIS STILL HAS A DECENT RIDGE OVER THE S PLAINS AND
S ROCKIES. FORECAST WILL STILL KEEP SOME 30/40 POPS FOR THIS
MORNING AS EXPECT THERE TO BE AT LEAST SOME CONVECTION WITH
DAYTIME HEATING. THE PROBLEM IS THAT GOES SOUNDER DATA DOES SHOW
DRIER AIR IN THE GULF WITH PRECIP WATER VALUES NEAR 1.6 INCHES
THAT THE MODELS FORECAST TO MOVE INTO THE REGION LATER TODAY. WITH
THAT IN MIND...WILL DROP POPS TO 30 PERCENT IN THE AFTERNOON BUT
THINK THAT MAY EVEN BE OPTIMISTIC. HRRR MESOSCALE MODEL SHOWS
SIMILAR EVOLUTION OF CONVECTION WITH MOST OF THE ACTIVITY
OCCURRING IN THE LATE MORNING/EARLY AFTERNOON HOURS. EVEN WRF-NMM
SHOWS CONVECTIVE TRENDS SIMILAR TO THIS THINKING.
DEEPER MOISTURE WILL BE RATHER TRANSIENT TUE/WED. AGAIN THINK THE
RIDGE WILL BE THE MAIN PROBLEM INHIBITING CONVECTION. THAT
SAID...MAY GET ENOUGH MOISTURE MAINLY ON WED TO GET A FEW STORMS
AND ENOUGH REASON TO KEEP 20/30 POPS IN THE FORECAST. BY THE END
OF THE WEEK THE RIDGE LOOKS TO EXPAND AND STRENGTHEN OVER THE
ROCKIES AND PLAINS. WITH LESS MOISTURE...DO NOT THINK THERE WILL
BE ANY RAIN CHANCES FOR THUR/FRI/SAT. ALSO SEE MAX TEMPS GETTING
INTO THE UPPER 90S PERHAPS A FEW 100S FOR THE NORTHERN COUNTIES OF
THE FORECAST AREA DUE TO THE RIDGE. BOTH THE GFS/ECMWF HAVE BEEN
HINTING AT A TROUGH/UPPER LOW DEVELOPING OVER THE APPALACHIANS AND
THEN RETROGRADING INTO THE AREA. GFS GOES AS FAR AS TO PUSH WEAK
BACK DOOR FRONT INTO THE AREA. THINK THIS MAY BE A BIT AGGRESSIVE
AND TRENDED THE FORECAST CLOSER TO THE ECMWF SOLUTION. ECMWF HAS
THE FRONT STALLING WELL BEFORE REACHING SE TX AND HAS MORE OF AN
ELONGATED TROUGH STRETCHING INTO THE AREA FOR NEXT WEEKEND. GIVEN
LOWER HEIGHTS...DECIDED 20 POPS MAY BE NEEDED WITH THE INFLUENCE
OF THE RIDGE MORE OVER THE C PLAINS. DID NOT TRIM BACK MAX TEMPS
TOO MUCH BUT STILL A COUPLE OF DEGREES ABOVE GFS GUIDANCE.
39
&&
.MARINE...
WINDS HAVE PICKED UP A BIT ACROSS THE FAR OFFSHORE WATERS WITH
SEAS SILL RUNNING AROUND 5 FEET. WILL CONTINUE THE SCEC THROUGH
MID MORNING BUT OVERALL TREND EXPECTED TO BE A LOWERING OF SEAS
THROUGH THE MORNING HOURS. SCATTERED SHOWERS EXPECTED TO DEVELOP
THIS MORNING AS A WEAK UPPPER DISTURBANCE PASSES OVERHEAD. EXPECT
DECREASING COVERAGE ACROSS THE COASTAL WATERS FOR THE AFTERNOON
AND EVENING HOURS TODAY. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 96 75 97 76 98 / 30 10 10 10 20
HOUSTON (IAH) 93 76 95 76 95 / 40 10 20 20 30
GALVESTON (GLS) 89 81 91 81 91 / 40 10 20 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 11 AM CDT THIS MORNING
FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
353 AM CDT MON JUL 8 2013
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 353 AM CDT MON JUL 8 2013
WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWING A MID-LEVEL
SHORTWAVE TROUGH EXTENDING FROM WESTERN LAKE SUPERIOR THROUGH
APPROXIMATELY SIOUX FALLS SD. PUSH OF 850MB MOIST TRANSPORT AND A
CONVERGENCE/WINDSHIFT LINE AT THE SURFACE WAS SUPPORTING A BROKEN
BAND OF SHOWERS AND THUNDERSTORMS EXTENDING FROM NORTHERN WI THROUGH
EASTERN IA/WESTERN IL. MODELS SHOW THIS MID-LEVEL TROUGH AND SURFACE
CONVERGENCE/WINDSHIFT LINE MOVING EAST AND SOUTHEAST OF THE AREA
THIS MORNING ALONG WITH ANY 850MB MOISTURE TRANSPORT. THIS WILL
BRING AN END TO THE SHOWER/THUNDER CHANCES TODAY AS MID-LEVEL
RIDGING BUILDS IN BEHIND THIS DEPARTING WAVE. THERE LOOKS TO BE A
CHANCE OF CONVECTION REDEVELOPING ALONG THIS SURFACE BOUNDARY JUST
TO OUR SOUTH...BUT BELIEVE THIS ACTION WILL REMAIN OUT OF OUR AREA.
OTHERWISE...LOOK FOR ANOTHER VERY WARM AND MUGGY DAY WITH HIGHS IN
THE 80S...WITH PERHAPS A FEW SPOTS ACROSS FAR SOUTHWEST WI/NORTHEAST
IA POKING AT THE 90 DEGREE MARK. WITH DEW POINTS SITTING IN THE
LOWER 70S...PLAN ON HEAT INDICES IN THE MID 90S ALONG AND SOUTH OF
THE I-94 CORRIDOR...WITH A FEW SPOTS IN THE 95 TO 100 DEGREE RANGE
ACROSS NORTHEAST IA.
FOCUS THEN SHIFTS TO MCS LIKELY DEVELOPING OVER SOUTH DAKOTA THIS
EVENING IN RESPONSE TO INCREASING LOW LEVEL JET/850MB MOISTURE
TRANSPORT AHEAD OF A SW U.S. MONSOONAL MID-LEVEL TROUGH AND LOW
PRESSURE OVER THE ROCKY MOUNTAIN FRONT OF WY. GFS/NAM IN FAIRLY GOOD
AGREEMENT THAT THIS MCS WILL PROPAGATE EASTWARD ACROSS SOUTHERN MN
AFTER MIDNIGHT. TRENDED POPS TOWARD THIS SOLUTION WITH BULK OF
SHOWER/THUNDER CHANCES STAYING WEST OF THE MISSISSIPPI THROUGH 12Z
MONDAY.
MODELS THEN DIVERGE A BIT TUESDAY ON THE PATH OF THE MCS. THE GFS
WANTS TO TAKE IT ALONG AND NORTH OF THE I-94 CORRIDOR WHEREAS THE
NAM TAKES IT MORE ACROSS THE I-90 CORRIDOR. ONE THING IS FOR
SURE...THE MODELS HAVE BEEN VERY CONSISTENT WITH THIS MCS SIGNATURE.
AND...WITH HIGHER-END PRECIPITABLE WATER VALUES IN THE 2-2.5 INCH
RANGE WHICH IS SOME 200 PERCENT ABOVE NORMAL...VERY HEAVY RAINFALL
WILL BE A REAL THREAT FOR SOMEWHERE IN OUR AREA. USED A BLEND
APPROACH FOR NOW...WHICH WOULD PUT THE HIGHEST LIKELIHOOD OF
HEAVIEST RAINFALL ALONG/NORTH OF THE I-90 CORRIDOR. SEE HYDROLOGY
SECTION BELOW FOR EXPECTED IMPACT OF THIS HEAVY RAIN.
OTHERWISE...LOOKS LIKE IF THE MCS/DEBRIS CLOUDS CLEAR THE AREA BY
LATER IN THE AFTERNOON...SEVERE THUNDERSTORMS COULD ERUPT AS A
RATHER VIGOROUS MID-LEVEL TROUGH DROPS SOUTHEAST OUT OF THE NORTHERN
PLAINS AND PUSHES A COLD FRONT INTO THE REGION. NAM/GFS SHOW THE
POTENTIAL FOR 0-1ML MUCAPE TO BUILD INTO THE 3500-5500J/KG RANGE BY
LATE AFTERNOON WITH AMPLE 0-3KM BULK SHEAR IN THE 30-50KT RANGE.
THIS COULD LEAD TO EXPLOSIVE DEEP CONVECTION MAINLY SOUTH OF THE
I-90 CORRIDOR. DAMAGING WIND/LARGE HAIL/LOCALIZED FLASH FLOODING/
ISOLATED TORNADO ALL A THREAT.
LINGERING SHOWER/THUNDERSTORM CHANCES WILL EXIST GOING INTO TUESDAY
NIGHT IN ASSOCIATION WITH THE MID-LEVEL TROUGH DROPPING SOUTHEAST
THROUGH THE AREA.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 353 AM CDT MON JUL 8 2013
DRIER/COOLER WEATHER EXPECTED WEDNESDAY THROUGH THURSDAY AS HIGH
PRESSURE DROPS IN FROM THE NORTHERN PLAINS. LOOK FOR HIGHS IN THE
76-81 DEGREE RANGE WEDNESDAY AND 78-82 ON THURSDAY...WITH DEW POINTS
IN THE MID-UPPER 50S.
MID-UPPER LEVEL RIDGING/INCREASING SOUTHERLY FLOW BRINGS WARMING AND
HIGHER HUMIDITY LEVELS BACK INTO THE AREA FRIDAY AND SATURDAY. WILL
HAVE TO WATCH FRIDAY NIGHT THROUGH SUNDAY FOR A CHANCE OF SHOWERS AND
THUNDERSTORMS AS THE EC/GFS SHOW A MID-LEVEL TROUGH/WEAK COLD FRONT
TOPPING THE RIDGE AND TOWARD THE AREA. OTHERWISE...LOOK FOR HIGHS IN
THE LOWER 80S FRIDAY AND SATURDAY THEN LOWERING SOME BACK INTO THE UPPER
70S/AROUND 80 ON SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT
1122 PM CDT SUN JUL 7 2013
A TROUGH OF LOW PRESSURE AT 05Z STRETCHED FROM OMAHA TO ROCHESTER
AND EAU CLAIRE...DROPPING SOUTHEAST WITH TIME. SOME SHOWERS ALONG
THIS TROUGH WERE IMPACTING RST...BUT THE END WAS RAPIDLY
APPROACHING SUCH THAT THE 06Z TAF STARTS OFF DRY. SHOWERS APPEAR
THAT THEY WILL MISS LSE...BUT COULD FORM NEARBY SO PUT A VCSH IN
THE TAF THERE BETWEEN 06-09Z. HIGH PRESSURE THEN BUILDS IN BEHIND
THE TROUGH FOR MONDAY...BRINGING WITH IT CLEARING SKIES AND DRIER
AIR. REGARDING FOG POTENTIAL IN THE WAKE OF THE TROUGH FOR LATE
TONIGHT...GIVEN LITTLE IF ANY PRECIPITATION OCCURRING AND
POTENTIAL FOR CLOUDS AROUND TO KEEP TEMPERATURE/DEWPOINT SPREADS
HIGH...CONCERN FOR FOG IS LOW. RAISED VISIBILITIES UP TO VFR FOR
THAT 09-13Z TIME PERIOD. WINDS DURING THE NEXT 24 HOURS LOOK QUITE
LIGHT...GENERALLY 5 KT OR LESS....WITH A WEAK PRESSURE GRADIENT IN
PLACE.
HEADING INTO MONDAY NIGHT...PARTICULARLY AFTER 06Z...THE TROUGH OF
LOW PRESSURE LOOKS TO MARCH BACK NORTH AS A WARM FRONT TOWARDS THE
TAF SITES. WILL NEED TO WATCH POTENTIAL FOR SHOWERS AND
THUNDERSTORMS LATE IN THE NIGHT OR PERHAPS TUESDAY MORNING.
&&
.HYDROLOGY...(TUESDAY)
ISSUED AT 353 AM CDT MON JUL 8 2013
SIGNAL REMAINS HIGH FOR A COMPLEX OF THUNDERSTORMS TO ROLL THROUGH
THE AREA TUESDAY. CONFIDENCE IS INCREASING THAT THIS COMPLEX WILL
MOVE THROUGH THE AREA SOMEWHERE IN THE 7 AM TO NOON TIME
FRAME...THEN MOVE EAST OF THE AREA AFTER THAT. HOWEVER...CONFIDENCE
IS LOWER WITH EXACT TRACK OF THE COMPLEX OF STORMS. RIGHT NOW...THE
HIGHEST POTENTIAL FOR HEAVIER RAINFALL LOOKS TO BE ALONG AND NORTH
OF THE I-90 CORRIDOR. WITH PRECIPITABLE WATER VALUES IN THE 2-2.5
INCH RANGE WHICH IS SOME 200 PERCENT ABOVE NORMAL...LOOK FOR THE
POTENTIAL OF VERY HEAVY RAINFALL WITH THIS COMPLEX OF STORMS. TWO
POSITIVE FACTORS TO LOOK AT. 1. THE COMPLEX WILL BE TRANSITORY IN
NATURE AND 2. 6-HOUR FLASH FLOOD GUIDANCE IS IN THE 3-5 INCH RANGE.
HOWEVER...IF DOWNPOURS ARE TORRENTIAL ENOUGH...LITTLE WILL BE
ABSORBED IMMEDIATELY IN THE GROUND AND COULD CAUSE SOME LOCALIZED
PONDING IN POUR DRAINAGE AREAS AND RUNOFF INTO AREA RIVERS. THIS
WILL LIKELY CAUSE SOME WITHIN BANK RISES...BUT NOT CONFIDENT ON ANY
WIDESPREAD FLOODING AT THIS POINT. AS A COLD FRONT DROPS THROUGH THE
AREA TUESDAY AFTERNOON...ANOTHER BATCH OF HEAVIER RAINFALL COULD
FALL. THIS AGAIN SHOULD BE TRANSITORY IN NATURE...BUT COULD CAUSE
SOME LOCALIZED PONDING/RUNOFF OF WATER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...AJ
HYDROLOGY...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1123 PM CDT SUN JUL 7 2013
.UPDATE...
ISSUED AT 949 PM CDT SUN JUL 7 2013
FORECAST STILL REMAINS PROBLEMATIC FOR TONIGHT. CONVECTION THAT
WENT UP ALONG THE SURFACE TROUGH CONTINUES TO PUSH TOWARDS THE
FORECAST AREA...IN PARTICULAR SOUTHEAST MINNESOTA. THIS IS DESPITE
MLCAPE VALUES THAT HAVE DROPPED TO 500-1000 J/KG AND MLCIN THAT
HAVE CLIMBED TO 100-150 J/KG. THE IMPACT OF THESE TWO VARIABLES
HAS DEFINITELY KNOCKED DOWN THE AMOUNT OF LIGHTNING...AND IT
APPEARS OUTFLOWS COMBINING WITH THE SURFACE TROUGH ARE WHAT IS
HELPING TO KEEP SOME SHOWER ACTIVITY GOING. NOT SURE IF THE
SHOWERS WILL LAST MORE THAN A FEW MORE HOURS...THOUGH...SINCE EACH
PASSING HOUR WILL MEAN LESS CAPE AND MORE CIN.
JUST TO OUR NORTH OVER NORTHERN WISCONSIN...NUMEROUS SHOWERS AND
SOME THUNDERSTORMS HAVE DEVELOPED THERE. THESE ARE ON THE NOSE OF
AN 850MB MOISTURE TRANSPORT CORE. THIS CORE LIFTS UP TOWARDS UPPER
MICHIGAN IN THE NEXT FEW HOURS...SO THINKING MUCH OF THE
CONVECTION MAY DO THE SAME...KEEPING TAYLOR/CLARK COUNTIES OUT OF
MUCH SHOWER ACTIVITY.
OVERNIGHT...LATEST 08.01Z RAP HAS ANOTHER 850MB MOISTURE TRANSPORT
SURGE COMING UP OUT OF CENTRAL IOWA...IGNITING CONVECTION BY 07Z
JUST EAST OF THE MS RIVER. HAVE LEFT THE 20-30 PERCENT CHANCES
GOING OVERNIGHT FOR THIS SCENARIO. CONFIDENCE IS STILL LOW ON WHAT
WILL HAPPEN OVERNIGHT...ESPECIALLY BECAUSE THE OVERALL LOW TO MID
LEVEL MOISTURE TRANSPORT IS VEERING MORE EASTERLY IN RESPONSE TO
THE 500MB FLOW TURNING ZONAL...AS WELL AS THAT SURFACE TROUGH
MOVING INTO THE FORECAST AREA.
UPDATE ISSUED AT 650 PM CDT SUN JUL 7 2013
CONVECTIVE THOUGHTS FOR TONIGHT...
AT 2330Z...CLUSTER OF UNORGANIZED SHOWERS AND THUNDERSTORMS
CONTINUES JUST NORTH AND WEST OF MINNEAPOLIS. THESE ARE ALONG A
LOW PRESSURE TROUGH STRETCHING FROM NORTHWEST WISCONSIN INTO
SOUTHWEST MN. TEMPERATURES IN THE UPPER 80S COMBINED WITH
DEWPOINTS POOLING TO NEAR 70F ALONG THE TROUGH RESULTING IN
MLCAPES 2000-2500 J/KG AND NO MLCIN. LACK OF 0-6 KM SHEAR HAS KEPT
THESE UNORGANIZED...WITH OUTFLOWS OCCASIONALLY POPPING UP STORMS. TO
THE WEST...ANOTHER CLUSTER OF SHOWERS AND THUNDERSTORMS BUT MUCH
MORE ORGANIZED HAS BEEN PROGRESSING ACROSS EASTERN SOUTH DAKOTA.
0-6KM SHEAR THERE IS AROUND 40 KT...COMPARED TO LESS THAN 30 OVER
CENTRAL MN. THE STORMS IN SOUTH DAKOTA ARE TAKING ON A
SOUTH/SOUTHEASTWARD MOTION...THOUGH...INTO THE HIGHER INSTABILITY
PRESENT IN EASTERN NEBRASKA WHERE UPWARDS OF 3500 J/KG OF MLCAPE IS
SUGGESTED BY THE RAP.
THE FORECAST TONIGHT IS VERY UNCERTAIN FOR PRECIPITATION BEING
OBSERVED OVER THE FORECAST AREA. STORMS OVER CENTRAL MINNESOTA ARE
SURFACE BASED INITIATED FROM DAYTIME HEATING...THUS ONCE
TEMPERATURES BEGIN TO COOL...THEY SHOULD ALL DIMINISH DURING THE
EVENING HOURS...PERHAPS BY 10 PM. ADDITIONALLY...RAP MLCAPE
ANALYSIS SHOWS AN AREA OF 50 TO 200 MLCIN ALREADY PRESENT FROM
NORTHEAST IOWA INTO SOUTHEAST MN...PROVIDING PROTECTION FROM
STORMS MOVING IN THERE. NOW SOME SURFACE BASED STORMS COULD GO UP
IN THE NEXT HOUR OR SO UP IN TAYLOR/CLARK COUNTIES IF THE LOW
PRESSURE TROUGH CAN SINK SOUTH INTO THAT AREA. TO THE WEST...THERE
WAS CONCERN FROM THE PREVIOUS FORECAST THE STORMS OVER SOUTH
DAKOTA COULD TRACK EAST INTO OUR AREA. HOWEVER...THESE AS NOTED
EARLIER ARE DROPPING MORE SOUTH. 07.22Z RAP 925-700MB MOISTURE
TRANSPORT FOR EARLY THIS EVENING IS FOCUSED MORE INTO
NEBRASKA...THEN VEERS EAST INTO IOWA AND FOCUSES JUST SOUTH OF THE
FORECAST AREA. THUS...IT IS ENTIRELY POSSIBLE THE FORECAST AREA
MOSTLY ENDS UP DRY TONIGHT. OVERALL PRECIPITATION CHANCES SEEM
REASONABLE FOR NOW...BUT MAY HAVE TO LOWER THEM OR DRY THEM OUT
ENTIRELY IN A FEW HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 305 PM CDT SUN JUL 7 2013
THE MAIN FOCUS GOING INTO TOMORROW IS WITH THE CHANCES FOR RAIN
SHOWERS/THUNDERSTORMS AS A COLD FRONT MOVES THROUGH THE REGION.
CURRENTLY...A HUMID AIR MASS IS IN PLACE AT THE SURFACE AS DEW
POINTS CONTINUE TO RISE IN RESPONSE TO AN INCREASE OF LOW LEVEL
MOISTURE TRANSPORT OUT OF THE GULF. SURFACE ANALYSIS SHOWS TWO
COLD FRONTS IN THE VICINITY OF WESTERN MINNESOTA. THE FIRST ONE
EXTENDS FROM NORTHERN WISCONSIN DOWN THROUGH SOUTH CENTRAL
MINNESOTA AND EASTERN NEBRASKA. THE SECOND COLD FRONT IS JUST TO
THE WEST OF THIS OTHER FRONT AND EXTENDS FROM A SURFACE LOW IN
SOUTHERN MANITOBA DOWN THROUGH WESTERN MINNESOTA AND EASTERN SOUTH
DAKOTA. WITH DEW POINTS IN THE LOW 70S BETWEEN THESE TWO
FRONTS...07.19Z RAP ANALYSIS SHOWS AN AXIS OF 3000 J/KG OF SURFACE
BASED CAPE. CONVECTION HAS INITIATED ALONG THE FIRST FRONT AND A
LAKE BREEZE BOUNDARY NORTHWEST OF THE TWIN CITES AND DOWN ALONG
THE FRONT. FURTHER ALOFT...MID LEVEL RIDGING EXTENDS FROM THE
SOUTHERN PLAINS THROUGH THE UPPER GREAT LAKES. A MID LEVEL SHORT
WAVE TROUGH IS CURRENT IN THE DAKOTAS AND WILL TRACK TO THE EAST
THROUGH TONIGHT AND IS TIED TO THE SECONDARY COLD FRONT.
THE ENVIRONMENT AHEAD OF THE COLD FRONTS APPEARS TO BE CAPPED
AROUND 800MB...SO AM NOT EXPECTING ANY DEVELOPMENT OUT IN THE WARM
SECTOR DESPITE THE HIGH CAPE ENVIRONMENT. THE MAIN CHANCES WILL
BE AS THE FRONT AND WEAKENING MID LEVEL TROUGH COME THROUGH THIS
EVENING AND OVERNIGHT. THE FRONT WILL THEN PUSH THROUGH AND STALL
TO THE SOUTH OF THE REGION IN IOWA ON MONDAY. HAVE DROPPED THE
PRECIPITATION CHANCES DOWN A LITTLE ON MONDAY AS IT LOOKS LIKE
SURFACE TO UPPER LEVEL RIDGING WILL SETTLE IN FOR A BRIEF PERIOD
AND KEEP THE REGION MORE ON THE DRY SIDE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 305 PM CDT SUN JUL 7 2013
THE MAIN FOCUS IN THE LONG TERM IS ON MONDAY NIGHT INTO TUESDAY
AND WITH WHERE A MESOSCALE CONVECTIVE SYSTEM WILL DEVELOP AND
TRACK THROUGH ON TUESDAY MORNING.
THE 07.12Z GUIDANCE CONTINUES TO GIVE SOME UNCERTAINTY WITH THE
TRAJECTORY OF THIS MCS. THE GFS/NAM TAKE A MORE SOUTHERLY ROUTE
ACROSS IOWA DUE TO THE LOW LEVEL JET/MOISTURE TRANSPORT ONLY
REACHING EASTERN NEBRASKA BY 6Z TUESDAY. THE PREFERRED GUIDANCE IS
FROM THE ECMWF/GEM SOLUTION WHICH PUSH THE LLJ NOSE INTO EASTERN
SOUTH DAKOTA BY THIS TIME...AND DESPITE THE GEM/ECMWF SHOWING THE
MAIN QPF STAYING WELL TO THE NORTH OF THE REGION TOWARD
DULUTH...AM CONCERNED THAT THE MCS WOULD DEVELOP IN WESTERN
MINNESOTA AND RUN EAST SOUTHEAST ALONG THE NOSE OF THE LOW LEVEL
JET AND INSTABILITY GRADIENT. THIS IDEA FOLLOWS WELL WITH FORECAST
CORFIDI VECTORS WHICH POINT TO THE SOUTHEAST TUESDAY
MORNING...WHICH WOULD TAKE IT STRAIGHT THROUGH THE MIDDLE OF THE
FORECAST AREA ALONG THE MINNESOTA/IOWA BORDER INTO WESTERN
WISCONSIN. GIVEN THE MODEL DIFFERENCES...HAVE NOT HIT THE
PRECIPITATION CHANCES TOO HIGH YET AND WILL HAVE TO SEE HOW THE
PATTERN EVOLVES INTO TOMORROW. WITH THE INCREASING MOISTURE
TRANSPORT AND POTENTIAL FOR HEAVY RAIN...FLASH FLOODING WILL BE A
THREAT DESPITE THE RECENT DRY SPELL. DETAILS ARE OUTLINED IN THE
HYDROLOGY AFD SECTION.
THIS MCS CAUSES SOME HAVOC GOING INTO THE AFTERNOON ON TUESDAY
AND WHAT THE SEVERE THUNDERSTORM CHANCES ARE AFTER ITS PASSAGE. IF
THE SYSTEM TRACKS TO THE SOUTH...THEN IT LIKELY KEEPS THE MAIN
WARM FRONT DOWN THERE AS WELL AND LIMITS THE SEVERE POTENTIAL. IF
IT TRACKS THROUGH THE HEART OF THE FORECAST AREA...AS WE THINK IT
MAY...THE QUESTION WILL BE HOW FAST DOES IT CLEAR AND ALLOW THE
ENVIRONMENT TO RECHARGE BY PEAK HEATING. IF THE SYSTEM WERE TO
CLEAR EARLY ENOUGH AND ALLOW FOR DESTABILIZATION BY LATE AFTERNOON
OUR SEVERE THREAT WOULD BE FAIRLY HIGH DUE TO A VEERING 0-6KM
SHEAR PROFILE...HIGH INSTABILITY...AND DEEP FORCING FROM A SURFACE
LOW AND MID LEVEL TROUGH. WITH A LINGERING OUTFLOW BOUNDARY/WARM
FRONT IN THE REGION...THE HAZARDS WOULD INCLUDE LARGE
HAIL...FLASH FLOODING...DAMAGING WINDS AND THE POSSIBILITY OF A
TORNADO OR TWO GIVEN THE HIGH 0-1KM SHEAR/HELICITY. THE THING
IS...CONFIDENCE IS JUST NOT THERE YET TO LEAN ONE WAY OR ANOTHER
UNTIL THERE IS BETTER CONSENSUS ON THE TRACK OF THE EARLY MORNING
MCS.
BEYOND THIS SYSTEM...IT LOOKS LIKE A DRY AND SEASONAL PERIOD
THROUGH THE REST OF THE WEEK AS UPPER LEVEL RIDGING SETS UP ACROSS
THE UPPER MISSISSIPPI RIVER VALLEY. A COLD FRONT WILL APPROACH THE
REGION FROM THE WEST BY NEXT WEEKEND AND COULD BRING THE NEXT SHOT
OF RAIN ALONG WITH IT. THERE ARE SOME TIMING DIFFERENCES BETWEEN
THE 07.12Z GFS AND ECMWF WITH THIS FEATURE THAT WILL BE RUNNING
INTO THE RIDGING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1122 PM CDT SUN JUL 7 2013
A TROUGH OF LOW PRESSURE AT 05Z STRETCHED FROM OMAHA TO ROCHESTER
AND EAU CLAIRE...DROPPING SOUTHEAST WITH TIME. SOME SHOWERS ALONG
THIS TROUGH WERE IMPACTING RST...BUT THE END WAS RAPIDLY
APPROACHING SUCH THAT THE 06Z TAF STARTS OFF DRY. SHOWERS APPEAR
THAT THEY WILL MISS LSE...BUT COULD FORM NEARBY SO PUT A VCSH IN
THE TAF THERE BETWEEN 06-09Z. HIGH PRESSURE THEN BUILDS IN BEHIND
THE TROUGH FOR MONDAY...BRINGING WITH IT CLEARING SKIES AND DRIER
AIR. REGARDING FOG POTENTIAL IN THE WAKE OF THE TROUGH FOR LATE
TONIGHT...GIVEN LITTLE IF ANY PRECIPITATION OCCURRING AND
POTENTIAL FOR CLOUDS AROUND TO KEEP TEMPERATURE/DEWPOINT SPREADS
HIGH...CONCERN FOR FOG IS LOW. RAISED VISIBILITIES UP TO VFR FOR
THAT 09-13Z TIME PERIOD. WINDS DURING THE NEXT 24 HOURS LOOK QUITE
LIGHT...GENERALLY 5 KT OR LESS....WITH A WEAK PRESSURE GRADIENT IN
PLACE.
HEADING INTO MONDAY NIGHT...PARTICULARLY AFTER 06Z...THE TROUGH OF
LOW PRESSURE LOOKS TO MARCH BACK NORTH AS A WARM FRONT TOWARDS THE
TAF SITES. WILL NEED TO WATCH POTENTIAL FOR SHOWERS AND
THUNDERSTORMS LATE IN THE NIGHT OR PERHAPS TUESDAY MORNING.
&&
.HYDROLOGY...TUESDAY
ISSUED AT 305 PM CDT SUN JUL 7 2013
THE MAIN HYDRO CONCERNS COME IN ON TUESDAY AS A COMPLEX OF
THUNDERSTORMS IS FORECAST TO TRACK THROUGH THE REGION. THE
QUESTION IS WHERE AND WHEN WILL IT COME THROUGH? MOST OF THE MODEL
GUIDANCE SUGGEST THAT THIS SYSTEM WILL FORM IN NORTHWEST NEBRASKA
AND RUN EAST ACROSS IOWA MONDAY NIGHT INTO TUESDAY MORNING. WITH
SHOWERS AND THUNDERSTORMS EXPECTED TO DEVELOP AHEAD OF THIS
COMPLEX NORTH OF A WARM FRONT...THE POTENTIAL IS THERE FOR SOME
HEAVY RAIN TO FALL. THANKFULLY...CONDITIONS HAVE BEEN DRY FOR THE
PAST WEEK...SO FLASH FLOOD GUIDANCE HAS COME UP CONSIDERABLY AND
THE SOIL SHOULD BE ABLE TO HANDLE THE EXCESS MOISTURE REASONABLY
WELL FOR A PERIOD. THAT SAID...INCREASING PRECIPITABLE WATER
VALUES AND LOW LEVEL MOISTURE TRANSPORT AIMING INTO THE
REGION...EXPECT THAT HEAVY RAIN AND FLASH FLOODING IS POSSIBLE
WITH SOME RENEWED RISES ON AREA RIVERS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...AJ
HYDROLOGY...HALBACH
AREA FORECAST DISCUSSION
NWS ALBANY NY
1121 AM EDT MON JUL 8 2013
.SYNOPSIS...
A STRONG MID LEVEL DISTURBANCE WILL MOVE INTO OUR REGION
THIS AFTERNOON FOCUSING ANOTHER ROUND OF NUMEROUS SHOWERS AND
THUNDERSTORMS...SOME OF WHICH COULD CONTAIN HEAVY RAINFALL. THIS
SYSTEM WILL MOVE TO OUR EAST ALLOWING SLIGHTLY DRIER AIR TO MOVE IN
ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A FLASH FLOOD WATCH CONTINUES FOR OUR ENTIRE COUNTY WARNING AREA
(CWA) FROM 1100 AM EDT THROUGH MIDNIGHT.
AS OF 11 AM EDT...THE RADAR HAS BEEN QUIET AND POPS AND WEATHER
HAVE BEEN RETRENDED. CLOUDS MAY LIMIT THE COVERAGE TODAY...BUT THE
LATEST HIRESWRF AND HRRR DUE SHOW COVERAGE INCREASING IN THE
AFTERNOON WITH THE CLOSE LOW APPROACHING FROM W-CNTRL PA. THIS LOW
HAS A NEUTRAL TILT...WHICH CSTAR RESEARCH FROM ALY HAS SHOWN A
THREAT WITH FLOODING AND STRONG TO SEVERE THUNDERSTORMS.
HOWEVER...THE AMOUNT OF SFC HEATING MAY LIMIT THIS THREAT QUITE A
BIT...ALSO THE CLOSED/CUT-OFF LOW MAY OPEN...AND BECOME AN OPEN
WAVE LATER TODAY.
THE LATEST PWAT FROM THE KALB SOUNDING HAS FALLEN CONSIDERABLY
FROM 00Z FROM 2.18" /ABOUT AS HIGH AS YOU GET IT/...AND IT HAS
SUNK TO 1.42 INCHES WITH SLIGHTLY DRIER AIR IN THE WAKE OF THE SFC
TROUGH LAST NIGHT. THE AMOUNT OF CLOUD COVER FROM THE CAPITAL
REGION NORTH AND WEST MAY LIMIT SIGNIFICANT THUNDERSTORM AND
SHOWER COVERAGE. LOCATIONS SOUTH AND EAST WOULD BE THE MOST
VULNERABLE FOR STRONG CONVECTION. THE SVR THREAT LOOKS LESS WITH
VERY WEAK LAPSE RATES...AND WEAK DEEP SHEAR. FZL HEIGHTS ARE HIGH
AROUND 15 KFT AGL. WE WILL CONTINUE TO MONITOR FOR SOME PULSE
TSRAS.
TEMPS MAY NEED TO BE CURTAILED DOWNWARD LATER TOO. SOME SLIGHT
TWEAKS DOWNWARD FROM DONE OVER THE SRN DACKS AND LAKE GEORGE
REGION WITH 70S TO NEAR 80F. MID AND U80S ARE POSSIBLE OVER THE
VALLEYS AND HILLS FROM THE CAPITAL REGION SOUTH AND EAST.
MORE ON THE HYDRO/FLASH FLOOD DISCUSSION BELOW...
THE BIGGER CONCERN WITH THE STORMS WOULD BE EXCESSIVE RAINFALL. PWAT
VALUES WHILE DOWN A LITTLE FROM LAST EVENING...WILL STILL RANGE
BETWEEN 1.75-2.00 INCH...UP TO 3 STANDARDS ABOVE NORMAL. THE
FREEZING LEVEL IS FORECAST TO DROP A LITTLE FROM 15,000 TO ABOUT
13,000 BY DAY/S END BUT STILL PLENTY HIGH FOR EFFICIENT RAIN
FORMATION IN THE CLOUDS (WARM CLOUD PROCESSES). ALSO...MOST OF OUR
AREA HAS EXCESSIVE MOIST SOILS DUE TO THE RASH OF HEAVY RAINFALL
DURING THE PAST SIX WEEKS.
WE HAVE PLACED OUR ENTIRE REGION IN A FLASH FLOOD WATCH FROM MIDDAY
THROUGH THE EVENING HOURS. FLASH FLOOD GUIDANCE (FFG) VALUES ARE
QUITE LOW...RANGING FROM 1-2 INCHES FOR HOURLY RAINFALL RATES ACROSS
THE REGION.
THE BOTTOM LINE...IT WOULD NOT TAKE A WHOLE LOT OF RAIN TO INDUCE
POTENTIAL FLASH FLOODING TODAY...ESPECIALLY IN HERKIMER
COUNTY...WHERE A PLETHORA OF FLASH FLOODS HAVE ALREADY ENSUED IN THE
PAST WEEKS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE UPPER LEVEL LOW WILL STILL BE WORKING ACROSS OUR EASTERN REGIONS
THROUGH THE EVENING HOURS WITH ON GOING SHOWERS AND THUNDERSTORMS.
THESE SHOULD WANE LATER OVERNIGHT AND TOWARD DAYBREAK MOST OF THE
REGION SHOULD BE PRECIPITATION FREE ONCE MORE...ALTHOUGH SOME
SHOWERS MIGHT LINGER TO THE EAST OF THE HUDSON VALLEY.
A TRAILING WEAK COLD FRONT LOOKS TO CROSS THE REGION THROUGH THE
NIGHT. THE AIR BEHIND THIS FRONT WILL BE ONLY VERY SLIGHTLY COOLER
IN THE MID LEVELS AND DRIER TOO.
TUESDAY...WITH WEAK SUBSIDENCE AND THE SLIGHT DRYING...IT LOOKS AS
IF THE SHOWER AND THUNDERSTORM COVERAGE WILL BE MUCH LOWER.
STILL...THERE WILL STILL ENOUGH LOW LEVEL MOISTURE AROUND FOR
INSTABILITY AND A RANDOM POP-UP THUNDERSTORM OR TWO DURING THE
AFTERNOON..ESPECIALLY IN OUR SOUTHERN ZONES.
WITH MORE SUNSHINE THAN MONDAY...RESULTANT HIGH TEMPERATURES WILL
ACTUALLY BE A FEW POINTS HIGHER...ESPECIALLY IN THE VALLEYS WHERE
85-90 WILL COMMON WHILE THE HIGHER TERRAIN WILL RANGE FROM THE
80-85. A LIGHT WEST WIND WILL BECOME SOUTH BY LATE IN THE DAY.
A SLIGHTLY STRONGER COLD FRONT IS POISED TO SLIP FROM THE GREAT
LAKES AND HEAD TOWARD OUR REGION LATER TUESDAY NIGHT INTO WEDNESDAY.
THIS FEATURE WILL TAKE ITS TIME APPROACHING AND ESPECIALLY CLEARING
OUR REGION.
IT LOOKS MAINLY DRY TUESDAY NIGHT (BUT DID KEEP 20 POPS FOR SHOWER
OR THUNDERSTORM). BY WEDNESDAY...THE CHANCES WILL RAMP UP AGAIN AS
THE FRONT NEAR AND THE ATMOSPHERE BECOMES MORE UNSTABLE. THE TIMING
OF THE FRONT WILL HELP DETERMINE WHETHER OR NOT WE COULD BE LOOKING
AT A POTENTIAL SEVERE WEATHER EVENT. RIGHT NOW...IT APPEARS THAT THE
ACTUAL FRONT WILL NOT WORK ACROSS THE REGION UNTIL LATER WEDNESDAY
NIGHT OR EARLY THURSDAY. WE WILL HAVE PLENTY OF TIME TO MONITOR
THESE TRENDS.
WEDNESDAY...AHEAD OF THE FRONT...TEMPERATURES WILL BE UNCOMFORTABLY
WARM AND HUMID REACHING NEAR 90 IN THE MID HUDSON VALLEY...MID TO
UPPER 80S MOST OTHER PLACES.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
MEDIUM RANGE MODELS (GFS/ECMWF) ARE NOW OFFERING SOME HOPE THAT MUCH
OF THE LONG TERM PERIOD MAY BE RELATIVELY QUIET WEATHERIZE AND NOT
AS HUMID. THE FORECAST FOR THE MAIN WEATHER FEATURES CALLS FOR THE
COLD FRONT TO SHIFT SOUTH OF THE REGION EARLY ON THURSDAY...
RESULTING IN MAINLY DRY WEATHER BY LATE IN THE DAY. THE UPPER LEVEL
TROF THAT PUSHED THIS FRONT THROUGH IS THEN FORECAST TO CLOSE
OFF/CUTOFF WELL TO THE SOUTHWEST OF THE REGION (OVER THE CENTRAL AND
SOUTHERN APPALACHIANS) BY SATURDAY...AND THEN CONTINUE RETROGRADING
WESTWARD DURING THE REST OF NEXT WEEKEND. AT THE SAME TIME THE RIDGE
OVER THE WESTERN ATLANTIC WILL BUILD WESTWARD.
THE RESULT OF ALL THIS IS THAT ONCE THE MOISTURE ASSOCIATED WITH
FRONTAL BOUNDARY MOVES THROUGH...IT WILL HAVE A HARD TIME RETURNING
NORTHWARD UNTIL THE RIDGE BUILDS WESTWARD AND THE SOUTHWEST FLOW
AROUND IT BRINGS THE MOISTURE NORTHWARD AGAIN. HOWEVER...THIS IS NOT
FORECAST TO HAPPEN UNTIL EARLY NEXT WEEK...SO THE PERIOD FROM
THURSDAY NIGHT THROUGH SUNDAY IS GENERALLY FORECAST TO BE DRY BY
BOTH THE GFS AND ECMWF.
CONSIDERING THE WET PATTERN WE HAVE BEEN IN LATELY AND THAT THIS IS
THE FIRST TIME BOTH MODELS SEEM TO INDICATE THE POSSIBILITY OF A DRY
PERIOD...WILL NOT COMPLETELY REMOVE PCPN FROM THE FORECAST FOR NOW
UNTIL LATER RUNS ALSO SUPPORT THIS DRIER PATTERN.
AS THE FRONT SAGS SOUTH ON THURSDAY...HAVE FORECAST DECREASING POPS
DURING THE DAY...THE DRY CONDITIONS THURSDAY NIGHT. ONLY A SLIGHT
CHANCE FOR A SHOWER ON FRIDAY AND FRIDAY NIGHT...THEN A 30 PERCENT
OF SHOWERS SATURDAY THROUGH SUNDAY WITH THUNDERSTORMS ALSO POSSIBLE
SUNDAY AFTN/EVE.
TEMPS WILL NOT BE AS WARM AS RECENTLY AND DEWPOINTS WILL ALSO BE 5
TO 10 DEGREES LOWER THAN RECENTLY. HIGHS THURSDAY WILL BE IN THE
UPPER 70S TO MID 80S...MID 70S TO LOWER 80S FRIDAY...UPPER 70S TO
MID 80S SATURDAY AND SUNDAY. LOWS THURSDAY AND FRIDAY NIGHTS WILL BE
IN THE MID 50S TO MID 60S...AND UPPER 50S TO MID 60S SATURDAY NIGHT.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AS AN UPPER LEVEL LOW TRACKS BY TO THE SOUTH OF THE REGION...
EXPECT SCT TO NUMEROUS SHOWERS/TSTMS EXPECTED TO DEVELOP AGAIN
THIS AFTERNOON...BUT AS WITH RECENT DAYS...TIMING AND LOCATION OF
SHOWERS IS NOT POSSIBLE AT THIS TIME SO WILL ONLY FORECAST VCSH FOR
NOW BETWEEN 08/16Z AND 09/01Z. WHERE SHOWERS/TSTMS DO OCCUR...WOULD
EXPECT MVFR TO POSSIBLY IFR CIGS/VSBYS. OTHERWISE...HAVE FORECAST
VFR CONDITIONS AT THE KALB/KGFL/KPOU/KPSF TAF SITES THROUGH LATE
THIS EVENING. AFT AROUND 06Z TUESDAY...HAVE FORECAST SOME MVFR FOG
AT KGFL AND KPSF.
WINDS WILL BE CALM OR LIGHT AND VARIABLE THROUGH MID MORNING...THEN
THEN BECOMING WEST-SOUTHWEST LATER ON TODAY AT SPEEDS OF 8 KTS OR
LESS...THEN LIGHT AND VARIABLE AGAIN TONIGHT.
OUTLOOK...
TUE...MAINLY VFR. SCT -SHRA/-TSRA.
WED...VFR/MVFR/IFR DUE TO SCT TO NUM -SHRA/-TSRA.
THU-FRI...MAINLY VFR. SCT PM -SHRA/-TSRA.
MVFR/IFR OVERNIGHT FOG POSSIBLE TUE-FRI.
&&
.FIRE WEATHER...
NO FIRE WEATHER ISSUES ARE EXPECTED OVER THE NEXT SEVERAL DAYS.
SHOWERS AND THUNDERSTORMS WILL BECOME NUMEROUS ONCE MORE THIS
AFTERNOON AND EARLY EVENING.
THERE WILL BE LESS COVERAGE ON TUESDAY WITH MANY PLACES PERHAPS NOT
RECEIVING ANY MEASURABLE RAINFALL.
HOWEVER...MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED WEDNESDAY.
NORMAL RH RECOVERIES EACH NIGHT BETWEEN 80 TO 100 PERCENT WILL ALLOW
FOR WIDESPREAD DEW FORMATION. DAYTIME RH VALUES WILL GENERALLY BE IN
THE 40 TO 60 PERCENT RANGE.
&&
.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN ISSUED FOR OUR ENTIRE HSA FROM 1100 AM
EDT THROUGH MIDNIGHT. THIS IS THE RESULT OF AN UPPER LEVEL LOW
PRESSURE MOVING ACROSS THE REGION WITH ABOVE NORMAL PWAT VALUES.
THE MOHAWK RIVER AT UTICA CONTINUES TO EXPERIENCE MINOR FLOODING.
THE RIVER AND CREEK FLOWS NEAR THE WEST CENTRAL MOHAWK RIVER ARE
EXPECTED TO GRADUALLY RECEDE INTO THE WEEKEND...UNLESS ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS OCCUR OVER OR NEAR THE BASIN.
WHILE THE AVERAGE BASIN RAINFALL FORECAST INDICATED LESS THAN AN
INCH OF RAIN TO FALL THROUGH THIS EVENING...THE COMBINATION OF MOIST
SOILS...THE SLOW MOVING NATURE OF THE THUNDERSTORMS TODAY AND A VERY
MOIST AIRMASS STILL IN PLACE WITH PWATS IN THE 1.33-1.75 INCHES...HAS
PROMPTED THE FLASH FLOOD WATCH.
1-HR FLASH FLOOD GUIDANCE REMAINS UNUSUALLY LOW...IN THE 1-2 INCH
RANGE. ANY THUNDERSTORM TODAY WOULD BE CAPABLE OF PRODUCING
LOCALIZED RAINFALL AMOUNTS OF AN INCH OR BETTER IN HOUR OR LESS
TIME AND THEREFORE THE NEED FOR THE WATCH.
THUNDERSTORMS LOOK TO DIMINISH TONIGHT. TUESDAY...MUCH OF THE REGION
COULD RECEIVE A BREAK IN THE ACTION...BUT A STRAY SHOWER OR
THUNDERSTORM CANNOT BE ENTIRELY RULED...ESPECIALLY TO THE SOUTH OF
ALBANY. PWATS LOOK TO DROP A LITTLE...DOWN TO AROUND 1.5 INCHES OR
LITTLE LESS TO THE NORTH OF ALBANY.
UNFORTUNATELY...A SLIGHTLY STRONGER COLD FRONT WILL APPROACH THE
REGION WEDNESDAY REIGNITING THE THREAT OF SHOWERS AND THUNDERSTORMS
INTO EARLY EARLY THURSDAY.
WE MIGHT FINALLY CATCH A LITTLE MORE SUBSTANTIAL BREAK WITH POSSIBLE
DRY WEATHER FRIDAY LASTING INTO THE BEGINNING OF THE WEEKEND.
WHILE ADDITIONAL FLOODING IS NOT ANTICIPATED ON ANY MAIN STEM RIVER
POINTS...LOCALLY SHARP RISES ARE POSSIBLE DUE TO ANY CONVECTION THAT
MAY OCCUR OVER THE NEXT SEVERAL DAYS...ESPECIALLY FOR THOSE POINTS
THAT ARE MORE FLASHIER IN NATURE.
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...FLASH FLOOD WATCH THROUGH THIS EVENING FOR CTZ001-013.
NY...FLASH FLOOD WATCH THROUGH THIS EVENING FOR NYZ032-033-038>043-
047>054-058>061-063>066-082>084.
MA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR MAZ001-025.
VT...FLASH FLOOD WATCH THROUGH THIS EVENING FOR VTZ013>015.
&&
$$
SYNOPSIS...HWJIV/WASULA
NEAR TERM...HWJIV/WASULA
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...GJM
FIRE WEATHER...HWJIV
HYDROLOGY...HWJIV/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1031 AM EDT MON JUL 8 2013
.SYNOPSIS...
A STRONG MID LEVEL DISTURBANCE WILL MOVE INTO OUR REGION
THIS AFTERNOON FOCUSING ANOTHER ROUND OF NUMEROUS SHOWERS AND
THUNDERSTORMS...SOME OF WHICH COULD CONTAIN HEAVY RAINFALL. THIS
SYSTEM WILL MOVE TO OUR EAST ALLOWING SLIGHTLY DRIER AIR TO MOVE IN
ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A FLASH FLOOD WATCH CONTINUES HAS FOR OUR ENTIRE COUNTY WARNING
AREA (CWA) FROM 1100 AM EDT THROUGH MIDNIGHT.
AS OF 1030 AM EDT...THE RADAR HAS BEEN QUIET AND POPS AND WEATHER
HAVE BEEN RETRENDED. CLOUDS MAY LIMIT THE COVERAGE TODAY...BUT THE
LATEST HIRESWRF AND HRRR DUE SHOW COVERAGE INCREASING IN THE
AFTERNOON.
AN UPPER AIR LOW...THE SAME ONE THAT CAUSED FLOODING PROBLEMS LAST
WEEK...IS MOVING BACK TOWARD OUR REGION FROM WESTERN PA. THIS LOW
PRESSURE WILL PROVIDE ASCENT (ALBEIT WEAK) AND ALSO COOL THE MID
LEVELS OF THE ATMOSPHERE DOWN A LITTLE.
THIS WILL GENERATE MORE SHOWERS AND THUNDERSTORMS...BECOMING
NUMEROUS IN MOST PLACES BY AFTERNOON. INSTABILITY WILL BE SIMILAR TO
YESTERDAY...WITH MUCAPES AROUND 1500 J/KG. HOWEVER...THE WIND WILL
FIELD WILL BE LIGHTER WITH THE 0-6KM BULK SHEAR UNDER 25KTS. MID
LEVEL LAPSE RATES STILL LOOK TO FALL BELOW 6.0 KM/C.
OVERALL...CONVECTIVE PARAMETERS INDICATED A LOW CHANCE FOR ORGANIZED
SEVERE THUNDERSTORMS. HOWEVER...LIKE YESTERDAY...ANY DISCREET CELL
COULD BRIEFLY PULSE TO SEVERE LIMITS...FEATURING LARGE HAIL AND
PERHAPS LOCALIZED WIND DAMAGE. AT THIS POINT...THE STORM PREDICTION
CENTER HAS NOT PLACED ANY OF OUR REGION IN SLIGHT RISK.
THE BIGGER CONCERN WITH THE STORMS WOULD BE EXCESSIVE RAINFALL. PWAT
VALUES WHILE DOWN A LITTLE FROM LAST EVENING...WILL STILL RANGE
BETWEEN 1.75-2.00 INCH...UP TO 3 STANDARDS ABOVE NORMAL. THE
FREEZING LEVEL IS FORECAST TO DROP A LITTLE FROM 15,000 TO ABOUT
13,000 BY DAY/S END BUT STILL PLENTY HIGH FOR EFFICIENT RAIN
FORMATION IN THE CLOUDS (WARM CLOUD PROCESSES). ALSO...MOST OF OUR
AREA HAS EXCESSIVE MOIST SOILS DUE TO THE RASH OF HEAVY RAINFALL
DURING THE PAST SIX WEEKS.
CSTAR RESEARCH WOULD DICTATE NOT GOING WITH A GENERAL FLASH FLOOD
WATCH DUE TO THE FACT THE THE AFOREMENTIONED UPPER AIR LOW PRESSURE
BECOMES AN OPEN WAVE (AS OPPOSED TO A CUT-OFF).
HOWEVER...AGAIN...DUE TO THE EXCESSIVE RAINFALL OUR REGION HAS
EXPERIENCED WE FELT IT PRUDENT TO ISSUE ONE.
WE HAVE PLACED OUR ENTIRE REGION IN A FLASH FLOOD WATCH FROM MIDDAY
THROUGH THE EVENING HOURS. FLASH FLOOD GUIDANCE (FFG) VALUES ARE
QUITE LOW...RANGING FROM 1-2 INCHES FOR HOURLY RAINFALL RATES ACROSS
THE REGION.
THE BOTTOM LINE...IT WOULD NOT TAKE A WHOLE LOT OF RAIN TO INDUCE
POTENTIAL FLASH FLOODING TODAY...ESPECIALLY IN HERKIMER
COUNTY...WHERE A PLETHORA OF FLASH FLOODS HAVE ALREADY ENSUED IN THE
PAST WEEKS.
IT WILL BE VERY HUMID ONCE MORE TODAY. THE CLOUDS AND MORE NUMEROUS
SHOWERS/STORMS SHOULD KEEP HIGH TEMPERATURES A LITTLE LOWER THAN
YESTERDAY...GENERALLY IN THE 80S...BUT AROUND 90 IN THE MID HUDSON
VALLEY AND LOWER LITCHFIELD COUNTY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE UPPER LEVEL LOW WILL STILL BE WORKING ACROSS OUR EASTERN REGIONS
THROUGH THE EVENING HOURS WITH ON GOING SHOWERS AND THUNDERSTORMS.
THESE SHOULD WANE LATER OVERNIGHT AND TOWARD DAYBREAK MOST OF THE
REGION SHOULD BE PRECIPITATION FREE ONCE MORE...ALTHOUGH SOME
SHOWERS MIGHT LINGER TO THE EAST OF THE HUDSON VALLEY.
A TRAILING WEAK COLD FRONT LOOKS TO CROSS THE REGION THROUGH THE
NIGHT. THE AIR BEHIND THIS FRONT WILL BE ONLY VERY SLIGHTLY COOLER
IN THE MID LEVELS AND DRIER TOO.
TUESDAY...WITH WEAK SUBSIDENCE AND THE SLIGHT DRYING...IT LOOKS AS
IF THE SHOWER AND THUNDERSTORM COVERAGE WILL BE MUCH LOWER.
STILL...THERE WILL STILL ENOUGH LOW LEVEL MOISTURE AROUND FOR
INSTABILITY AND A RANDOM POP-UP THUNDERSTORM OR TWO DURING THE
AFTERNOON..ESPECIALLY IN OUR SOUTHERN ZONES.
WITH MORE SUNSHINE THAN MONDAY...RESULTANT HIGH TEMPERATURES WILL
ACTUALLY BE A FEW POINTS HIGHER...ESPECIALLY IN THE VALLEYS WHERE
85-90 WILL COMMON WHILE THE HIGHER TERRAIN WILL RANGE FROM THE
80-85. A LIGHT WEST WIND WILL BECOME SOUTH BY LATE IN THE DAY.
A SLIGHTLY STRONGER COLD FRONT IS POISED TO SLIP FROM THE GREAT
LAKES AND HEAD TOWARD OUR REGION LATER TUESDAY NIGHT INTO WEDNESDAY.
THIS FEATURE WILL TAKE ITS TIME APPROACHING AND ESPECIALLY CLEARING
OUR REGION.
IT LOOKS MAINLY DRY TUESDAY NIGHT (BUT DID KEEP 20 POPS FOR SHOWER
OR THUNDERSTORM). BY WEDNESDAY...THE CHANCES WILL RAMP UP AGAIN AS
THE FRONT NEAR AND THE ATMOSPHERE BECOMES MORE UNSTABLE. THE TIMING
OF THE FRONT WILL HELP DETERMINE WHETHER OR NOT WE COULD BE LOOKING
AT A POTENTIAL SEVERE WEATHER EVENT. RIGHT NOW...IT APPEARS THAT THE
ACTUAL FRONT WILL NOT WORK ACROSS THE REGION UNTIL LATER WEDNESDAY
NIGHT OR EARLY THURSDAY. WE WILL HAVE PLENTY OF TIME TO MONITOR
THESE TRENDS.
WEDNESDAY...AHEAD OF THE FRONT...TEMPERATURES WILL BE UNCOMFORTABLY
WARM AND HUMID REACHING NEAR 90 IN THE MID HUDSON VALLEY...MID TO
UPPER 80S MOST OTHER PLACES.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
MEDIUM RANGE MODELS (GFS/ECMWF) ARE NOW OFFERING SOME HOPE THAT MUCH
OF THE LONG TERM PERIOD MAY BE RELATIVELY QUIET WEATHERIZE AND NOT
AS HUMID. THE FORECAST FOR THE MAIN WEATHER FEATURES CALLS FOR THE
COLD FRONT TO SHIFT SOUTH OF THE REGION EARLY ON THURSDAY...
RESULTING IN MAINLY DRY WEATHER BY LATE IN THE DAY. THE UPPER LEVEL
TROF THAT PUSHED THIS FRONT THROUGH IS THEN FORECAST TO CLOSE
OFF/CUTOFF WELL TO THE SOUTHWEST OF THE REGION (OVER THE CENTRAL AND
SOUTHERN APPALACHIANS) BY SATURDAY...AND THEN CONTINUE RETROGRADING
WESTWARD DURING THE REST OF NEXT WEEKEND. AT THE SAME TIME THE RIDGE
OVER THE WESTERN ATLANTIC WILL BUILD WESTWARD.
THE RESULT OF ALL THIS IS THAT ONCE THE MOISTURE ASSOCIATED WITH
FRONTAL BOUNDARY MOVES THROUGH...IT WILL HAVE A HARD TIME RETURNING
NORTHWARD UNTIL THE RIDGE BUILDS WESTWARD AND THE SOUTHWEST FLOW
AROUND IT BRINGS THE MOISTURE NORTHWARD AGAIN. HOWEVER...THIS IS NOT
FORECAST TO HAPPEN UNTIL EARLY NEXT WEEK...SO THE PERIOD FROM
THURSDAY NIGHT THROUGH SUNDAY IS GENERALLY FORECAST TO BE DRY BY
BOTH THE GFS AND ECMWF.
CONSIDERING THE WET PATTERN WE HAVE BEEN IN LATELY AND THAT THIS IS
THE FIRST TIME BOTH MODELS SEEM TO INDICATE THE POSSIBILITY OF A DRY
PERIOD...WILL NOT COMPLETELY REMOVE PCPN FROM THE FORECAST FOR NOW
UNTIL LATER RUNS ALSO SUPPORT THIS DRIER PATTERN.
AS THE FRONT SAGS SOUTH ON THURSDAY...HAVE FORECAST DECREASING POPS
DURING THE DAY...THE DRY CONDITIONS THURSDAY NIGHT. ONLY A SLIGHT
CHANCE FOR A SHOWER ON FRIDAY AND FRIDAY NIGHT...THEN A 30 PERCENT
OF SHOWERS SATURDAY THROUGH SUNDAY WITH THUNDERSTORMS ALSO POSSIBLE
SUNDAY AFTN/EVE.
TEMPS WILL NOT BE AS WARM AS RECENTLY AND DEWPOINTS WILL ALSO BE 5
TO 10 DEGREES LOWER THAN RECENTLY. HIGHS THURSDAY WILL BE IN THE
UPPER 70S TO MID 80S...MID 70S TO LOWER 80S FRIDAY...UPPER 70S TO
MID 80S SATURDAY AND SUNDAY. LOWS THURSDAY AND FRIDAY NIGHTS WILL BE
IN THE MID 50S TO MID 60S...AND UPPER 50S TO MID 60S SATURDAY NIGHT.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AS AN UPPER LEVEL LOW TRACKS BY TO THE SOUTH OF THE REGION...
EXPECT SCT TO NUMEROUS SHOWERS/TSTMS EXPECTED TO DEVELOP AGAIN
THIS AFTERNOON...BUT AS WITH RECENT DAYS...TIMING AND LOCATION OF
SHOWERS IS NOT POSSIBLE AT THIS TIME SO WILL ONLY FORECAST VCSH FOR
NOW BETWEEN 08/16Z AND 09/01Z. WHERE SHOWERS/TSTMS DO OCCUR...WOULD
EXPECT MVFR TO POSSIBLY IFR CIGS/VSBYS. OTHERWISE...HAVE FORECAST
VFR CONDITIONS AT THE KALB/KGFL/KPOU/KPSF TAF SITES THROUGH LATE
THIS EVENING. AFT AROUND 06Z TUESDAY...HAVE FORECAST SOME MVFR FOG
AT KGFL AND KPSF.
WINDS WILL BE CALM OR LIGHT AND VARIABLE THROUGH MID MORNING...THEN
THEN BECOMING WEST-SOUTHWEST LATER ON TODAY AT SPEEDS OF 8 KTS OR
LESS...THEN LIGHT AND VARIABLE AGAIN TONIGHT.
OUTLOOK...
TUE...MAINLY VFR. SCT -SHRA/-TSRA.
WED...VFR/MVFR/IFR DUE TO SCT TO NUM -SHRA/-TSRA.
THU-FRI...MAINLY VFR. SCT PM -SHRA/-TSRA.
MVFR/IFR OVERNIGHT FOG POSSIBLE TUE-FRI.
&&
.FIRE WEATHER...
NO FIRE WEATHER ISSUES ARE EXPECTED OVER THE NEXT SEVERAL DAYS.
SHOWERS AND THUNDERSTORMS WILL BECOME NUMEROUS ONCE MORE THIS
AFTERNOON AND EARLY EVENING.
THERE WILL BE LESS COVERAGE ON TUESDAY WITH MANY PLACES PERHAPS NOT
RECEIVING ANY MEASURABLE RAINFALL.
HOWEVER...MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED WEDNESDAY.
NORMAL RH RECOVERIES EACH NIGHT BETWEEN 80 TO 100 PERCENT WILL ALLOW
FOR WIDESPREAD DEW FORMATION. DAYTIME RH VALUES WILL GENERALLY BE IN
THE 40 TO 60 PERCENT RANGE.
&&
.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN ISSUED FOR OUR ENTIRE HSA FROM 1100 AM
EDT THROUGH MIDNIGHT. THIS IS THE RESULT OF AN UPPER LEVEL LOW
PRESSURE MOVING ACROSS THE REGION WITH VERY HIGH PWAT VALUES NEAR
2.00 INCHES.
THE MOHAWK RIVER AT UTICA CONTINUES TO EXPERIENCE MINOR FLOODING.
THE RIVER AND CREEK FLOWS NEAR THE WEST CENTRAL MOHAWK RIVER ARE
EXPECTED TO GRADUALLY RECEDE INTO THE WEEKEND...UNLESS ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS OCCUR OVER OR NEAR THE BASIN.
WHILE THE AVERAGE BASIN RAINFALL FORECAST INDICATED LESS THAN AN
INCH OF RAIN TO FALL THROUGH THIS EVENING...THE COMBINATION OF MOIST
SOILS...THE SLOW MOVING NATURE OF THE THUNDERSTORMS TODAY AND A VERY
MOIST AIRMASS STILL IN PLACE WITH PWATS NEAR 2 INCHES...HAS PROMPTED
THE FLOOD FLOOD WATCH.
FLASH FLOOD GUIDANCE REMAINS UNUSUALLY LOW...IN THE 1-2 INCH RANGE.
ANY THUNDERSTORM TODAY WOULD BE CAPABLE OF PRODUCING LOCALIZED
RAINFALL AMOUNTS OF AN INCH OR BETTER IN HOUR OR LESS TIME AND
THEREFORE THE NEED FOR THE WATCH.
THUNDERSTORMS LOOK TO DIMINISH TONIGHT. TUESDAY...MUCH OF THE REGION
COULD RECEIVE A BREAK IN THE ACTION...BUT A STRAY SHOWER OR
THUNDERSTORM CANNOT BE ENTIRELY RULED...ESPECIALLY TO THE SOUTH OF
ALBANY. PWATS LOOK TO DROP A LITTLE...DOWN TO AROUND 1.5 INCHES OR
LITTLE LESS TO THE NORTH OF ALBANY.
UNFORTUNATELY...A SLIGHTLY STRONGER COLD FRONT WILL APPROACH THE
REGION WEDNESDAY REIGNITING THE THREAT OF SHOWERS AND THUNDERSTORMS
INTO EARLY EARLY THURSDAY.
WE MIGHT FINALLY CATCH A LITTLE MORE SUBSTANTIAL BREAK WITH POSSIBLE
DRY WEATHER FRIDAY LASTING INTO THE BEGINNING OF THE WEEKEND.
WHILE ADDITIONAL FLOODING IS NOT ANTICIPATED ON ANY MAIN STEM RIVER
POINTS...LOCALLY SHARP RISES ARE POSSIBLE DUE TO ANY CONVECTION THAT
MAY OCCUR OVER THE NEXT SEVERAL DAYS...ESPECIALLY FOR THOSE POINTS
THAT ARE MORE FLASHIER IN NATURE.
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...FLASH FLOOD WATCH THROUGH THIS EVENING FOR CTZ001-013.
NY...FLASH FLOOD WATCH THROUGH THIS EVENING FOR NYZ032-033-038>043-
047>054-058>061-063>066-082>084.
MA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR MAZ001-025.
VT...FLASH FLOOD WATCH THROUGH THIS EVENING FOR VTZ013>015.
&&
$$
SYNOPSIS...HWJIV/WASULA
NEAR TERM...HWJIV/WASULA
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...GJM
FIRE WEATHER...HWJIV
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
659 AM EDT MON JUL 8 2013
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY MOVES THROUGH THE AREA LATE TODAY...WITH A
COUPLE MORE AFFECTING THE AREA THROUGH MID WEEK. A SLOWLY MOVING COLD
FRONT WILL PASS THROUGH THE REGION LATE THIS WEEKEND...AND MAY LINGER
INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST MAINLY ON TRACK...WITH ONLY MINOR ADJUSTMENTS TO POPS
BASED ON LATEST ENSEMBLE MESOSCALE OUTPUT. REMOVED SLIGHT CHANCE
POPS FOR LIGHT RAIN MOVING UP FROM SE PA/DELMARVA THIS MORNING
BASED ON LATEST HRRR AND LLJ MOVING EAST.
OTHERWISE...A DISTINCT SHORTWAVE OVER WESTERN PA EARLY THIS
MORNING SLOWLY SLIDING INTO THE REGION LATE THIS
AFTERNOON/EVENING...WITH SURFACE/THERMAL TROUGHING CONTINUING
ACROSS WESTERN ZONES.
SUNSHINE WILL BE FILTERED BY SOME HIGH AND MID CLOUDS AHEAD OF
THE SHORTWAVE...AND SCT CU DEVELOPMENT LIKELY ACROSS INTERIOR
AND IN VICINITY OF SURFACE TROUGH AND SEABREEZE BOUNDARIES BY
EARLY AFTERNOON.
WITH BERMUDA RIDGING PUSHING TO THE EAST...WARMEST AIRMASS SHUNTED
TO THE EAST AS WELL WITH TEMPS EXPECTED TO BE SEVERAL DEGREES
COOLER TODAY. MODEL GUIDANCE AND UPSTREAM DEWPOINTS ARE POINTING
TOWARDS DEWPOINTS RUNNING 3 TO 5 DEGREES LOWER TODAY THAN YESTERDAY
AS WELL. HIGHS GENERALLY EXPECTED TO BE IN THE MID TO UPPER 80S
ALONG THE COAST...AND UPPER 80S TO AROUND 90 INTERIOR AND NYC/NJ
METRO. MAX HEAT INDICES ARE EXPECTED TO STAY CLOSE TO ACTUAL TEMPS
ACROSS NYC/NJ METRO AND INTERIOR...GENERALLY LOWER 90S.
SLIGHTLY STEEPENING MID LEVEL LAPSE RATES AND DAYTIME HEATING
SHOULD RESULT IN MARGINAL TO MODERATE INSTABILITY LEVELS TO THE
INTERIOR OF SEABREEZE BOUNDARIES. SHEAR LOOKS TO BE WEAK AS LLJ IS
MAINLY EAST OF THE REGION. BASED ON ABOVE...EXPECTATION IS FOR
ACTIVITY TO BE MORE PULSE IN NATURE. INITIALLY ACTIVITY SHOULD BE
ISOLATED ACROSS HIGHER TERRAIN AND IN VICINITY OF SURFACE TROUGH
AND SEABREEZE BOUNDARY EARLY THIS AFTERNOON. THEN AS SHORTWAVE
ENERGY APPROACHES IN THE MID TO LATE AFTERNOON THE CONVECTIVE
COVERAGE SHOULD INCREASE TO SCATTERED ACROSS THESE AREAS AND
GRADUALLY PUSH EAST INTO THE EVENING. THIS IS GENERALLY
CHARACTERIZED IN ENSEMBLE HIGH RES MODEL OUTPUT.
ISOLATED PULSE STRONG TO SEVERE STORMS ARE POSSIBLE BASED ON
INSTABILITY...WITH STRONG WINDS AND HEAVY RAINS THE HIGHER PROB
HAZARDS. WITH PWATS FALLING CLOSER TO NORMAL AND MBE VECTORS
SHOWING ENOUGH MOVEMENT TO STORMS...FLASH FLOODING LOOKS TO BE
ISOLATED TO ANY TRAINING ALONG SEABREEZE/THERMAL TROUGHING.
A MODERATE RISK OF RIP CURRENT CONTINUES FOR EASTERN LONG ISLAND
ATLANTIC BEACHES TODAY. THERE IS POTENTIAL FOR SEABREEZE ACTIVITY
TO INCREASE THE RIP CURRENT RISK TO MODERATE ACROSS THE REMAINDER
OF THE ATLANTIC BEACHES LATE TODAY INTO THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
SHORTWAVE ENERGY/SURFACE TROUGH MOVE EAST TONIGHT WITH ANY
CONVECTION EXPECTED TO DIMINISH.
WEAK TROUGHING REMAIN OVER THE REGION ON TUESDAY...WITH A WARM FRONT
TO THE SW OF THE REGION. MODELS INDICATING MCS DEVELOPING OVER THE
GREAT LAKES THIS AFTERNOON INTO TONIGHT TRACKING SE ALONG THE WARM
FRONT. BASED ON WARM FRONTAL POSITION AND SYNOPTIC FORCING REMAINING
WELL S&W OF AREA...NOT EXPECTING TO BE AFFECTED DIRECTLY BY THIS
ACTIVITY. COULD BE DEALING WITH CLOUD COVER FILTERING SUNSHINE
THOUGH.
CONVECTIVELY INDUCED VORTS AND MARGINAL TO MODERATE INSTABILITY
COULD ALLOW FOR ISOLATED CONVECTION OFF THE HIGHER ELEVATIONS.
OTHERWISE...WILL HAVE TO WATCH FOR ANY CONVECTION DEVELOPING OFF THE
OUTFLOW FROM MCS ACTIVITY ACROSS PA...TRACKING INTO FAR W PORTIONS
OF THE AREA LATE IN THE DAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
WEAK H5 TROUGH/SHORTWAVE COMBO SLIDES THROUGH THE REGION TUESDAY
EVENING...AND ANY LINGERING SHOWERS/TSTMS WILL TAPER OFF IN THE
EVENING. THEREAFTER...LOW PRES WILL TRACK FROM THE NORTHERN PLAINS
STATES INTO THE UPPER GREAT LAKES...AND THEN INTO EASTERN CANADA.
THIS WILL PUSH A WARM FRONT NORTH INTO THE REGION ON WEDNESDAY...AND
THEN THE TRAILING COLD FRONT WILL SLOWLY PUSH THROUGH THE REGION
THURSDAY INTO FRIDAY.
WITH INCREASING SOUTHERLY FLOW ON WEDNESDAY...VERY WARM AND HUMID
CONDS ON TAP WITH TEMPS GENERALLY IN THE UPPER 80S TO LOWER 90S.
WITH DEWPOINTS RISING INTO THE LOWER 70S...CAN EXPECT A HEAT INDEX
GENERALLY IN THE LOW/MID 90S...AND IN THE MID/UPPER 90S ACROSS PARTS
OF NYC AND NE NJ. TRAILING COLD FRONT WILL PUSH TOWARDS THE
APPALACHIANS WEDNESDAY...AND SCT-NUM SHOWERS/TSTMS WILL DEVELOP
AHEAD OF THE FRONT WITH THE BEST CHANCES OVER FAR NW ZONES. WILL
INCREASE POPS TO LIKELY IN THOSE AREAS.
UNSETTLED WEATHER CONTINUES THROUGH AT LEAST THURSDAY-FRIDAY AS COLD
FRONT WORKS ITS WAY THROUGH THE REGION...BUT APPEARS TO GET HUNG UP
JUST SOUTH AND EAST OF THE AREA. SOME MODEL DISCREPANCIES...AS THE
GFS DEVELOPS A CLOSED LOW JUST OVER NYC ON FRIDAY...BUT THE ECMWF
DOES NOT REALLY REFLECT THIS. UPPER TROUGH SLOWLY MOVES THROUGH THE
REGION LATE FRIDAY/SATURDAY...AND DEPENDING ON HOW CLOSE THE FRONT
HANGS TO THE COAST WILL DEPEND IF UNSETTLED WEATHER CONTINUES
THROUGH THE WEEKEND.
TEMPS WILL BE IN THE MID TO UPPER 80S THROUGH THURSDAY. BEHIND THE
FRONT...TEMPS FALL BACK INTO THE LOW TO MID 80S FOR THE END OF THE
WEEK AND OVER THE WEEKEND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A WEAK SURFACE TROF WILL REMAIN NEAR THE TERMINALS THROUGH THE TAF
PERIOD.
MAINLY VFR. SOUTHWEST TO WEST-SOUTHWEST WINDS INCREASE TO 10-15KT
AFTER THE MORNING PUSH. AFTERNOON GUSTS AT KEWR/KTEB/KLGA
ARE EXPECTED ONCE AGAIN...UP TO AROUND 20KT. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED ONCE AGAIN THIS AFTERNOON...HOWEVER IN
TIMING AND PLACEMENT TOO LOW TO INCLUDE IN THE TAFS. BEST CHANCES
WILL BE AFTER 20Z. BRIEF SUB-VFR CONDITIONS AND GUSTY WINDS CAN BE
EXPECTED WITH ANY THUNDERSTORMS.
WINDS DIMINISH TONIGHT TO LESS THAN 10 KT.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: WINDS COULD BECOME MORE SOUTHERLY THAN
FORECAST. BEST CHANCE OF ANY CONVECTION WILL BE AFTER 20Z.
KLGA FCSTER COMMENTS: TIMING OF GUSTS MAY START AN HOUR EARLIER
THAN FORECAST. BEST CHANCE OF ANY CONVECTION WILL BE AFTER 20Z.
KEWR FCSTER COMMENTS: TIMING OF GUSTS MAY START AN HOUR EARLIER
THAN FORECAST. BEST CHANCE OF ANY CONVECTION WILL BE AFTER 20Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: TIMING OF GUSTS MAY START AN HOUR EARLIER
THAN FORECAST. BEST CHANCE OF ANY CONVECTION WILL BE AFTER 20Z.
KHPN FCSTER COMMENTS: BEST CHANCE OF ANY CONVECTION WILL BE AFTER
20Z.
KISP FCSTER COMMENTS: WIND SPEEDS COULD BE A FEW KNOTS HIGHER THAN
FORECAST.
.OUTLOOK FOR 12Z MONDAY THROUGH FRI...
.MON NIGHT-FRI...MAINLY VFR...BUT SUB-VFR POSSIBLE IN SCT TSTMS THRU
THE ENTIRE PERIOD.
&&
.MARINE...
SUB SCA CONDS THROUGH TUESDAY WITH GENERAL SW WINDS EXPECTED. WINDS
WILL INCREASE EACH AFT/EVE DUE TO ENHANCEMENT FROM SEA
BREEZES.
WINDS AND WAVES WILL REMAIN BELOW SCA CRITERIA TUESDAY THROUGH
THURSDAY. A COLD FRONT WILL THEN APPROACH THE WATERS WITH A LOW
LEVEL JET DEVELOPING. SEAS WILL BE ON THE INCREASE AND OCEAN SEAS
COULD BE ABOVE 5 FT BUT THURSDAY MORNING AND REMAIN ELEVATED THROUGH
FRIDAY. WINDS WILL ALSO BE AT MARGINAL SCA CRITERIA BEGINNING
THURSDAY MORNING AND CONTINUING THROUGH FRIDAY.
&&
.HYDROLOGY...
SCATTERED SHOWERS/THUNDERSTORMS WILL PRODUCE LOCALLY HEAVY RAIN THIS
AFTERNOON. FLASH FLOODING LOOKS TO BE ISOLATED TO ANY TRAINING
ALONG SEABREEZE/THERMAL TROUGHING....WITH MINOR URBAN/POOR
DRAINAGE/SMALL STREAM FLOODING THE MORE PROBABLE HAZARD.
SHOWERS AND THUNDERSTORMS WILL INCREASE IN COVERAGE FOR THE MIDDLE
TO THE END OF THE WEEK AS A COLD FRONT SLOWLY MOVES THROUGH THE
REGION. ALTHOUGH THE PROBABILITY OF WIDESPREAD HEAVY RAIN IS
LOW...LOCALLY HEAVY RAIN IS POSSIBLE IN ANY THUNDERSTORMS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MPS/NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...MPS
AVIATION...BC
MARINE...MPS/NV
HYDROLOGY...MPS/NV
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1106 AM EDT Mon Jul 8 2013
.NEAR TERM [Through Tonight]...
An upper level low moving northeast through New England has tilted
a tropical moisture plume on SW/NE axis across our CWA. There is a
subtle boundary currently draped across southeast Alabama and
central Georgia that is expected to move SE during the day. This
boundary, the afternoon sea breeze, and subsequent mesoscale
boundaries will serve as sources for lift to initiate
thunderstorms. Thus the PoP forecast for today reflects this
forecast thinking. Higher PoPs will begin in the west and then
shift east throughout the day. Our local WRF and the HRRR depict a
similar pattern evolving throughout the afternoon. The concern
today is with light flow in the 1000-700mb layer storm motion
will be slow. Therefore where thunderstorms fire, they will be
slow to move and could potentially dump lots of rain.
For today expect partly cloudy skies with light winds and high
temperatures reaching the lower 90s.
&&
.SHORT TERM [Tuesday Through Wednesday]...
Our forecast area will be situated in between two areas of high
pressure, one over the western CONUS and one over the western
Atlantic. Despite being in this weakness, the global models are not
forecasting much synoptic scale forcing, which means that any forcing
for rain will come from the sea breeze front and associated
outflow boundary interactions during the afternoon and evening hours.
The MOS PoP consensus is near to slightly below climatology, held
in check by a band of dry air aloft, currently along the western
flank of a Tropical Upper Tropospheric Low over the Bahamas that
was translating westward. High temperatures will be warmer than
the past several days...solidly in the mid 90s away from the
beaches. However, heat index values will likely remain below
105 deg.
&&
.LONG TERM [Wednesday Night through Sunday]...
A rather unsettled pattern will continue across the region into
next weekend with abundant low level moisture supporting typical
summer-like thunderstorms in the afternoon and evening. Models
drift weakening mid/upper low into the nern Gulf of Mexico by mid-
week, and amplify large upper high over the srn/central Rockies.
This should reestablish a well defined trough over the eastern 1/3
of the CONUS, with mid/upper low perhaps digging sswwd into the
area next weekend. Overall, expect near seasonal temperatures.
&&
.AVIATION [Beginning 14Z Monday]...
Scattered showers and thunderstorms should develop once again
across our area, possibly affecting all terminals after 17-18Z. A
slightly drier airmass will be moving into our easternmost zones
today so went with VCTS at VLD. Otherwise, convective TEMPO groups
at all of the remaining TAF sites for this afternoon.
&&
.MARINE...
The coastal waters will be near a weakness in the subtropical
Atlantic ridge, resulting in typically low summertime levels of
winds and seas.
&&
.FIRE WEATHER...
No fire weather concerns.
&&
.HYDROLOGY...
The WPC 5-day QPF (through Friday afternoon) is only about an inch
for our forecast area, which is about what we would expect for this
time of year. Of course isolated amounts could be several times this
amount, but they would likely be too spotty to significantly affect
river stages, and would only be a flash flooding concern if they
occurred in an urban area.
Because most of the heavy rain last week fell across the lower
portions of the river basins, most of the local forecast points that
had significant river stage rises were already on their way down,
including:
the Choctawhatchee River at Geneva, AL (Action stage), Apalachicola
River at Blountstown, FL (minor flood), Ochlockonee River at
Thomasville, GA and Concord, FL, (both Action stage), the
Withlacoochee River at Valdosta, GA (minor flood), St. Marks River
near Newport, FL (minor flood), the Shoal River at Mossy Head
(Action stage), Sopchoppy River at Sopchoppy, FL (moderate flood),
and Aucilla River at Lamont, FL (minor flood).
Some forecast points farther downstream were still on the rise,
however, including:
the Choctawhatchee River at Caryville (minor flood) and Bruce, FL
(major flood), the Chipola River at Marianna, FL (Action stage), the
Withlacoochee River at Pinetta, FL (Action stage), and the Econfina
River near Perry, FL (Action stage).
For the latest, detailed information on river stages near you,
please visit our website at weather.gov, and follow the links to the
"Advanced Hydrologic Prediction Center" (AHPS).
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 91 73 93 73 92 / 50 30 30 20 30
Panama City 89 75 89 75 88 / 40 20 30 20 30
Dothan 91 72 93 74 92 / 40 20 40 20 30
Albany 92 73 93 73 92 / 50 30 40 20 30
Valdosta 92 72 96 71 95 / 40 30 30 20 30
Cross City 92 72 93 71 91 / 40 20 30 20 40
Apalachicola 88 75 88 75 88 / 40 10 20 20 30
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Navarro/DVD
SHORT TERM...Fournier
LONG TERM...Evans
AVIATION...Barry
MARINE...Fournier
FIRE WEATHER...Barry
HYDROLOGY...Fournier
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
752 AM EDT MON JUL 8 2013
.PREV DISCUSSION... /ISSUED 350 AM EDT MON JUL 8 2013/
SHORT TERM /TODAY THROUGH TUESDAY/...
500MB ANALYSIS SHOWS AN UPPER LOW MOVING INTO THE WESTERN MIDDLE
ATLANTIC WITH A WEAK SHEAR AXIS EXTENDING INTO THE CENTRAL CWFA THIS
MORNING. WV STILL DEPICTS THE HIGH MOISTURE PLUME VERY WELL ACROSS
THE CENTRAL AND SOUTHERN CWFA...BUT ALSO SHOWS SOME DRIER AIR HAS
WORKED ITS WAY INTO THE NORTHERN CWFA. THE TROUGH/SHEAR AXIS IS
EXPECTED TO PUSH SOUTH TODAY.
FORECAST PROBLEM OF THE DAY WILL BE POPS. SUSPECT THE CURRENT
ACTIVITY ON THE REGIONAL RADAR LOOP HAS DEVELOP ALONG AND SOUTH OF
THE SHEAR AXIS. DO THINK THE SHEAR AXIS WILL HELP SUPPORT CONVECTIVE
DEVELOPMENT TODAY...ESPECIALLY ACROSS THE CENTRAL CWFA. THE LATEST
RUN OF THE HRRR DOES SHOW SOME EARLY DEVELOPMENT ACROSS THE NORTHERN
TIER OF ZONES THIS MORNING...AND THAT COULD BE ASSOCIATED WITH WEAK
SHORTWAVE DROPPING SOUTH IN THE FLOW. ALSO...ACROSS THE SOUTHERN
CWFA...CONVECTIVE DEVELOPMENT COULD BE ENHANCED BY ANY ACTIVITY THAT
DEVELOPS ALONG THE SEA BREEZE AND MOVES INLAND. THE BEST CHANCES FOR
THUNDER SHOULD BE IN THE CENTRAL AND SOUTHERN ZONES...WHERE MORE
BREAKS IN THE CLOUD COVER COULD OCCUR...SURFACE INSTABILITY WILL BE
A LITTLE HIGHER AND THE SEA BREEZE COULD AID WITH LIFT.
THE SHEAR AXIS SHOULD SET UP TO THE SOUTH TOMORROW...BUT BOTH THE
GFS AND NAM ARE PROGGING ANOTHER PIECE OF SHORTWAVE ENERGY TO DROP
SOUTH IN THE FLOW TOMORROW AFTERNOON. IN ADDITION...THE MOISTURE
PLUME SHOULD BE LOCATED FURTHER SOUTH THAN TODAY. SO...EXPECT
CONVECTION TO BE A LITTLE MORE DIURNAL IN NATURE. FOR NOW...LEFT
GENERAL SCT POPS.
WILL GO AHEAD AND LEAVE THE FLASH FLOOD WATCH IN EFFECT THROUGH
TODAY. EVEN THOUGH THE COVERAGE OF POPS MAY BE LOWER THAN IN
PREVIOUS DAYS ACROSS THE NORTH...ANY THUNDERSTORM COULD PRODUCE
LOCALLY HEAVY RAINFALL. PWATS WILL DROP TO AROUND AN INCH AND A HALF
IN THE NORTH...BUT A THUNDERSTORM COULD EASILY DROP A QUICK INCH OR
MORE. FFG VALUES ARE AROUND AN INCH ACROSS MUCH OF THE AREA...WITH
SOME AREAS LESS THAN A QUARTER OF AN INCH.
NLISTEMAA
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE EXTENDED BEGINS WITH THE SOUTHEAST IN A GENERAL WEAKNESS
PATTERN ALOFT...SANDWICHED BETWEEN THE TWO UPPER HIGHS /ONE IN
THE ATLANTIC AND ONE IN THE SOUTHWEST STATES/ AND TWO UPPER LOWS
OR TROUGHS /WEAK WAVE IN THE EASTERLIES OVER FLORIDA AND LONGWAVE
TROUGH IN CANADA/. WEAK SURFACE BOUNDARY REMAINS IN PLACE TUESDAY
NIGHT AND WEDNESDAY AND WHILE THERE IS VERY LITTLE FORCING...
THERE WILL BE ENOUGH MOISTURE AND INSTABILITY TO KEEP SLIGHT TO
LOW CHANCE POPS ACROSS THE AREA.
WEDNESDAY NIGHT INTO THURSDAY...THE LONGWAVE TROUGH DEEPENS IN
RESPONSE TO A SHORTWAVE RIDING DOWN THE NORTHWEST FLOW TOWARD THE
OHIO VALLEY. THIS PUSHES A REINFORCING FRONT THROUGH THE TENNESSEE
VALLEY AND INTO THE SOUTHEAST...WARRANTING HIGHER POPS FOR
THURSDAY AFTERNOON. KEPT TREND OF LIKELY POPS UP NORTH. AS THE
POSITIVELY TILTED TROUGH CONTINUES TO DEEPEN THE FRONT WILL PRETTY
MUCH STALL ACROSS THE SOUTHEAST...THOUGH THERE IS SOME QUESTION AS
TO HOW STRONG THE GREAT LAKES SURFACE HIGH WILL BE AND IF PORTIONS
OF THE STATE ARE ABLE TO CLEAR OUT LATE IN THE WEEK...AS PER THE
00Z GFS...OR IF SIGNIFICANT MOISTURE REMAINS OVER THE ENTIRE AREA
AS PER THE 00Z ECMWF. IF THE GFS IS TO BE BELIEVE...DRY AIR IS
ABLE TO PUSH IN FRIDAY INTO SATURDAY LEADING TO OVERNIGHT LOWS IN
THE 60S. ADD THIS TO TEMPS CONTINUING AT OR BELOW NORMAL...NOT BAD
AT ALL FOR THIS TIME OF YEAR.
BY SATURDAY MORNING THE GFS HAS ALREADY CUT OFF THE UPPER LOW
ACROSS GEORGIA WHILE THE ECMWF JUST HAS A VERY LONG AND SKINNY
TROUGH IN PLACE. THIS IS A PRETTY INTERESTING AND PERPLEXING CHANGE
FROM LAST NIGHT/S SOLUTIONS...WHERE THE GFS AND ECMWF WERE IN
REMARKABLE AGREEMENT WITH THE CUTOFF LOW. WITH TONIGHT/S RUNS...
WHILE THE SENSIBLE WEATHER RESULTS ARE NOT ALL THAT DIFFERENT...
THE MASS FIELDS ARE ACTUALLY QUITE A BIT DIFFERENT. IN EITHER CASE
THOUGH...ABOVE-NORMAL PWATS REMAIN OVER THE SOUTHEAST. ADD TO
THIS WHATEVER HAPPENS WITH CHANTAL...OR THE REMNANTS THEREOF.
ENSEMBLE GUIDANCE TAKE THE SYSTEM SOMEWHERE INTO THE SOUTHEAST
LATE IN THE PERIOD...GFS WITH A MORE NOTICEABLE CIRCULATION INTO
THE JACKSONVILLE FLORIDA AREA...BUT THE ECMWF WITH JUST A GENERAL
AREA OF MOISTURE INTO THE FLORIDA PENINSULA. SO ALL THAT SAID...
HAVE KEPT POPS JUST ABOVE CLIMO FOR THE WEEKEND ESPECIALLY SUNDAY.
TEMPS REMAIN AT OR BELOW NORMAL THROUGH THE WEEKEND.
TDP
&&
.AVIATION...
12Z UPDATE...
LOW CIGS HAVE BEEN PROBLEMATIC THIS MORNING. CIGS HAVE BEEN
BOUNCING BACK AND FORTH FROM VFR TO IFR/LIFR FOR THE LAST 4 HOURS
AT SEVERAL TERMINAL SITES. LOW LIGHT VIS IMAGERY SHOWING A BANK OF
LOW LEVEL STRATUS NEARING ATL...MIGHT HAVE TO AMD FOR THE LOW CIGS
FOR A FEW HOURS THIS MORNING. DO THINK THEY WILL BURN OFF BY
14-15Z. SCT/BKN DIURNAL CU EXPECTED FOR THE AFTERNOON AROUND
040-050. LIGHT SW WINDS EXPECTED THROUGH THE DAY.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 71 87 72 / 40 40 40 30
ATLANTA 84 72 86 73 / 40 40 40 30
BLAIRSVILLE 81 64 81 67 / 40 40 40 30
CARTERSVILLE 85 70 86 72 / 40 40 40 30
COLUMBUS 86 73 90 74 / 40 40 40 20
GAINESVILLE 83 70 85 72 / 40 40 40 30
MACON 86 73 90 73 / 40 40 40 20
ROME 87 70 87 72 / 40 40 40 30
PEACHTREE CITY 84 70 87 72 / 40 40 40 30
VIDALIA 89 74 91 74 / 40 40 40 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES:
BANKS...BARROW...BARTOW...CARROLL...CATOOSA...CHATTOOGA...
CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...DADE...DAWSON...
DEKALB...DOUGLAS...FANNIN...FAYETTE...FLOYD...FORSYTH...GILMER...
GORDON...GREENE...GWINNETT...HALL...HARALSON...HEARD...HENRY...
JACKSON...LUMPKIN...MADISON...MORGAN...MURRAY...NEWTON...NORTH
FULTON...OCONEE...OGLETHORPE...PAULDING...PICKENS...POLK...
ROCKDALE...SOUTH FULTON...TALIAFERRO...TOWNS...UNION...WALKER...
WALTON...WHITE...WHITFIELD...WILKES.
&&
$$
SHORT TERM...ATWELL
LONG TERM....ATWELL
AVIATION...ATWELL
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1047 AM CDT MON JUL 8 2013
.DISCUSSION...
ISSUED 1045 AM CDT MON JUL 8 2013
FORECAST WAS ALREADY UPDATED EARLIER THIS MORNING AND WILL JUST
NEED TO MAKE SLIGHT MODIFICATIONS OF THE CHANCES OF SHOWERS AND
THUNDERSTORMS THE REST OF TODAY. WILL CONTINUE CHANCES (30-50%) OF
SHOWERS AND THUNDERSTORMS OVER CENTRAL IL THIS AFTERNOON WITH JUST
SLIGHT CHANCE (20%) OVER SOUTHEAST IL FROM I-70 SE. VERY WARM AND
HUMID TODAY WITH HIGHS IN THE UPPER 80S AND LOWER 90S WITH
DEWPOINTS IN THE LOWER 70S.
AREA OF SHOWERS AND ISOLATED THUNDERSTORMS IS WEAKENING AS IT
PRESSED SE INTO CENTRAL IL DURING THIS MORNING WITH LEADING EDGE
OF LIGHTER SHOWERS AS FAR SOUTH AS I-72 WITH A FEW THUNDERSTORMS
RECENTLY AROUND PEORIA. MODELS GENERALLY KEEP AREAS SE OF I-70 DRY
THROUGH SUNSET WHILE TRYING TO DEVELOP MORE ISOLATED TO SCATTERED
CONVECTION IN UNSTABLE AIRMASS THIS AFTERNOON OVER PARTS OF
CENTRAL IL. SLIGHT RISK OF SEVERE STORMS IS OVER IA AND NORTHERN
INDIANA AND COULD BE EXTENDED INTO NE IL BY CHICAGO. SPC HAS 5%
RISK OF DAMAGING WIND GUSTS AND LARGE HAIL FROM I-72 NORTH SO
CHANCES ARE VERY SMALL.
07
&&
.AVIATION...
ISSUED 647 AM CDT MON JUL 8 2013
BAND OF SHOWERS AND ISOLATED STORMS MOVING THROUGH CENTRAL
ILLINOIS EARLY THIS MORNING. CURRENTLY LOOKS LIKE MOST OF THE
STORMS WILL PASS NORTH OF KPIA OVER THE NEXT HOUR OR TWO...BUT
MORE EXPECTED TO DEVELOP LATER THIS MORNING. CONFIDENCE IN
PLACEMENT OF ANY STORMS IS NOT VERY HIGH AT THE MOMENT...AS THERE
IS POOR MODEL AGREEMENT IN ANY PARTICULAR TREND...SO HAVE GONE
WITH MAINLY VCSH/VCTS MUCH OF THE DAY. THERE WILL PROBABLY BE A
PERIOD OF DRIER CONDITIONS MUCH OF THE EVENING AND OVERNIGHT...
HOWEVER A CONVECTIVE COMPLEX IS EXPECTED TO DEVELOP OVER
MINNESOTA/IOWA TONIGHT...AND MAY AFFECT KPIA TOWARD SUNRISE.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 300 AM CDT MON JUL 8 2013
WARM AND HUMID CONDITIONS WITH PERIODIC CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL PREVAIL FOR THE NEXT COUPLE OF DAYS...BEFORE
COOLER AND DRIER WEATHER ARRIVES BY THE END OF THE WEEK.
07Z/2AM SURFACE ANALYSIS SHOWS LOW PRESSURE CENTERED OVER WESTERN
WISCONSIN...WITH NEARLY STATIONARY BOUNDARY EXTENDING SOUTHWESTWARD
INTO NEBRASKA. CONVECTION HAS DEVELOPED ALONG THIS BOUNDARY...AIDED
BY A SUBTLE 500MB SHORT-WAVE OVER MINNESOTA AND A 30-35KT 850MB
JET FROM THE SOUTHERN PLAINS INTO IOWA.
SHORT TERM...TODAY THROUGH WEDNESDAY
00Z MODELS ARE PERFORMING VERY POORLY THUS FAR...WITH NONE OF THEM
ADEQUATELY SHOWING THE CURRENT CONVECTION TO THE N/NW OF ILLINOIS.
ONLY THE 05Z HRRR HAS A REASONABLE HANDLE ON THE SITUATION...SO
WILL FOLLOW ITS SOLUTION CLOSELY FOR THE IMMEDIATE SHORT-TERM
FORECAST. HRRR SHOWS A LINE OF SHOWERS AND THUNDERSTORMS
DEVELOPING ACROSS EASTERN IOWA/FAR NORTHERN MISSOURI OVER THE NEXT
COUPLE OF HOURS...THEN PUSHES THE LINE INTO THE NORTHERN KILX CWA
AFTER 10Z. GIVEN 30KT LOW-LEVEL JET ORIENTED FROM KANSAS E/NE
INTO WESTERN ILLINOIS THIS MORNING...THINK THIS IS A PLAUSIBLE
SOLUTION. RADAR MOSAIC IS ALREADY SHOWING A BROKEN LINE OF
CONVECTION DEVELOPING ALONG/WEST OF THE MISSISSIPPI RIVER...SO
HAVE BUMPED POPS TO LIKELY ALONG AND NORTHWEST OF A RUSHVILLE TO
BLOOMINGTON-NORMAL LINE THIS MORNING. AS LOW-LEVEL JET WEAKENS AND
SHIFTS BACK WESTWARD...SHOWERS/THUNDER WILL TEND TO DISSIPATE
LATER THIS MORNING AS IT SAGS SOUTHEASTWARD TOWARD THE I-72
CORRIDOR. WILL CARRY CHANCE POPS AS FAR SOUTH AS A SPRINGFIELD TO
MATTOON LINE ACCORDINGLY...WITH ONLY SLIGHT CHANCES FOR ISOLATED
THUNDER ACROSS THE FAR SE CWA THIS AFTERNOON. WILL BE A VERY WARM
AND HUMID DAY...WITH HIGHS REACHING THE UPPER 80S AND LOWER 90S.
LOW PRESSURE WILL TRACK THROUGH THE GREAT LAKES TONIGHT...WITH
TRAILING FRONTAL BOUNDARY SINKING SLIGHTLY FURTHER SOUTHWARD TO
NEAR THE ILLINOIS/WISCONSIN BORDER. SCATTERED SHOWERS/THUNDER WILL
PERSIST NEAR THE BOUNDARY...RESULTING IN LOW CHANCE POPS FOR THE
NORTHERN TWO-THIRDS OF THE CWA TONIGHT. FURTHER SOUTH...LITTLE OR
NO PRECIP IS ANTICIPATED ALONG/SOUTH OF I-70. AS LOW-LEVEL JET
STRENGTHENS AND SHORT-WAVE CURRENTLY OVER UTAH TRACKS E/NE INTO
THE NORTHERN PLAINS...AN MCS WILL LIKELY DEVELOP OVER SOUTHERN
MINNESOTA/NORTHERN IOWA LATE TONIGHT. TRAJECTORIES TAKE THIS
SYSTEM MAINLY EASTWARD ACROSS WISCONSIN AND NORTHERN ILLINOIS
TUESDAY MORNING. THINK BULK OF THE CONVECTION WILL REMAIN JUST
NORTH OF CENTRAL ILLINOIS...PRIMARILY ALONG/NORTH OF I-80. WILL
FEATURE HIGHEST POPS ACROSS THE NORTHERN CWA ACCORDINGLY...WITH
ONLY LOW CHANCE TO SLIGHT CHANCE POPS ACROSS THE CENTRAL AND
SOUTHERN ZONES. MAIN STORY ON TUESDAY WILL BE THE HEAT AND
HUMIDITY. AFTERNOON HIGH TEMPERATURES IN THE LOWER 90S COMBINED
WITH DEWPOINTS IN THE LOWER TO MIDDLE 70S...WILL RESULT IN HEAT
INDEX VALUES APPROACHING 100 DEGREES.
BEST CHANCE FOR WIDESPREAD CONVECTION STILL ON TARGET FOR TUESDAY
NIGHT INTO WEDNESDAY...AS NORTHERN STREAM WAVE CURRENTLY OVER THE
PACIFIC NORTHWEST PUSHES COLD FRONT SOUTHWARD INTO CENTRAL
ILLINOIS. WITH FRONT INTERACTING WITH A VERY MOIST AIR MASS
CHARACTERIZED BY PRECIPITABLE WATER VALUES IN EXCESS OF 2
INCHES...WILL CONTINUE TO FEATURE LIKELY POPS WITH FROPA. SEVERE
WEATHER THREAT REMAINS UNCERTAIN...HOWEVER LOCALLY HEAVY RAINFALL
WILL BE A GOOD BET WITH THE STORMS LATE TUESDAY NIGHT INTO WEDNESDAY.
FRONT WILL DROP SOUTHWARD INTO THE OHIO RIVER VALLEY BY WEDNESDAY
EVENING...ENDING THE THREAT FOR RAIN FROM NORTH TO SOUTH ACROSS
THE AREA. WILL LINGER CHANCE POPS ALONG/SOUTH OF I-70 THROUGH
WEDNESDAY EVENING...THEN WILL GO DRY ACROSS THE BOARD AFTER MIDNIGHT.
LONG TERM...THURSDAY THROUGH SUNDAY
COOLER/DRIER WEATHER WILL PREVAIL THROUGH THE EXTENDED...AS HIGH
PRESSURE BUILDS INTO THE GREAT LAKES. HIGH TEMPERATURES WILL ONLY
REACH THE LOWER TO MIDDLE 80S...WHILE OVERNIGHT LOWS DROP INTO THE
LOWER TO MIDDLE 60S.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
918 AM CDT MON JUL 8 2013
.DISCUSSION...
330 AM CDT
THE FORECAST CHALLENGES ARE PRIMARILY WITHIN THE NEXT 48 HOURS AS
THE AREA HAS BEEN OVERTAKEN BY THE SOUPIEST AIR MASS OF THE
SEASON...IN FACT THE MOST PROLONGED HIGH DEW POINT EPISODE SINCE
THE HEAT WAVE JUST OVER ONE YEAR AGO /JUL 4-7/. WITH THIS COMES
SEVERE STORM AND HEAVY RAIN POTENTIAL...MORE SO ON TUESDAY. IN
ADDITION...THE HIGHEST HEAT INDICES OF THE SEASON ARE
FORECAST...AND WHILE NOT AT ADVISORY CRITERIA THESE LOOK TO
FLIRT WITH 100 DEGREES IN SOME SOUTHERN CWA LOCATIONS ON TUESDAY
AFTERNOON.
SYNOPSIS...THE UPPER LEVEL RIDGE ACROSS THE CENTRAL AND SOUTHERN
PLAINS IS EVOLVING EAST EARLY THIS MORNING WITH TURBULENT MOIST
FLOW AROUND ITS NORTHERN PERIPHERY. NUMEROUS AREAS OF CONVECTION
ARE PRESENT ASSOCIATED WITH SHORT WAVE ASCENT AND MOIST ADVECTION
ON THE LOW-LEVEL JET. A WEAK LOW-LEVEL TROUGH IS PRESENT FROM
NORTHERN WI TO NORTHERN KS. TO THE EAST AND SOUTH OF THIS
FEATURE...UPPER 60S TO MID 70S DEW POINTS PREVAIL ON MOST
OBSERVATIONS ALL THE WAY TO THE ATLANTIC AND GULF COASTS. THE
RIDGE WILL TRY TO EXPAND INTO THE AREA THIS AFTERNOON AND MORE SO
TONIGHT WITH CONTINUED SYNOPTIC SOUTHERLY SURFACE FLOW ACROSS THE
AREA. THE SURFACE TROUGH WILL WORK ITS WAY LIKELY INTO FAR
SOUTHERN WI BY LATE AFTERNOON. TWO SURFACE LOWS LOOK TO RIDE ALONG
THIS...ONE DURING THE DAY TUE ASSOCIATED WITH A STRONG SHORT WAVE
EXITING THE GREAT BASIN EARLY THIS MORNING...AND ANOTHER STRONGER
SURFACE LOW ASSOCIATED WITH AN UPPER TROUGH THAT WILL DEVELOP INTO
THE GREAT LAKES BY LATE TUE NIGHT. THIS SECOND WAVE WILL USHER A
COOL FRONT THROUGH THE AREA WED MORNING WITH THE SOMEWHAT
COOLER/DRIER AIR BEING REALIZED BY WED NIGHT.
THIS MORNING...IT APPEARS THERE ARE TWO IMMEDIATE UPSTREAM SHORT
WAVES...ONE BETTER DEFINED ONE PER WATER VAPOR AND RADAR MOSAIC
ACROSS NORTHEAST IA...AND ANOTHER ACROSS FAR SOUTHERN IA/NORTHERN
MO. TOGETHER THESE WILL MOVE EAST AND LOOK TO SLOWLY
WEAKEN LATER THIS MORNING ACROSS THE EASTERN FORECAST AREA WITH
THE MORE DOMINANT JET TO THE NORTH. PROFILER DATA INDICATES 35 KT
850-925MB FLOW INTO THE AREA WHICH LOOKS TO CONTINUE PAST
DAYBREAK. SO EXPECT THAT SHOWER AND EMBEDDED STORM ACTIVITY WILL
BE SUSTAINED AS FAR EAST AS CHICAGO BY MID-MORNING. THE HRRR SEEMS
TO HAVE A FIRM HANDLE ON THE ONGOING CONVECTION AND ITS EVOLUTION
MAKES SENSE AND HAVE FOLLOWED CLOSELY IN OUR FORECAST HOURLY POPS.
HAVE SEEN A COUPLE 20 KT PLUS GUSTS IN SW WI INDICATING THAT A
COLD POOL MAY BE TRYING TO DEVELOP. THIS AND ANY MCV DEVELOPMENT
WOULD ALSO AID IN SUSTAINING THE ACTIVITY EASTWARD. SEVERE
POTENTIAL IS MAINLY LOW WITH THIS THROUGH THE MORNING AND RADAR
TRENDS FROM ARX/DVN CONFIRM NOTHING POTENT IN THE STORM
BEHAVIORS...THOUGH CANT RULE OUT SMALL HAIL OR GUSTY WINDS. IN
ADDITION...STORMS WILL BE VERY EFFICIENT RAIN PRODUCERS GIVEN HIGH
ATMOSPHERIC MOISTURE CONTENT /PWATS AOA 1.65 INCHES AND 700MB TDS
AOA 4C/.
CONFIDENCE...HIGH.
THIS AFTERNOON AND TONIGHT...WITH THE PRIMARY SHORT WAVE IMPULSES
HAVING MOVED EAST...COVERAGE OF PRECIP SHOULD AT LEAST TEMPORARILY
DIMINISH IN THE EARLY AFTERNOON. OUTFLOW BOUNDARIES FROM THE
MORNING ACTIVITY...EVEN IF ELEVATED COULD CONTINUE FESTERING
CONVECTION THIS AFTERNOON GIVEN ATTAINABLE CONVECTIVE TEMPS. THIS
WOULD SEEM MOST FAVORED ALONG AND SOUTH OF I-80. THE SURFACE
BOUNDARY WILL BE NEAR THE IL/WI STATE LINE...AND SIMILAR TO PREV
FORECAST REASONING COULD SEE SOME SCATTERED DEVELOPMENT LATER THIS
AFTERNOON ALONG THAT AS WELL. AFTER WHAT WILL LIKELY BE A SLOW
TEMPERATURE CLIMB THIS MORNING...THIS AFTERNOON SHOULD SEE
RECOVERY INTO THE UPPER 80S AND MAYBE EVEN 90...ESPECIALLY ACROSS
THE WESTERN HALF OF THE FORECAST AREA. WITH SUCH HIGH DEW POINT
AIR...SURFACE BASED INSTABILITY OF 1500-2500 J/KG WOULD BE
SUPPORTED BY THESE FORECAST TEMPS AND DEW POINTS. MOST GUIDANCE
DOES HAVE A SPLOTCHY QPF PRODUCED OVER THE AREA. ANY SCATTERED
CONVECTION THAT CAN DEVELOP THIS AFTERNOON INTO THE EVE WOULD HAVE
SOME SEVERE WEATHER THREAT. THE HIGH PWAT AIR WILL SUPPORT HEAVY
RAIN ALONG WITH PRECIP LOADING CONCERNS TOWARDS ISOLATED DOWNBURSTS
IN ANY MORE ROBUST CELLS OR MULTI-CELL CLUSTERS...BUT OVERALL
THREAT COVERAGE IS LOW. AS WE HEAD TO AFTER SUNDOWN...HEIGHT
FALLS AND THE LLJ NOSE CONTINUE TO BE FOCUSED TO THE NORTHWEST OF
THE AREA /OVER MN AND NORTHERN IA/. THIS IS WHERE LIKELY MCS
DEVELOPMENT WILL OCCUR LATE. IN ADVANCE...BROAD WARM AND MOIST
ADVECTION ALOFT MAY ALLOW FOR ISOLATED TO SCATTERED CONVECTIVE
DEVELOPMENT OVER THE AREA. DEEP WARM CLOUD PROCESSES WILL BE AT
PLAY WITH PWATS CONTINUING TO INCH UP...MEANING HEAVY RAIN WILL BE
THE GREATEST THREAT. GIVEN A SOMEWHAT DIFFUSE 850MB BAROCLINIC
ZONE AND FORWARD PROPAGATION INDICATED...THE TRAINING SETUP IS
SOMEWHAT MARGINAL IN THE FORECAST AREA AT LEAST PRIOR TO DAYBREAK
TUE. SO NO FLASH FLOOD WATCH BEING ISSUED AT THIS TIME BUT THIS
WILL NEED TO BE MONITORED.
CONFIDENCE...MEDIUM.
TUESDAY AND TUESDAY NIGHT...THESE ARE THE PERIODS WITH THE GREATER
POTENTIAL FOR HIGHER IMPACT WEATHER. MANY MODELS IN THE SUITE OF
GUIDANCE CONTINUE TO ADVERTISE A PRIMARY MCS DEVELOPING BY TUE
MORNING AHEAD OF A STRONG IMPULSE. THERE ARE VARIANCES IN
LATITUDE ON THIS...BUT CERTAINLY THE PATTERN WOULD SUPPORT SUCH
EVOLUTION WITH AMPLE INSTABILITY AHEAD OF AN MCS EVEN IN THE
MORNING GIVEN THE HIGH ABSOLUTE MOISTURE. THE SPC HAS OUTLOOKED A
30 PERCENT AREA FOR THEIR DAY TWO OUTLOOK FOR THIS REASON AND THE
AREA THEY INDICATED IS WHAT HAS BEEN FAVORED IN OUR FORECAST. IT
IS INTERESTING TO NOTE THAT THE CIPS ANALOG GUIDANCE FOR MULTIPLE
DAYS HAS INDICATED MATCHES ON SEVERE WIND EVENTS FROM NORTHERN IA
INTO SOUTHERN WI AND FAR NORTHERN IL AND CONTINUES TO DO SUCH
BASED ON THE NAM FORECAST. SO THE MOST FAVORED AREA WOULD LIKELY
BE NORTH OF I-80...AND MAYBE EVEN NORTH OF I-88 FOR POTENTIALLY A
STRONG WIND COMPLEX ON TUE. SOME OF THE SLOWER GUIDANCE HAS THIS
EVEN HAPPENING IN THE AFTERNOON. CONFIDENCE ON EXACT DEVELOPMENT
BY AFTERNOON AND NIGHTTIME DROPS...ESPECIALLY IF ANYTHING CAN
SPARK OFF OUTFLOWS. CERTAINLY A SEVERE WEATHER POTENTIAL EXISTS
THROUGH THE REST OF THE DAY WITH GRADUALLY INCREASING DEEP LAYER
SHEAR AND PLENTY OF INSTABILITY. THE SOUTHERN FORECAST AREA COULD
WARM INTO THE LOWER TO MID 90S. RIGHT NOW HEAD INDICES ARE
FORECAST AROUND 100 FOR MULTIPLE AFTERNOON HOURS IN THE SOUTHERN
FORECAST AREA...WHILE AROUND THE MID 90S IN ROCKFORD AND CHICAGO
THOUGH CONFIDENCE THERE IS LOW BASED ON PROBABLE MORNING/EARLY
AFTERNOON CONVECTION. HAVE MENTIONED HEAVY RAIN IN THE FORECAST
FOR TUE AND TUE NIGHT GIVEN THE ATMOSPHERIC SETUP AND DO HAVE CHC
SEVERE MENTIONED IN FAR NORTHERN IL GIVEN THE CONSISTENT SIGNAL
AND PATTERN SUPPORT FOR AT THE LEAST A NEARBY MCS.
CONFIDENCE...OVERALL MEDIUM.
WEDNESDAY...THE COOL FRONT...OR AT LEAST THE WIND SHIFT IS MAINLY
AGREED ON BY GUIDANCE TO BE MOVING SOUTHEAST THROUGH THE AREA
EARLY WED. THE COOLER TEMPERATURES IN THE MIX DOWN LAYER LOOK TO
ARRIVE LATE IN THE AFTERNOON INTO THE EVE...SO HIGHS IN THE MID TO
UPPER 80S ARE STILL FORECAST. SOME ONGOING CONVECTION IS LIKELY
IN THE SOUTHEAST CWA AT LEAST ON WED MORNING...THOUGH COVERAGE IS
TOUGH TO TELL AT THIS POINT. DEW POINTS LOOK TO FALL BY WED EVE.
CONFIDENCE...HIGH.
EXTENDED...HAVE NOT MADE TOO MANY CHANGES FROM A SMART BLEND OF
GUIDANCE WITH GOING FORECAST. THIS PERIOD LOOKS MAINLY QUIET AS
THE PATTERN EVOLVES THROUGH THE WEEKEND TO ONCE AGAIN A BLOCKED
SETUP. SURFACE HIGH PRESSURE LOOKS TO PREVAIL WITH ONSHORE FLOW
INTO CHICAGOLAND AND NORTHWEST INDIANA. THIS SHOULD OFFER ONLY
MINIMAL COOLING THOUGH WITH BASICALLY TEMPERATURES AT OR JUST
BELOW SEASONAL NORMALS IN MOST PLACES.
CONFIDENCE...HIGH.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* CLUSTERS OF TSRA NOW TIL AROUND 16Z WITH BRIEF IFR VSBY.
* SOUTH-SOUTHWEST WINDS TURN TO WEST-SOUTHWEST SOMETIME EARLY THIS
AFTERNOON.
* LOW CHANCE FOR ADDITIONAL SHRA/TSRA THIS AFTERNOON.
* ANOTHER ROUND OF SHRA/TSRA POSSIBLE EARLY TUESDAY MORNING.
MDB
//DISCUSSION...UPDATED 14Z...
NEW BAND OF TSRA CLUSTERS CONTINUES TO MOVE EAST-SOUTHEAST INTO
THE CHI METRO AREA AND WILL BE AFFECTING THE TERMINALS THROUGH
16/17Z AND PROBABLY SLIGHTLY LONGER AT GYY. RFD SHOULD BE CLEAR OF
ACTIVITY BY 15Z AS UPPER WAVE RESPONSIBLE FOR THE ACTIVITY EXITS
TO THE EAST. EXPECT THAT THERE WILL A LULL IN ACTIVITY EARLY/MID
AFTERNOON BUT SOME LOW CHANCE WILL CONTINUE. LESS CONFIDENT LATER
THIS AFTERNOON AS WE WILL BE UNSTABLE AND A FRONTAL BOUNDARY WILL
BE SAGGING SOUTHWARD ACROSS SOUTHERN WI BUT ANY FOCUS FOR
DEVELOPMENT OVER THE IMMEDIATE AREA LOOKS TO BE ABSENT. NEEDED TO
REMOVE PROB30 FOR TSRA THIS AFTERNOON AS WE ENTERED THE FIRST 9
HOURS OF THE FORECAST WHERE IT CANNOT BE USED...BUT POTENTIAL FOR
TSRA REMAINS AROUND 30 PERCENT. OTHER CONCERN IS WINDS...WINDS
HAVE BECOME A BIT VARIABLE BETWEEN SOUTH AND SOUTHWEST AND NEAR
TERM TRENDS SUPPORT A MORE SOUTHERLY DIRECTION WITH WEST-SOUTHWEST
WINDS ARRIVING THIS AFTERNOON. ITS UNCLEAR HOW QUICKLY WINDS WILL
SHIFT DUE TO THE ONGOING SHRA/TSRA.
MDB
FROM 12Z...
SHOWERS WITH ISOLATED TS CURRENTLY PUSHING ACROSS TERMINALS THIS
MORNING AS LARGE AREA OF PRECIP SPANNING MUCH OF THE REGION SHIFTS
EAST. ALTHOUGH COVERAGE OF THIS PRECIP HAS HELD TOGETHER...THE
OVERALL CONVECTIVE NATURE OF THIS SYSTEM HAS DIMINISHED OVER THE
LAST ONE TO TWO HOURS WITH LIGHTNING BECOMING MORE LIMITED.
NONETHELESS...HAVE OBSERVED A PERIODIC LIGHTNING STRIKE WITH THIS
AREA OF PRECIP OVER THE LAST HOUR...AND SO HAVE MAINTAINED THE
TEMPO GROUP FOR TS OVER THE NEXT COUPLE OF HOURS BEFORE THIS
PRECIP CONTINUES TO SHIFT EAST OF THE TERMINALS. ALTHOUGH A BRIEF
DRY PERIOD WILL BE OBSERVED WITH THE DEPARTURE OF THIS MORNINGS
PRECIP...DO THINK THAT SCATTERED DEVELOPMENT WILL REMAIN POSSIBLE
THIS AFTERNOON BUT WITH CONFIDENCE LOWER WITH REGARDS TO COVERAGE
AS WELL AS INTENSITY. MOST OF THIS EVENING AND OVERNIGHT SHOULD
REMAIN DRY...BUT WILL NEED TO CONTINUE MONITORING ANY DEVELOPMENT
WEST OF THE REGION TONIGHT AS THIS PRECIP WILL BE CAPABLE OF
SHIFTING EAST TOWARDS THE TERMINALS LATE TONIGHT EARLY TUESDAY
MORNING AND COULD HAVE IMPACTS FOR THE TERMINALS.
SOUTHWEST WEST WINDS WILL BE LIKELY TODAY WITH GUSTS INCREASING TO
THE UPPER TEENS TODAY...BEFORE DIMINISHING THIS EVENING. THERE HAS
BEEN A SLIGHT INCREASE IN GUSTS TO AROUND 20 KT MORE FROM A
WESTERLY DIRECTION WITH THESE SHOWERS THIS MORNING. HAVE ADJUSTED
THE TAFS TO REFLECT THIS POSSIBILITY AND TRENDS...BUT WITH THIS
REMAINING BRIEF.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN TSRA CLUSTERS TIL AROUND 16Z...WITH BRIEF IFR
VSBY.
* MEDIUM CONFIDENCE IN SOUTH-SOUTHWEST WINDS TURNING WEST-
SOUTHWEST...LOW-MEDIUM CONFIDENCE IN TIMING.
* MEDIUM CONFIDENCE THAT POTENTIAL FOR ADDITIONAL SHRA/TSRA THIS
AFTERNOON IS LOW.
* LOW CONFIDENCE IN SHRA/TSRA TIMING/COVERAGE TUESDAY MORNING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...LIKELY TSRA. MVFR/GUSTY WINDS POSSIBLE.
WEDNESDAY...CHANCE OF TSRA...OTHERWISE VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
RODRIGUEZ
&&
.MARINE...
425 AM CDT
AS AN AREA OF LOW PRESSURE OVER THE UPPER MISSISSIPPI VALLEY
SHIFTS EAST TOWARDS THE LAKE THIS MORNING...SOUTH TO SOUTHEAST
WINDS OF 10 TO 20 KT ARE BEING OBSERVED ACROSS THE LAKE. WITH THIS
LOW CONTINUING ACROSS THE LAKE TODAY...EXPECT FAIRLY DIFFERENT
CONDITIONS FROM THE NORTH HALF TO THE SOUTH HALF. WITH THIS LOW
MOVING THROUGH AND A BOUNDARY LEFT OVER THE LAKE...THE NORTHERN
HALF OF THE LAKE WILL OBSERVE WINDS SHIFTING TO THE NORTHEAST AND
EAST TODAY/TONIGHT WHILE THE SOUTHERN HALF REMAINS SOUTHWEST AND
WEST. AN EASTERLY COMPONENT TO THE WIND LATE TONIGHT INTO TUESDAY
WILL ONCE AGAIN TURN MORE SOUTHERLY AS NEW LOW PRESSURE DEVELOPS
TO THE WEST. SPEEDS WILL INCREASE TO 10 TO 20 KT ON TUESDAY BEFORE
TURNING TO THE SOUTHWEST AND WEST TUESDAY NIGHT...BEFORE A PERIOD
OF NORTHERLY WINDS SETTLES IN ON WEDNESDAY THROUGH THE REMAINDER
OF THE FORECAST PERIOD.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
705 AM CDT MON JUL 8 2013
.DISCUSSION...
330 AM CDT
THE FORECAST CHALLENGES ARE PRIMARILY WITHIN THE NEXT 48 HOURS AS
THE AREA HAS BEEN OVERTAKEN BY THE SOUPIEST AIR MASS OF THE
SEASON...IN FACT THE MOST PROLONGED HIGH DEW POINT EPISODE SINCE
THE HEAT WAVE JUST OVER ONE YEAR AGO /JUL 4-7/. WITH THIS COMES
SEVERE STORM AND HEAVY RAIN POTENTIAL...MORE SO ON TUESDAY. IN
ADDITION...THE HIGHEST HEAT INDICES OF THE SEASON ARE
FORECAST...AND WHILE NOT AT ADVISORY CRITERIA THESE LOOK TO
FLIRT WITH 100 DEGREES IN SOME SOUTHERN CWA LOCATIONS ON TUESDAY
AFTERNOON.
SYNOPSIS...THE UPPER LEVEL RIDGE ACROSS THE CENTRAL AND SOUTHERN
PLAINS IS EVOLVING EAST EARLY THIS MORNING WITH TURBULENT MOIST
FLOW AROUND ITS NORTHERN PERIPHERY. NUMEROUS AREAS OF CONVECTION
ARE PRESENT ASSOCIATED WITH SHORT WAVE ASCENT AND MOIST ADVECTION
ON THE LOW-LEVEL JET. A WEAK LOW-LEVEL TROUGH IS PRESENT FROM
NORTHERN WI TO NORTHERN KS. TO THE EAST AND SOUTH OF THIS
FEATURE...UPPER 60S TO MID 70S DEW POINTS PREVAIL ON MOST
OBSERVATIONS ALL THE WAY TO THE ATLANTIC AND GULF COASTS. THE
RIDGE WILL TRY TO EXPAND INTO THE AREA THIS AFTERNOON AND MORE SO
TONIGHT WITH CONTINUED SYNOPTIC SOUTHERLY SURFACE FLOW ACROSS THE
AREA. THE SURFACE TROUGH WILL WORK ITS WAY LIKELY INTO FAR
SOUTHERN WI BY LATE AFTERNOON. TWO SURFACE LOWS LOOK TO RIDE ALONG
THIS...ONE DURING THE DAY TUE ASSOCIATED WITH A STRONG SHORT WAVE
EXITING THE GREAT BASIN EARLY THIS MORNING...AND ANOTHER STRONGER
SURFACE LOW ASSOCIATED WITH AN UPPER TROUGH THAT WILL DEVELOP INTO
THE GREAT LAKES BY LATE TUE NIGHT. THIS SECOND WAVE WILL USHER A
COOL FRONT THROUGH THE AREA WED MORNING WITH THE SOMEWHAT
COOLER/DRIER AIR BEING REALIZED BY WED NIGHT.
THIS MORNING...IT APPEARS THERE ARE TWO IMMEDIATE UPSTREAM SHORT
WAVES...ONE BETTER DEFINED ONE PER WATER VAPOR AND RADAR MOSAIC
ACROSS NORTHEAST IA...AND ANOTHER ACROSS FAR SOUTHERN IA/NORTHERN
MO. TOGETHER THESE WILL MOVE EAST AND LOOK TO SLOWLY
WEAKEN LATER THIS MORNING ACROSS THE EASTERN FORECAST AREA WITH
THE MORE DOMINANT JET TO THE NORTH. PROFILER DATA INDICATES 35 KT
850-925MB FLOW INTO THE AREA WHICH LOOKS TO CONTINUE PAST
DAYBREAK. SO EXPECT THAT SHOWER AND EMBEDDED STORM ACTIVITY WILL
BE SUSTAINED AS FAR EAST AS CHICAGO BY MID-MORNING. THE HRRR SEEMS
TO HAVE A FIRM HANDLE ON THE ONGOING CONVECTION AND ITS EVOLUTION
MAKES SENSE AND HAVE FOLLOWED CLOSELY IN OUR FORECAST HOURLY POPS.
HAVE SEEN A COUPLE 20 KT PLUS GUSTS IN SW WI INDICATING THAT A
COLD POOL MAY BE TRYING TO DEVELOP. THIS AND ANY MCV DEVELOPMENT
WOULD ALSO AID IN SUSTAINING THE ACTIVITY EASTWARD. SEVERE
POTENTIAL IS MAINLY LOW WITH THIS THROUGH THE MORNING AND RADAR
TRENDS FROM ARX/DVN CONFIRM NOTHING POTENT IN THE STORM
BEHAVIORS...THOUGH CANT RULE OUT SMALL HAIL OR GUSTY WINDS. IN
ADDITION...STORMS WILL BE VERY EFFICIENT RAIN PRODUCERS GIVEN HIGH
ATMOSPHERIC MOISTURE CONTENT /PWATS AOA 1.65 INCHES AND 700MB TDS
AOA 4C/.
CONFIDENCE...HIGH.
THIS AFTERNOON AND TONIGHT...WITH THE PRIMARY SHORT WAVE IMPULSES
HAVING MOVED EAST...COVERAGE OF PRECIP SHOULD AT LEAST TEMPORARILY
DIMINISH IN THE EARLY AFTERNOON. OUTFLOW BOUNDARIES FROM THE
MORNING ACTIVITY...EVEN IF ELEVATED COULD CONTINUE FESTERING
CONVECTION THIS AFTERNOON GIVEN ATTAINABLE CONVECTIVE TEMPS. THIS
WOULD SEEM MOST FAVORED ALONG AND SOUTH OF I-80. THE SURFACE
BOUNDARY WILL BE NEAR THE IL/WI STATE LINE...AND SIMILAR TO PREV
FORECAST REASONING COULD SEE SOME SCATTERED DEVELOPMENT LATER THIS
AFTERNOON ALONG THAT AS WELL. AFTER WHAT WILL LIKELY BE A SLOW
TEMPERATURE CLIMB THIS MORNING...THIS AFTERNOON SHOULD SEE
RECOVERY INTO THE UPPER 80S AND MAYBE EVEN 90...ESPECIALLY ACROSS
THE WESTERN HALF OF THE FORECAST AREA. WITH SUCH HIGH DEW POINT
AIR...SURFACE BASED INSTABILITY OF 1500-2500 J/KG WOULD BE
SUPPORTED BY THESE FORECAST TEMPS AND DEW POINTS. MOST GUIDANCE
DOES HAVE A SPLOTCHY QPF PRODUCED OVER THE AREA. ANY SCATTERED
CONVECTION THAT CAN DEVELOP THIS AFTERNOON INTO THE EVE WOULD HAVE
SOME SEVERE WEATHER THREAT. THE HIGH PWAT AIR WILL SUPPORT HEAVY
RAIN ALONG WITH PRECIP LOADING CONCERNS TOWARDS ISOLATED DOWNBURSTS
IN ANY MORE ROBUST CELLS OR MULTI-CELL CLUSTERS...BUT OVERALL
THREAT COVERAGE IS LOW. AS WE HEAD TO AFTER SUNDOWN...HEIGHT
FALLS AND THE LLJ NOSE CONTINUE TO BE FOCUSED TO THE NORTHWEST OF
THE AREA /OVER MN AND NORTHERN IA/. THIS IS WHERE LIKELY MCS
DEVELOPMENT WILL OCCUR LATE. IN ADVANCE...BROAD WARM AND MOIST
ADVECTION ALOFT MAY ALLOW FOR ISOLATED TO SCATTERED CONVECTIVE
DEVELOPMENT OVER THE AREA. DEEP WARM CLOUD PROCESSES WILL BE AT
PLAY WITH PWATS CONTINUING TO INCH UP...MEANING HEAVY RAIN WILL BE
THE GREATEST THREAT. GIVEN A SOMEWHAT DIFFUSE 850MB BAROCLINIC
ZONE AND FORWARD PROPAGATION INDICATED...THE TRAINING SETUP IS
SOMEWHAT MARGINAL IN THE FORECAST AREA AT LEAST PRIOR TO DAYBREAK
TUE. SO NO FLASH FLOOD WATCH BEING ISSUED AT THIS TIME BUT THIS
WILL NEED TO BE MONITORED.
CONFIDENCE...MEDIUM.
TUESDAY AND TUESDAY NIGHT...THESE ARE THE PERIODS WITH THE GREATER
POTENTIAL FOR HIGHER IMPACT WEATHER. MANY MODELS IN THE SUITE OF
GUIDANCE CONTINUE TO ADVERTISE A PRIMARY MCS DEVELOPING BY TUE
MORNING AHEAD OF A STRONG IMPULSE. THERE ARE VARIANCES IN
LATITUDE ON THIS...BUT CERTAINLY THE PATTERN WOULD SUPPORT SUCH
EVOLUTION WITH AMPLE INSTABILITY AHEAD OF AN MCS EVEN IN THE
MORNING GIVEN THE HIGH ABSOLUTE MOISTURE. THE SPC HAS OUTLOOKED A
30 PERCENT AREA FOR THEIR DAY TWO OUTLOOK FOR THIS REASON AND THE
AREA THEY INDICATED IS WHAT HAS BEEN FAVORED IN OUR FORECAST. IT
IS INTERESTING TO NOTE THAT THE CIPS ANALOG GUIDANCE FOR MULTIPLE
DAYS HAS INDICATED MATCHES ON SEVERE WIND EVENTS FROM NORTHERN IA
INTO SOUTHERN WI AND FAR NORTHERN IL AND CONTINUES TO DO SUCH
BASED ON THE NAM FORECAST. SO THE MOST FAVORED AREA WOULD LIKELY
BE NORTH OF I-80...AND MAYBE EVEN NORTH OF I-88 FOR POTENTIALLY A
STRONG WIND COMPLEX ON TUE. SOME OF THE SLOWER GUIDANCE HAS THIS
EVEN HAPPENING IN THE AFTERNOON. CONFIDENCE ON EXACT DEVELOPMENT
BY AFTERNOON AND NIGHTTIME DROPS...ESPECIALLY IF ANYTHING CAN
SPARK OFF OUTFLOWS. CERTAINLY A SEVERE WEATHER POTENTIAL EXISTS
THROUGH THE REST OF THE DAY WITH GRADUALLY INCREASING DEEP LAYER
SHEAR AND PLENTY OF INSTABILITY. THE SOUTHERN FORECAST AREA COULD
WARM INTO THE LOWER TO MID 90S. RIGHT NOW HEAD INDICES ARE
FORECAST AROUND 100 FOR MULTIPLE AFTERNOON HOURS IN THE SOUTHERN
FORECAST AREA...WHILE AROUND THE MID 90S IN ROCKFORD AND CHICAGO
THOUGH CONFIDENCE THERE IS LOW BASED ON PROBABLE MORNING/EARLY
AFTERNOON CONVECTION. HAVE MENTIONED HEAVY RAIN IN THE FORECAST
FOR TUE AND TUE NIGHT GIVEN THE ATMOSPHERIC SETUP AND DO HAVE CHC
SEVERE MENTIONED IN FAR NORTHERN IL GIVEN THE CONSISTENT SIGNAL
AND PATTERN SUPPORT FOR AT THE LEAST A NEARBY MCS.
CONFIDENCE...OVERALL MEDIUM.
WEDNESDAY...THE COOL FRONT...OR AT LEAST THE WIND SHIFT IS MAINLY
AGREED ON BY GUIDANCE TO BE MOVING SOUTHEAST THROUGH THE AREA
EARLY WED. THE COOLER TEMPERATURES IN THE MIX DOWN LAYER LOOK TO
ARRIVE LATE IN THE AFTERNOON INTO THE EVE...SO HIGHS IN THE MID TO
UPPER 80S ARE STILL FORECAST. SOME ONGOING CONVECTION IS LIKELY
IN THE SOUTHEAST CWA AT LEAST ON WED MORNING...THOUGH COVERAGE IS
TOUGH TO TELL AT THIS POINT. DEW POINTS LOOK TO FALL BY WED EVE.
CONFIDENCE...HIGH.
EXTENDED...HAVE NOT MADE TOO MANY CHANGES FROM A SMART BLEND OF
GUIDANCE WITH GOING FORECAST. THIS PERIOD LOOKS MAINLY QUIET AS
THE PATTERN EVOLVES THROUGH THE WEEKEND TO ONCE AGAIN A BLOCKED
SETUP. SURFACE HIGH PRESSURE LOOKS TO PREVAIL WITH ONSHORE FLOW
INTO CHICAGOLAND AND NORTHWEST INDIANA. THIS SHOULD OFFER ONLY
MINIMAL COOLING THOUGH WITH BASICALLY TEMPERATURES AT OR JUST
BELOW SEASONAL NORMALS IN MOST PLACES.
CONFIDENCE...HIGH.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* SHOWERS WITH ISOLATED TS THROUGH 15Z...WITH POSSIBLE LOWER VIS.
* CHANCES FOR SHOWERS AND POSSIBLE TS ONCE AGAIN LATER THIS
AFTERNOON.
* ANOTHER ROUND OF SHOWERS/THUNDERSTORMS POSSIBLE EARLY TUESDAY
MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
SHOWERS WITH ISOLATED TS CURRENTLY PUSHING ACROSS TERMINALS THIS
MORNING AS LARGE AREA OF PRECIP SPANNING MUCH OF THE REGION SHIFTS
EAST. ALTHOUGH COVERAGE OF THIS PRECIP HAS HELD TOGETHER...THE
OVERALL CONVECTIVE NATURE OF THIS SYSTEM HAS DIMINISHED OVER THE
LAST ONE TO TWO HOURS WITH LIGHTNING BECOMING MORE LIMITED.
NONETHELESS...HAVE OBSERVED A PERIODIC LIGHTNING STRIKE WITH THIS
AREA OF PRECIP OVER THE LAST HOUR...AND SO HAVE MAINTAINED THE
TEMPO GROUP FOR TS OVER THE NEXT COUPLE OF HOURS BEFORE THIS
PRECIP CONTINUES TO SHIFT EAST OF THE TERMINALS. ALTHOUGH A BRIEF
DRY PERIOD WILL BE OBSERVED WITH THE DEPARTURE OF THIS MORNINGS
PRECIP...DO THINK THAT SCATTERED DEVELOPMENT WILL REMAIN POSSIBLE
THIS AFTERNOON BUT WITH CONFIDENCE LOWER WITH REGARDS TO COVERAGE
AS WELL AS INTENSITY. MOST OF THIS EVENING AND OVERNIGHT SHOULD
REMAIN DRY...BUT WILL NEED TO CONTINUE MONITORING ANY DEVELOPMENT
WEST OF THE REGION TONIGHT AS THIS PRECIP WILL BE CAPABLE OF
SHIFTING EAST TOWARDS THE TERMINALS LATE TONIGHT EARLY TUESDAY
MORNING AND COULD HAVE IMPACTS FOR THE TERMINALS.
SOUTHWEST WEST WINDS WILL BE LIKELY TODAY WITH GUSTS INCREASING TO
THE UPPER TEENS TODAY...BEFORE DIMINISHING THIS EVENING. THERE HAS
BEEN A SLIGHT INCREASE IN GUSTS TO AROUND 20 KT MORE FROM A
WESTERLY DIRECTION WITH THESE SHOWERS THIS MORNING. HAVE ADJUSTED
THE TAFS TO REFLECT THIS POSSIBILITY AND TRENDS...BUT WITH THIS
REMAINING BRIEF.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE WITH SHOWERS/TS TRENDS THIS MORNING.
* LOW MEDIUM CONFIDENCE WITH SHOWERS/TS COVERAGE AND TIMING LATER
THIS AFTERNOON.
* LOW CONFIDENCE WITH SHOWERS/TS EARLY TUESDAY MORNING.
* MEDIUM CONFIDENCE WITH WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...LIKELY TSRA. MVFR/GUSTY WINDS POSSIBLE.
WEDNESDAY...CHANCE OF TSRA...OTHERWISE VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
RODRIGUEZ
&&
.MARINE...
425 AM CDT
AS AN AREA OF LOW PRESSURE OVER THE UPPER MISSISSIPPI VALLEY
SHIFTS EAST TOWARDS THE LAKE THIS MORNING...SOUTH TO SOUTHEAST
WINDS OF 10 TO 20 KT ARE BEING OBSERVED ACROSS THE LAKE. WITH THIS
LOW CONTINUING ACROSS THE LAKE TODAY...EXPECT FAIRLY DIFFERENT
CONDITIONS FROM THE NORTH HALF TO THE SOUTH HALF. WITH THIS LOW
MOVING THROUGH AND A BOUNDARY LEFT OVER THE LAKE...THE NORTHERN
HALF OF THE LAKE WILL OBSERVE WINDS SHIFTING TO THE NORTHEAST AND
EAST TODAY/TONIGHT WHILE THE SOUTHERN HALF REMAINS SOUTHWEST AND
WEST. AN EASTERLY COMPONENT TO THE WIND LATE TONIGHT INTO TUESDAY
WILL ONCE AGAIN TURN MORE SOUTHERLY AS NEW LOW PRESSURE DEVELOPS
TO THE WEST. SPEEDS WILL INCREASE TO 10 TO 20 KT ON TUESDAY BEFORE
TURNING TO THE SOUTHWEST AND WEST TUESDAY NIGHT...BEFORE A PERIOD
OF NORTHERLY WINDS SETTLES IN ON WEDNESDAY THROUGH THE REMAINDER
OF THE FORECAST PERIOD.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
647 AM CDT MON JUL 8 2013
.DISCUSSION...
ISSUED 300 AM CDT MON JUL 8 2013
WARM AND HUMID CONDITIONS WITH PERIODIC CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL PREVAIL FOR THE NEXT COUPLE OF DAYS...BEFORE
COOLER AND DRIER WEATHER ARRIVES BY THE END OF THE WEEK.
07Z/2AM SURFACE ANALYSIS SHOWS LOW PRESSURE CENTERED OVER WESTERN
WISCONSIN...WITH NEARLY STATIONARY BOUNDARY EXTENDING SOUTHWESTWARD
INTO NEBRASKA. CONVECTION HAS DEVELOPED ALONG THIS BOUNDARY...AIDED
BY A SUBTLE 500MB SHORT-WAVE OVER MINNESOTA AND A 30-35KT 850MB
JET FROM THE SOUTHERN PLAINS INTO IOWA.
SHORT TERM...TODAY THROUGH WEDNESDAY
00Z MODELS ARE PERFORMING VERY POORLY THUS FAR...WITH NONE OF THEM
ADEQUATELY SHOWING THE CURRENT CONVECTION TO THE N/NW OF ILLINOIS.
ONLY THE 05Z HRRR HAS A REASONABLE HANDLE ON THE SITUATION...SO
WILL FOLLOW ITS SOLUTION CLOSELY FOR THE IMMEDIATE SHORT-TERM
FORECAST. HRRR SHOWS A LINE OF SHOWERS AND THUNDERSTORMS
DEVELOPING ACROSS EASTERN IOWA/FAR NORTHERN MISSOURI OVER THE NEXT
COUPLE OF HOURS...THEN PUSHES THE LINE INTO THE NORTHERN KILX CWA
AFTER 10Z. GIVEN 30KT LOW-LEVEL JET ORIENTED FROM KANSAS E/NE
INTO WESTERN ILLINOIS THIS MORNING...THINK THIS IS A PLAUSIBLE
SOLUTION. RADAR MOSAIC IS ALREADY SHOWING A BROKEN LINE OF
CONVECTION DEVELOPING ALONG/WEST OF THE MISSISSIPPI RIVER...SO
HAVE BUMPED POPS TO LIKELY ALONG AND NORTHWEST OF A RUSHVILLE TO
BLOOMINGTON-NORMAL LINE THIS MORNING. AS LOW-LEVEL JET WEAKENS AND
SHIFTS BACK WESTWARD...SHOWERS/THUNDER WILL TEND TO DISSIPATE
LATER THIS MORNING AS IT SAGS SOUTHEASTWARD TOWARD THE I-72
CORRIDOR. WILL CARRY CHANCE POPS AS FAR SOUTH AS A SPRINGFIELD TO
MATTOON LINE ACCORDINGLY...WITH ONLY SLIGHT CHANCES FOR ISOLATED
THUNDER ACROSS THE FAR SE CWA THIS AFTERNOON. WILL BE A VERY WARM
AND HUMID DAY...WITH HIGHS REACHING THE UPPER 80S AND LOWER 90S.
LOW PRESSURE WILL TRACK THROUGH THE GREAT LAKES TONIGHT...WITH
TRAILING FRONTAL BOUNDARY SINKING SLIGHTLY FURTHER SOUTHWARD TO
NEAR THE ILLINOIS/WISCONSIN BORDER. SCATTERED SHOWERS/THUNDER WILL
PERSIST NEAR THE BOUNDARY...RESULTING IN LOW CHANCE POPS FOR THE
NORTHERN TWO-THIRDS OF THE CWA TONIGHT. FURTHER SOUTH...LITTLE OR
NO PRECIP IS ANTICIPATED ALONG/SOUTH OF I-70. AS LOW-LEVEL JET
STRENGTHENS AND SHORT-WAVE CURRENTLY OVER UTAH TRACKS E/NE INTO
THE NORTHERN PLAINS...AN MCS WILL LIKELY DEVELOP OVER SOUTHERN
MINNESOTA/NORTHERN IOWA LATE TONIGHT. TRAJECTORIES TAKE THIS
SYSTEM MAINLY EASTWARD ACROSS WISCONSIN AND NORTHERN ILLINOIS
TUESDAY MORNING. THINK BULK OF THE CONVECTION WILL REMAIN JUST
NORTH OF CENTRAL ILLINOIS...PRIMARILY ALONG/NORTH OF I-80. WILL
FEATURE HIGHEST POPS ACROSS THE NORTHERN CWA ACCORDINGLY...WITH
ONLY LOW CHANCE TO SLIGHT CHANCE POPS ACROSS THE CENTRAL AND
SOUTHERN ZONES. MAIN STORY ON TUESDAY WILL BE THE HEAT AND
HUMIDITY. AFTERNOON HIGH TEMPERATURES IN THE LOWER 90S COMBINED
WITH DEWPOINTS IN THE LOWER TO MIDDLE 70S...WILL RESULT IN HEAT
INDEX VALUES APPROACHING 100 DEGREES.
BEST CHANCE FOR WIDESPREAD CONVECTION STILL ON TARGET FOR TUESDAY
NIGHT INTO WEDNESDAY...AS NORTHERN STREAM WAVE CURRENTLY OVER THE
PACIFIC NORTHWEST PUSHES COLD FRONT SOUTHWARD INTO CENTRAL
ILLINOIS. WITH FRONT INTERACTING WITH A VERY MOIST AIR MASS
CHARACTERIZED BY PRECIPITABLE WATER VALUES IN EXCESS OF 2
INCHES...WILL CONTINUE TO FEATURE LIKELY POPS WITH FROPA. SEVERE
WEATHER THREAT REMAINS UNCERTAIN...HOWEVER LOCALLY HEAVY RAINFALL
WILL BE A GOOD BET WITH THE STORMS LATE TUESDAY NIGHT INTO WEDNESDAY.
FRONT WILL DROP SOUTHWARD INTO THE OHIO RIVER VALLEY BY WEDNESDAY
EVENING...ENDING THE THREAT FOR RAIN FROM NORTH TO SOUTH ACROSS
THE AREA. WILL LINGER CHANCE POPS ALONG/SOUTH OF I-70 THROUGH
WEDNESDAY EVENING...THEN WILL GO DRY ACROSS THE BOARD AFTER MIDNIGHT.
LONG TERM...THURSDAY THROUGH SUNDAY
COOLER/DRIER WEATHER WILL PREVAIL THROUGH THE EXTENDED...AS HIGH
PRESSURE BUILDS INTO THE GREAT LAKES. HIGH TEMPERATURES WILL ONLY
REACH THE LOWER TO MIDDLE 80S...WHILE OVERNIGHT LOWS DROP INTO THE
LOWER TO MIDDLE 60S.
BARNES
&&
.AVIATION...
ISSUED 647 AM CDT MON JUL 8 2013
BAND OF SHOWERS AND ISOLATED STORMS MOVING THROUGH CENTRAL
ILLINOIS EARLY THIS MORNING. CURRENTLY LOOKS LIKE MOST OF THE
STORMS WILL PASS NORTH OF KPIA OVER THE NEXT HOUR OR TWO...BUT
MORE EXPECTED TO DEVELOP LATER THIS MORNING. CONFIDENCE IN
PLACEMENT OF ANY STORMS IS NOT VERY HIGH AT THE MOMENT...AS THERE
IS POOR MODEL AGREEMENT IN ANY PARTICULAR TREND...SO HAVE GONE
WITH MAINLY VCSH/VCTS MUCH OF THE DAY. THERE WILL PROBABLY BE A
PERIOD OF DRIER CONDITIONS MUCH OF THE EVENING AND OVERNIGHT...
HOWEVER A CONVECTIVE COMPLEX IS EXPECTED TO DEVELOP OVER
MINNESOTA/IOWA TONIGHT...AND MAY AFFECT KPIA TOWARD SUNRISE.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
640 AM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 640 AM CDT MON JUL 8 2013
REVISED AVIATION DISCUSSION FOR 12Z TAFS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 329 AM CDT MON JUL 8 2013
A LITTLE BIT OF A BALANCING ACT IN THE SHORT TERM. GIVEN THE
SLIGHTLY STRONGER SUBSIDENCE OF THE RIDGE MOVING INTO THE WFO PAH
FORECAST AREA FROM THE WEST ON SUNDAY...ANTICIPATE SLIGHTLY BETTER
SUBSIDENCE /WARMING/ TODAY...ESPECIALLY IN THE SOUTHERN 1/2 OF
SOUTHEAST MO.
THERE WILL BE A ZONE OF UNCERTAINTY FOR SHOWER/THUNDERSTORM
GENERATION THIS AFTERNOON...MAINLY ALONG AND NORTH OF ROUTE 13 IN
SOUTHERN IL...THEN NORTHEAST TO NORTH OF KEHR AND KOWB. LOOKING AT
THE LATEST GFS/NAM/RAP/SREF SOUNDINGS SUGGEST FOR ANYTHING TO GET
GOING THIS AFTERNOON...IT WOULD HAVE TO COME FROM AIR PARCELS MOVE
FROM AROUND 800 MB. EVEN THE MOST UNSTABLE SOUNDINGS STILL HAVE
SKINNY CAPE...LITTLE IN THE WAY OF SIGNIFICANT INSTABILITY/BUOYANCY/
MOISTURE TO SUPPORT PERSISTENT AND SUSTAINED UPDRAFTS.
FOR NOW...HAVE BLENDED WITH THE HRRR TO HIGHLIGHT ANY ISOLATED
THUNDERSTORM CHANCES FOR THIS AFTERNOON...ALBEIT SMALL. FROM A
COMPLIMENTARY STANDPOINT...ADJUSTED MAX TEMPERATURES UP SLIGHTLY.
FOR NOW...TEMPERATURES THIS AFTERNOON SHOULD KEEP HEAT INDEX
VALUES FROM CRITICAL LEVELS THIS AFTERNOON.
HOWEVER...FOR TUESDAY AND WEDNESDAY...OUTSIDE OF THE RAIN
AREAS...THE SIGNAL HAS BEEN CONSISTENT OVER SOUTHEAST MO AND PARTS
OF SOUTHERN IL AND THE PURCHASE AREA OF WEST KENTUCKY FOR MEETING
HEAT ADVISORY CRITERIA DURING THE AFTERNOON HOURS...MAINLY FROM
18Z TO 00Z /1 PM TO 7 PM CDT. PLAN ON MENTIONING THIS POTENTIAL IN
THE HWO...AS WELL HIGHLIGHTING IT IN A SPECIAL WEATHER STATEMENT.
OF COURSE...MOST OF THE POTENTIAL WILL BE OUTSIDE OF RAIN AREAS.
TUESDAYS CONVECTIVE ACTIVITY...GIVEN LESSER SHEAR ALOFT...WILL
LIKELY BECOME OUTFLOW DOMINATED AS IT DEVELOPS FURTHER
SOUTH...WITH A STRONG DIURNAL COMPONENT.
FOR WEDNESDAY...AM NOT SURPRISED WITH THE LOCATION OF THE SLIGHT
RISK AREA FROM SPC...GIVEN THE SHEAR AND FORCING IN PLACE. STILL
BELIEVE HEAVY RAIN WILL BE THE DOMINATE HAZARD. HAIL WILL
INITIALLY BE MARGINAL...BUT WIND GUSTS BETWEEN 45 AND 55 MPH MAY
BE POSSIBLE. THE SIGNAL FOR THE HIGHEST POPS/WEATHER ON WEDNESDAY
HAS BEEN CONSISTENT FOR NEARLY SEVEN DAYS NOW.
WITH RESPECT TO TEMPERATURES TUESDAY...WENT A LEAST ANOTHER
DEGREE HIGHER AS THE RIDGE STILL HAS SOME INFLUENCE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 329 AM CDT MON JUL 8 2013
THE COLD FRONT RESPONSIBLE FOR FOCUSING THE MID WEEK PRECIPITATION
EVENT WILL BE DRAPED ALONG OR JUST SOUTH OF THE OHIO RIVER THURSDAY
MORNING. A FEW SHOWERS AND THUNDERSTORMS MAY LINGER MAINLY SOUTH AND
EAST OF THE OHIO RIVER THURSDAY MORNING BEFORE THE FRONT COMPLETELY
SLIPS SOUTH OF THE AREA.
LATE IN THE WEEK...HIGH PRESSURE WILL BUILD SOUTH FROM CANADA...
BRINGING ANOTHER SPELL OF TEMPERATURES BELOW SEASONAL NORMS. GOOD
CONTINUITY AMONG THE RECENT OPERATIONAL AND ENSEMBLE DEPICTIONS FROM
THE GFS...ECMWF...AND GEM LENDS RELATIVELY HIGH CONFIDENCE TO THE
LATE WEEK FORECAST. ALONG WITH THE MILDER TEMPERATURES WILL COME
LESS HUMIDITY...AS DEW POINTS BOTTOM OUT IN THE UPPER 50S AND LOWER
60S FRIDAY AND SATURDAY.
IN THE UPPER LEVELS...A BUILDING RIDGE OVER THE CENTRAL U.S. WILL
SQUEEZE A TROUGH INTO THE EAST. THIS MAY EVENTUALLY LEAD TO THE
DEVELOPMENT OF A CUT-OFF LOW OVER THE SOUTHERN GULF STATES LATE IN
THE WEEKEND...BUT THIS IS WHERE FORECAST CONFIDENCE DECREASES
MARKEDLY. ENOUGH MOISTURE MAY CREEP NORTH AND WEST INTO THE FORECAST
AREA TO WARRANT A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS BY
SUNDAY. TEMPERATURES WILL GRADUALLY WARM OVER THE WEEKEND AS WELL...
BUT SHOULD REMAIN WITHIN SEASONAL RANGE.
&&
.AVIATION...
ISSUED AT 640 AM CDT MON JUL 8 2013
DRY WEATHER WITH VFR CONDITIONS WILL PREVAIL OVER THE NEXT 24 HOURS.
SCATTERED CU DEVELOPMENT IS EXPECTED BY LATE MORNING...AND MID TO
HIGH CLOUDS WILL BE ON THE INCREASE LATER TODAY INTO TONIGHT.
PREVAILING WIND WILL BE SOUTHERLY AOB 10 KNOTS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...SMITH
LONG TERM...RJP
AVIATION...RJP
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
754 AM EDT MON JUL 8 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 508 AM EDT MON JUL 8 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE NRN CONUS AND SRN CANADA. AT THE SFC...A FRONTAL BOUNDARY
EXTENDED ACROSS NRN WI THROUGH SRN UPPER MI. A SHORTWAVE TROUGH FROM
NRN ONTARIO THROUGH WRN LAKE SUPERIOR INTO NW WI SUPPORTED A LARGE
AREA OF SHOWERS AND THUNDERSTORMS ACROSS CNTRL UPPER MI INTO NE WI
AND NRN LAKE MICHIGAN. EVEN THOUGH THE GREATER MUCAPE VALUES OF
500-1000 J/KG AND STRONGER TSRA WERE LOCATED ALONG AND SOUTH OF THE
FRONT...FORCING ASSOCIATED WITH THE SHRTWV WAS STRONG ENOUGH TO
SUPPORT TSRA OVER N CNTRL UPPER MI. MANY LOCATIONS FROM GOGEBIC
COUNTY THROUGH SRN UPPER MI HAVE RECEIVED RAINFALL AMOUNTS IN THE 1
TO 2 INCH RANGE...PER RADAR ESTIMATES.
TODAY...EXPECT THAT AS THE SHRTWV MOVES OFF TO THE EAST THIS
MORNING...THE SHRA/TSRA WILL ALSO SHIFT INTO THE ERN CWA. WITH SOME
CLEARING IN THE AFTERNOON...TEMPS COULD AGAIN REBOUND TO
THE LOWER 80S OVER THE SOUTH HALF OF UPPER MICHIGAN. EVEN THOUGH THIS
WOULD BOOST MLCAPE VALUES BACK INTO THE 1K-2K J/KG RANGE...WITH MID
LEVEL RIDGING AND WEAK QVECTOR DIV BUILDING INTO THE AREA IN THE WAKE
OF THE SHORTWAVE....PCPN CHANCES WILL BE MINIMAL. NEVERTHELESS...SOME
ISOLD SHRA/TSRA WILL STILL BE POSSIBLE...MAINLY OVER THE S CNTRL CWA
WHERE MODELS SUGGEST A WEAK SFC TROUGH AXIS WOULD MAXIMIZE LOW LEVEL
CONVERGENCE.
TONIGHT...WEAK MID-LEVEL RIDGING SHOULD AND LOSS OF DAYTIME HEATING
SHOULD BRING AN END TO ANY LINGERING PCPN. MID LEVEL DRYING AND A
DEVELOPING SUBSIDENCE INVERSION ABOVE LINGERING LOW-LEVEL MOISTURE
WILL FAVOR ANOTHER ROUND OF FOG ACROSS INTERIOR LOCATIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 508 AM EDT MON JUL 8 2013
THE MODELS CONTINUE TO AGREE ON THE GENERAL IDEA THAT AN MCS WILL BE
ONGOING AT THE START OF THE PERIOD NEAR THE NOSE OF THE 40-45KT LLJ
OVER THE UPPER MISSISSIPPI VALLEY. HOWEVER...THERE TENDS TO BE SOME
MODEL DISAGREEMENT ON THE EXACT PLACEMENT OF THE MCS...WHICH WILL
PROVE CRITICAL IN THE PRECIPITATION AND POP FORECAST ESPECIALLY
TUESDAY AFTERNOON INTO TUESDAY EVENING. IN GENERAL...THE MODELS HAVE
TRENDED NORTHWARD WITH THE NOSE OF THE LOW LEVEL JET. THE REGIONAL
GEM IS THE MOST AGGRESSIVE...WITH THE BEST LOW LEVEL JET ENERGY
FOCUSED WELL INTO NRN MN AND WESTERN LAKE SUPERIOR TUESDAY...WHILE
THE NAM AND GFS SUPPRESS IT FURTHER SOUTH INTO CENTRAL WI AND
SOUTH-CENTRAL UPPER MI RESPECTIVELY. DUE TO CONVECTIVE FEEDBACK FROM
BOTH THE MODELS...IT IS UNCLEAR WHERE THIS MCS WILL TRACK ON
TUESDAY...HOWEVER CLIMATOLOGY...PAST EXPERIENCE AND MODEL FORWARD
PROPAGATING CORFIDI VECTORS WOULD SUGGEST THAT ANY MCS OVER
SOUTHERN/CENTRAL MN TUE MORNING WOULD LIKELY STAY NEAR OR JUST SOUTH
OF THE WI/MI BORDER AND PERHAPS CLIP MENOMINEE COUNTY LATER TUESDAY
AFTERNOON. THIS SCENARIO WOULD POTENTIALLY LEAVE MUCH OF UPPER
MICHIGAN DRY ON TUESDAY OR JUST WITH RESIDUAL STRATIFORM RAIN AND
EMBEDDED THUNDER TUE AFTN INTO THE EVENING. IN ADDITION...THIS MCS
MAY HELP DISRUPT THE MOISTURE INFLOW INTO THE MAIN SYSTEM AND COLD
FRONT OVER THE NRN PLAINS/NW ONTARIO LATER TUESDAY INTO TUESDAY
NIGHT. RESIDUAL CLOUD COVER BLOWOFF FROM THE MCS MAY ALSO ALLOW FOR
DIMINISHED INSTABILITY ACROSS THE REGION AS THE COLD FRONT
APPROACHES FROM THE NORTHWEST TUESDAY NIGHT. AS SUCH...AS PREVIOUS
FORECASTS HAVE INDICATED...CONFIDENCE REMAINS RATHER LOW REGARDING
THE POP/QPF FORECAST TUESDAY AFTERNOON INTO TUESDAY NIGHT. FOR
NOW...HAVE MAINTAINED LIKELY POPS ACROSS THE SOUTH CENTRAL TUE AFTN
WITH CHANCE POPS ELSEWHERE. FOR TUESDAY NIGHT...HAVE OPTED TO GO
WITH LIKELY POPS NEAR LAKE MICHIGAN WITH CHANCE POPS ELSEWHERE AS
THE MAIN UPPER WAVE AND ASSOCIATED COLD FRONT PASS THROUGH.
MUCH LESS HUMID AND MORE SEASONABLE TEMPS ON WEDNESDAY BEHIND THE
COLD FRONT. CANNOT RULE OUT A PASSING SHOWER EARLY ACROSS THE
EASTERN HALF OF UPPER MI EARLY WED MORNING AS THE UPPER TROUGH AXIS
WILL HAVE YET TO PASS THROUGH. OTHERWISE...HIGH PRESSURE WILL BUILD
ACROSS THE AREA WED NIGHT-THURSDAY LEADING TO VERY SEASONABLE AND
DRY CONDITIONS. UPPER HEIGHTS BUILD ON FRIDAY ACROSS THE WESTERN
LAKES...GIVING SOME WARMER TEMPS BUT DRY CONDITIONS WILL CONTINUE.
ON SATURDAY...THE GFS AND 00Z ECMWF ARE IN BETTER AGREEMENT IN
SHOWING A WEAK DISTURBANCE MOVING OVER THE RIDGE AXIS. ALTHOUGH
MOISTURE WILL BE LACKING...CANNOT TOTALLY RULE OUT SHOWERS/STORMS
ACROSS THE WEST SAT AFTN AS AS SUCH HAVE ADDED A 30 PCT CHANCE ON
SATURDAY. NEXT SYSTEM MOVES INTO THE WESTERN LAKES LATE IN THE
WEEKEND OR EARLY MONDAY. STILL SOME TIMING ISSUES WITH THE ECMWF
BEING FASTER THAN THE GFS. WITH THIS IN MIND...HAVE KEPT ANY MENTION
OF PRECIPITATION OUT OF THE FORECAST FOR SUNDAY...BUT MAY NEED TO BE
INTRODUCED IN LATER FORECASTS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 753 AM EDT MON JUL 8 2013
EXPECT LIFR/VLIFR CONDITIONS AT CMX/IWD WILL GRADUALLY IMPROVE THIS
MORNING WITH DAYTIME HEATING/MIXING. AT SAW...WHERE RAIN HAS KEPT
CONDITIONS FROM DROPPING OFF AS LOW...MAINLY IFR CONDITIONS WILL
PERSIST INTO THIS AFTERNOON WITH PERSISTENT WEAK NE UPSLOPE FLOW.
CIGS SHOULD ALSO LIFT TO MVFR/VFR BY MID AFTERNOON. MORE FOG/VLIFR
CONDITIONS ARE EXPECTED TONIGHT WITH LINGERING LOW LEVEL MOISTURE...
LIGHT WINDS/NOCTURNAL COOLING UNDER DRY AIR ALOFT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 508 AM EDT MON JUL 8 2013
A DENSE FOG ADVISORY REMAINS TODAY FOR ALL OF LAKE SUPERIOR GIVEN SEVERAL
SHIP REPORTS OF NEAR ZERO VISIBILITY AND VERY HUMID AIR OVER
RELATIVELY CHILLY LAKE SUPERIOR WATERS. THE FOG MAY ALSO LINGER INTO
TONIGHT BEFORE DISSIPATING TUESDAY. A SURFACE FRONT MOVING ACROSS
LAKE SUPERIOR TUESDAY EVENING WILL ALLOW WINDS TO SHIFT TO THE
NORTHWEST AT 15 TO 25 KNOTS FOR A SHORT TIME LATE TUESDAY NIGHT INTO
WEDNESDAY. HIGH PRESSURE WILL SETTLE BACK OVER THE LAKE FOR THE
LATER HALF OF THE WEEK WITH WINDS LESS THAN 15 KNOTS EXPECTED INTO
NEXT WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
LSZ162-240>251-263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
619 AM CDT MON JUL 8 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 312 AM CDT MON JUL 8 2013
ANOTHER ACTIVE SEVERE WEATHER DAY IS EXPECTED BEGINNING THIS
AFTERNOON THROUGH THE OVERNIGHT HOURS TONIGHT. THE FOCUS FOR STORM
DEVELOPMENT REVOLVES AROUND A STRONG UPPER LEVEL DISTURBANCE MOVING
THROUGH THE DAKOTAS. A WEAKER DISTURBANCE WILL APPROACH SWRN NEB
LATE THIS AFTERNOON PERHAPS FOCUSING ANOTHER CLUSTER OF STRONG TO
SEVERE STORMS. THE DISTURBANCE MOVING THROUGH THE DAKOTAS IS
EXPECTED TO LIFT A 700 MB WARM FRONT THROUGH SWRN NEB...PERHAPS
CAPPING THE ATMOSPHERE THIS EVENING. IT WOULD APPEAR THERE IS A
WINDOW FOR SEVERE STORM DEVELOPMENT ACROSS SWRN NEB LATE THIS
AFTERNOON BEFORE THE ATMOSPHERE BECOMES CAPPED THIS EVENING. THERE
ARE NO HOLDS BARRED ACROSS NCNTL AND NW NEB LATE THIS AFTN AND
THIS EVENING WHERE THE CAP WILL BE WEAKER AND JUST AS UNSTABLE AS
THE SOUTHWEST.
THE RAP SUGGESTS STORMS COULD FIRE ACROSS NCNTL NEB LATE THIS AFTN
JUST AHEAD OF THE MID LEVEL WARM FRONT. AT THE SFC A WARM FRONT WILL
LIE ALONG INTERSTATE 80 PROVIDING AN OPPORTUNITY FOR STORM
DEVELOPMENT THERE. THUS THE FCST USES A MULTIMODEL BLEND FOR HIGHEST
POPS...40S...ACROSS THE NORTH AND ISOLATED POPS ACROSS SWRN NEB.
HIGHS TODAY SHOULD REACH WELL INTO THE 90S ALONG AND SOUTH OF THE
SFC FRONT NEAR INTERSTATE 80 AND 80S ACROSS NCNTL NEB. LOWS TONIGHT
FALL INTO THE 60S TO AROUND 70.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 312 AM CDT MON JUL 8 2013
A COLD FRONT WILL BE DRIVEN SOUTH THROUGH THE AREA TUESDAY...AS A
STRONG SHORT WAVE TROUGH SKIRTS EAST ACROSS THE NORTHERN PLAINS
AND SOUTHERN CANADA. THIS WILL BRING A TEMPORARY REST FROM T-STORM
ACTIVITY...AS THE BEST FOCUS WILL SHIFT SOUTH AND EAST OF THE AREA
ALONG THE FRONT. WEDNESDAY THE FRONT WILL BEGIN TO LIFT BACK NORTH
AS A WARM FRONT...WITH A WARM MOIST EASTERLY UPSLOPE FLOW LIKELY
TO IGNITE T-STORMS ACROSS THE PANHANDLE WEDNESDAY AFTERNOON. THESE
SHOULD MOVE EAST INTO CENTRAL/SOUTHWEST NEBRASKA WEDNESDAY
EVENING.
THE UPPER LEVEL RIDGE OF HIGH PRESSURE IS STILL EXPECTED TO BUILD
NORTH OVER THE AREA THURSDAY INTO FRIDAY. WARMING MID LEVEL
TEMPERATURES WILL LIKELY CAP THE ATMOSPHERE...AND T-STORM CHANCES
WILL DIMINISH. HOT WEATHER CAN ALSO BE ANTICIPATED AS THE RIDGE
BUILDS IN...WITH HIGHS IN THE MID 90S TO AROUND 100 DEGREES.
ANOTHER STRONG SHORTWAVE TROUGH WILL PUSH EAST ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA SATURDAY AND SUNDAY. THIS APPEARS TO
DRIVE ANOTHER COLD FRONT SOUTH INTO THE AREA...WITH RETURNING
CHANCES FOR T-STORMS AND SOMEWHAT COOLER TEMPERATURES BY SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 614 AM CDT MON JUL 8 2013
LIFR ACROSS KVTN AND KANW SHOULD MIX OUT TO VFR BY 13Z-15Z AT THE
LATEST. SIMILARLY...THE SCATTERED THUNDERSTORMS ACROSS NW NEB
SHOULD WEAKEN AFTER SUNRISE BEFORE REACHING KVTN...THIS IS
ASSUMING THEY ARE NOCTURNALLY DRIVEN. OTHERWISE THERE IS NO REAL CHANGE
TO THE FORECAST...SCATTERED STRONG OR SEVERE THUNDERSTORMS ARE
EXPECTED TO REDEVELOP LATE THIS AFTERNOON OR EARLY EVENING ROUGHLY
22Z-02Z WITH ACTIVITY CONTINUING WELL INTO THE EVENING HOURS.
SCATTERED STORMS SHOULD FORM FIRST ACROSS THE NORTH AND LAST THE
LONGEST ACROSS NRN NEB. ISOLATED STORMS COULD DISSIPATE THIS
EVENING AROUND KLBF AS A CAP IS EXPECTED TO DEVELOP. THUS VFR
COULD DEVELOP ACROSS SWRN NEB THIS EVENING WHILE STORMS CONTINUE
ACROSS NRN NEB.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1024 AM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 1015 AM CDT MON JUL 8 2013
UPDATE MAINLY TO FINE TUNE POPS THROUGH LATE MORNING AND
AFTERNOON. ISOLATED SHOWERS AND STORMS HAVE EXITED THE NORTHEAST
THIS MORNING. STORMS EXPECTED TO REDEVELOP EARLY TO MID
AFTERNOON...MAINLY WEST NEAR A STATIONARY FRONT. ANY STORMS THAT
DEVELOP THIS AFTERNOON COULD BECOME SEVERE QUICKLY. A LARGE
THUNDERSTORM COMPLEX IS EXPECTED TO ROLL ACROSS THE STATE LATER
TONIGHT...WITH THREATS OF DAMAGING STRAIGHT LINE WINDS AND VERY
HEAVY RAIN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT MON JUL 8 2013
THE MAIN CONCERN IN THE SHORT TERM WILL BE THE CHANCE OF
THUNDERSTORMS...SOME POSSIBLY SEVERE. EARLY MORNING RADAR MOSAIC
SHOWS THUNDERSTORMS MOVING ACROSS NORTHEAST MONTANA INTO NORTHWEST
NORTH DAKOTA. THE HRRR CAPTURES THIS ACTIVITY AND MOVES IT INTO
THE NORTH CENTRAL PART OF THE STATE LATER THIS MORNING. MUCAPE
FROM THE SPC MESOSCALE ANALYSIS PAGE SHOWS VALUES NEAR 1000 J/KG
THIS MORNING ACROSS NORTHWEST / NORTH CENTRAL NORTH DAKOTA...SO AN
ISOLATED STRONG STORM IS POSSIBLE.
ATTENTION THIS AFTERNOON SHIFTS TO A BOUNDARY THAT IS EXPECTED TO
BECOME ESTABLISHED FROM SOUTHWEST NORTH DAKOTA INTO THE NORTH
CENTRAL PART OF THE STATE. THE LATEST RAP SHOWS CONVECTION
DEVELOPING ALONG THE BOUNDARY BY EARLY AFTERNOON. THERE WILL BE
GOOD INSTABILITY IN PLACE WITH MLCAPE VALUES OF 1500-2500
J/KG...AND DEEP LAYER SHEAR OF 40 KTS SHOULD SUPPORT SUPERCELLS.
THE MAIN THREATS ARE EXPECTED TO BE LARGE HAIL AND DAMAGING
WINDS...THOUGH AN ISOLATED TORNADO IS ALSO POSSIBLE.
LATER TONIGHT...A STRONG H5 WAVE IS EXPECTED TO MOVE ACROSS MONTANA
INTO NORTH DAKOTA. THIS WILL HELP INCREASE THUNDERSTORM
COVERAGE...WITH THE POTENTIAL DEVELOPMENT OF AN EASTWARD
PROPAGATING MCS. THIS WILL GRADUALLY SHIFT THE PRIMARY
THUNDERSTORM THREATS TO DAMAGING WINDS AND HEAVY RAIN LATER
TONIGHT. SEE THE HYDRO SECTION BELOW WHICH DISCUSSES THE HEAVY
RAIN POTENTIAL.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT MON JUL 8 2013
THE CHALLENGE IN THE EXTENDED WILL BE ENDING THE PRECIPITATION
CHANCES TUESDAY AS THE SHORTWAVE EXITS THE REGION. BELIEVE RESIDUAL
SHOWERS AND THUNDERSTORMS WILL BE IN THE NORTH AND EAST TUESDAY
MORNING...WITH ONLY A SLIGHT CHANCE SOUTH. THE PRECIPITATION WILL
LIKELY BE EXITING THE REGION BY EARLY AFTERNOON...SO BY EVENING
TUESDAY IT SHOULD BE DRY ACROSS THE REGION. THIS WILL BE FOLLOWED BY
A RELATIVELY QUIET PERIOD WEDNESDAY AND THURSDAY AS AN H500 RIDGE
BUILDS INTO THE REGION. HOWEVER...MUCH WARMER TEMPERATURES
ASSOCIATED WITH THE RIDGE WILL ALSO ARRIVE IN THE WEST ON THURSDAY
AND CONTINUE INTO FRIDAY. BOTH GFS AND ECMWF MODELS SUPPORT THIS
SCENARIO. EXPECT HIGH TEMPERATURES WEDNESDAY INTO THE LOW TO MIDDLE
90S WEST...UPPER 80S TO AROUND 90 CENTRAL. AS THE RIDGE MOVES EAST
ON FRIDAY INTO THE WEEKEND...WILL BE PICKING UP MORE CHANCES FOR
THUNDERSTORMS AS SHORTWAVE ENERGY WILL AGAIN BE MOVING THROUGH THE
NORTHERN PLAINS. THAT BEING 5 TO 7 DAYS OUT...AND WITH MODELS
DIFFERING IN THE FLOW ALOFT...JUST MENTIONED SLIGHT CHANCE FOR
THUNDERSTORMS FRIDAY INTO WEEKEND. GFS HAS BUILDING HEIGHTS FOR THIS
PERIOD ALOFT WHILE THE EUROPEAN IS MORE ACTIVE WITH SHORTWAVE ENERGY
MOVING THROUGH....ALTHOUGH BOTH MODELS WOULD SUPPORT SOME
THUNDERSTORMS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1015 AM CDT MON JUL 8 2013
MAIN HAZARDS TO AVIATION THIS FORECAST PERIOD MAINLY THUNDERSTORMS.
OTHERWISE...EXPECT VFR CONDITIONS. BEST ESTIMATE FOR THUNDERSTORM
TIMING IS BETWEEN 00Z- 12Z TONIGHT. ENHANCED WINDS POSSIBLE WITH
FAST MOVING LINES OF THUNDERSTORMS. ALTHOUGH THESE SEVERE WEATHER
ELEMENTS WILL BE POSSIBLE..TOO UNCERTAIN IN TIMING TO INCLUDE IN
TAF FORECAST. AVIATION PLANNERS SHOULD ANTICIPATE MULTIPLE LINES
OF THUNDERSTORMS MOVING WEST TO EAST ACROSS THE STATE AFTER 02Z.
&&
.HYDROLOGY...
ISSUED AT 325 AM CDT MON JUL 8 2013
HEAVY RAIN IS POSSIBLE WITH MULTIPLE ROUNDS OF THUNDERSTORMS TODAY
INTO TONIGHT. PRECIPITABLE WATER VALUES AROUND 1.5 INCHES ARE
EXPECTED TONIGHT ACROSS MUCH OF THE FORECAST AREA. THE HEAVIEST
RAIN POTENTIAL APPEARS TO BE ALONG AND NORTH OF HIGHWAY 200...WHERE
AN EASTWARD PROPAGATING THUNDERSTORM COMPLEX IS POSSIBLE. 1 HOUR
FLASH FLOOD GUIDANCE VALUES ARE AT LEAST 1.5 INCHES...AND 3 HOUR
VALUES ARE GENERALLY IN THE 1.5 - 3.0 INCH RANGE. DECIDED TO HOLD
OFF ON ANY FLASH FLOOD WATCHES FOR NOW DUE TO THE RELATIVELY HIGH
FLASH FLOOD GUIDANCE VALUES AND EXPECTED PROGRESSIVE STORM
MOTIONS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RP KINNEY
SHORT TERM...CK
LONG TERM/AVIATION...WAA
HYDROLOGY...CK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
936 AM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 931 AM CDT MON JUL 8 2013
SHORTWAVE RIDING ALONG INTERNATIONAL BORDER AND WEAK SURFACE
BOUNDARY JUST NORTH OF HIGHWAY 2 ENOUGH TO SUSTAIN ISOLD
CONVECTION PROPAGATING INTO FAR WESTERN FA WEST OF DVL. CELLS
WEAKENING AND SHORT RANGE MESOSCALE MODELS GENERALLY DISSIPATE
CONVECTION BY NOON. TRIMMED BACK ON POPS TO COVER JUST THE FAR
WEST AND IF TRENDS CONTINUE WILL LIKELY BE ABLE TO PULL POPS REST
OF TODAY. ADJUSTED SKY CONDITION OTHERWISE NO OTHER CHANGES FOR
THIS UPDATE PERIOD.
UPDATE ISSUED AT 643 AM CDT MON JUL 8 2013
STORMS OVER NORTHWESTERN ND HAVE BEEN HOLDING A BIT BETTER THAN
EXPECTED. IN ADDITION...LATEST RUNS OF THE RAP HAVE A FEW REMNANTS
OF CONVECTION REACHING THE FAR NORTHWESTERN CWA THIS MORNING.
THUS...INCLUDED SOME 20 POPS IN THAT AREA STARTING AT 15Z.
OTHERWISE...THINK THAT MORE SIGNIFICANT ACTIVITY WILL HOLD OFF
UNTIL TONIGHT SO WILL KEEP HIGHEST POPS FOR THAT TIME PERIOD.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 302 AM CDT MON JUL 8 2013
CONVECTION TIMING WILL BE THE MAIN HEADACHE FOR THE SHORT TERM.
WV LOOP SHOWS NEAR ZONAL FLOW OVER THE NORTHERN PLAINS...WITH
VARIOUS WEAK SHORTWAVES APPROACHING FROM THE WEST. WEAK SFC HIGH
PRESSURE REMAINS IN PLACE OVER THE CWA...AND MODELS ARE IN FAIRLY
GOOD AGREEMENT ON IT MOVING TO THE EAST TODAY AS LOW PRESSURE
DEVELOPS IN THE LEE OF THE ROCKIES. SPC MESOANALYSIS HAS THE CWA
UNDER A RELATIVELY STABLE AND DRIER AIRMASS THAN THE SURROUNDING
AREAS. WILL HAVE TO MONITOR CONVECTION CURRENTLY ENTERING FAR
NORTHWESTERN ND. AT THIS POINT IT SEEMS LIKE IT WILL DISSIPATE
BEFORE APPROACHING OUR CWA LATER THIS MORNING WHICH THE
RAP...GFS...ECMWF...AND GEM SHOW. A FEW OF THE MODELS SUCH AS NAM
AND HRR HOWEVER HAVE IT HOLDING TOGETHER ENOUGH TO ENTER THE
DEVILS LAKE BASIN LATER ON THIS MORNING. AT THIS POINT THINK THE
STORMS WILL OUTRUN THEIR SUPPLY OF ELEVATED INSTABILITY AND DIE
OUT BUT WILL KEEP AN EYE ON RADAR TRENDS BEFORE SENDING EVERYTHING
OUT. JUST HAVE SOME LOW POPS IN THE FAR WEST THIS AFTERNOON
BETWEEN 18-00Z FOR ANYTHING DRIFTING INTO THE AREA FROM CENTRAL ND.
THINK THAT THE MAIN THREAT WILL BE LATER TONIGHT AS A MORE
SIGNIFICANT UPPER SHORTWAVE COMES OUT INTO THE NORTHERN PLAINS.
THE SFC LOW WILL MOVE OUT INTO THE EASTERN DAKOTAS...AND THERE
SHOULD BE A GOOD AMOUNT OF BULK SHEAR TO WORK WITH AS THE SYSTEM
COMES OUT. SOME OF THE MODELS SHOW MORE THAN 1500 J/KG OF CAPE IN
THE WESTERN CWA...BUT OTHERS HAVE ONLY SOME LIMITED ELEVATED CAPE
THIS EVENING. THE GFS HAS A STRONGER CONVECTIVE COMPLEX OVER SD
WHILE THE NORTHERN ACTIVITY IS A BIT LESS. ON THE OTHER
HAND...THINK THERE COULD BE ENOUGH INSTABILITY TO GET STORMS GOING
OVER WESTERN ND THIS AFTERNOON AND THEN COME EASTWARD AS AN MCS
LATER TONIGHT. KEPT FAIRLY HIGH POPS GOING FOR TONIGHT AND WILL
MENTION HAIL AND DAMAGING WIND THREAT IN THE HWO.
HOW TUESDAY PLAYS OUT WILL DEPEND SOMEWHAT ON HOW CONVECTION
BEHAVES TONIGHT. THE UPPER SHORTWAVE TROUGH WILL MOVE INTO THE
CWA...BUT THE SFC LOW WILL BE WELL TO OUR SOUTHEAST AND THE COLD
FRONT MAY BE THROUGH MOST OF THE CWA BY PEAK HEATING. WILL
CONTINUE TO KEEP POPS FAIRLY HIGH BUT THE COLDER AIR BUILDING IN
AS WELL AS ANY CONVECTIVE DEBRIS FROM EARLY MORNING ACTIVITY COULD
PUT A DAMPER ON ANY STRONGER STORMS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 302 AM CDT MON JUL 8 2013
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT SHOULD BE FAIRLY QUIET WITH
NORTHWESTERLY FLOW ALOFT AND SFC HIGH PRESSURE OVER THE AREA. COLD
AIR ADVECTION BEHIND THE EARLY WEEK SYSTEM SHOULD KNOCK BACK TEMPS
A BIT. HIGHS ON WEDNESDAY WILL BE IN THE 70S TO LOW 80S WITH LOWS
MAINLY IN THE 50S.
THURSDAY-SUNDAY...THE UPPER RIDGE WILL AMPLIFY ACROSS THE ROCKIES
AND HIGH PLAINS ON THURSDAY. RETURN FLOW WILL ENSUE AS THE SFC HIGH
DRIFTS EAST TOWARDS THE WESTERN GREAT LAKES. 925 MB WARM A BIT FROM
WEDNESDAY...WHICH SHOULD ALLOW TEMPS TO RISE INTO THE LOW TO MID 80S.
THE 00Z GFS/ECMWF INDICATE A STRONGER UPPER WAVE/JET STREAK
PROPAGATING INTO CENTRAL CANADA ON FRIDAY...DRAGGING A SFC BOUNDARY
INTO THE REGION...AND PROVIDING SOME POSSIBLE FOCUS FOR CONVECTION
FRI/FRI NIGHT. KEPT HIGH TEMPS ON FRIDAY IN THE LOW TO MID 80S. THE ECMWF
NOSES THE THERMAL RIDGE ACROSS THE AREA AHEAD OF THE FRONT...AND
WOULD SUGGEST A BIT WARMER TEMPS...BUT MUCH WILL DEPEND ON THE
TIMING OF THE WAVE AND ORIENTATION OF THE FLOW FIELDS.
FORECAST CONFIDENCE IS LOW FOR NEXT WEEKEND. BOTH THE GFS/ECMWF KEEP
THE UPPER RIDGE ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH
MORE ZONAL FLOW ACROSS THE NORTHERN PLAINS AS EMBEDDED SHORTWAVES
HELP TO FLATTEN THE RIDGE. THERE ARE SIGNIFICANT DIFFERENCES BETWEEN
THE GFS/ECMWF IN THE POSITION OF SURFACE AND UPPER FEATURES...WITH
THE ECMWF THE COOLER AND MORE PROGRESSIVE SOLUTION. AS SUCH...WILL
CONTINUE TO MENTION LOW POPS WITH FAIRLY SEASONABLE TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 643 AM CDT MON JUL 8 2013
THERE HAVE BEEN BRIEF PERIODS THIS MORNING WHEN KDVL AND KTVF WENT
DOWN IN VIS...BUT WEB CAMS SHOW NO SIGNIFICANT FOGGING AND THE
OBSERVATIONS HAVE IMPROVED. WILL CONTINUE TO GO WITH VFR
CONDITIONS THROUGHOUT THE PERIOD. THUNDERSTORMS WILL BEGIN MOVING
INTO THE FORECAST AREA TOWARDS THE END OF THE PERIOD...AROUND KDVL
BEFORE 06Z TONIGHT AND TO THE SITES FURTHER EAST AFTER 06Z.
WILL INCLUDE A VCTS MENTION FOR NOW DUE TO UNCERTAINTIES WITH TIMING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
649 AM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 641 AM CDT MON JUL 8 2013
THIS UPDATE WILL FOCUS ON CLUSTER OF EARLY MORNING THUNDERSTORMS
MOVING THROUGH THE NORTH CENTRAL. THIS ACTIVITY MOVED THROUGH
MONTANA OVER NIGHT AND WILL CONTINUE FOR A FEW MORE HOURS NORTH
CENTRAL SUPPORTED BY THE LOW LEVEL JET. NAM LOOKS TO GAVE A GOOD
HANDLE ON THIS ACTIVITY...TRENDING IT DOWN BY NOON. SHOULD HEN WAIT
FOR NEXT THUNDERSTORM DEVELOPMENT IN THE AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT MON JUL 8 2013
THE MAIN CONCERN IN THE SHORT TERM WILL BE THE CHANCE OF
THUNDERSTORMS...SOME POSSIBLY SEVERE. EARLY MORNING RADAR MOSAIC
SHOWS THUNDERSTORMS MOVING ACROSS NORTHEAST MONTANA INTO NORTHWEST
NORTH DAKOTA. THE HRRR CAPTURES THIS ACTIVITY AND MOVES IT INTO
THE NORTH CENTRAL PART OF THE STATE LATER THIS MORNING. MUCAPE
FROM THE SPC MESOSCALE ANALYSIS PAGE SHOWS VALUES NEAR 1000 J/KG
THIS MORNING ACROSS NORTHWEST / NORTH CENTRAL NORTH DAKOTA...SO AN
ISOLATED STRONG STORM IS POSSIBLE.
ATTENTION THIS AFTERNOON SHIFTS TO A BOUNDARY THAT IS EXPECTED TO
BECOME ESTABLISHED FROM SOUTHWEST NORTH DAKOTA INTO THE NORTH
CENTRAL PART OF THE STATE. THE LATEST RAP SHOWS CONVECTION
DEVELOPING ALONG THE BOUNDARY BY EARLY AFTERNOON. THERE WILL BE
GOOD INSTABILITY IN PLACE WITH MLCAPE VALUES OF 1500-2500
J/KG...AND DEEP LAYER SHEAR OF 40 KTS SHOULD SUPPORT SUPERCELLS.
THE MAIN THREATS ARE EXPECTED TO BE LARGE HAIL AND DAMAGING
WINDS...THOUGH AN ISOLATED TORNADO IS ALSO POSSIBLE.
LATER TONIGHT...A STRONG H5 WAVE IS EXPECTED TO MOVE ACROSS MONTANA
INTO NORTH DAKOTA. THIS WILL HELP INCREASE THUNDERSTORM
COVERAGE...WITH THE POTENTIAL DEVELOPMENT OF AN EASTWARD
PROPAGATING MCS. THIS WILL GRADUALLY SHIFT THE PRIMARY
THUNDERSTORM THREATS TO DAMAGING WINDS AND HEAVY RAIN LATER
TONIGHT. SEE THE HYDRO SECTION BELOW WHICH DISCUSSES THE HEAVY
RAIN POTENTIAL.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT MON JUL 8 2013
THE CHALLENGE IN THE EXTENDED WILL BE ENDING THE PRECIPITATION
CHANCES TUESDAY AS THE SHORTWAVE EXITS THE REGION. BELIEVE RESIDUAL
SHOWERS AND THUNDERSTORMS WILL BE IN THE NORTH AND EAST TUESDAY
MORNING...WITH ONLY A SLIGHT CHANCE SOUTH. THE PRECIPITATION WILL
LIKELY BE EXITING THE REGION BY EARLY AFTERNOON...SO BY EVENING
TUESDAY IT SHOULD BE DRY ACROSS THE REGION. THIS WILL BE FOLLOWED BY
A RELATIVELY QUIET PERIOD WEDNESDAY AND THURSDAY AS AN H500 RIDGE
BUILDS INTO THE REGION. HOWEVER...MUCH WARMER TEMPERATURES
ASSOCIATED WITH THE RIDGE WILL ALSO ARRIVE IN THE WEST ON THURSDAY
AND CONTINUE INTO FRIDAY. BOTH GFS AND ECMWF MODELS SUPPORT THIS
SCENARIO. EXPECT HIGH TEMPERATURES WEDNESDAY INTO THE LOW TO MIDDLE
90S WEST...UPPER 80S TO AROUND 90 CENTRAL. AS THE RIDGE MOVES EAST
ON FRIDAY INTO THE WEEKEND...WILL BE PICKING UP MORE CHANCES FOR
THUNDERSTORMS AS SHORTWAVE ENERGY WILL AGAIN BE MOVING THROUGH THE
NORTHERN PLAINS. THAT BEING 5 TO 7 DAYS OUT...AND WITH MODELS
DIFFERING IN THE FLOW ALOFT...JUST MENTIONED SLIGHT CHANCE FOR
THUNDERSTORMS FRIDAY INTO WEEKEND. GFS HAS BUILDING HEIGHTS FOR THIS
PERIOD ALOFT WHILE THE EUROPEAN IS MORE ACTIVE WITH SHORTWAVE ENERGY
MOVING THROUGH....ALTHOUGH BOTH MODELS WOULD SUPPORT SOME
THUNDERSTORMS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 641 AM CDT MON JUL 8 2013
MAIN HAZARDS TO AVIATION THIS FORECAST PERIOD MAINLY
THUNDERSTORMS. OTHERWISE...EXPECT VFR CONDITIONS. EARLY MORNING
LINE OF STORMS WILL MOVE THROUGH THE NORTH CENTRAL...BRUSHING BY
KMOT BETWEEN 12-15Z. AFTER THAT...MUST WAIT FOR THUNDERSTORMS TO
DEVELOP. BEST ESTIMATE WILL BE BETWEEN 00Z-12Z TONIGHT. ENHANCED
WINDS POSSIBLE WITH FAST MOVING LINES OF THUNDERSTORMS. ALTHOUGH
THESE SEVERE WEATHER ELEMENTS WILL BE POSSIBLE..TOO UNCERTAIN IN
TIMING TO INCLUDE IN TAF FORECAST. AVIATION PLANNERS SHOULD
ANTICIPATE MULTIPLE LINES OF THUNDERSTORMS MOVING WEST TO EAST
ACROSS THE STATE AFTER 02Z.
&&
.HYDROLOGY...
ISSUED AT 325 AM CDT MON JUL 8 2013
HEAVY RAIN IS POSSIBLE WITH MULTIPLE ROUNDS OF THUNDERSTORMS TODAY
INTO TONIGHT. PRECIPITABLE WATER VALUES AROUND 1.5 INCHES ARE
EXPECTED TONIGHT ACROSS MUCH OF THE FORECAST AREA. THE HEAVIEST
RAIN POTENTIAL APPEARS TO BE ALONG AND NORTH OF HIGHWAY
200...WHERE AN EASTWARD PROPAGATING MCS IS POSSIBLE. 1 HOUR FLASH
FLOOD GUIDANCE VALUES ARE AT LEAST 1.5 INCHES...AND 3 HOUR VALUES
ARE GENERALLY IN THE 1.5 - 3.0 INCH RANGE. DECIDED TO HOLD OFF ON
ANY FLASH FLOOD WATCHES FOR NOW DUE TO THE RELATIVELY HIGH FLASH
FLOOD GUIDANCE VALUES AND EXPECTED PROGRESSIVE STORM MOTIONS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...CK
LONG TERM...WAA
AVIATION...WAA
HYDROLOGY...CK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
643 AM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 643 AM CDT MON JUL 8 2013
STORMS OVER NORTHWESTERN ND HAVE BEEN HOLDING A BIT BETTER THAN
EXPECTED. IN ADDITION...LATEST RUNS OF THE RAP HAVE A FEW REMNANTS
OF CONVECTION REACHING THE FAR NORTHWESTERN CWA THIS MORNING.
THUS...INCLUDED SOME 20 POPS IN THAT AREA STARTING AT 15Z.
OTHERWISE...THINK THAT MORE SIGNIFICANT ACTIVITY WILL HOLD OFF
UNTIL TONIGHT SO WILL KEEP HIGHEST POPS FOR THAT TIME PERIOD.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 302 AM CDT MON JUL 8 2013
CONVECTION TIMING WILL BE THE MAIN HEADACHE FOR THE SHORT TERM.
WV LOOP SHOWS NEAR ZONAL FLOW OVER THE NORTHERN PLAINS...WITH
VARIOUS WEAK SHORTWAVES APPROACHING FROM THE WEST. WEAK SFC HIGH
PRESSURE REMAINS IN PLACE OVER THE CWA...AND MODELS ARE IN FAIRLY
GOOD AGREEMENT ON IT MOVING TO THE EAST TODAY AS LOW PRESSURE
DEVELOPS IN THE LEE OF THE ROCKIES. SPC MESOANALYSIS HAS THE CWA
UNDER A RELATIVELY STABLE AND DRIER AIRMASS THAN THE SURROUNDING
AREAS. WILL HAVE TO MONITOR CONVECTION CURRENTLY ENTERING FAR
NORTHWESTERN ND. AT THIS POINT IT SEEMS LIKE IT WILL DISSIPATE
BEFORE APPROACHING OUR CWA LATER THIS MORNING WHICH THE
RAP...GFS...ECMWF...AND GEM SHOW. A FEW OF THE MODELS SUCH AS NAM
AND HRR HOWEVER HAVE IT HOLDING TOGETHER ENOUGH TO ENTER THE
DEVILS LAKE BASIN LATER ON THIS MORNING. AT THIS POINT THINK THE
STORMS WILL OUTRUN THEIR SUPPLY OF ELEVATED INSTABILITY AND DIE
OUT BUT WILL KEEP AN EYE ON RADAR TRENDS BEFORE SENDING EVERYTHING
OUT. JUST HAVE SOME LOW POPS IN THE FAR WEST THIS AFTERNOON
BETWEEN 18-00Z FOR ANYTHING DRIFTING INTO THE AREA FROM CENTRAL ND.
THINK THAT THE MAIN THREAT WILL BE LATER TONIGHT AS A MORE
SIGNIFICANT UPPER SHORTWAVE COMES OUT INTO THE NORTHERN PLAINS.
THE SFC LOW WILL MOVE OUT INTO THE EASTERN DAKOTAS...AND THERE
SHOULD BE A GOOD AMOUNT OF BULK SHEAR TO WORK WITH AS THE SYSTEM
COMES OUT. SOME OF THE MODELS SHOW MORE THAN 1500 J/KG OF CAPE IN
THE WESTERN CWA...BUT OTHERS HAVE ONLY SOME LIMITED ELEVATED CAPE
THIS EVENING. THE GFS HAS A STRONGER CONVECTIVE COMPLEX OVER SD
WHILE THE NORTHERN ACTIVITY IS A BIT LESS. ON THE OTHER
HAND...THINK THERE COULD BE ENOUGH INSTABILITY TO GET STORMS GOING
OVER WESTERN ND THIS AFTERNOON AND THEN COME EASTWARD AS AN MCS
LATER TONIGHT. KEPT FAIRLY HIGH POPS GOING FOR TONIGHT AND WILL
MENTION HAIL AND DAMAGING WIND THREAT IN THE HWO.
HOW TUESDAY PLAYS OUT WILL DEPEND SOMEWHAT ON HOW CONVECTION
BEHAVES TONIGHT. THE UPPER SHORTWAVE TROUGH WILL MOVE INTO THE
CWA...BUT THE SFC LOW WILL BE WELL TO OUR SOUTHEAST AND THE COLD
FRONT MAY BE THROUGH MOST OF THE CWA BY PEAK HEATING. WILL
CONTINUE TO KEEP POPS FAIRLY HIGH BUT THE COLDER AIR BUILDING IN
AS WELL AS ANY CONVECTIVE DEBRIS FROM EARLY MORNING ACTIVITY COULD
PUT A DAMPER ON ANY STRONGER STORMS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 302 AM CDT MON JUL 8 2013
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT SHOULD BE FAIRLY QUIET WITH
NORTHWESTERLY FLOW ALOFT AND SFC HIGH PRESSURE OVER THE AREA. COLD
AIR ADVECTION BEHIND THE EARLY WEEK SYSTEM SHOULD KNOCK BACK TEMPS
A BIT. HIGHS ON WEDNESDAY WILL BE IN THE 70S TO LOW 80S WITH LOWS
MAINLY IN THE 50S.
THURSDAY-SUNDAY...THE UPPER RIDGE WILL AMPLIFY ACROSS THE ROCKIES
AND HIGH PLAINS ON THURSDAY. RETURN FLOW WILL ENSUE AS THE SFC HIGH
DRIFTS EAST TOWARDS THE WESTERN GREAT LAKES. 925 MB WARM A BIT FROM
WEDNESDAY...WHICH SHOULD ALLOW TEMPS TO RISE INTO THE LOW TO MID 80S.
THE 00Z GFS/ECMWF INDICATE A STRONGER UPPER WAVE/JET STREAK
PROPAGATING INTO CENTRAL CANADA ON FRIDAY...DRAGGING A SFC BOUNDARY
INTO THE REGION...AND PROVIDING SOME POSSIBLE FOCUS FOR CONVECTION
FRI/FRI NIGHT. KEPT HIGH TEMPS ON FRIDAY IN THE LOW TO MID 80S. THE ECMWF
NOSES THE THERMAL RIDGE ACROSS THE AREA AHEAD OF THE FRONT...AND
WOULD SUGGEST A BIT WARMER TEMPS...BUT MUCH WILL DEPEND ON THE
TIMING OF THE WAVE AND ORIENTATION OF THE FLOW FIELDS.
FORECAST CONFIDENCE IS LOW FOR NEXT WEEKEND. BOTH THE GFS/ECMWF KEEP
THE UPPER RIDGE ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH
MORE ZONAL FLOW ACROSS THE NORTHERN PLAINS AS EMBEDDED SHORTWAVES
HELP TO FLATTEN THE RIDGE. THERE ARE SIGNIFICANT DIFFERENCES BETWEEN
THE GFS/ECMWF IN THE POSITION OF SURFACE AND UPPER FEATURES...WITH
THE ECMWF THE COOLER AND MORE PROGRESSIVE SOLUTION. AS SUCH...WILL
CONTINUE TO MENTION LOW POPS WITH FAIRLY SEASONABLE TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 643 AM CDT MON JUL 8 2013
THERE HAVE BEEN BRIEF PERIODS THIS MORNING WHEN KDVL AND KTVF WENT
DOWN IN VIS...BUT WEB CAMS SHOW NO SIGNIFICANT FOGGING AND THE
OBSERVATIONS HAVE IMPROVED. WILL CONTINUE TO GO WITH VFR
CONDITIONS THROUGHOUT THE PERIOD. THUNDERSTORMS WILL BEGIN MOVING
INTO THE FORECAST AREA TOWARDS THE END OF THE PERIOD...AROUND KDVL
BEFORE 06Z TONIGHT AND TO THE SITES FURTHER EAST AFTER 06Z.
WILL INCLUDE A VCTS MENTION FOR NOW DUE TO UNCERTAINTIES WITH TIMING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...JR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1155 AM EDT MON JUL 8 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS WILL
PERSIST UNTIL A COLD FRONT PASSES THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE UPPER LOW SHOWS UP WELL ON SATELLITE AND RUC ANALYSIS OVER
WESTERN PA. REGIONAL RADAR MOSAIC SHOWS SCATTERED CONVECTION
PINWHEELING AROUND THIS FEATURE FROM OHIO TO THE MID ATL COAST.
HIGH PRESSURE WILL REMAIN IN CONTROL FOR THE MOST PART TODAY IN
THE WAKE OF THE UPPER TROF/LOW. WITH THE UPPER SYSTEM PRETTY MUCH
OVERHEAD TO START THE DAY...LARGE SCALE ASCENT AND SOME MODEST
INSTABILITY WILL HELP TRIGGER SCATTERED SHOWERS/TSTMS. GRAVITY
WAVE SLIDING SE HAS HELPED KICK OFF SCT TSTMS ALONG A NORTH-
SOUTH LINE SPLITTING CWA...AND THIS CONVECTION WILL DRIFT EASTWARD
THROUGH EARLY AFTERNOON. TIMING OF THE UPPER TROF/LOW SUGGESTS
THAT MOST CONVECTION WILL LAST INTO MID AFTERNOON...WITH EXPECTED
RISING HEIGHTS AND MID LEVEL WARMING HELPING TO PUT A LID ON
THINGS LATER IN THE DAY. THE CLOUDS AND SCATTERED SHOWERS WILL
HELP LIMIT TODAY`S MAX TEMPS WITH HIGHS RANGING FROM THE MID 70S
TO MID 80S FROM NW TO SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
IN THE WAKE OF OUR DEPARTING LOW...WE WILL BEGIN TO SEE THE UPPER
FLOW BECOMING MORE WESTERLY WITH THE LOCAL AREA BEING CLOSE TO THE
SOUTHERN EDGE OF THIS WESTERLY FLOW. FOR THE OVERNIGHT THERE IS
SOME MEASURE OF AGREEMENT THAT CONVECTION CURRENTLY OVER THE
WESTERN GR LAKES WILL SPILL DOWN AND COME THROUGH THE AREA LATER AT
NIGHT AS AN MCS. THE SREF AND GEFS BOTH LATCH ONTO THIS...WITH
SLIGHT PLACEMENT DIFFERENCES. I USED THIS TO BRING HIGHER POPS
INTO THE AREA AFTER MIDNIGHT AND INTO TUESDAY MORNING. THE MODELS
DIMINISH THE INSTABILITY AFTER SUNSET SO AM NOT TOO CONCERNED
ABOUT LATE NIGHT SEVERE WEATHER...BUT SOME NOCTURNAL ELEVATED
THUNDER LOOKS LIKE A REASONABLE POSSIBILITY.
ONCE THE CONVECTION PASSES...PROBABLY BY MID TO LATE MORNING
TUESDAY...THE AFTERNOON SHOULD BE RELATIVELY QUIET WITH
TEMPERATURES REBOUNDING WELL INTO THE 80S REGION-WIDE...WITH THE
HUMIDITY HANGING IN TOUGH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD OF NEARLY ZONAL FLOW ALOFT WILL BE RELATIVELY SHORT-LIVED
AS THE ROCKIES RIDGE IS EXPECTED TO EXPERIENCE A
RESURGENCE...RESULTING IN THE DOWNSTREAM TROUGH DIGGING OVER THE
EASTERN US.
YESTERDAY`S MODEL RUNS SHOWED THE DEVELOPMENT OF A PATTERN THAT
LOOKED MUCH LIKE WHAT WE WERE RECENTLY SADDLED WITH FOR OVER A
WEEK WITH A DEEP LOW OVER THE TN/OH VALLEY AND A STRONG BERMUDA
RIDGE NOSING INTO THE EASTERN SEABOARD KEEPING A DEEP SOUTHERLY
FLOW OF TROPICAL AIR LOCKED IN OVER THE EASTERN US. THE LATEST
RUNS DO CREATE AN UPPER LOW/TROUGH BUT TONIGHT THE GUIDANCE
IS FASTER AND DOESN`T STALL THE LOW. INDICATIONS ARE THAT WHATEVER
FORMS BETWEEN THE BERMUDA RIDGE AND THE RIDGE IN THE ROCKIES WILL
BE RELATIVELY WEAK AND EITHER SETTLE SOUTH INTO THE GULF OR BECOME
LOST AS A GENERAL WEAKNESS BETWEEN WHAT THE GEFS SHOWS AS A HUGE
AREA OF ANOMALOUSLY HIGH HEIGHTS ASSOCIATED WITH THE SUBTROPICAL
RIDGE FROM THE CENTRAL ATLANTIC ALL THE WAY WEST TO THE ROCKY
MOUNTAINS BY NEXT WEEKEND.
THIS IS INTERESTING FOR THE EVENTUAL DEVELOPMENTS ASSOCIATED WITH
CHANTAL. WHILE THE STORM IS EXPECTED TO ENCOUNTER LAND AS WELL AS
INCREASING WIND SHEAR...AND THERE IS SOME QUESTION THAT IT WILL
EVEN SURVIVE AS IT TREKS WESTWARD TOWARD THE CARIBBEAN OR
BAHAMAS...IF IT DOES SURVIVE...THE EVENTUAL PATH SEEMS PAVED FOR
A TRACK INTO THE SERN US OR THE EAST COAST AS THE SUBTROPICAL
RIDGE LOOKS ABNORMALLY MIGHTY FOR THIS TIME OF YEAR. STILL THE
BETTER PART OF A WEEK BEFORE THAT HAPPENS.
IN THE MEAN TIME A DECENT LOOKING COLD FRONT IS EXPECTED TO PASS
THROUGH THE REGION ALONG ABOUT THURSDAY ASSOCIATED WITH THE UPPER
TROUGH THAT IS EXPECTED TO DEVELOP OVER THE EASTERN US. IT SHOULD
USHER IN SOME DRIER AIR FOR THE WEEK`S END THAT COULD LAST A DAY
OR TWO BEFORE THE RIDGE REASSERTS ITSELF LOCALLY. OVERALL IT LOOKS
LIKE ANOTHER VERY SUMMERY WEEK...PRETTY TYPICAL FOR EARLY JULY.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
EXPECT WIDESPREAD VFR CONDS THIS AFTERNOON. HOWEVER...PASSAGE OF
UPPER LVL TROUGH WILL BRING A CHC OF BRIEF SHRA/TSRA AND
ACCOMPANYING LOCAL RESTRICTIONS THROUGH AFTERNOON HOURS.
WE/LL SEE A MINIMUM OF CONVECTION THIS EVE. BUT LATER
TONIGHT INTO EARLY TUES...MODELS SHOWING MCS SYSTEM DROPPING
ACROSS CWA FROM GLAKES.
WED COULD FEATURE SOME STRONG STORMS WITH PASSAGE OF A COLD
FRONT...GIVEN STRONG DYNAMICS AND WARM ADVECTION.
PERHAPS BETTER AVIATION WEATHER BY LATE IN THE WEEK.
OUTLOOK...
TUE...AM SHRA/LOW CIGS POSS W MTNS.
WED-THU...AM LOW CIGS POSS W MTNS. SCT TSRA IMPACTS
POSS...MAINLY PM.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...LA CORTE/RXR
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...MARTIN/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
827 AM EDT MON JUL 8 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS WILL
PERSIST UNTIL A COLD FRONT PASSES THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE UPPER LOW SHOWS UP WELL ON SATELLITE AND RUC ANALYSIS OVER
WESTERN PA. REGIONAL RADAR MOSAIC SHOWS SCATTERED CONVECTION
PINWHEELING AROUND THIS FEATURE FROM OHIO TO THE MID ATL COAST.
HIGH PRESSURE WILL REMAIN IN CONTROL FOR THE MOST PART TODAY IN
THE WAKE OF THE UPPER TROF/LOW. WITH THE UPPER SYSTEM PRETTY MUCH
OVERHEAD TO START THE DAY...LARGE SCALE ASCENT AND SOME MODEST
INSTABILITY WILL HELP TRIGGER SOME SCATTERED SHOWERS. TIMING OF
THE UPPER TROF/LOW SUGGESTS THAT MOST SHOWERS WILL BE FROM LATE
MORNING THROUGH MID AFTERNOON...WITH EXPECTED RISING HEIGHTS AND
MID LEVEL WARMING HELPING TO PUT A LID ON THINGS LATER IN THE DAY.
THE CLOUDS AND SCATTERED SHOWERS WILL HELP LIMIT TODAY`S MAX TEMPS
WITH HIGHS RANGING FROM THE MID 70S TO MID 80S FROM NW TO SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
IN THE WAKE OF OUR DEPARTING LOW...WE WILL BEGIN TO SEE THE UPPER
FLOW BECOMING MORE WESTERLY WITH THE LOCAL AREA BEING CLOSE TO THE
SOUTHERN EDGE OF THIS WESTERLY FLOW. FOR THE OVERNIGHT THERE IS
SOME MEASURE OF AGREEMENT THAT CONVECTION CURRENTLY OVER THE
WESTERN GR LAKES WILL SPILL DOWN AND COME THROUGH THE AREA LATER AT
NIGHT AS AN MCS. THE SREF AND GEFS BOTH LATCH ONTO THIS...WITH
SLIGHT PLACEMENT DIFFERENCES. I USED THIS TO BRING HIGHER POPS
INTO THE AREA AFTER MIDNIGHT AND INTO TUESDAY MORNING. THE MODELS
DIMINISH THE INSTABILITY AFTER SUNSET SO AM NOT TOO CONCERNED
ABOUT LATE NIGHT SEVERE WEATHER...BUT SOME NOCTURNAL ELEVATED
THUNDER LOOKS LIKE A REASONABLE POSSIBILITY.
ONCE THE CONVECTION PASSES...PROBABLY BY MID TO LATE MORNING
TUESDAY...THE AFTERNOON SHOULD BE RELATIVELY QUIET WITH
TEMPERATURES REBOUNDING WELL INTO THE 80S REGION-WIDE...WITH THE
HUMIDITY HANGING IN TOUGH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD OF NEARLY ZONAL FLOW ALOFT WILL BE RELATIVELY SHORT-LIVED
AS THE ROCKIES RIDGE IS EXPECTED TO EXPERIENCE A
RESURGENCE...RESULTING IN THE DOWNSTREAM TROUGH DIGGING OVER THE
EASTERN US.
YESTERDAY`S MODEL RUNS SHOWED THE DEVELOPMENT OF A PATTERN THAT
LOOKED MUCH LIKE WHAT WE WERE RECENTLY SADDLED WITH FOR OVER A
WEEK WITH A DEEP LOW OVER THE TN/OH VALLEY AND A STRONG BERMUDA
RIDGE NOSING INTO THE EASTERN SEABOARD KEEPING A DEEP SOUTHERLY
FLOW OF TROPICAL AIR LOCKED IN OVER THE EASTERN US. THE LATEST
RUNS DO CREATE AN UPPER LOW/TROUGH BUT TONIGHT THE GUIDANCE
IS FASTER AND DOESN`T STALL THE LOW. INDICATIONS ARE THAT WHATEVER
FORMS BETWEEN THE BERMUDA RIDGE AND THE RIDGE IN THE ROCKIES WILL
BE RELATIVELY WEAK AND EITHER SETTLE SOUTH INTO THE GULF OR BECOME
LOST AS A GENERAL WEAKNESS BETWEEN WHAT THE GEFS SHOWS AS A HUGE
AREA OF ANOMALOUSLY HIGH HEIGHTS ASSOCIATED WITH THE SUBTROPICAL
RIDGE FROM THE CENTRAL ATLANTIC ALL THE WAY WEST TO THE ROCKY
MOUNTAINS BY NEXT WEEKEND.
THIS IS INTERESTING FOR THE EVENTUAL DEVELOPMENTS ASSOCIATED WITH
CHANTAL. WHILE THE STORM IS EXPECTED TO ENCOUNTER LAND AS WELL AS
INCREASING WIND SHEAR...AND THERE IS SOME QUESTION THAT IT WILL
EVEN SURVIVE AS IT TREKS WESTWARD TOWARD THE CARIBBEAN OR
BAHAMAS...IF IT DOES SURVIVE...THE EVENTUAL PATH SEEMS PAVED FOR
A TRACK INTO THE SERN US OR THE EAST COAST AS THE SUBTROPICAL
RIDGE LOOKS ABNORMALLY MIGHTY FOR THIS TIME OF YEAR. STILL THE
BETTER PART OF A WEEK BEFORE THAT HAPPENS.
IN THE MEAN TIME A DECENT LOOKING COLD FRONT IS EXPECTED TO PASS
THROUGH THE REGION ALONG ABOUT THURSDAY ASSOCIATED WITH THE UPPER
TROUGH THAT IS EXPECTED TO DEVELOP OVER THE EASTERN US. IT SHOULD
USHER IN SOME DRIER AIR FOR THE WEEK`S END THAT COULD LAST A DAY
OR TWO BEFORE THE RIDGE REASSERTS ITSELF LOCALLY. OVERALL IT LOOKS
LIKE ANOTHER VERY SUMMERY WEEK...PRETTY TYPICAL FOR EARLY JULY.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
EXPECT A WIDE RANGE OF CONDITIONS FOR ANOTHER HOUR OR SO.
SOME SITES WILL BE VFR...WHILE OTHERS WILL HAVE FOG AND LOWER
CIGS...IFR AT TIMES.
ANY EARLY LOW CIGS/FOG SHOULD MIX OUT TO VFR CONDS BY 14Z.
FOR THE REST OF MONDAY...EXPECT WIDESPREAD VFR CONDS.
HOWEVER...PASSAGE OF UPPER LVL TROUGH WILL BRING A CHC OF
A BRIEF SHRA/TSRA AND ACCOMPANYING DROP IN VSBY. AS THE
UPPER LVL TROUGH IS FURTHER EAST TODAY...WOULD NOT EXPECT
THE WIDESPREAD SHOWERS AND STORMS THAT WE HAD ON SUNDAY.
AS OF RECENT LOOPS...UPPER LVL LOW ACROSS WARREN COUNTY.
WHILE NOT LOOKING FOR SEVERE STORMS TODAY OR WIDESPREAD
HEAVY RAIN...HAVE TO WATCH STORMS...AS THEY WILL BE SLOW
TO MOVE.
LATER TONIGHT...MODELS AND DATA HINT AT MORE STORMS...MAINLY
ACROSS THE FAR WEST.
MORE ACTIVE WEATHER ON TUE AND WED. WED COULD FEATURE SOME
STRONG STORMS...GIVEN STRONG DYNAMICS AND WARM ADVECTION.
PERHAPS BETTER AVIATION WEATHER BY LATE IN THE WEEK.
OUTLOOK...
TUE...AM SHRA/LOW CIGS POSS W MTNS.
WED-THU...AM LOW CIGS POSS W MTNS. SCT TSRA IMPACTS
POSS...MAINLY PM.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...LA CORTE/RXR
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
747 AM EDT MON JUL 8 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS WILL
PERSIST UNTIL A COLD FRONT PASSES THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE UPPER LOW SHOWS UP WELL ON SATELLITE AND RUC ANALYSIS OVER
WESTERN PA. REGIONAL RADAR MOSAIC SHOWS SCATTERED CONVECTION
PINWHEELING AROUND THIS FEATURE FROM OHIO TO THE MID ATL COAST.
SOME SHOWERS LOOK TO BE AIMING AT FAR SERN PA FOR THE NEXT FEW
HOURS...OTHERWISE THE REGION IS DRY.
HIGH PRESSURE WILL REMAIN IN CONTROL FOR THE MOST PART TODAY IN
THE WAKE OF THE UPPER TROF/LOW. WITH THE UPPER SYSTEM PRETTY MUCH
OVERHEAD TO START THE DAY...LARGE SCALE ASCENT AND SOME MODEST
INSTABILITY WILL HELP TRIGGER SOME SCATTERED SHOWERS. TIMING OF
THE UPPER TROF/LOW SUGGESTS THAT MOST SHOWERS WILL BE FROM LATE
MORNING THROUGH MID AFTERNOON...WITH EXPECTED RISING HEIGHTS AND
MID LEVEL WARMING HELPING TO PUT A LID ON THINGS LATER IN THE DAY.
THE CLOUDS AND SCATTERED SHOWERS WILL HELP LIMIT TODAY`S MAX TEMPS
WITH HIGHS RANGING FROM THE MID 70S TO MID 80S FROM NW TO SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
IN THE WAKE OF OUR DEPARTING LOW...WE WILL BEGIN TO SEE THE UPPER
FLOW BECOMING MORE WESTERLY WITH THE LOCAL AREA BEING CLOSE TO THE
SOUTHERN EDGE OF THIS WESTERLY FLOW. FOR THE OVERNIGHT THERE IS
SOME MEASURE OF AGREEMENT THAT CONVECTION CURRENTLY OVER THE
WESTERN GR LAKES WILL SPILL DOWN AND COME THROUGH THE AREA LATER AT
NIGHT AS AN MCS. THE SREF AND GEFS BOTH LATCH ONTO THIS...WITH
SLIGHT PLACEMENT DIFFERENCES. I USED THIS TO BRING HIGHER POPS
INTO THE AREA AFTER MIDNIGHT AND INTO TUESDAY MORNING. THE MODELS
DIMINISH THE INSTABILITY AFTER SUNSET SO AM NOT TOO CONCERNED
ABOUT LATE NIGHT SEVERE WEATHER...BUT SOME NOCTURNAL ELEVATED
THUNDER LOOKS LIKE A REASONABLE POSSIBILITY.
ONCE THE CONVECTION PASSES...PROBABLY BY MID TO LATE MORNING
TUESDAY...THE AFTERNOON SHOULD BE RELATIVELY QUIET WITH
TEMPERATURES REBOUNDING WELL INTO THE 80S REGION-WIDE...WITH THE
HUMIDITY HANGING IN TOUGH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD OF NEARLY ZONAL FLOW ALOFT WILL BE RELATIVELY SHORT-LIVED
AS THE ROCKIES RIDGE IS EXPECTED TO EXPERIENCE A
RESURGENCE...RESULTING IN THE DOWNSTREAM TROUGH DIGGING OVER THE
EASTERN US.
YESTERDAY`S MODEL RUNS SHOWED THE DEVELOPMENT OF A PATTERN THAT
LOOKED MUCH LIKE WHAT WE WERE RECENTLY SADDLED WITH FOR OVER A
WEEK WITH A DEEP LOW OVER THE TN/OH VALLEY AND A STRONG BERMUDA
RIDGE NOSING INTO THE EASTERN SEABOARD KEEPING A DEEP SOUTHERLY
FLOW OF TROPICAL AIR LOCKED IN OVER THE EASTERN US. THE LATEST
RUNS DO CREATE AN UPPER LOW/TROUGH BUT TONIGHT THE GUIDANCE
IS FASTER AND DOESN`T STALL THE LOW. INDICATIONS ARE THAT WHATEVER
FORMS BETWEEN THE BERMUDA RIDGE AND THE RIDGE IN THE ROCKIES WILL
BE RELATIVELY WEAK AND EITHER SETTLE SOUTH INTO THE GULF OR BECOME
LOST AS A GENERAL WEAKNESS BETWEEN WHAT THE GEFS SHOWS AS A HUGE
AREA OF ANOMALOUSLY HIGH HEIGHTS ASSOCIATED WITH THE SUBTROPICAL
RIDGE FROM THE CENTRAL ATLANTIC ALL THE WAY WEST TO THE ROCKY
MOUNTAINS BY NEXT WEEKEND.
THIS IS INTERESTING FOR THE EVENTUAL DEVELOPMENTS ASSOCIATED WITH
CHANTAL. WHILE THE STORM IS EXPECTED TO ENCOUNTER LAND AS WELL AS
INCREASING WIND SHEAR...AND THERE IS SOME QUESTION THAT IT WILL
EVEN SURVIVE AS IT TREKS WESTWARD TOWARD THE CARIBBEAN OR
BAHAMAS...IF IT DOES SURVIVE...THE EVENTUAL PATH SEEMS PAVED FOR
A TRACK INTO THE SERN US OR THE EAST COAST AS THE SUBTROPICAL
RIDGE LOOKS ABNORMALLY MIGHTY FOR THIS TIME OF YEAR. STILL THE
BETTER PART OF A WEEK BEFORE THAT HAPPENS.
IN THE MEAN TIME A DECENT LOOKING COLD FRONT IS EXPECTED TO PASS
THROUGH THE REGION ALONG ABOUT THURSDAY ASSOCIATED WITH THE UPPER
TROUGH THAT IS EXPECTED TO DEVELOP OVER THE EASTERN US. IT SHOULD
USHER IN SOME DRIER AIR FOR THE WEEK`S END THAT COULD LAST A DAY
OR TWO BEFORE THE RIDGE REASSERTS ITSELF LOCALLY. OVERALL IT LOOKS
LIKE ANOTHER VERY SUMMERY WEEK...PRETTY TYPICAL FOR EARLY JULY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
EXPECT A WIDE RANGE OF CONDITIONS FOR ANOTHER HOUR OR SO.
SOME SITES WILL BE VFR...WHILE OTHERS WILL HAVE FOG AND LOWER
CIGS...IFR AT TIMES.
ANY EARLY LOW CIGS/FOG SHOULD MIX OUT TO VFR CONDS BY 14Z.
FOR THE REST OF MONDAY...EXPECT WIDESPREAD VFR CONDS.
HOWEVER...PASSAGE OF UPPER LVL TROUGH WILL BRING A CHC OF
A BRIEF SHRA/TSRA AND ACCOMPANYING DROP IN VSBY. AS THE
UPPER LVL TROUGH IS FURTHER EAST TODAY...WOULD NOT EXPECT
THE WIDESPREAD SHOWERS AND STORMS THAT WE HAD ON SUNDAY.
AS OF RECENT LOOPS...UPPER LVL LOW ACROSS WARREN COUNTY.
WHILE NOT LOOKING FOR SEVERE STORMS TODAY OR WIDESPREAD
HEAVY RAIN...HAVE TO WATCH STORMS...AS THEY WILL BE SLOW
TO MOVE.
LATER TONIGHT...MODELS AND DATA HINT AT MORE STORMS...MAINLY
ACROSS THE FAR WEST.
MORE ACTIVE WEATHER ON TUE AND WED. WED COULD FEATURE SOME
STRONG STORMS...GIVEN STRONG DYNAMICS AND WARM ADVECTION.
PERHAPS BETTER AVIATION WEATHER BY LATE IN THE WEEK.
OUTLOOK...
TUE...AM SHRA/LOW CIGS POSS W MTNS.
WED-THU...AM LOW CIGS POSS W MTNS. SCT TSRA IMPACTS
POSS...MAINLY PM.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
614 AM EDT MON JUL 8 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS WILL
PERSIST UNTIL A COLD FRONT PASSES THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE UPPER LOW SHOWS UP WELL ON SATELLITE AND RUC ANALYSIS OVER
WESTERN PA. REGIONAL RADAR MOSAIC SHOWS SCATTERED CONVECTION
PINWHEELING AROUND THIS FEATURE FROM OHIO TO THE MID ATL COAST.
SOME SHOWERS LOOK TO BE AIMING AT FAR SERN PA FOR THE NEXT FEW
HOURS...OTHERWISE THE REGION IS DRY.
HIGH PRESSURE WILL REMAIN IN CONTROL FOR THE MOST PART TODAY IN
THE WAKE OF THE UPPER TROF/LOW. WITH THE UPPER SYSTEM PRETTY MUCH
OVERHEAD TO START THE DAY...LARGE SCALE ASCENT AND SOME MODEST
INSTABILITY WILL HELP TRIGGER SOME SCATTERED SHOWERS. TIMING OF
THE UPPER TROF/LOW SUGGESTS THAT MOST SHOWERS WILL BE FROM LATE
MORNING THROUGH MID AFTERNOON...WITH EXPECTED RISING HEIGHTS AND
MID LEVEL WARMING HELPING TO PUT A LID ON THINGS LATER IN THE DAY.
THE CLOUDS AND SCATTERED SHOWERS WILL HELP LIMIT TODAY`S MAX TEMPS
WITH HIGHS RANGING FROM THE MID 70S TO MID 80S FROM NW TO SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
IN THE WAKE OF OUR DEPARTING LOW...WE WILL BEGIN TO SEE THE UPPER
FLOW BECOMING MORE WESTERLY WITH THE LOCAL AREA BEING CLOSE TO THE
SOUTHERN EDGE OF THIS WESTERLY FLOW. FOR THE OVERNIGHT THERE IS
SOME MEASURE OF AGREEMENT THAT CONVECTION CURRENTLY OVER THE
WESTERN GR LAKES WILL SPILL DOWN AND COME THROUGH THE AREA LATER AT
NIGHT AS AN MCS. THE SREF AND GEFS BOTH LATCH ONTO THIS...WITH
SLIGHT PLACEMENT DIFFERENCES. I USED THIS TO BRING HIGHER POPS
INTO THE AREA AFTER MIDNIGHT AND INTO TUESDAY MORNING. THE MODELS
DIMINISH THE INSTABILITY AFTER SUNSET SO AM NOT TOO CONCERNED
ABOUT LATE NIGHT SEVERE WEATHER...BUT SOME NOCTURNAL ELEVATED
THUNDER LOOKS LIKE A REASONABLE POSSIBILITY.
ONCE THE CONVECTION PASSES...PROBABLY BY MID TO LATE MORNING
TUESDAY...THE AFTERNOON SHOULD BE RELATIVELY QUIET WITH
TEMPERATURES REBOUNDING WELL INTO THE 80S REGION-WIDE...WITH THE
HUMIDITY HANGING IN TOUGH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD OF NEARLY ZONAL FLOW ALOFT WILL BE RELATIVELY SHORT-LIVED
AS THE ROCKIES RIDGE IS EXPECTED TO EXPERIENCE A
RESURGENCE...RESULTING IN THE DOWNSTREAM TROUGH DIGGING OVER THE
EASTERN US.
YESTERDAY`S MODEL RUNS SHOWED THE DEVELOPMENT OF A PATTERN THAT
LOOKED MUCH LIKE WHAT WE WERE RECENTLY SADDLED WITH FOR OVER A
WEEK WITH A DEEP LOW OVER THE TN/OH VALLEY AND A STRONG BERMUDA
RIDGE NOSING INTO THE EASTERN SEABOARD KEEPING A DEEP SOUTHERLY
FLOW OF TROPICAL AIR LOCKED IN OVER THE EASTERN US. THE LATEST
RUNS DO CREATE AN UPPER LOW/TROUGH BUT TONIGHT THE GUIDANCE
IS FASTER AND DOESN`T STALL THE LOW. INDICATIONS ARE THAT WHATEVER
FORMS BETWEEN THE BERMUDA RIDGE AND THE RIDGE IN THE ROCKIES WILL
BE RELATIVELY WEAK AND EITHER SETTLE SOUTH INTO THE GULF OR BECOME
LOST AS A GENERAL WEAKNESS BETWEEN WHAT THE GEFS SHOWS AS A HUGE
AREA OF ANOMALOUSLY HIGH HEIGHTS ASSOCIATED WITH THE SUBTROPICAL
RIDGE FROM THE CENTRAL ATLANTIC ALL THE WAY WEST TO THE ROCKY
MOUNTAINS BY NEXT WEEKEND.
THIS IS INTERESTING FOR THE EVENTUAL DEVELOPMENTS ASSOCIATED WITH
CHANTAL. WHILE THE STORM IS EXPECTED TO ENCOUNTER LAND AS WELL AS
INCREASING WIND SHEAR...AND THERE IS SOME QUESTION THAT IT WILL
EVEN SURVIVE AS IT TREKS WESTWARD TOWARD THE CARIBBEAN OR
BAHAMAS...IF IT DOES SURVIVE...THE EVENTUAL PATH SEEMS PAVED FOR
A TRACK INTO THE SERN US OR THE EAST COAST AS THE SUBTROPICAL
RIDGE LOOKS ABNORMALLY MIGHTY FOR THIS TIME OF YEAR. STILL THE
BETTER PART OF A WEEK BEFORE THAT HAPPENS.
IN THE MEAN TIME A DECENT LOOKING COLD FRONT IS EXPECTED TO PASS
THROUGH THE REGION ALONG ABOUT THURSDAY ASSOCIATED WITH THE UPPER
TROUGH THAT IS EXPECTED TO DEVELOP OVER THE EASTERN US. IT SHOULD
USHER IN SOME DRIER AIR FOR THE WEEK`S END THAT COULD LAST A DAY
OR TWO BEFORE THE RIDGE REASSERTS ITSELF LOCALLY. OVERALL IT LOOKS
LIKE ANOTHER VERY SUMMERY WEEK...PRETTY TYPICAL FOR EARLY JULY.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
CONDITIONS CONTINUE TO GO DOWNHILL. SOME UPDATES DONE...
WILL CONTINUE TO MONITOR.
EXPECT A WIDE RANGE OF CONDITIONS EARLY THIS MORNING.
SOME SITES WILL BE VFR...WHILE OTHERS WILL HAVE FOG AND
LOWER CIGS...IFR AT TIMES.
ANY EARLY LOW CIGS/FOG SHOULD MIX OUT TO VFR CONDS BY 14Z.
FOR THE REST OF MONDAY...EXPECT WIDESPREAD VFR CONDS.
HOWEVER...PASSAGE OF UPPER LVL TROUGH WILL BRING A CHC OF
A BRIEF SHRA/TSRA AND ACCOMPANYING DROP IN VSBY. AS THE
UPPER LVL TROUGH IS FURTHER EAST TODAY...WOULD NOT EXPECT
THE WIDESPREAD SHOWERS AND STORMS THAT WE HAD ON SUNDAY.
OUTLOOK...
TUE...AM SHRA/LOW CIGS POSS W MTNS.
WED-THU...AM LOW CIGS POSS W MTNS. SCT TSRA IMPACTS
POSS...MAINLY PM.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1011 AM CDT MON JUL 8 2013
UPDATE...
THE MUCH NEEDED AND ANTICIPATED RAINFALL AND ITS RECENT
BEHAVIOR HAS CERTAINLY SEPARATED THE HAVE AND THE HAVE NOTS WITH
SOME COUNTIES...SUCH AS JACKSON AND WHARTON...RECEIVING OVER AN
INCH OR TWO WHILE MOST OTHERS HAVE BEEN FORTUNATE TO HAVE ONLY
PICKED UP A FEW HUNDREDTHS OF AN INCH (OR LESS).
MOISTURE DEFINITELY HAS NOT BEEN A PROBLEM...THE TROPICAL AIR
MASS OVER THE CWA IS GREATER THAN 2 INCHES (75 PERCENTILE FOR
EARLY JULY) WITH THE DEEPEST REGIONAL MOISTURE UP THROUGH 700 MB
CENTERED RIGHT OVER SOUTHEASTERN TEXAS. WITH NO SIGNIFICANT
TRIGGER (UPSTREAM DISTURBANCE OR RESIDUAL BOUNDARIES) TO INITIATE
BETTER CONVECTIVE AREAL COVERAGE...THE RAGGED NATURE OF THIS
MORNING`S ACTIVITY WILL HAVE TO RELY UPON INSOLATION FOR
SUSTAINABILITY. AS THE SUN ROSE TO MOSTLY CLOUDY CONDITIONS...MODEST
CHANCE MORNING POPS WILL SHARPLY DECLINE THROUGH THE AFTERNOON.
COLUMN WILL BEGIN TO DRY OUT PER THE SOUTHERN TRANSPORT OF A
DRIER AIR MASS INLAND...UPPER 90 CONVECTIVE TEMPERATURES WILL BE
HARD TO REACH PER THIS EARLY DAY CLOUD DECK. THE 594 DAM UPPER
RIDGE CENTERED OVER NORTHERN TEXAS WILL BE WHAT CONTROLS OUR
WEATHER PATTERN IN THE FORESEEABLE FUTURE. HEAT AND THE LACK OF
RAIN WILL BE THE TOPICS DU JOUR. 31
&&
PREV DISCUSSION... /ISSUED 619 AM CDT MON JUL 8 2013/
AVIATION...
SHOWERS FILLING IN ACROSS THE WESTERN THIRD OF THE REGION WITH
SOME ADDITIONAL ACTIVITY MOVING IN FROM THE GULF OF MEXICO. BEST
COVERAGE WILL REMAIN WEST OF THE TAF SITES BUT WILL CARRY VCSH FOR
MOST OF THE MORNING BEFORE DRIER AIR BEGINS TO MOVE INTO THE
REGION. MODELS ARE HINTING AT THE POTENTIAL FOR SOME MVFR/IFR CIGS
AROUND DAYBREAK ON TUESDAY BUT THIS SEEMS A BIT AGGRESSIVE. WILL
PUT SOME LOW CLOUDS INTO THE TAF BUT HAVE HELD OFF ON ANY CIGS FOR
THIS ISSUANCE. 38
&&
PREV DISCUSSION... /ISSUED 430 AM CDT MON JUL 8 2013/
DISCUSSION...
THE FORECAST HAS BEEN FRUSTRATING THE LAST 24 HOURS GIVEN THE
PROSPECTS OF RAIN CHANCES FOR YESTERDAY. GOES SOUNDER PRECIP WATER
AND 00Z SOUNDINGS FROM CRP AND LCH SHOW THAT A TROPICAL AIRMASS
WITH PW AROUND 2.2 INCHES HAS MOVED OVER SE TX. DESPITE THAT THERE
HAS BEEN VERY LITTLE SIGNIFICANT RAINFALL ACROSS THE AREA. IT
SEEMS THAT THE UPPER LEVEL PATTERN HAS NOT BEEN SUPPORTIVE OF
CONVECTION IN HIND SIGHT. THE LAST COUPLE OF DAYS HAVE FEATURED A
SHEAR AXIS OVER THE AREA WITH AN UPPER LEVEL RIDGE EXPANDING INTO
THE PLAINS AS AN UPPER LOW EXITS THE REGION TOWARDS THE GREAT
LAKES. SEEMS LIKE THE SHEAR AXIS DID NOT WEAKEN AS MUCH AS THE
MODELS SUGGESTED AND WHEN IT DID...SUBSIDENCE FROM THE RIDGE WAS
APPARENTLY STRONG ENOUGH TO LIMIT CONVECTION.
GOING FORWARD TO TODAY...THINK WE WILL SEE MUCH OF THE SAME.
UPPER AIR ANALYSIS STILL HAS A DECENT RIDGE OVER THE S PLAINS AND
S ROCKIES. FORECAST WILL STILL KEEP SOME 30/40 POPS FOR THIS
MORNING AS EXPECT THERE TO BE AT LEAST SOME CONVECTION WITH
DAYTIME HEATING. THE PROBLEM IS THAT GOES SOUNDER DATA DOES SHOW
DRIER AIR IN THE GULF WITH PRECIP WATER VALUES NEAR 1.6 INCHES
THAT THE MODELS FORECAST TO MOVE INTO THE REGION LATER TODAY. WITH
THAT IN MIND...WILL DROP POPS TO 30 PERCENT IN THE AFTERNOON BUT
THINK THAT MAY EVEN BE OPTIMISTIC. HRRR MESOSCALE MODEL SHOWS
SIMILAR EVOLUTION OF CONVECTION WITH MOST OF THE ACTIVITY
OCCURRING IN THE LATE MORNING/EARLY AFTERNOON HOURS. EVEN WRF-NMM
SHOWS CONVECTIVE TRENDS SIMILAR TO THIS THINKING.
DEEPER MOISTURE WILL BE RATHER TRANSIENT TUE/WED. AGAIN THINK THE
RIDGE WILL BE THE MAIN PROBLEM INHIBITING CONVECTION. THAT
SAID...MAY GET ENOUGH MOISTURE MAINLY ON WED TO GET A FEW STORMS
AND ENOUGH REASON TO KEEP 20/30 POPS IN THE FORECAST. BY THE END
OF THE WEEK THE RIDGE LOOKS TO EXPAND AND STRENGTHEN OVER THE
ROCKIES AND PLAINS. WITH LESS MOISTURE...DO NOT THINK THERE WILL
BE ANY RAIN CHANCES FOR THUR/FRI/SAT. ALSO SEE MAX TEMPS GETTING
INTO THE UPPER 90S PERHAPS A FEW 100S FOR THE NORTHERN COUNTIES OF
THE FORECAST AREA DUE TO THE RIDGE. BOTH THE GFS/ECMWF HAVE BEEN
HINTING AT A TROUGH/UPPER LOW DEVELOPING OVER THE APPALACHIANS AND
THEN RETROGRADING INTO THE AREA. GFS GOES AS FAR AS TO PUSH WEAK
BACK DOOR FRONT INTO THE AREA. THINK THIS MAY BE A BIT AGGRESSIVE
AND TRENDED THE FORECAST CLOSER TO THE ECMWF SOLUTION. ECMWF HAS
THE FRONT STALLING WELL BEFORE REACHING SE TX AND HAS MORE OF AN
ELONGATED TROUGH STRETCHING INTO THE AREA FOR NEXT WEEKEND. GIVEN
LOWER HEIGHTS...DECIDED 20 POPS MAY BE NEEDED WITH THE INFLUENCE
OF THE RIDGE MORE OVER THE C PLAINS. DID NOT TRIM BACK MAX TEMPS
TOO MUCH BUT STILL A COUPLE OF DEGREES ABOVE GFS GUIDANCE. 39
&&
MARINE...
WINDS HAVE PICKED UP A BIT ACROSS THE FAR OFFSHORE WATERS WITH
SEAS SILL RUNNING AROUND 5 FEET. WILL CONTINUE THE SCEC THROUGH
MID MORNING BUT OVERALL TREND EXPECTED TO BE A LOWERING OF SEAS
THROUGH THE MORNING HOURS. SCATTERED SHOWERS EXPECTED TO DEVELOP
THIS MORNING AS A WEAK UPPER DISTURBANCE PASSES OVERHEAD. EXPECT
DECREASING COVERAGE ACROSS THE COASTAL WATERS FOR THE AFTERNOON
AND EVENING HOURS TODAY. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 97 75 98 76 98 / 30 10 10 10 20
HOUSTON (IAH) 94 76 95 76 96 / 50 10 20 20 30
GALVESTON (GLS) 89 81 91 81 91 / 20 10 20 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 1 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
HIGH ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...31/43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
950 AM CDT MON JUL 8 2013
.UPDATE...
THE MUCH NEEDED AND ANTICIPATED RAINFALL AND ITS RECENT BEHAVIOR
HAS CERTAINLY SEPARATED THE HAVE AND THE HAVE NOTS WITH SOME
COUNTIES...SUCH AS JACKSON AND WHARTON...RECEIVING OVER AN INCH OR
TWO WHILE MOST OTHERS HAVE BEEN FORTUNATE TO HAVE ONLY PICKED UP
A FEW HUNDREDTHS OF AN INCH (OR LESS).
MOISTURE DEFINITELY HAS NOT BEEN A PROBLEM...THE TROPICAL AIR
MASS OVER THE CWA IS GREATER THAN 2 INCHES (75 PERCENTILE FOR
EARLY JULY) WITH THE DEEPEST REGIONAL MOISTURE UP THROUGH 700 MB
CENTERED RIGHT OVER SOUTHEASTERN TEXAS. WITH NO SIGNIFICANT
TRIGGER (UPSTREAM DISTURBANCE OR RESIDUAL BOUNDARIES) TO INITIATE
BETTER CONVECTIVE AREAL COVERAGE...THE RAGGED NATURE OF THIS
MORNING`S ACTIVITY WILL HAVE TO RELY UPON INSOLATION FOR
SUSTAINABILITY. AS THE SUN ROSE TO MOSTLY CLOUDY CONDITIONS...MODEST
CHANCE MORNING POPS WILL SHARPLY DECLINE THROUGH THE AFTERNOON.
COLUMN WILL BEGIN TO DRY OUT PER THE SOUTHERN TRANSPORT OF A
DRIER AIR MASS INLAND...UPPER 90 CONVECTIVE TEMPERATURES WILL BE
HARD TO REACH PER THIS EARLY DAY CLOUD DECK. THE 594 DAM UPPER
RIDGE CENTERED OVER NORTHERN TEXAS WILL BE WHAT CONTROLS OUR
WEATHER PATTERN IN THE FORESEEABLE FUTURE. HEAT AND THE LACK OF
RAIN WILL BE THE TOPICS DU JOUR. 31
&&
.PREV DISCUSSION... /ISSUED 619 AM CDT MON JUL 8 2013/
AVIATION...
SHOWERS FILLING IN ACROSS THE WESTERN THIRD OF THE REGION WITH
SOME ADDITIONAL ACTIVITY MOVING IN FROM THE GULF OF MEXICO. BEST
COVERAGE WILL REMAIN WEST OF THE TAF SITES BUT WILL CARRY VCSH FOR
MOST OF THE MORNING BEFORE DRIER AIR BEGINS TO MOVE INTO THE
REGION. MODELS ARE HINTING AT THE POTENTIAL FOR SOME MVFR/IFR CIGS
AROUND DAYBREAK ON TUESDAY BUT THIS SEEMS A BIT AGGRESSIVE. WILL
PUT SOME LOW CLOUDS INTO THE TAF BUT HAVE HELD OFF ON ANY CIGS FOR
THIS ISSUANCE. 38
PREV DISCUSSION... /ISSUED 430 AM CDT MON JUL 8 2013/
DISCUSSION...
THE FORECAST HAS BEEN FRUSTRATING THE LAST 24 HOURS GIVEN THE
PROSPECTS OF RAIN CHANCES FOR YESTERDAY. GOES SOUNDER PRECIP WATER
AND 00Z SOUNDINGS FROM CRP AND LCH SHOW THAT A TROPICAL AIRMASS
WITH PW AROUND 2.2 INCHES HAS MOVED OVER SE TX. DESPITE THAT THERE
HAS BEEN VERY LITTLE SIGNIFICANT RAINFALL ACROSS THE AREA. IT
SEEMS THAT THE UPPER LEVEL PATTERN HAS NOT BEEN SUPPORTIVE OF
CONVECTION IN HIND SIGHT. THE LAST COUPLE OF DAYS HAVE FEATURED A
SHEAR AXIS OVER THE AREA WITH AN UPPER LEVEL RIDGE EXPANDING INTO
THE PLAINS AS AN UPPER LOW EXITS THE REGION TOWARDS THE GREAT
LAKES. SEEMS LIKE THE SHEAR AXIS DID NOT WEAKEN AS MUCH AS THE
MODELS SUGGESTED AND WHEN IT DID...SUBSIDENCE FROM THE RIDGE WAS
APPARENTLY STRONG ENOUGH TO LIMIT CONVECTION.
GOING FORWARD TO TODAY...THINK WE WILL SEE MUCH OF THE SAME.
UPPER AIR ANALYSIS STILL HAS A DECENT RIDGE OVER THE S PLAINS AND
S ROCKIES. FORECAST WILL STILL KEEP SOME 30/40 POPS FOR THIS
MORNING AS EXPECT THERE TO BE AT LEAST SOME CONVECTION WITH
DAYTIME HEATING. THE PROBLEM IS THAT GOES SOUNDER DATA DOES SHOW
DRIER AIR IN THE GULF WITH PRECIP WATER VALUES NEAR 1.6 INCHES
THAT THE MODELS FORECAST TO MOVE INTO THE REGION LATER TODAY. WITH
THAT IN MIND...WILL DROP POPS TO 30 PERCENT IN THE AFTERNOON BUT
THINK THAT MAY EVEN BE OPTIMISTIC. HRRR MESOSCALE MODEL SHOWS
SIMILAR EVOLUTION OF CONVECTION WITH MOST OF THE ACTIVITY
OCCURRING IN THE LATE MORNING/EARLY AFTERNOON HOURS. EVEN WRF-NMM
SHOWS CONVECTIVE TRENDS SIMILAR TO THIS THINKING.
DEEPER MOISTURE WILL BE RATHER TRANSIENT TUE/WED. AGAIN THINK THE
RIDGE WILL BE THE MAIN PROBLEM INHIBITING CONVECTION. THAT
SAID...MAY GET ENOUGH MOISTURE MAINLY ON WED TO GET A FEW STORMS
AND ENOUGH REASON TO KEEP 20/30 POPS IN THE FORECAST. BY THE END
OF THE WEEK THE RIDGE LOOKS TO EXPAND AND STRENGTHEN OVER THE
ROCKIES AND PLAINS. WITH LESS MOISTURE...DO NOT THINK THERE WILL
BE ANY RAIN CHANCES FOR THUR/FRI/SAT. ALSO SEE MAX TEMPS GETTING
INTO THE UPPER 90S PERHAPS A FEW 100S FOR THE NORTHERN COUNTIES OF
THE FORECAST AREA DUE TO THE RIDGE. BOTH THE GFS/ECMWF HAVE BEEN
HINTING AT A TROUGH/UPPER LOW DEVELOPING OVER THE APPALACHIANS AND
THEN RETROGRADING INTO THE AREA. GFS GOES AS FAR AS TO PUSH WEAK
BACK DOOR FRONT INTO THE AREA. THINK THIS MAY BE A BIT AGGRESSIVE
AND TRENDED THE FORECAST CLOSER TO THE ECMWF SOLUTION. ECMWF HAS
THE FRONT STALLING WELL BEFORE REACHING SE TX AND HAS MORE OF AN
ELONGATED TROUGH STRETCHING INTO THE AREA FOR NEXT WEEKEND. GIVEN
LOWER HEIGHTS...DECIDED 20 POPS MAY BE NEEDED WITH THE INFLUENCE
OF THE RIDGE MORE OVER THE C PLAINS. DID NOT TRIM BACK MAX TEMPS
TOO MUCH BUT STILL A COUPLE OF DEGREES ABOVE GFS GUIDANCE.
39
MARINE...
WINDS HAVE PICKED UP A BIT ACROSS THE FAR OFFSHORE WATERS WITH
SEAS SILL RUNNING AROUND 5 FEET. WILL CONTINUE THE SCEC THROUGH
MID MORNING BUT OVERALL TREND EXPECTED TO BE A LOWERING OF SEAS
THROUGH THE MORNING HOURS. SCATTERED SHOWERS EXPECTED TO DEVELOP
THIS MORNING AS A WEAK UPPER DISTURBANCE PASSES OVERHEAD. EXPECT
DECREASING COVERAGE ACROSS THE COASTAL WATERS FOR THE AFTERNOON
AND EVENING HOURS TODAY. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 97 75 98 76 98 / 30 10 10 10 20
HOUSTON (IAH) 94 76 95 76 96 / 30 10 20 20 30
GALVESTON (GLS) 89 81 91 81 91 / 20 10 20 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 11 AM CDT THIS MORNING
FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...31
AREA FORECAST DISCUSSION
NWS SPOKANE WA
645 AM PDT Mon Jul 8 2013
.SYNOPSIS...
A weather system passing through the Inland Northwest today will
promote scattered showers and thunderstorms across the northern
mountains of Washington and Idaho...as well as southeast Washington.
Warm and dry conditions are expected around mid-week before a cold
front knocks temperatures down closer to seasonal norms. Slight
shower and thunderstorms chances will be common for all mountain
zones. Otherwise expect dry and occasionally windy conditions
Wednesday through Friday.
&&
.DISCUSSION...
Quick update for this morning: Two lines of elevated thunderstorms
continue to impact the Inland NW this morning. One extends from NE
Oregon through the Camas Prairie...western Nez Perce County...into
Shoshone County. This line is showing signs of decreasing lightning
activity and continues to slowly drift east, but generally slower
then expected. The second line of storms has made very little
eastward progress this morning and remains from Grand Coulee NE
through extreme southeastern Okanogan...central Ferry...and
northern Stevens/Pend Oreille Counties. This line continues to
produce a decent amount of lightning...or 4-6 strikes every 5 minutes.
The upper-level trof is now over the Cascades and should continue
east and take this line with east over the next few hours. HRRR
does indicate this activity will begin to wane over the next few hours.
We have also increased Pops across NE WA and the Nrn ID Panhandle
including the Spokane-CDA area. 06z NAM initialized the 12z
sounding well and 06z GFS is quite unstable as well btwn 18-23z
over these areas. Additionally, HRRR shows numerous storms firing
around noon today and given the break in the action between the
aforementioned ongoing lines of convection, we should warm
sufficiently to achieve the convective temperature of 80F near
20z. Activity may fire quicker given the presence of lift along
the approaching shortwave. GFS/NAM modeled CAPES range from
700-1100 J/kg. Shear is best now and will be decreasing below
30kts so there is a small window which both may be achieved,
otherwise a modest CAPE and low shear profile could still support
a few organized storms capable of small hail, gusty winds, heavy
downpours, and frequent lightning. /sb
&&
.AVIATION...
12Z TAFS: Two areas of elevated thunderstorm activity currently over
the region...one over the northern mountains of WA and second frm
KMLP to KPUW and points south. Expect this activity to persist
through 13z vcnty KPUW/KLWS and 17z in extreme NE WA before shifting
east into Nrn ID and Wrn MT. Following a few hours of heating btwn
15-19z...Sct -shra and -tsra are expected across a majority of NE WA
and Nrn ID. This activity will wane arnd 00z in WA and 02Z in ID.
A few storms will be capable of small hail, gusty winds, and heavy
downpours. Drier conditions will be present near the Cascades
today. High pressure will build in overnight delivering clearing
skies, light winds, and drier conditions. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 83 58 90 60 89 59 / 40 0 0 0 0 0
Coeur d`Alene 80 55 87 58 87 58 / 40 10 0 0 0 0
Pullman 82 52 88 55 88 55 / 30 0 0 0 10 10
Lewiston 90 61 96 64 95 63 / 60 0 0 0 10 10
Colville 84 52 92 56 92 56 / 70 10 0 0 0 0
Sandpoint 77 49 86 53 86 54 / 60 20 0 0 0 0
Kellogg 78 54 88 57 87 58 / 70 10 0 0 0 10
Moses Lake 91 59 94 62 94 60 / 0 0 0 0 0 0
Wenatchee 88 63 93 65 91 62 / 0 0 0 0 0 0
Omak 88 58 94 60 92 59 / 20 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
607 AM CDT MON JUL 8 2013
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 353 AM CDT MON JUL 8 2013
WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWING A MID-LEVEL
SHORTWAVE TROUGH EXTENDING FROM WESTERN LAKE SUPERIOR THROUGH
APPROXIMATELY SIOUX FALLS SD. PUSH OF 850MB MOIST TRANSPORT AND A
CONVERGENCE/WINDSHIFT LINE AT THE SURFACE WAS SUPPORTING A BROKEN
BAND OF SHOWERS AND THUNDERSTORMS EXTENDING FROM NORTHERN WI THROUGH
EASTERN IA/WESTERN IL. MODELS SHOW THIS MID-LEVEL TROUGH AND SURFACE
CONVERGENCE/WINDSHIFT LINE MOVING EAST AND SOUTHEAST OF THE AREA
THIS MORNING ALONG WITH ANY 850MB MOISTURE TRANSPORT. THIS WILL
BRING AN END TO THE SHOWER/THUNDER CHANCES TODAY AS MID-LEVEL
RIDGING BUILDS IN BEHIND THIS DEPARTING WAVE. THERE LOOKS TO BE A
CHANCE OF CONVECTION REDEVELOPING ALONG THIS SURFACE BOUNDARY JUST
TO OUR SOUTH...BUT BELIEVE THIS ACTION WILL REMAIN OUT OF OUR AREA.
OTHERWISE...LOOK FOR ANOTHER VERY WARM AND MUGGY DAY WITH HIGHS IN
THE 80S...WITH PERHAPS A FEW SPOTS ACROSS FAR SOUTHWEST WI/NORTHEAST
IA POKING AT THE 90 DEGREE MARK. WITH DEW POINTS SITTING IN THE
LOWER 70S...PLAN ON HEAT INDICES IN THE MID 90S ALONG AND SOUTH OF
THE I-94 CORRIDOR...WITH A FEW SPOTS IN THE 95 TO 100 DEGREE RANGE
ACROSS NORTHEAST IA.
FOCUS THEN SHIFTS TO MCS LIKELY DEVELOPING OVER SOUTH DAKOTA THIS
EVENING IN RESPONSE TO INCREASING LOW LEVEL JET/850MB MOISTURE
TRANSPORT AHEAD OF A SW U.S. MONSOONAL MID-LEVEL TROUGH AND LOW
PRESSURE OVER THE ROCKY MOUNTAIN FRONT OF WY. GFS/NAM IN FAIRLY GOOD
AGREEMENT THAT THIS MCS WILL PROPAGATE EASTWARD ACROSS SOUTHERN MN
AFTER MIDNIGHT. TRENDED POPS TOWARD THIS SOLUTION WITH BULK OF
SHOWER/THUNDER CHANCES STAYING WEST OF THE MISSISSIPPI THROUGH 12Z
MONDAY.
MODELS THEN DIVERGE A BIT TUESDAY ON THE PATH OF THE MCS. THE GFS
WANTS TO TAKE IT ALONG AND NORTH OF THE I-94 CORRIDOR WHEREAS THE
NAM TAKES IT MORE ACROSS THE I-90 CORRIDOR. ONE THING IS FOR
SURE...THE MODELS HAVE BEEN VERY CONSISTENT WITH THIS MCS SIGNATURE.
AND...WITH HIGHER-END PRECIPITABLE WATER VALUES IN THE 2-2.5 INCH
RANGE WHICH IS SOME 200 PERCENT ABOVE NORMAL...VERY HEAVY RAINFALL
WILL BE A REAL THREAT FOR SOMEWHERE IN OUR AREA. USED A BLEND
APPROACH FOR NOW...WHICH WOULD PUT THE HIGHEST LIKELIHOOD OF
HEAVIEST RAINFALL ALONG/NORTH OF THE I-90 CORRIDOR. SEE HYDROLOGY
SECTION BELOW FOR EXPECTED IMPACT OF THIS HEAVY RAIN.
OTHERWISE...LOOKS LIKE IF THE MCS/DEBRIS CLOUDS CLEAR THE AREA BY
LATER IN THE AFTERNOON...SEVERE THUNDERSTORMS COULD ERUPT AS A
RATHER VIGOROUS MID-LEVEL TROUGH DROPS SOUTHEAST OUT OF THE NORTHERN
PLAINS AND PUSHES A COLD FRONT INTO THE REGION. NAM/GFS SHOW THE
POTENTIAL FOR 0-1ML MUCAPE TO BUILD INTO THE 3500-5500J/KG RANGE BY
LATE AFTERNOON WITH AMPLE 0-3KM BULK SHEAR IN THE 30-50KT RANGE.
THIS COULD LEAD TO EXPLOSIVE DEEP CONVECTION MAINLY SOUTH OF THE
I-90 CORRIDOR. DAMAGING WIND/LARGE HAIL/LOCALIZED FLASH FLOODING/
ISOLATED TORNADO ALL A THREAT.
LINGERING SHOWER/THUNDERSTORM CHANCES WILL EXIST GOING INTO TUESDAY
NIGHT IN ASSOCIATION WITH THE MID-LEVEL TROUGH DROPPING SOUTHEAST
THROUGH THE AREA.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 353 AM CDT MON JUL 8 2013
DRIER/COOLER WEATHER EXPECTED WEDNESDAY THROUGH THURSDAY AS HIGH
PRESSURE DROPS IN FROM THE NORTHERN PLAINS. LOOK FOR HIGHS IN THE
76-81 DEGREE RANGE WEDNESDAY AND 78-82 ON THURSDAY...WITH DEW POINTS
IN THE MID-UPPER 50S.
MID-UPPER LEVEL RIDGING/INCREASING SOUTHERLY FLOW BRINGS WARMING AND
HIGHER HUMIDITY LEVELS BACK INTO THE AREA FRIDAY AND SATURDAY. WILL
HAVE TO WATCH FRIDAY NIGHT THROUGH SUNDAY FOR A CHANCE OF SHOWERS AND
THUNDERSTORMS AS THE EC/GFS SHOW A MID-LEVEL TROUGH/WEAK COLD FRONT
TOPPING THE RIDGE AND TOWARD THE AREA. OTHERWISE...LOOK FOR HIGHS IN
THE LOWER 80S FRIDAY AND SATURDAY THEN LOWERING SOME BACK INTO THE UPPER
70S/AROUND 80 ON SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 607 AM CDT MON JUL 8 2013
A WEAK COLD FRONT IS PROGRESSING SOUTHEAST ACROSS THE AREA THIS
MORNING. THE WINDS HAVE ALREADY SWUNG AROUND TO THE NORTHWEST
BEHIND THE FRONT AT KRST AND EXPECT THAT THEY WILL DO THE SAME AT
KLSE BY MID MORNING. IR SATELLITE THIS MORNING SHOWS LITTLE IN THE
WAY OF CLOUD COVER ALONG AND BEHIND THE WEAK FRONT AND THE 08.06Z
NAM BUFKIT SOUNDINGS INDICATE IT SHOULD STAY THAT WAY FOR MUCH OF
THE DAY. FOCUS THEN TURNS TO THE THUNDERSTORM CHANCES FOR THE
OVERNIGHT HOURS. THE FRONT WILL START TO RETURN BACK TO THE NORTH
AS A WARM FRONT AS A SHORT WAVE TROUGH CURRENTLY OVER WYOMING
MOVES INTO THE AREA. THUNDERSTORMS WITH THIS FEATURE ARE EXPECTED
TO DEVELOP ACROSS SOUTH DAKOTA THIS AFTERNOON AND THEN TRACK EAST
ALONG AND NORTH OF THE WARM FRONT THROUGH THE OVERNIGHT. CURRENT
EXPECTATIONS ARE THAT THESE STORMS WILL IMPACT BOTH TAF SITES BUT
NOT UNTIL LATE IN THE FORECAST PERIOD SO WILL JUST SHOW A VCTS
WITH VFR CONDITIONS. WOULD EXPECT THE STORMS TO HAVE THE POTENTIAL
TO PRODUCE MVFR CONDITIONS IF THE HEAVIEST RAINFALL CAN COME
ACROSS THE AIRPORTS.
&&
.HYDROLOGY...(TUESDAY)
ISSUED AT 353 AM CDT MON JUL 8 2013
SIGNAL REMAINS HIGH FOR A COMPLEX OF THUNDERSTORMS TO ROLL THROUGH
THE AREA TUESDAY. CONFIDENCE IS INCREASING THAT THIS COMPLEX WILL
MOVE THROUGH THE AREA SOMEWHERE IN THE 7 AM TO NOON TIME
FRAME...THEN MOVE EAST OF THE AREA AFTER THAT. HOWEVER...CONFIDENCE
IS LOWER WITH EXACT TRACK OF THE COMPLEX OF STORMS. RIGHT NOW...THE
HIGHEST POTENTIAL FOR HEAVIER RAINFALL LOOKS TO BE ALONG AND NORTH
OF THE I-90 CORRIDOR. WITH PRECIPITABLE WATER VALUES IN THE 2-2.5
INCH RANGE WHICH IS SOME 200 PERCENT ABOVE NORMAL...LOOK FOR THE
POTENTIAL OF VERY HEAVY RAINFALL WITH THIS COMPLEX OF STORMS. TWO
POSITIVE FACTORS TO LOOK AT. 1. THE COMPLEX WILL BE TRANSITORY IN
NATURE AND 2. 6-HOUR FLASH FLOOD GUIDANCE IS IN THE 3-5 INCH RANGE.
HOWEVER...IF DOWNPOURS ARE TORRENTIAL ENOUGH...LITTLE WILL BE
ABSORBED IMMEDIATELY IN THE GROUND AND COULD CAUSE SOME LOCALIZED
PONDING IN POUR DRAINAGE AREAS AND RUNOFF INTO AREA RIVERS. THIS
WILL LIKELY CAUSE SOME WITHIN BANK RISES...BUT NOT CONFIDENT ON ANY
WIDESPREAD FLOODING AT THIS POINT. AS A COLD FRONT DROPS THROUGH THE
AREA TUESDAY AFTERNOON...ANOTHER BATCH OF HEAVIER RAINFALL COULD
FALL. THIS AGAIN SHOULD BE TRANSITORY IN NATURE...BUT COULD CAUSE
SOME LOCALIZED PONDING/RUNOFF OF WATER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...04
HYDROLOGY...DAS
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
213 PM EDT MON JUL 8 2013
.PREV DISCUSSION... /ISSUED 752 AM EDT MON JUL 8 2013/
PREV DISCUSSION... /ISSUED 350 AM EDT MON JUL 8 2013/
SHORT TERM /TODAY THROUGH TUESDAY/...
500MB ANALYSIS SHOWS AN UPPER LOW MOVING INTO THE WESTERN MIDDLE
ATLANTIC WITH A WEAK SHEAR AXIS EXTENDING INTO THE CENTRAL CWFA THIS
MORNING. WV STILL DEPICTS THE HIGH MOISTURE PLUME VERY WELL ACROSS
THE CENTRAL AND SOUTHERN CWFA...BUT ALSO SHOWS SOME DRIER AIR HAS
WORKED ITS WAY INTO THE NORTHERN CWFA. THE TROUGH/SHEAR AXIS IS
EXPECTED TO PUSH SOUTH TODAY.
FORECAST PROBLEM OF THE DAY WILL BE POPS. SUSPECT THE CURRENT
ACTIVITY ON THE REGIONAL RADAR LOOP HAS DEVELOP ALONG AND SOUTH OF
THE SHEAR AXIS. DO THINK THE SHEAR AXIS WILL HELP SUPPORT CONVECTIVE
DEVELOPMENT TODAY...ESPECIALLY ACROSS THE CENTRAL CWFA. THE LATEST
RUN OF THE HRRR DOES SHOW SOME EARLY DEVELOPMENT ACROSS THE NORTHERN
TIER OF ZONES THIS MORNING...AND THAT COULD BE ASSOCIATED WITH WEAK
SHORTWAVE DROPPING SOUTH IN THE FLOW. ALSO...ACROSS THE SOUTHERN
CWFA...CONVECTIVE DEVELOPMENT COULD BE ENHANCED BY ANY ACTIVITY THAT
DEVELOPS ALONG THE SEA BREEZE AND MOVES INLAND. THE BEST CHANCES FOR
THUNDER SHOULD BE IN THE CENTRAL AND SOUTHERN ZONES...WHERE MORE
BREAKS IN THE CLOUD COVER COULD OCCUR...SURFACE INSTABILITY WILL BE
A LITTLE HIGHER AND THE SEA BREEZE COULD AID WITH LIFT.
THE SHEAR AXIS SHOULD SET UP TO THE SOUTH TOMORROW...BUT BOTH THE
GFS AND NAM ARE PROGGING ANOTHER PIECE OF SHORTWAVE ENERGY TO DROP
SOUTH IN THE FLOW TOMORROW AFTERNOON. IN ADDITION...THE MOISTURE
PLUME SHOULD BE LOCATED FURTHER SOUTH THAN TODAY. SO...EXPECT
CONVECTION TO BE A LITTLE MORE DIURNAL IN NATURE. FOR NOW...LEFT
GENERAL SCT POPS.
WILL GO AHEAD AND LEAVE THE FLASH FLOOD WATCH IN EFFECT THROUGH
TODAY. EVEN THOUGH THE COVERAGE OF POPS MAY BE LOWER THAN IN
PREVIOUS DAYS ACROSS THE NORTH...ANY THUNDERSTORM COULD PRODUCE
LOCALLY HEAVY RAINFALL. PWATS WILL DROP TO AROUND AN INCH AND A HALF
IN THE NORTH...BUT A THUNDERSTORM COULD EASILY DROP A QUICK INCH OR
MORE. FFG VALUES ARE AROUND AN INCH ACROSS MUCH OF THE AREA...WITH
SOME AREAS LESS THAN A QUARTER OF AN INCH.
NLISTEMAA
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE EXTENDED BEGINS WITH THE SOUTHEAST IN A GENERAL WEAKNESS
PATTERN ALOFT...SANDWICHED BETWEEN THE TWO UPPER HIGHS /ONE IN
THE ATLANTIC AND ONE IN THE SOUTHWEST STATES/ AND TWO UPPER LOWS
OR TROUGHS /WEAK WAVE IN THE EASTERLIES OVER FLORIDA AND LONGWAVE
TROUGH IN CANADA/. WEAK SURFACE BOUNDARY REMAINS IN PLACE TUESDAY
NIGHT AND WEDNESDAY AND WHILE THERE IS VERY LITTLE FORCING...
THERE WILL BE ENOUGH MOISTURE AND INSTABILITY TO KEEP SLIGHT TO
LOW CHANCE POPS ACROSS THE AREA.
WEDNESDAY NIGHT INTO THURSDAY...THE LONGWAVE TROUGH DEEPENS IN
RESPONSE TO A SHORTWAVE RIDING DOWN THE NORTHWEST FLOW TOWARD THE
OHIO VALLEY. THIS PUSHES A REINFORCING FRONT THROUGH THE TENNESSEE
VALLEY AND INTO THE SOUTHEAST...WARRANTING HIGHER POPS FOR
THURSDAY AFTERNOON. KEPT TREND OF LIKELY POPS UP NORTH. AS THE
POSITIVELY TILTED TROUGH CONTINUES TO DEEPEN THE FRONT WILL PRETTY
MUCH STALL ACROSS THE SOUTHEAST...THOUGH THERE IS SOME QUESTION AS
TO HOW STRONG THE GREAT LAKES SURFACE HIGH WILL BE AND IF PORTIONS
OF THE STATE ARE ABLE TO CLEAR OUT LATE IN THE WEEK...AS PER THE
00Z GFS...OR IF SIGNIFICANT MOISTURE REMAINS OVER THE ENTIRE AREA
AS PER THE 00Z ECMWF. IF THE GFS IS TO BE BELIEVE...DRY AIR IS
ABLE TO PUSH IN FRIDAY INTO SATURDAY LEADING TO OVERNIGHT LOWS IN
THE 60S. ADD THIS TO TEMPS CONTINUING AT OR BELOW NORMAL...NOT BAD
AT ALL FOR THIS TIME OF YEAR.
BY SATURDAY MORNING THE GFS HAS ALREADY CUT OFF THE UPPER LOW
ACROSS GEORGIA WHILE THE ECMWF JUST HAS A VERY LONG AND SKINNY
TROUGH IN PLACE. THIS IS A PRETTY INTERESTING AND PERPLEXING CHANGE
FROM LAST NIGHT/S SOLUTIONS...WHERE THE GFS AND ECMWF WERE IN
REMARKABLE AGREEMENT WITH THE CUTOFF LOW. WITH TONIGHT/S RUNS...
WHILE THE SENSIBLE WEATHER RESULTS ARE NOT ALL THAT DIFFERENT...
THE MASS FIELDS ARE ACTUALLY QUITE A BIT DIFFERENT. IN EITHER CASE
THOUGH...ABOVE-NORMAL PWATS REMAIN OVER THE SOUTHEAST. ADD TO
THIS WHATEVER HAPPENS WITH CHANTAL...OR THE REMNANTS THEREOF.
ENSEMBLE GUIDANCE TAKE THE SYSTEM SOMEWHERE INTO THE SOUTHEAST
LATE IN THE PERIOD...GFS WITH A MORE NOTICEABLE CIRCULATION INTO
THE JACKSONVILLE FLORIDA AREA...BUT THE ECMWF WITH JUST A GENERAL
AREA OF MOISTURE INTO THE FLORIDA PENINSULA. SO ALL THAT SAID...
HAVE KEPT POPS JUST ABOVE CLIMO FOR THE WEEKEND ESPECIALLY SUNDAY.
TEMPS REMAIN AT OR BELOW NORMAL THROUGH THE WEEKEND.
TDP
&&
.AVIATION...
18Z UPDATE...
SCT TO BKN CLOUDS OVER THE AREA AT THE MOMENT. CLOUD HEIGHTS ARE
VFR AND SHOULD STAY THERE THROUGH 06Z. LOW STRATUS EXPECTED TO
MOVE BACK IN ACROSS THE TAF SITES TONIGHT WITH IFR CEILINGS
EXPECTED FROM 07Z TO 14 OR 15Z TUESDAY. THERE ARE SOME POP UP
SHOWERS AND THUNDERSTORMS OUT THERE AND WE COULD SEE SOME AT THE
ATL AREA TAF SITES THIS AFTERNOON. WILL SEE MVFR CEILINGS AND
VSBYS IN AND AROUND ANY TSRA DEVELOPMENT. WINDS WILL STAY OUT OF
THE W TO SW IN THE 5-10KT RANGE.
//ATL CONFIDENCE...18Z UPDATE...
CONFIDENCE MEDIUM TO HIGH ON ALL ELEMENTS.
01
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 71 88 71 / 40 30 40 30
ATLANTA 84 72 87 72 / 40 30 40 30
BLAIRSVILLE 81 64 82 66 / 40 30 40 30
CARTERSVILLE 85 70 87 71 / 40 30 40 30
COLUMBUS 86 73 91 73 / 40 30 40 20
GAINESVILLE 83 70 86 71 / 40 30 40 30
MACON 86 73 91 72 / 40 30 40 20
ROME 87 70 88 71 / 40 30 40 30
PEACHTREE CITY 84 70 88 71 / 40 30 40 30
VIDALIA 89 73 92 73 / 40 30 40 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR THE FOLLOWING ZONES:
BANKS...BARROW...BARTOW...CARROLL...CATOOSA...CHATTOOGA...
CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...DADE...DAWSON...
DEKALB...DOUGLAS...FANNIN...FAYETTE...FLOYD...FORSYTH...GILMER...
GORDON...GREENE...GWINNETT...HALL...HARALSON...HEARD...HENRY...
JACKSON...LUMPKIN...MADISON...MORGAN...MURRAY...NEWTON...NORTH
FULTON...OCONEE...OGLETHORPE...PAULDING...PICKENS...POLK...
ROCKDALE...SOUTH FULTON...TALIAFERRO...TOWNS...UNION...WALKER...
WALTON...WHITE...WHITFIELD...WILKES.
&&
$$
SHORT TERM...01
LONG TERM....41
AVIATION...01
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
256 PM CDT MON JUL 8 2013
.DISCUSSION...
1142 AM CDT
FOR MORNING UPDATE...
MCS CONTINUES TO MOVE SLOWLY TO THE EAST-SOUTHEAST ACROSS THE REGION
LATE THIS MORNING...IN ASSOCIATION WITH A PAIR OF SHORT WAVE TROUGHS
ANALYZED OVER LAKE MICHIGAN AND NORTHEAST IA/SOUTHWEST WI. MOST OF
THE STRONGER CONVECTIVE ACTIVITY HAS BEEN OVER NORTHEAST IL OVER THE
LAST COUPLE OF HOURS...ON NOSE OF 35-40 KT H8 WSWLY LOW LEVEL JET
AND WITHIN PLUME OF SLIGHTLY STEEPER MID LEVEL LAPSE RATES PER
SPC/RAP MESOANALYSIS. TRAINING CELLS HAVE PRODUCED SOME LOCALLY
HEAVY RAINFALL AMOUNTS (1-3 INCHES FROM OBS/RADAR) ALONG A NARROW
AXIS FROM JUST SOUTH OF ROCKFORD TO SYCAMORE/ELBURN AND THE SOUTH
SIDE OF CHICAGO. CURRENT TRENDS INDICATE THIS AREA OF THUNDERSTORMS
WILL CONTINUE TO TRACK OFF TO THE EAST-SOUTHEAST ACROSS NORTHWEST
INDIANA INTO THE EARLY AFTERNOON HOURS...WITH DECREASING COVERAGE OF
SHOWERS AND STORMS EXPECTED FROM THE WEST WITH SUBSIDENCE ASSOCIATED
WITH PASSAGE OF MID-LEVEL SHORT WAVE TROUGH. WHILE LARGER SCALE
FORCING SHOULD BECOME LESS FAVORABLE FOR ADDITIONAL DEVELOPMENT THIS
AFTERNOON...EXPLICIT CONVECTION MODEL RUNS CONTINUE TO INDICATE SOME
MORE SCATTERED REDEVELOPMENT OF CONVECTION ACROSS PARTS OF THE AREA
THIS AFTERNOON. MORNING HRRR RUNS ARE ESPECIALLY BULLISH ON
REDEVELOPING THUNDERSTORMS OVER NORTHEAST IL THIS AFTERNOON...
THOUGH IT MAY NOT BE HANDLING LOW LEVEL WIND FIELD VERY WELL AND
SUSPECT IT IS SOMEWHAT OVERDONE WITH ACTIVITY. VERY WARM/MOIST AND
UNSTABLE ENVIRONMENT WILL BE PRESENT HOWEVER AS PARTIAL SUNSHINE
DEVELOPS...WITH UPWARDS OF 2000 J/KG MLCAPE AVAILABLE PER WRF-NAM
SOUNDINGS. HAVE LOWERED POPS TO SLIGHT CHANCE ACROSS MUCH OF
NORTHERN IL AFTER CURRENT MCS EXITS THIS AFTERNOON...WITH SLIGHTLY
HIGHER CHANCE POPS ACROSS THE SOUTH/SOUTHEAST WHERE PERSISTENT WARM
ADVECTION AND OUTFLOW FROM MORNING STORMS MAY PROVIDE BETTER
POTENTIAL FOR SOME REDEVELOPMENT.
CLOUDS/RAIN HAVE HELD TEMPS IN THE 70S MOST AREAS THROUGH 11 AM.
SUBSIDENCE WITH THE AFOREMENTIONED SHORT WAVE WAS ALLOWING SOME
PARTIAL CLEARING FROM THE NORTHWEST AT MIDDAY HOWEVER. PROVIDED WE
CAN GET A FEW HOURS OF PARTLY SUNNY SKIES...THERMAL RIDGE SHOULD
EASILY PRODUCE HIGH TEMPS IN THE UPPER 80S ACROSS NORTHERN IL THIS
AFTERNOON IF NOT A FEW LOWER 90S FAR WEST. EASTERN AREAS WILL BE A
LITTLE TRICKIER BUT ALSO SHOULD BE CAPABLE OF SOME UPPER 80S WITH A
LITTLE SUN.
RATZER
//PREV DISCUSSION...
330 AM CDT
THE FORECAST CHALLENGES ARE PRIMARILY WITHIN THE NEXT 48 HOURS AS
THE AREA HAS BEEN OVERTAKEN BY THE SOUPIEST AIR MASS OF THE
SEASON...IN FACT THE MOST PROLONGED HIGH DEW POINT EPISODE SINCE
THE HEAT WAVE JUST OVER ONE YEAR AGO /JUL 4-7/. WITH THIS COMES
SEVERE STORM AND HEAVY RAIN POTENTIAL...MORE SO ON TUESDAY. IN
ADDITION...THE HIGHEST HEAT INDICES OF THE SEASON ARE
FORECAST...AND WHILE NOT AT ADVISORY CRITERIA THESE LOOK TO
FLIRT WITH 100 DEGREES IN SOME SOUTHERN CWA LOCATIONS ON TUESDAY
AFTERNOON.
SYNOPSIS...THE UPPER LEVEL RIDGE ACROSS THE CENTRAL AND SOUTHERN
PLAINS IS EVOLVING EAST EARLY THIS MORNING WITH TURBULENT MOIST
FLOW AROUND ITS NORTHERN PERIPHERY. NUMEROUS AREAS OF CONVECTION
ARE PRESENT ASSOCIATED WITH SHORT WAVE ASCENT AND MOIST ADVECTION
ON THE LOW-LEVEL JET. A WEAK LOW-LEVEL TROUGH IS PRESENT FROM
NORTHERN WI TO NORTHERN KS. TO THE EAST AND SOUTH OF THIS
FEATURE...UPPER 60S TO MID 70S DEW POINTS PREVAIL ON MOST
OBSERVATIONS ALL THE WAY TO THE ATLANTIC AND GULF COASTS. THE
RIDGE WILL TRY TO EXPAND INTO THE AREA THIS AFTERNOON AND MORE SO
TONIGHT WITH CONTINUED SYNOPTIC SOUTHERLY SURFACE FLOW ACROSS THE
AREA. THE SURFACE TROUGH WILL WORK ITS WAY LIKELY INTO FAR
SOUTHERN WI BY LATE AFTERNOON. TWO SURFACE LOWS LOOK TO RIDE ALONG
THIS...ONE DURING THE DAY TUE ASSOCIATED WITH A STRONG SHORT WAVE
EXITING THE GREAT BASIN EARLY THIS MORNING...AND ANOTHER STRONGER
SURFACE LOW ASSOCIATED WITH AN UPPER TROUGH THAT WILL DEVELOP INTO
THE GREAT LAKES BY LATE TUE NIGHT. THIS SECOND WAVE WILL USHER A
COOL FRONT THROUGH THE AREA WED MORNING WITH THE SOMEWHAT
COOLER/DRIER AIR BEING REALIZED BY WED NIGHT.
THIS MORNING...IT APPEARS THERE ARE TWO IMMEDIATE UPSTREAM SHORT
WAVES...ONE BETTER DEFINED ONE PER WATER VAPOR AND RADAR MOSAIC
ACROSS NORTHEAST IA...AND ANOTHER ACROSS FAR SOUTHERN IA/NORTHERN
MO. TOGETHER THESE WILL MOVE EAST AND LOOK TO SLOWLY
WEAKEN LATER THIS MORNING ACROSS THE EASTERN FORECAST AREA WITH
THE MORE DOMINANT JET TO THE NORTH. PROFILER DATA INDICATES 35 KT
850-925MB FLOW INTO THE AREA WHICH LOOKS TO CONTINUE PAST
DAYBREAK. SO EXPECT THAT SHOWER AND EMBEDDED STORM ACTIVITY WILL
BE SUSTAINED AS FAR EAST AS CHICAGO BY MID-MORNING. THE HRRR SEEMS
TO HAVE A FIRM HANDLE ON THE ONGOING CONVECTION AND ITS EVOLUTION
MAKES SENSE AND HAVE FOLLOWED CLOSELY IN OUR FORECAST HOURLY POPS.
HAVE SEEN A COUPLE 20 KT PLUS GUSTS IN SW WI INDICATING THAT A
COLD POOL MAY BE TRYING TO DEVELOP. THIS AND ANY MCV DEVELOPMENT
WOULD ALSO AID IN SUSTAINING THE ACTIVITY EASTWARD. SEVERE
POTENTIAL IS MAINLY LOW WITH THIS THROUGH THE MORNING AND RADAR
TRENDS FROM ARX/DVN CONFIRM NOTHING POTENT IN THE STORM
BEHAVIORS...THOUGH CANT RULE OUT SMALL HAIL OR GUSTY WINDS. IN
ADDITION...STORMS WILL BE VERY EFFICIENT RAIN PRODUCERS GIVEN HIGH
ATMOSPHERIC MOISTURE CONTENT /PWATS AOA 1.65 INCHES AND 700MB TDS
AOA 4C/.
CONFIDENCE...HIGH.
THIS AFTERNOON AND TONIGHT...WITH THE PRIMARY SHORT WAVE IMPULSES
HAVING MOVED EAST...COVERAGE OF PRECIP SHOULD AT LEAST TEMPORARILY
DIMINISH IN THE EARLY AFTERNOON. OUTFLOW BOUNDARIES FROM THE
MORNING ACTIVITY...EVEN IF ELEVATED COULD CONTINUE FESTERING
CONVECTION THIS AFTERNOON GIVEN ATTAINABLE CONVECTIVE TEMPS. THIS
WOULD SEEM MOST FAVORED ALONG AND SOUTH OF I-80. THE SURFACE
BOUNDARY WILL BE NEAR THE IL/WI STATE LINE...AND SIMILAR TO PREV
FORECAST REASONING COULD SEE SOME SCATTERED DEVELOPMENT LATER THIS
AFTERNOON ALONG THAT AS WELL. AFTER WHAT WILL LIKELY BE A SLOW
TEMPERATURE CLIMB THIS MORNING...THIS AFTERNOON SHOULD SEE
RECOVERY INTO THE UPPER 80S AND MAYBE EVEN 90...ESPECIALLY ACROSS
THE WESTERN HALF OF THE FORECAST AREA. WITH SUCH HIGH DEW POINT
AIR...SURFACE BASED INSTABILITY OF 1500-2500 J/KG WOULD BE
SUPPORTED BY THESE FORECAST TEMPS AND DEW POINTS. MOST GUIDANCE
DOES HAVE A SPLOTCHY QPF PRODUCED OVER THE AREA. ANY SCATTERED
CONVECTION THAT CAN DEVELOP THIS AFTERNOON INTO THE EVE WOULD HAVE
SOME SEVERE WEATHER THREAT. THE HIGH PWAT AIR WILL SUPPORT HEAVY
RAIN ALONG WITH PRECIP LOADING CONCERNS TOWARDS ISOLATED DOWNBURSTS
IN ANY MORE ROBUST CELLS OR MULTI-CELL CLUSTERS...BUT OVERALL
THREAT COVERAGE IS LOW. AS WE HEAD TO AFTER SUNDOWN...HEIGHT
FALLS AND THE LLJ NOSE CONTINUE TO BE FOCUSED TO THE NORTHWEST OF
THE AREA /OVER MN AND NORTHERN IA/. THIS IS WHERE LIKELY MCS
DEVELOPMENT WILL OCCUR LATE. IN ADVANCE...BROAD WARM AND MOIST
ADVECTION ALOFT MAY ALLOW FOR ISOLATED TO SCATTERED CONVECTIVE
DEVELOPMENT OVER THE AREA. DEEP WARM CLOUD PROCESSES WILL BE AT
PLAY WITH PWATS CONTINUING TO INCH UP...MEANING HEAVY RAIN WILL BE
THE GREATEST THREAT. GIVEN A SOMEWHAT DIFFUSE 850MB BAROCLINIC
ZONE AND FORWARD PROPAGATION INDICATED...THE TRAINING SETUP IS
SOMEWHAT MARGINAL IN THE FORECAST AREA AT LEAST PRIOR TO DAYBREAK
TUE. SO NO FLASH FLOOD WATCH BEING ISSUED AT THIS TIME BUT THIS
WILL NEED TO BE MONITORED.
CONFIDENCE...MEDIUM.
TUESDAY AND TUESDAY NIGHT...THESE ARE THE PERIODS WITH THE GREATER
POTENTIAL FOR HIGHER IMPACT WEATHER. MANY MODELS IN THE SUITE OF
GUIDANCE CONTINUE TO ADVERTISE A PRIMARY MCS DEVELOPING BY TUE
MORNING AHEAD OF A STRONG IMPULSE. THERE ARE VARIANCES IN
LATITUDE ON THIS...BUT CERTAINLY THE PATTERN WOULD SUPPORT SUCH
EVOLUTION WITH AMPLE INSTABILITY AHEAD OF AN MCS EVEN IN THE
MORNING GIVEN THE HIGH ABSOLUTE MOISTURE. THE SPC HAS OUTLOOKED A
30 PERCENT AREA FOR THEIR DAY TWO OUTLOOK FOR THIS REASON AND THE
AREA THEY INDICATED IS WHAT HAS BEEN FAVORED IN OUR FORECAST. IT
IS INTERESTING TO NOTE THAT THE CIPS ANALOG GUIDANCE FOR MULTIPLE
DAYS HAS INDICATED MATCHES ON SEVERE WIND EVENTS FROM NORTHERN IA
INTO SOUTHERN WI AND FAR NORTHERN IL AND CONTINUES TO DO SUCH
BASED ON THE NAM FORECAST. SO THE MOST FAVORED AREA WOULD LIKELY
BE NORTH OF I-80...AND MAYBE EVEN NORTH OF I-88 FOR POTENTIALLY A
STRONG WIND COMPLEX ON TUE. SOME OF THE SLOWER GUIDANCE HAS THIS
EVEN HAPPENING IN THE AFTERNOON. CONFIDENCE ON EXACT DEVELOPMENT
BY AFTERNOON AND NIGHTTIME DROPS...ESPECIALLY IF ANYTHING CAN
SPARK OFF OUTFLOWS. CERTAINLY A SEVERE WEATHER POTENTIAL EXISTS
THROUGH THE REST OF THE DAY WITH GRADUALLY INCREASING DEEP LAYER
SHEAR AND PLENTY OF INSTABILITY. THE SOUTHERN FORECAST AREA COULD
WARM INTO THE LOWER TO MID 90S. RIGHT NOW HEAD INDICES ARE
FORECAST AROUND 100 FOR MULTIPLE AFTERNOON HOURS IN THE SOUTHERN
FORECAST AREA...WHILE AROUND THE MID 90S IN ROCKFORD AND CHICAGO
THOUGH CONFIDENCE THERE IS LOW BASED ON PROBABLE MORNING/EARLY
AFTERNOON CONVECTION. HAVE MENTIONED HEAVY RAIN IN THE FORECAST
FOR TUE AND TUE NIGHT GIVEN THE ATMOSPHERIC SETUP AND DO HAVE CHC
SEVERE MENTIONED IN FAR NORTHERN IL GIVEN THE CONSISTENT SIGNAL
AND PATTERN SUPPORT FOR AT THE LEAST A NEARBY MCS.
CONFIDENCE...OVERALL MEDIUM.
WEDNESDAY...THE COOL FRONT...OR AT LEAST THE WIND SHIFT IS MAINLY
AGREED ON BY GUIDANCE TO BE MOVING SOUTHEAST THROUGH THE AREA
EARLY WED. THE COOLER TEMPERATURES IN THE MIX DOWN LAYER LOOK TO
ARRIVE LATE IN THE AFTERNOON INTO THE EVE...SO HIGHS IN THE MID TO
UPPER 80S ARE STILL FORECAST. SOME ONGOING CONVECTION IS LIKELY
IN THE SOUTHEAST CWA AT LEAST ON WED MORNING...THOUGH COVERAGE IS
TOUGH TO TELL AT THIS POINT. DEW POINTS LOOK TO FALL BY WED EVE.
CONFIDENCE...HIGH.
EXTENDED...HAVE NOT MADE TOO MANY CHANGES FROM A SMART BLEND OF
GUIDANCE WITH GOING FORECAST. THIS PERIOD LOOKS MAINLY QUIET AS
THE PATTERN EVOLVES THROUGH THE WEEKEND TO ONCE AGAIN A BLOCKED
SETUP. SURFACE HIGH PRESSURE LOOKS TO PREVAIL WITH ONSHORE FLOW
INTO CHICAGOLAND AND NORTHWEST INDIANA. THIS SHOULD OFFER ONLY
MINIMAL COOLING THOUGH WITH BASICALLY TEMPERATURES AT OR JUST
BELOW SEASONAL NORMALS IN MOST PLACES.
CONFIDENCE...HIGH.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* CHANCE FOR ISOLD/SCATTERED TSRA LATE THIS AFTERNOON.
* ANOTHER ROUND OF SHRA/TSRA POSSIBLE TUESDAY MORNING...WITH
ADDITIONAL ACTIVITY LATER TUESDAY AFTERNOON/EVENING.
MDB
//DISCUSSION...UPDATED 20Z...
CONTINUING TO MONITOR TSRA CHANCES THIS AFTERNOON AND HAVE A BIT
BETTER CONFIDENCE IN THE POTENTIAL FOR ISOLD/SCATTERED ACTIVITY
AFFECTING THE TERMINALS IN A FEW HOURS. SATELLITE AND RADAR SHOW
THE DEVELOPMENT OF SPOTTY ACTIVITY ACROSS SOUTHEAST WI NORTH AND
WEST OF MKE WHICH IS DRIFTING SOUTHEASTWARD. WITH THE UNSTABLE
ATMOSPHERE IN PLACE AND SOME OF THE FORCING IN SE WI MOVING TOWARD
THE AREA EXPECT THAT THIS ACTIVITY WILL MOVE INTO THE AREA IN A
FEW HOURS SO WILL CONTINUE WITH VCTS MENTION.
MDB
FROM 18Z...
BAND OF TSRA IS FINALLY EXITING THE CHI METRO AREA TO THE EAST.
SSW WINDS ARE BECOMING SW WITH SOME GUSTS TO 18 OR 20 KT
DEVELOPING AS CLOUD COVER DIMINISHES. MVFR CIGS NEAR GYY WILL
IMPROVE IN THE NEXT HOUR OR TWO AS PRECIP EXITS. ATTENTION TURNS
TO NEW SHRA/TSRA POTENTIAL LATER THIS AFTERNOON. A COOL FRONT
MOVING SOUTHEAST ACROSS WISCONSIN MAY SERVE AS A TRIGGER FOR
ADDITIONAL DEVELOPMENT AS IT REACHES THE AREA BUT THE UPPER WAVE
RESPONSIBLE FOR THE MORNING STORMS LOOKS TO BE LEAVING A FAIR
AMOUNT OF SINKING AIR IN ITS WAKE. THAT SAID...THE LOCAL AREA IS
BECOMING UNSTABLE BEHIND THE CURRENT STORMS SO IT MAY NOT TAKE
MUCH TO KICK OFF SOME ISOLATED ACTIVITY. HAD VCSH GOING IN THE
PREVIOUS TAFS FOR THIS BUT WITH INSTABILITY GROWING TSRA WOULD
LIKELY RESULT IF SOMETHING CAN DEVELOP SO CONVERTED TO VCTS. WITH
CHANCE FOR DEVELOPMENT LOW...DEBATED REMOVING ANY MENTION
ALTOGETHER BUT WANTED TO CONTINUE TO HIGHLIGHT THE CHANCE WHICH IS
STILL IN THE 35-40 PERCENT RANGE. HAVE BETTER CONFIDENCE IN THE
EVENING AND OVERNIGHT HOURS BEING DRY WITH DIMINISHING BUT
VARIABLE WINDS. GIVEN THE RAINFALL AND THE LIGHT WINDS FOG WILL BE
POSSIBLE AND HAVE INCLUDED PATCHY FOG /BCFG/ AT RFD/DPA/GYY...WITH
AT LEAST SOME POTENTIAL FOR PERIODIC IFR CIGS LATE.
SHRA/TSRA CHANCES CONTINUE TUESDAY. HAVE DECENT CONFIDENCE THAT
THERE WILL BE A STORM COMPLEX DEVELOPING ACROSS NEBRASKA/IOWA
TONIGHT WHICH WOULD THEN AFFECT THE LOCAL AREA SOME TIME TUESDAY
MORNING. ADDITIONAL STORMS ARE POSSIBLE LATER TUESDAY BUT
DEVELOPMENT MAY HINGE ON WHAT OCCURS EARLIER IN THE DAY.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM-CONFIDENCE IN ISOLD/SCATTERED IN THE AREA LATE THIS
AFTERNOON.
* MEDIUM CONFIDENCE IN SHRA/TSRA ACTIVITY TUESDAY MORNING...LOW
CONFIDENCE IN COVERAGE AND TIMING...LOW CONFIDENCE IN SHRA/TSRA
FORECAST TUESDAY AFTERNOON/EVENING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...LIKELY TSRA. MVFR/GUSTY WINDS POSSIBLE.
WEDNESDAY...CHANCE OF TSRA...OTHERWISE VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
RODRIGUEZ
&&
.MARINE...
425 AM CDT
AS AN AREA OF LOW PRESSURE OVER THE UPPER MISSISSIPPI VALLEY
SHIFTS EAST TOWARDS THE LAKE THIS MORNING...SOUTH TO SOUTHEAST
WINDS OF 10 TO 20 KT ARE BEING OBSERVED ACROSS THE LAKE. WITH THIS
LOW CONTINUING ACROSS THE LAKE TODAY...EXPECT FAIRLY DIFFERENT
CONDITIONS FROM THE NORTH HALF TO THE SOUTH HALF. WITH THIS LOW
MOVING THROUGH AND A BOUNDARY LEFT OVER THE LAKE...THE NORTHERN
HALF OF THE LAKE WILL OBSERVE WINDS SHIFTING TO THE NORTHEAST AND
EAST TODAY/TONIGHT WHILE THE SOUTHERN HALF REMAINS SOUTHWEST AND
WEST. AN EASTERLY COMPONENT TO THE WIND LATE TONIGHT INTO TUESDAY
WILL ONCE AGAIN TURN MORE SOUTHERLY AS NEW LOW PRESSURE DEVELOPS
TO THE WEST. SPEEDS WILL INCREASE TO 10 TO 20 KT ON TUESDAY BEFORE
TURNING TO THE SOUTHWEST AND WEST TUESDAY NIGHT...BEFORE A PERIOD
OF NORTHERLY WINDS SETTLES IN ON WEDNESDAY THROUGH THE REMAINDER
OF THE FORECAST PERIOD.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
110 PM CDT MON JUL 8 2013
.DISCUSSION...
1142 AM CDT
FOR MORNING UPDATE...
MCS CONTINUES TO MOVE SLOWLY TO THE EAST-SOUTHEAST ACROSS THE REGION
LATE THIS MORNING...IN ASSOCIATION WITH A PAIR OF SHORT WAVE TROUGHS
ANALYZED OVER LAKE MICHIGAN AND NORTHEAST IA/SOUTHWEST WI. MOST OF
THE STRONGER CONVECTIVE ACTIVITY HAS BEEN OVER NORTHEAST IL OVER THE
LAST COUPLE OF HOURS...ON NOSE OF 35-40 KT H8 WSWLY LOW LEVEL JET
AND WITHIN PLUME OF SLIGHTLY STEEPER MID LEVEL LAPSE RATES PER
SPC/RAP MESOANALYSIS. TRAINING CELLS HAVE PRODUCED SOME LOCALLY
HEAVY RAINFALL AMOUNTS (1-3 INCHES FROM OBS/RADAR) ALONG A NARROW
AXIS FROM JUST SOUTH OF ROCKFORD TO SYCAMORE/ELBURN AND THE SOUTH
SIDE OF CHICAGO. CURRENT TRENDS INDICATE THIS AREA OF THUNDERSTORMS
WILL CONTINUE TO TRACK OFF TO THE EAST-SOUTHEAST ACROSS NORTHWEST
INDIANA INTO THE EARLY AFTERNOON HOURS...WITH DECREASING COVERAGE OF
SHOWERS AND STORMS EXPECTED FROM THE WEST WITH SUBSIDENCE ASSOCIATED
WITH PASSAGE OF MID-LEVEL SHORT WAVE TROUGH. WHILE LARGER SCALE
FORCING SHOULD BECOME LESS FAVORABLE FOR ADDITIONAL DEVELOPMENT THIS
AFTERNOON...EXPLICIT CONVECTION MODEL RUNS CONTINUE TO INDICATE SOME
MORE SCATTERED REDEVELOPMENT OF CONVECTION ACROSS PARTS OF THE AREA
THIS AFTERNOON. MORNING HRRR RUNS ARE ESPECIALLY BULLISH ON
REDEVELOPING THUNDERSTORMS OVER NORTHEAST IL THIS AFTERNOON...
THOUGH IT MAY NOT BE HANDLING LOW LEVEL WIND FIELD VERY WELL AND
SUSPECT IT IS SOMEWHAT OVERDONE WITH ACTIVITY. VERY WARM/MOIST AND
UNSTABLE ENVIRONMENT WILL BE PRESENT HOWEVER AS PARTIAL SUNSHINE
DEVELOPS...WITH UPWARDS OF 2000 J/KG MLCAPE AVAILABLE PER WRF-NAM
SOUNDINGS. HAVE LOWERED POPS TO SLIGHT CHANCE ACROSS MUCH OF
NORTHERN IL AFTER CURRENT MCS EXITS THIS AFTERNOON...WITH SLIGHTLY
HIGHER CHANCE POPS ACROSS THE SOUTH/SOUTHEAST WHERE PERSISTENT WARM
ADVECTION AND OUTFLOW FROM MORNING STORMS MAY PROVIDE BETTER
POTENTIAL FOR SOME REDEVELOPMENT.
CLOUDS/RAIN HAVE HELD TEMPS IN THE 70S MOST AREAS THROUGH 11 AM.
SUBSIDENCE WITH THE AFOREMENTIONED SHORT WAVE WAS ALLOWING SOME
PARTIAL CLEARING FROM THE NORTHWEST AT MIDDAY HOWEVER. PROVIDED WE
CAN GET A FEW HOURS OF PARTLY SUNNY SKIES...THERMAL RIDGE SHOULD
EASILY PRODUCE HIGH TEMPS IN THE UPPER 80S ACROSS NORTHERN IL THIS
AFTERNOON IF NOT A FEW LOWER 90S FAR WEST. EASTERN AREAS WILL BE A
LITTLE TRICKIER BUT ALSO SHOULD BE CAPABLE OF SOME UPPER 80S WITH A
LITTLE SUN.
RATZER
//PREV DISCUSSION...
330 AM CDT
THE FORECAST CHALLENGES ARE PRIMARILY WITHIN THE NEXT 48 HOURS AS
THE AREA HAS BEEN OVERTAKEN BY THE SOUPIEST AIR MASS OF THE
SEASON...IN FACT THE MOST PROLONGED HIGH DEW POINT EPISODE SINCE
THE HEAT WAVE JUST OVER ONE YEAR AGO /JUL 4-7/. WITH THIS COMES
SEVERE STORM AND HEAVY RAIN POTENTIAL...MORE SO ON TUESDAY. IN
ADDITION...THE HIGHEST HEAT INDICES OF THE SEASON ARE
FORECAST...AND WHILE NOT AT ADVISORY CRITERIA THESE LOOK TO
FLIRT WITH 100 DEGREES IN SOME SOUTHERN CWA LOCATIONS ON TUESDAY
AFTERNOON.
SYNOPSIS...THE UPPER LEVEL RIDGE ACROSS THE CENTRAL AND SOUTHERN
PLAINS IS EVOLVING EAST EARLY THIS MORNING WITH TURBULENT MOIST
FLOW AROUND ITS NORTHERN PERIPHERY. NUMEROUS AREAS OF CONVECTION
ARE PRESENT ASSOCIATED WITH SHORT WAVE ASCENT AND MOIST ADVECTION
ON THE LOW-LEVEL JET. A WEAK LOW-LEVEL TROUGH IS PRESENT FROM
NORTHERN WI TO NORTHERN KS. TO THE EAST AND SOUTH OF THIS
FEATURE...UPPER 60S TO MID 70S DEW POINTS PREVAIL ON MOST
OBSERVATIONS ALL THE WAY TO THE ATLANTIC AND GULF COASTS. THE
RIDGE WILL TRY TO EXPAND INTO THE AREA THIS AFTERNOON AND MORE SO
TONIGHT WITH CONTINUED SYNOPTIC SOUTHERLY SURFACE FLOW ACROSS THE
AREA. THE SURFACE TROUGH WILL WORK ITS WAY LIKELY INTO FAR
SOUTHERN WI BY LATE AFTERNOON. TWO SURFACE LOWS LOOK TO RIDE ALONG
THIS...ONE DURING THE DAY TUE ASSOCIATED WITH A STRONG SHORT WAVE
EXITING THE GREAT BASIN EARLY THIS MORNING...AND ANOTHER STRONGER
SURFACE LOW ASSOCIATED WITH AN UPPER TROUGH THAT WILL DEVELOP INTO
THE GREAT LAKES BY LATE TUE NIGHT. THIS SECOND WAVE WILL USHER A
COOL FRONT THROUGH THE AREA WED MORNING WITH THE SOMEWHAT
COOLER/DRIER AIR BEING REALIZED BY WED NIGHT.
THIS MORNING...IT APPEARS THERE ARE TWO IMMEDIATE UPSTREAM SHORT
WAVES...ONE BETTER DEFINED ONE PER WATER VAPOR AND RADAR MOSAIC
ACROSS NORTHEAST IA...AND ANOTHER ACROSS FAR SOUTHERN IA/NORTHERN
MO. TOGETHER THESE WILL MOVE EAST AND LOOK TO SLOWLY
WEAKEN LATER THIS MORNING ACROSS THE EASTERN FORECAST AREA WITH
THE MORE DOMINANT JET TO THE NORTH. PROFILER DATA INDICATES 35 KT
850-925MB FLOW INTO THE AREA WHICH LOOKS TO CONTINUE PAST
DAYBREAK. SO EXPECT THAT SHOWER AND EMBEDDED STORM ACTIVITY WILL
BE SUSTAINED AS FAR EAST AS CHICAGO BY MID-MORNING. THE HRRR SEEMS
TO HAVE A FIRM HANDLE ON THE ONGOING CONVECTION AND ITS EVOLUTION
MAKES SENSE AND HAVE FOLLOWED CLOSELY IN OUR FORECAST HOURLY POPS.
HAVE SEEN A COUPLE 20 KT PLUS GUSTS IN SW WI INDICATING THAT A
COLD POOL MAY BE TRYING TO DEVELOP. THIS AND ANY MCV DEVELOPMENT
WOULD ALSO AID IN SUSTAINING THE ACTIVITY EASTWARD. SEVERE
POTENTIAL IS MAINLY LOW WITH THIS THROUGH THE MORNING AND RADAR
TRENDS FROM ARX/DVN CONFIRM NOTHING POTENT IN THE STORM
BEHAVIORS...THOUGH CANT RULE OUT SMALL HAIL OR GUSTY WINDS. IN
ADDITION...STORMS WILL BE VERY EFFICIENT RAIN PRODUCERS GIVEN HIGH
ATMOSPHERIC MOISTURE CONTENT /PWATS AOA 1.65 INCHES AND 700MB TDS
AOA 4C/.
CONFIDENCE...HIGH.
THIS AFTERNOON AND TONIGHT...WITH THE PRIMARY SHORT WAVE IMPULSES
HAVING MOVED EAST...COVERAGE OF PRECIP SHOULD AT LEAST TEMPORARILY
DIMINISH IN THE EARLY AFTERNOON. OUTFLOW BOUNDARIES FROM THE
MORNING ACTIVITY...EVEN IF ELEVATED COULD CONTINUE FESTERING
CONVECTION THIS AFTERNOON GIVEN ATTAINABLE CONVECTIVE TEMPS. THIS
WOULD SEEM MOST FAVORED ALONG AND SOUTH OF I-80. THE SURFACE
BOUNDARY WILL BE NEAR THE IL/WI STATE LINE...AND SIMILAR TO PREV
FORECAST REASONING COULD SEE SOME SCATTERED DEVELOPMENT LATER THIS
AFTERNOON ALONG THAT AS WELL. AFTER WHAT WILL LIKELY BE A SLOW
TEMPERATURE CLIMB THIS MORNING...THIS AFTERNOON SHOULD SEE
RECOVERY INTO THE UPPER 80S AND MAYBE EVEN 90...ESPECIALLY ACROSS
THE WESTERN HALF OF THE FORECAST AREA. WITH SUCH HIGH DEW POINT
AIR...SURFACE BASED INSTABILITY OF 1500-2500 J/KG WOULD BE
SUPPORTED BY THESE FORECAST TEMPS AND DEW POINTS. MOST GUIDANCE
DOES HAVE A SPLOTCHY QPF PRODUCED OVER THE AREA. ANY SCATTERED
CONVECTION THAT CAN DEVELOP THIS AFTERNOON INTO THE EVE WOULD HAVE
SOME SEVERE WEATHER THREAT. THE HIGH PWAT AIR WILL SUPPORT HEAVY
RAIN ALONG WITH PRECIP LOADING CONCERNS TOWARDS ISOLATED DOWNBURSTS
IN ANY MORE ROBUST CELLS OR MULTI-CELL CLUSTERS...BUT OVERALL
THREAT COVERAGE IS LOW. AS WE HEAD TO AFTER SUNDOWN...HEIGHT
FALLS AND THE LLJ NOSE CONTINUE TO BE FOCUSED TO THE NORTHWEST OF
THE AREA /OVER MN AND NORTHERN IA/. THIS IS WHERE LIKELY MCS
DEVELOPMENT WILL OCCUR LATE. IN ADVANCE...BROAD WARM AND MOIST
ADVECTION ALOFT MAY ALLOW FOR ISOLATED TO SCATTERED CONVECTIVE
DEVELOPMENT OVER THE AREA. DEEP WARM CLOUD PROCESSES WILL BE AT
PLAY WITH PWATS CONTINUING TO INCH UP...MEANING HEAVY RAIN WILL BE
THE GREATEST THREAT. GIVEN A SOMEWHAT DIFFUSE 850MB BAROCLINIC
ZONE AND FORWARD PROPAGATION INDICATED...THE TRAINING SETUP IS
SOMEWHAT MARGINAL IN THE FORECAST AREA AT LEAST PRIOR TO DAYBREAK
TUE. SO NO FLASH FLOOD WATCH BEING ISSUED AT THIS TIME BUT THIS
WILL NEED TO BE MONITORED.
CONFIDENCE...MEDIUM.
TUESDAY AND TUESDAY NIGHT...THESE ARE THE PERIODS WITH THE GREATER
POTENTIAL FOR HIGHER IMPACT WEATHER. MANY MODELS IN THE SUITE OF
GUIDANCE CONTINUE TO ADVERTISE A PRIMARY MCS DEVELOPING BY TUE
MORNING AHEAD OF A STRONG IMPULSE. THERE ARE VARIANCES IN
LATITUDE ON THIS...BUT CERTAINLY THE PATTERN WOULD SUPPORT SUCH
EVOLUTION WITH AMPLE INSTABILITY AHEAD OF AN MCS EVEN IN THE
MORNING GIVEN THE HIGH ABSOLUTE MOISTURE. THE SPC HAS OUTLOOKED A
30 PERCENT AREA FOR THEIR DAY TWO OUTLOOK FOR THIS REASON AND THE
AREA THEY INDICATED IS WHAT HAS BEEN FAVORED IN OUR FORECAST. IT
IS INTERESTING TO NOTE THAT THE CIPS ANALOG GUIDANCE FOR MULTIPLE
DAYS HAS INDICATED MATCHES ON SEVERE WIND EVENTS FROM NORTHERN IA
INTO SOUTHERN WI AND FAR NORTHERN IL AND CONTINUES TO DO SUCH
BASED ON THE NAM FORECAST. SO THE MOST FAVORED AREA WOULD LIKELY
BE NORTH OF I-80...AND MAYBE EVEN NORTH OF I-88 FOR POTENTIALLY A
STRONG WIND COMPLEX ON TUE. SOME OF THE SLOWER GUIDANCE HAS THIS
EVEN HAPPENING IN THE AFTERNOON. CONFIDENCE ON EXACT DEVELOPMENT
BY AFTERNOON AND NIGHTTIME DROPS...ESPECIALLY IF ANYTHING CAN
SPARK OFF OUTFLOWS. CERTAINLY A SEVERE WEATHER POTENTIAL EXISTS
THROUGH THE REST OF THE DAY WITH GRADUALLY INCREASING DEEP LAYER
SHEAR AND PLENTY OF INSTABILITY. THE SOUTHERN FORECAST AREA COULD
WARM INTO THE LOWER TO MID 90S. RIGHT NOW HEAD INDICES ARE
FORECAST AROUND 100 FOR MULTIPLE AFTERNOON HOURS IN THE SOUTHERN
FORECAST AREA...WHILE AROUND THE MID 90S IN ROCKFORD AND CHICAGO
THOUGH CONFIDENCE THERE IS LOW BASED ON PROBABLE MORNING/EARLY
AFTERNOON CONVECTION. HAVE MENTIONED HEAVY RAIN IN THE FORECAST
FOR TUE AND TUE NIGHT GIVEN THE ATMOSPHERIC SETUP AND DO HAVE CHC
SEVERE MENTIONED IN FAR NORTHERN IL GIVEN THE CONSISTENT SIGNAL
AND PATTERN SUPPORT FOR AT THE LEAST A NEARBY MCS.
CONFIDENCE...OVERALL MEDIUM.
WEDNESDAY...THE COOL FRONT...OR AT LEAST THE WIND SHIFT IS MAINLY
AGREED ON BY GUIDANCE TO BE MOVING SOUTHEAST THROUGH THE AREA
EARLY WED. THE COOLER TEMPERATURES IN THE MIX DOWN LAYER LOOK TO
ARRIVE LATE IN THE AFTERNOON INTO THE EVE...SO HIGHS IN THE MID TO
UPPER 80S ARE STILL FORECAST. SOME ONGOING CONVECTION IS LIKELY
IN THE SOUTHEAST CWA AT LEAST ON WED MORNING...THOUGH COVERAGE IS
TOUGH TO TELL AT THIS POINT. DEW POINTS LOOK TO FALL BY WED EVE.
CONFIDENCE...HIGH.
EXTENDED...HAVE NOT MADE TOO MANY CHANGES FROM A SMART BLEND OF
GUIDANCE WITH GOING FORECAST. THIS PERIOD LOOKS MAINLY QUIET AS
THE PATTERN EVOLVES THROUGH THE WEEKEND TO ONCE AGAIN A BLOCKED
SETUP. SURFACE HIGH PRESSURE LOOKS TO PREVAIL WITH ONSHORE FLOW
INTO CHICAGOLAND AND NORTHWEST INDIANA. THIS SHOULD OFFER ONLY
MINIMAL COOLING THOUGH WITH BASICALLY TEMPERATURES AT OR JUST
BELOW SEASONAL NORMALS IN MOST PLACES.
CONFIDENCE...HIGH.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MORNING SHRA/TSRA EXITING BY ABOUT 19Z.
* CHANCE FOR ADDITIONAL TSRA ACTIVITY LATE THIS AFTERNOON.
* ANOTHER ROUND OF SHRA/TSRA POSSIBLE TUESDAY MORNING...WITH MORE
ACTIVITY POSSIBLE LATER TUESDAY AFTERNOON/EVENING.
MDB
//DISCUSSION...UPDATED 18Z...
BAND OF TSRA IS FINALLY EXITING THE CHI METRO AREA TO THE EAST.
SSW WINDS ARE BECOMING SW WITH SOME GUSTS TO 18 OR 20 KT
DEVELOPING AS CLOUD COVER DIMINISHES. MVFR CIGS NEAR GYY WILL
IMPROVE IN THE NEXT HOUR OR TWO AS PRECIP EXITS. ATTENTION TURNS
TO NEW SHRA/TSRA POTENTIAL LATER THIS AFTERNOON. A COOL FRONT
MOVING SOUTHEAST ACROSS WISCONSIN MAY SERVE AS A TRIGGER FOR
ADDITIONAL DEVELOPMENT AS IT REACHES THE AREA BUT THE UPPER WAVE
RESPONSIBLE FOR THE MORNING STORMS LOOKS TO BE LEAVING A FAIR
AMOUNT OF SINKING AIR IN ITS WAKE. THAT SAID...THE LOCAL AREA IS
BECOMING UNSTABLE BEHIND THE CURRENT STORMS SO IT MAY NOT TAKE
MUCH TO KICK OFF SOME ISOLATED ACTIVITY. HAD VCSH GOING IN THE
PREVIOUS TAFS FOR THIS BUT WITH INSTABILITY GROWING TSRA WOULD
LIKELY RESULT IF SOMETHING CAN DEVELOP SO CONVERTED TO VCTS. WITH
CHANCE FOR DEVELOPMENT LOW...DEBATED REMOVING ANY MENTION
ALTOGETHER BUT WANTED TO CONTINUE TO HIGHLIGHT THE CHANCE WHICH IS
STILL IN THE 35-40 PERCENT RANGE. HAVE BETTER CONFIDENCE IN THE
EVENING AND OVERNIGHT HOURS BEING DRY WITH DIMINISHING BUT
VARIABLE WINDS. GIVEN THE RAINFALL AND THE LIGHT WINDS FOG WILL BE
POSSIBLE AND HAVE INCLUDED PATCHY FOG /BCFG/ AT RFD/DPA/GYY...WITH
AT LEAST SOME POTENTIAL FOR PERIODIC IFR CIGS LATE.
SHRA/TSRA CHANCES CONTINUE TUESDAY. HAVE DECENT CONFIDENCE THAT
THERE WILL BE A STORM COMPLEX DEVELOPING ACROSS NEBRASKA/IOWA
TONIGHT WHICH WOULD THEN AFFECT THE LOCAL AREA SOME TIME TUESDAY
MORNING. ADDITIONAL STORMS ARE POSSIBLE LATER TUESDAY BUT
DEVELOPMENT MAY HINGE ON WHAT OCCURS EARLIER IN THE DAY.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN CURRENT SHRA/TSRA EXITING BY ABOUT 19Z.
* MEDIUM-HIGH CONFIDENCE THAT AFTERNOON TSRA CHANCE IS LOW.
* MEDIUM CONFIDENCE IN SHRA/TSRA ACTIVITY TUESDAY MORNING...LOW
CONFIDENCE IN COVERAGE AND TIMING...LOW CONFIDENCE IN SHRA/TSRA
FORECAST TUESDAY AFTERNOON/EVENING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...LIKELY TSRA. MVFR/GUSTY WINDS POSSIBLE.
WEDNESDAY...CHANCE OF TSRA...OTHERWISE VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
RODRIGUEZ
&&
.MARINE...
425 AM CDT
AS AN AREA OF LOW PRESSURE OVER THE UPPER MISSISSIPPI VALLEY
SHIFTS EAST TOWARDS THE LAKE THIS MORNING...SOUTH TO SOUTHEAST
WINDS OF 10 TO 20 KT ARE BEING OBSERVED ACROSS THE LAKE. WITH THIS
LOW CONTINUING ACROSS THE LAKE TODAY...EXPECT FAIRLY DIFFERENT
CONDITIONS FROM THE NORTH HALF TO THE SOUTH HALF. WITH THIS LOW
MOVING THROUGH AND A BOUNDARY LEFT OVER THE LAKE...THE NORTHERN
HALF OF THE LAKE WILL OBSERVE WINDS SHIFTING TO THE NORTHEAST AND
EAST TODAY/TONIGHT WHILE THE SOUTHERN HALF REMAINS SOUTHWEST AND
WEST. AN EASTERLY COMPONENT TO THE WIND LATE TONIGHT INTO TUESDAY
WILL ONCE AGAIN TURN MORE SOUTHERLY AS NEW LOW PRESSURE DEVELOPS
TO THE WEST. SPEEDS WILL INCREASE TO 10 TO 20 KT ON TUESDAY BEFORE
TURNING TO THE SOUTHWEST AND WEST TUESDAY NIGHT...BEFORE A PERIOD
OF NORTHERLY WINDS SETTLES IN ON WEDNESDAY THROUGH THE REMAINDER
OF THE FORECAST PERIOD.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1143 AM CDT MON JUL 8 2013
.DISCUSSION...
1142 AM CDT
FOR MORNING UPDATE...
MCS CONTINUES TO MOVE SLOWLY TO THE EAST-SOUTHEAST ACROSS THE REGION
LATE THIS MORNING...IN ASSOCIATION WITH A PAIR OF SHORT WAVE TROUGHS
ANALYZED OVER LAKE MICHIGAN AND NORTHEAST IA/SOUTHWEST WI. MOST OF
THE STRONGER CONVECTIVE ACTIVITY HAS BEEN OVER NORTHEAST IL OVER THE
LAST COUPLE OF HOURS...ON NOSE OF 35-40 KT H8 WSWLY LOW LEVEL JET
AND WITHIN PLUME OF SLIGHTLY STEEPER MID LEVEL LAPSE RATES PER
SPC/RAP MESOANALYSIS. TRAINING CELLS HAVE PRODUCED SOME LOCALLY
HEAVY RAINFALL AMOUNTS (1-3 INCHES FROM OBS/RADAR) ALONG A NARROW
AXIS FROM JUST SOUTH OF ROCKFORD TO SYCAMORE/ELBURN AND THE SOUTH
SIDE OF CHICAGO. CURRENT TRENDS INDICATE THIS AREA OF THUNDERSTORMS
WILL CONTINUE TO TRACK OFF TO THE EAST-SOUTHEAST ACROSS NORTHWEST
INDIANA INTO THE EARLY AFTERNOON HOURS...WITH DECREASING COVERAGE OF
SHOWERS AND STORMS EXPECTED FROM THE WEST WITH SUBSIDENCE ASSOCIATED
WITH PASSAGE OF MID-LEVEL SHORT WAVE TROUGH. WHILE LARGER SCALE
FORCING SHOULD BECOME LESS FAVORABLE FOR ADDITIONAL DEVELOPMENT THIS
AFTERNOON...EXPLICIT CONVECTION MODEL RUNS CONTINUE TO INDICATE SOME
MORE SCATTERED REDEVELOPMENT OF CONVECTION ACROSS PARTS OF THE AREA
THIS AFTERNOON. MORNING HRRR RUNS ARE ESPECIALLY BULLISH ON
REDEVELOPING THUNDERSTORMS OVER NORTHEAST IL THIS AFTERNOON...
THOUGH IT MAY NOT BE HANDLING LOW LEVEL WIND FIELD VERY WELL AND
SUSPECT IT IS SOMEWHAT OVERDONE WITH ACTIVITY. VERY WARM/MOIST AND
UNSTABLE ENVIRONMENT WILL BE PRESENT HOWEVER AS PARTIAL SUNSHINE
DEVELOPS...WITH UPWARDS OF 2000 J/KG MLCAPE AVAILABLE PER WRF-NAM
SOUNDINGS. HAVE LOWERED POPS TO SLIGHT CHANCE ACROSS MUCH OF
NORTHERN IL AFTER CURRENT MCS EXITS THIS AFTERNOON...WITH SLIGHTLY
HIGHER CHANCE POPS ACROSS THE SOUTH/SOUTHEAST WHERE PERSISTENT WARM
ADVECTION AND OUTFLOW FROM MORNING STORMS MAY PROVIDE BETTER
POTENTIAL FOR SOME REDEVELOPMENT.
CLOUDS/RAIN HAVE HELD TEMPS IN THE 70S MOST AREAS THROUGH 11 AM.
SUBSIDENCE WITH THE AFOREMENTIONED SHORT WAVE WAS ALLOWING SOME
PARTIAL CLEARING FROM THE NORTHWEST AT MIDDAY HOWEVER. PROVIDED WE
CAN GET A FEW HOURS OF PARTLY SUNNY SKIES...THERMAL RIDGE SHOULD
EASILY PRODUCE HIGH TEMPS IN THE UPPER 80S ACROSS NORTHERN IL THIS
AFTERNOON IF NOT A FEW LOWER 90S FAR WEST. EASTERN AREAS WILL BE A
LITTLE TRICKIER BUT ALSO SHOULD BE CAPABLE OF SOME UPPER 80S WITH A
LITTLE SUN.
RATZER
&&
.PREV DISCUSSION...
330 AM CDT
THE FORECAST CHALLENGES ARE PRIMARILY WITHIN THE NEXT 48 HOURS AS
THE AREA HAS BEEN OVERTAKEN BY THE SOUPIEST AIR MASS OF THE
SEASON...IN FACT THE MOST PROLONGED HIGH DEW POINT EPISODE SINCE
THE HEAT WAVE JUST OVER ONE YEAR AGO /JUL 4-7/. WITH THIS COMES
SEVERE STORM AND HEAVY RAIN POTENTIAL...MORE SO ON TUESDAY. IN
ADDITION...THE HIGHEST HEAT INDICES OF THE SEASON ARE
FORECAST...AND WHILE NOT AT ADVISORY CRITERIA THESE LOOK TO
FLIRT WITH 100 DEGREES IN SOME SOUTHERN CWA LOCATIONS ON TUESDAY
AFTERNOON.
SYNOPSIS...THE UPPER LEVEL RIDGE ACROSS THE CENTRAL AND SOUTHERN
PLAINS IS EVOLVING EAST EARLY THIS MORNING WITH TURBULENT MOIST
FLOW AROUND ITS NORTHERN PERIPHERY. NUMEROUS AREAS OF CONVECTION
ARE PRESENT ASSOCIATED WITH SHORT WAVE ASCENT AND MOIST ADVECTION
ON THE LOW-LEVEL JET. A WEAK LOW-LEVEL TROUGH IS PRESENT FROM
NORTHERN WI TO NORTHERN KS. TO THE EAST AND SOUTH OF THIS
FEATURE...UPPER 60S TO MID 70S DEW POINTS PREVAIL ON MOST
OBSERVATIONS ALL THE WAY TO THE ATLANTIC AND GULF COASTS. THE
RIDGE WILL TRY TO EXPAND INTO THE AREA THIS AFTERNOON AND MORE SO
TONIGHT WITH CONTINUED SYNOPTIC SOUTHERLY SURFACE FLOW ACROSS THE
AREA. THE SURFACE TROUGH WILL WORK ITS WAY LIKELY INTO FAR
SOUTHERN WI BY LATE AFTERNOON. TWO SURFACE LOWS LOOK TO RIDE ALONG
THIS...ONE DURING THE DAY TUE ASSOCIATED WITH A STRONG SHORT WAVE
EXITING THE GREAT BASIN EARLY THIS MORNING...AND ANOTHER STRONGER
SURFACE LOW ASSOCIATED WITH AN UPPER TROUGH THAT WILL DEVELOP INTO
THE GREAT LAKES BY LATE TUE NIGHT. THIS SECOND WAVE WILL USHER A
COOL FRONT THROUGH THE AREA WED MORNING WITH THE SOMEWHAT
COOLER/DRIER AIR BEING REALIZED BY WED NIGHT.
THIS MORNING...IT APPEARS THERE ARE TWO IMMEDIATE UPSTREAM SHORT
WAVES...ONE BETTER DEFINED ONE PER WATER VAPOR AND RADAR MOSAIC
ACROSS NORTHEAST IA...AND ANOTHER ACROSS FAR SOUTHERN IA/NORTHERN
MO. TOGETHER THESE WILL MOVE EAST AND LOOK TO SLOWLY
WEAKEN LATER THIS MORNING ACROSS THE EASTERN FORECAST AREA WITH
THE MORE DOMINANT JET TO THE NORTH. PROFILER DATA INDICATES 35 KT
850-925MB FLOW INTO THE AREA WHICH LOOKS TO CONTINUE PAST
DAYBREAK. SO EXPECT THAT SHOWER AND EMBEDDED STORM ACTIVITY WILL
BE SUSTAINED AS FAR EAST AS CHICAGO BY MID-MORNING. THE HRRR SEEMS
TO HAVE A FIRM HANDLE ON THE ONGOING CONVECTION AND ITS EVOLUTION
MAKES SENSE AND HAVE FOLLOWED CLOSELY IN OUR FORECAST HOURLY POPS.
HAVE SEEN A COUPLE 20 KT PLUS GUSTS IN SW WI INDICATING THAT A
COLD POOL MAY BE TRYING TO DEVELOP. THIS AND ANY MCV DEVELOPMENT
WOULD ALSO AID IN SUSTAINING THE ACTIVITY EASTWARD. SEVERE
POTENTIAL IS MAINLY LOW WITH THIS THROUGH THE MORNING AND RADAR
TRENDS FROM ARX/DVN CONFIRM NOTHING POTENT IN THE STORM
BEHAVIORS...THOUGH CANT RULE OUT SMALL HAIL OR GUSTY WINDS. IN
ADDITION...STORMS WILL BE VERY EFFICIENT RAIN PRODUCERS GIVEN HIGH
ATMOSPHERIC MOISTURE CONTENT /PWATS AOA 1.65 INCHES AND 700MB TDS
AOA 4C/.
CONFIDENCE...HIGH.
THIS AFTERNOON AND TONIGHT...WITH THE PRIMARY SHORT WAVE IMPULSES
HAVING MOVED EAST...COVERAGE OF PRECIP SHOULD AT LEAST TEMPORARILY
DIMINISH IN THE EARLY AFTERNOON. OUTFLOW BOUNDARIES FROM THE
MORNING ACTIVITY...EVEN IF ELEVATED COULD CONTINUE FESTERING
CONVECTION THIS AFTERNOON GIVEN ATTAINABLE CONVECTIVE TEMPS. THIS
WOULD SEEM MOST FAVORED ALONG AND SOUTH OF I-80. THE SURFACE
BOUNDARY WILL BE NEAR THE IL/WI STATE LINE...AND SIMILAR TO PREV
FORECAST REASONING COULD SEE SOME SCATTERED DEVELOPMENT LATER THIS
AFTERNOON ALONG THAT AS WELL. AFTER WHAT WILL LIKELY BE A SLOW
TEMPERATURE CLIMB THIS MORNING...THIS AFTERNOON SHOULD SEE
RECOVERY INTO THE UPPER 80S AND MAYBE EVEN 90...ESPECIALLY ACROSS
THE WESTERN HALF OF THE FORECAST AREA. WITH SUCH HIGH DEW POINT
AIR...SURFACE BASED INSTABILITY OF 1500-2500 J/KG WOULD BE
SUPPORTED BY THESE FORECAST TEMPS AND DEW POINTS. MOST GUIDANCE
DOES HAVE A SPLOTCHY QPF PRODUCED OVER THE AREA. ANY SCATTERED
CONVECTION THAT CAN DEVELOP THIS AFTERNOON INTO THE EVE WOULD HAVE
SOME SEVERE WEATHER THREAT. THE HIGH PWAT AIR WILL SUPPORT HEAVY
RAIN ALONG WITH PRECIP LOADING CONCERNS TOWARDS ISOLATED DOWNBURSTS
IN ANY MORE ROBUST CELLS OR MULTI-CELL CLUSTERS...BUT OVERALL
THREAT COVERAGE IS LOW. AS WE HEAD TO AFTER SUNDOWN...HEIGHT
FALLS AND THE LLJ NOSE CONTINUE TO BE FOCUSED TO THE NORTHWEST OF
THE AREA /OVER MN AND NORTHERN IA/. THIS IS WHERE LIKELY MCS
DEVELOPMENT WILL OCCUR LATE. IN ADVANCE...BROAD WARM AND MOIST
ADVECTION ALOFT MAY ALLOW FOR ISOLATED TO SCATTERED CONVECTIVE
DEVELOPMENT OVER THE AREA. DEEP WARM CLOUD PROCESSES WILL BE AT
PLAY WITH PWATS CONTINUING TO INCH UP...MEANING HEAVY RAIN WILL BE
THE GREATEST THREAT. GIVEN A SOMEWHAT DIFFUSE 850MB BAROCLINIC
ZONE AND FORWARD PROPAGATION INDICATED...THE TRAINING SETUP IS
SOMEWHAT MARGINAL IN THE FORECAST AREA AT LEAST PRIOR TO DAYBREAK
TUE. SO NO FLASH FLOOD WATCH BEING ISSUED AT THIS TIME BUT THIS
WILL NEED TO BE MONITORED.
CONFIDENCE...MEDIUM.
TUESDAY AND TUESDAY NIGHT...THESE ARE THE PERIODS WITH THE GREATER
POTENTIAL FOR HIGHER IMPACT WEATHER. MANY MODELS IN THE SUITE OF
GUIDANCE CONTINUE TO ADVERTISE A PRIMARY MCS DEVELOPING BY TUE
MORNING AHEAD OF A STRONG IMPULSE. THERE ARE VARIANCES IN
LATITUDE ON THIS...BUT CERTAINLY THE PATTERN WOULD SUPPORT SUCH
EVOLUTION WITH AMPLE INSTABILITY AHEAD OF AN MCS EVEN IN THE
MORNING GIVEN THE HIGH ABSOLUTE MOISTURE. THE SPC HAS OUTLOOKED A
30 PERCENT AREA FOR THEIR DAY TWO OUTLOOK FOR THIS REASON AND THE
AREA THEY INDICATED IS WHAT HAS BEEN FAVORED IN OUR FORECAST. IT
IS INTERESTING TO NOTE THAT THE CIPS ANALOG GUIDANCE FOR MULTIPLE
DAYS HAS INDICATED MATCHES ON SEVERE WIND EVENTS FROM NORTHERN IA
INTO SOUTHERN WI AND FAR NORTHERN IL AND CONTINUES TO DO SUCH
BASED ON THE NAM FORECAST. SO THE MOST FAVORED AREA WOULD LIKELY
BE NORTH OF I-80...AND MAYBE EVEN NORTH OF I-88 FOR POTENTIALLY A
STRONG WIND COMPLEX ON TUE. SOME OF THE SLOWER GUIDANCE HAS THIS
EVEN HAPPENING IN THE AFTERNOON. CONFIDENCE ON EXACT DEVELOPMENT
BY AFTERNOON AND NIGHTTIME DROPS...ESPECIALLY IF ANYTHING CAN
SPARK OFF OUTFLOWS. CERTAINLY A SEVERE WEATHER POTENTIAL EXISTS
THROUGH THE REST OF THE DAY WITH GRADUALLY INCREASING DEEP LAYER
SHEAR AND PLENTY OF INSTABILITY. THE SOUTHERN FORECAST AREA COULD
WARM INTO THE LOWER TO MID 90S. RIGHT NOW HEAD INDICES ARE
FORECAST AROUND 100 FOR MULTIPLE AFTERNOON HOURS IN THE SOUTHERN
FORECAST AREA...WHILE AROUND THE MID 90S IN ROCKFORD AND CHICAGO
THOUGH CONFIDENCE THERE IS LOW BASED ON PROBABLE MORNING/EARLY
AFTERNOON CONVECTION. HAVE MENTIONED HEAVY RAIN IN THE FORECAST
FOR TUE AND TUE NIGHT GIVEN THE ATMOSPHERIC SETUP AND DO HAVE CHC
SEVERE MENTIONED IN FAR NORTHERN IL GIVEN THE CONSISTENT SIGNAL
AND PATTERN SUPPORT FOR AT THE LEAST A NEARBY MCS.
CONFIDENCE...OVERALL MEDIUM.
WEDNESDAY...THE COOL FRONT...OR AT LEAST THE WIND SHIFT IS MAINLY
AGREED ON BY GUIDANCE TO BE MOVING SOUTHEAST THROUGH THE AREA
EARLY WED. THE COOLER TEMPERATURES IN THE MIX DOWN LAYER LOOK TO
ARRIVE LATE IN THE AFTERNOON INTO THE EVE...SO HIGHS IN THE MID TO
UPPER 80S ARE STILL FORECAST. SOME ONGOING CONVECTION IS LIKELY
IN THE SOUTHEAST CWA AT LEAST ON WED MORNING...THOUGH COVERAGE IS
TOUGH TO TELL AT THIS POINT. DEW POINTS LOOK TO FALL BY WED EVE.
CONFIDENCE...HIGH.
EXTENDED...HAVE NOT MADE TOO MANY CHANGES FROM A SMART BLEND OF
GUIDANCE WITH GOING FORECAST. THIS PERIOD LOOKS MAINLY QUIET AS
THE PATTERN EVOLVES THROUGH THE WEEKEND TO ONCE AGAIN A BLOCKED
SETUP. SURFACE HIGH PRESSURE LOOKS TO PREVAIL WITH ONSHORE FLOW
INTO CHICAGOLAND AND NORTHWEST INDIANA. THIS SHOULD OFFER ONLY
MINIMAL COOLING THOUGH WITH BASICALLY TEMPERATURES AT OR JUST
BELOW SEASONAL NORMALS IN MOST PLACES.
CONFIDENCE...HIGH.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* RE-ORGANIZING LINE OF TSRA AFFECTING AREA TIL 18/19Z. PERIODIC
IFR VSBY POSSIBLE...MAINLY AT MDW.
* SOUTH-SOUTHWEST WINDS TURNING MORE SOUTHWEST EARLY THIS
AFTERNOON.
* LOW CHANCE FOR ADDITIONAL SHRA/TSRA LATER THIS AFTERNOON.
* ANOTHER ROUND OF TSRA POSSIBLE EARLY TUESDAY MORNING.
MDB
//DISCUSSION...UPDATED 16Z...
NARROW LINE OF TSRA HAS DEVELOPED FROM JUST NE OF DKB AND EXTENDS
ACROSS MDW AND GYY. CELLS CONTINUE TO BUILD ON THE WESTERN TAIL OF
THE LINE SUGGESTING THAT THE LINE WILL BE IN THE AREA FOR A FEW
HOURS AS IT TRAINS EASTWARD. MDW/DPA/GYY LOOK TO REMAIN IN CLOSE
PROXIMITY OR UNDERNEATH THE LINE WITH PERIODIC IFR VSBY AND HEAVY
DOWNPOURS. ORD LOOKS TO REMAIN TO THE NORTH OF THE LINE BUT WITH
THE NORTHWARD ARC BACK NEAR DKB AM CONCERNED THAT THEY MAY HAVE THE
TAIL OF THE LINE CROSS THE TERMINAL IN ANOTHER HOUR OR TWO IF IT
MAINTAINS ITSELF. WINDS HAVE BECOME STEADIER FROM THE SSW AND
EXPECT A TRANSITION TO SW EARLY THIS AFTERNOON. LOW CHANCES FOR
ADDITIONAL SHRA/TSRA CONTINUE THIS AFTERNOON.
MDB
FROM 12Z...
SHOWERS WITH ISOLATED TS CURRENTLY PUSHING ACROSS TERMINALS THIS
MORNING AS LARGE AREA OF PRECIP SPANNING MUCH OF THE REGION SHIFTS
EAST. ALTHOUGH COVERAGE OF THIS PRECIP HAS HELD TOGETHER...THE
OVERALL CONVECTIVE NATURE OF THIS SYSTEM HAS DIMINISHED OVER THE
LAST ONE TO TWO HOURS WITH LIGHTNING BECOMING MORE LIMITED.
NONETHELESS...HAVE OBSERVED A PERIODIC LIGHTNING STRIKE WITH THIS
AREA OF PRECIP OVER THE LAST HOUR...AND SO HAVE MAINTAINED THE
TEMPO GROUP FOR TS OVER THE NEXT COUPLE OF HOURS BEFORE THIS
PRECIP CONTINUES TO SHIFT EAST OF THE TERMINALS. ALTHOUGH A BRIEF
DRY PERIOD WILL BE OBSERVED WITH THE DEPARTURE OF THIS MORNINGS
PRECIP...DO THINK THAT SCATTERED DEVELOPMENT WILL REMAIN POSSIBLE
THIS AFTERNOON BUT WITH CONFIDENCE LOWER WITH REGARDS TO COVERAGE
AS WELL AS INTENSITY. MOST OF THIS EVENING AND OVERNIGHT SHOULD
REMAIN DRY...BUT WILL NEED TO CONTINUE MONITORING ANY DEVELOPMENT
WEST OF THE REGION TONIGHT AS THIS PRECIP WILL BE CAPABLE OF
SHIFTING EAST TOWARDS THE TERMINALS LATE TONIGHT EARLY TUESDAY
MORNING AND COULD HAVE IMPACTS FOR THE TERMINALS.
SOUTHWEST WEST WINDS WILL BE LIKELY TODAY WITH GUSTS INCREASING TO
THE UPPER TEENS TODAY...BEFORE DIMINISHING THIS EVENING. THERE HAS
BEEN A SLIGHT INCREASE IN GUSTS TO AROUND 20 KT MORE FROM A
WESTERLY DIRECTION WITH THESE SHOWERS THIS MORNING. HAVE ADJUSTED
THE TAFS TO REFLECT THIS POSSIBILITY AND TRENDS...BUT WITH THIS
REMAINING BRIEF.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN TSRA CONTINUING WITH PERIODIC IFR
VSBY...MEDIUM CONFIDENCE IN END TIME.
* HIGH CONFIDENCE IN WIND DIRECTION TRENDS BUT MEDIUM CONFIDENCE
IN TIMING OF CHANGES.
* MEDIUM HIGH CONFIDENCE THAT POTENTIAL FOR ADDITIONAL SHRA/TSRA
LATER THIS AFTERNOON IS LOW.
* LOW CONFIDENCE IN SHRA/TSRA TIMING/COVERAGE TUESDAY MORNING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...LIKELY TSRA. MVFR/GUSTY WINDS POSSIBLE.
WEDNESDAY...CHANCE OF TSRA...OTHERWISE VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
RODRIGUEZ
&&
.MARINE...
425 AM CDT
AS AN AREA OF LOW PRESSURE OVER THE UPPER MISSISSIPPI VALLEY
SHIFTS EAST TOWARDS THE LAKE THIS MORNING...SOUTH TO SOUTHEAST
WINDS OF 10 TO 20 KT ARE BEING OBSERVED ACROSS THE LAKE. WITH THIS
LOW CONTINUING ACROSS THE LAKE TODAY...EXPECT FAIRLY DIFFERENT
CONDITIONS FROM THE NORTH HALF TO THE SOUTH HALF. WITH THIS LOW
MOVING THROUGH AND A BOUNDARY LEFT OVER THE LAKE...THE NORTHERN
HALF OF THE LAKE WILL OBSERVE WINDS SHIFTING TO THE NORTHEAST AND
EAST TODAY/TONIGHT WHILE THE SOUTHERN HALF REMAINS SOUTHWEST AND
WEST. AN EASTERLY COMPONENT TO THE WIND LATE TONIGHT INTO TUESDAY
WILL ONCE AGAIN TURN MORE SOUTHERLY AS NEW LOW PRESSURE DEVELOPS
TO THE WEST. SPEEDS WILL INCREASE TO 10 TO 20 KT ON TUESDAY BEFORE
TURNING TO THE SOUTHWEST AND WEST TUESDAY NIGHT...BEFORE A PERIOD
OF NORTHERLY WINDS SETTLES IN ON WEDNESDAY THROUGH THE REMAINDER
OF THE FORECAST PERIOD.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1116 AM CDT MON JUL 8 2013
.DISCUSSION...
330 AM CDT
THE FORECAST CHALLENGES ARE PRIMARILY WITHIN THE NEXT 48 HOURS AS
THE AREA HAS BEEN OVERTAKEN BY THE SOUPIEST AIR MASS OF THE
SEASON...IN FACT THE MOST PROLONGED HIGH DEW POINT EPISODE SINCE
THE HEAT WAVE JUST OVER ONE YEAR AGO /JUL 4-7/. WITH THIS COMES
SEVERE STORM AND HEAVY RAIN POTENTIAL...MORE SO ON TUESDAY. IN
ADDITION...THE HIGHEST HEAT INDICES OF THE SEASON ARE
FORECAST...AND WHILE NOT AT ADVISORY CRITERIA THESE LOOK TO
FLIRT WITH 100 DEGREES IN SOME SOUTHERN CWA LOCATIONS ON TUESDAY
AFTERNOON.
SYNOPSIS...THE UPPER LEVEL RIDGE ACROSS THE CENTRAL AND SOUTHERN
PLAINS IS EVOLVING EAST EARLY THIS MORNING WITH TURBULENT MOIST
FLOW AROUND ITS NORTHERN PERIPHERY. NUMEROUS AREAS OF CONVECTION
ARE PRESENT ASSOCIATED WITH SHORT WAVE ASCENT AND MOIST ADVECTION
ON THE LOW-LEVEL JET. A WEAK LOW-LEVEL TROUGH IS PRESENT FROM
NORTHERN WI TO NORTHERN KS. TO THE EAST AND SOUTH OF THIS
FEATURE...UPPER 60S TO MID 70S DEW POINTS PREVAIL ON MOST
OBSERVATIONS ALL THE WAY TO THE ATLANTIC AND GULF COASTS. THE
RIDGE WILL TRY TO EXPAND INTO THE AREA THIS AFTERNOON AND MORE SO
TONIGHT WITH CONTINUED SYNOPTIC SOUTHERLY SURFACE FLOW ACROSS THE
AREA. THE SURFACE TROUGH WILL WORK ITS WAY LIKELY INTO FAR
SOUTHERN WI BY LATE AFTERNOON. TWO SURFACE LOWS LOOK TO RIDE ALONG
THIS...ONE DURING THE DAY TUE ASSOCIATED WITH A STRONG SHORT WAVE
EXITING THE GREAT BASIN EARLY THIS MORNING...AND ANOTHER STRONGER
SURFACE LOW ASSOCIATED WITH AN UPPER TROUGH THAT WILL DEVELOP INTO
THE GREAT LAKES BY LATE TUE NIGHT. THIS SECOND WAVE WILL USHER A
COOL FRONT THROUGH THE AREA WED MORNING WITH THE SOMEWHAT
COOLER/DRIER AIR BEING REALIZED BY WED NIGHT.
THIS MORNING...IT APPEARS THERE ARE TWO IMMEDIATE UPSTREAM SHORT
WAVES...ONE BETTER DEFINED ONE PER WATER VAPOR AND RADAR MOSAIC
ACROSS NORTHEAST IA...AND ANOTHER ACROSS FAR SOUTHERN IA/NORTHERN
MO. TOGETHER THESE WILL MOVE EAST AND LOOK TO SLOWLY
WEAKEN LATER THIS MORNING ACROSS THE EASTERN FORECAST AREA WITH
THE MORE DOMINANT JET TO THE NORTH. PROFILER DATA INDICATES 35 KT
850-925MB FLOW INTO THE AREA WHICH LOOKS TO CONTINUE PAST
DAYBREAK. SO EXPECT THAT SHOWER AND EMBEDDED STORM ACTIVITY WILL
BE SUSTAINED AS FAR EAST AS CHICAGO BY MID-MORNING. THE HRRR SEEMS
TO HAVE A FIRM HANDLE ON THE ONGOING CONVECTION AND ITS EVOLUTION
MAKES SENSE AND HAVE FOLLOWED CLOSELY IN OUR FORECAST HOURLY POPS.
HAVE SEEN A COUPLE 20 KT PLUS GUSTS IN SW WI INDICATING THAT A
COLD POOL MAY BE TRYING TO DEVELOP. THIS AND ANY MCV DEVELOPMENT
WOULD ALSO AID IN SUSTAINING THE ACTIVITY EASTWARD. SEVERE
POTENTIAL IS MAINLY LOW WITH THIS THROUGH THE MORNING AND RADAR
TRENDS FROM ARX/DVN CONFIRM NOTHING POTENT IN THE STORM
BEHAVIORS...THOUGH CANT RULE OUT SMALL HAIL OR GUSTY WINDS. IN
ADDITION...STORMS WILL BE VERY EFFICIENT RAIN PRODUCERS GIVEN HIGH
ATMOSPHERIC MOISTURE CONTENT /PWATS AOA 1.65 INCHES AND 700MB TDS
AOA 4C/.
CONFIDENCE...HIGH.
THIS AFTERNOON AND TONIGHT...WITH THE PRIMARY SHORT WAVE IMPULSES
HAVING MOVED EAST...COVERAGE OF PRECIP SHOULD AT LEAST TEMPORARILY
DIMINISH IN THE EARLY AFTERNOON. OUTFLOW BOUNDARIES FROM THE
MORNING ACTIVITY...EVEN IF ELEVATED COULD CONTINUE FESTERING
CONVECTION THIS AFTERNOON GIVEN ATTAINABLE CONVECTIVE TEMPS. THIS
WOULD SEEM MOST FAVORED ALONG AND SOUTH OF I-80. THE SURFACE
BOUNDARY WILL BE NEAR THE IL/WI STATE LINE...AND SIMILAR TO PREV
FORECAST REASONING COULD SEE SOME SCATTERED DEVELOPMENT LATER THIS
AFTERNOON ALONG THAT AS WELL. AFTER WHAT WILL LIKELY BE A SLOW
TEMPERATURE CLIMB THIS MORNING...THIS AFTERNOON SHOULD SEE
RECOVERY INTO THE UPPER 80S AND MAYBE EVEN 90...ESPECIALLY ACROSS
THE WESTERN HALF OF THE FORECAST AREA. WITH SUCH HIGH DEW POINT
AIR...SURFACE BASED INSTABILITY OF 1500-2500 J/KG WOULD BE
SUPPORTED BY THESE FORECAST TEMPS AND DEW POINTS. MOST GUIDANCE
DOES HAVE A SPLOTCHY QPF PRODUCED OVER THE AREA. ANY SCATTERED
CONVECTION THAT CAN DEVELOP THIS AFTERNOON INTO THE EVE WOULD HAVE
SOME SEVERE WEATHER THREAT. THE HIGH PWAT AIR WILL SUPPORT HEAVY
RAIN ALONG WITH PRECIP LOADING CONCERNS TOWARDS ISOLATED DOWNBURSTS
IN ANY MORE ROBUST CELLS OR MULTI-CELL CLUSTERS...BUT OVERALL
THREAT COVERAGE IS LOW. AS WE HEAD TO AFTER SUNDOWN...HEIGHT
FALLS AND THE LLJ NOSE CONTINUE TO BE FOCUSED TO THE NORTHWEST OF
THE AREA /OVER MN AND NORTHERN IA/. THIS IS WHERE LIKELY MCS
DEVELOPMENT WILL OCCUR LATE. IN ADVANCE...BROAD WARM AND MOIST
ADVECTION ALOFT MAY ALLOW FOR ISOLATED TO SCATTERED CONVECTIVE
DEVELOPMENT OVER THE AREA. DEEP WARM CLOUD PROCESSES WILL BE AT
PLAY WITH PWATS CONTINUING TO INCH UP...MEANING HEAVY RAIN WILL BE
THE GREATEST THREAT. GIVEN A SOMEWHAT DIFFUSE 850MB BAROCLINIC
ZONE AND FORWARD PROPAGATION INDICATED...THE TRAINING SETUP IS
SOMEWHAT MARGINAL IN THE FORECAST AREA AT LEAST PRIOR TO DAYBREAK
TUE. SO NO FLASH FLOOD WATCH BEING ISSUED AT THIS TIME BUT THIS
WILL NEED TO BE MONITORED.
CONFIDENCE...MEDIUM.
TUESDAY AND TUESDAY NIGHT...THESE ARE THE PERIODS WITH THE GREATER
POTENTIAL FOR HIGHER IMPACT WEATHER. MANY MODELS IN THE SUITE OF
GUIDANCE CONTINUE TO ADVERTISE A PRIMARY MCS DEVELOPING BY TUE
MORNING AHEAD OF A STRONG IMPULSE. THERE ARE VARIANCES IN
LATITUDE ON THIS...BUT CERTAINLY THE PATTERN WOULD SUPPORT SUCH
EVOLUTION WITH AMPLE INSTABILITY AHEAD OF AN MCS EVEN IN THE
MORNING GIVEN THE HIGH ABSOLUTE MOISTURE. THE SPC HAS OUTLOOKED A
30 PERCENT AREA FOR THEIR DAY TWO OUTLOOK FOR THIS REASON AND THE
AREA THEY INDICATED IS WHAT HAS BEEN FAVORED IN OUR FORECAST. IT
IS INTERESTING TO NOTE THAT THE CIPS ANALOG GUIDANCE FOR MULTIPLE
DAYS HAS INDICATED MATCHES ON SEVERE WIND EVENTS FROM NORTHERN IA
INTO SOUTHERN WI AND FAR NORTHERN IL AND CONTINUES TO DO SUCH
BASED ON THE NAM FORECAST. SO THE MOST FAVORED AREA WOULD LIKELY
BE NORTH OF I-80...AND MAYBE EVEN NORTH OF I-88 FOR POTENTIALLY A
STRONG WIND COMPLEX ON TUE. SOME OF THE SLOWER GUIDANCE HAS THIS
EVEN HAPPENING IN THE AFTERNOON. CONFIDENCE ON EXACT DEVELOPMENT
BY AFTERNOON AND NIGHTTIME DROPS...ESPECIALLY IF ANYTHING CAN
SPARK OFF OUTFLOWS. CERTAINLY A SEVERE WEATHER POTENTIAL EXISTS
THROUGH THE REST OF THE DAY WITH GRADUALLY INCREASING DEEP LAYER
SHEAR AND PLENTY OF INSTABILITY. THE SOUTHERN FORECAST AREA COULD
WARM INTO THE LOWER TO MID 90S. RIGHT NOW HEAD INDICES ARE
FORECAST AROUND 100 FOR MULTIPLE AFTERNOON HOURS IN THE SOUTHERN
FORECAST AREA...WHILE AROUND THE MID 90S IN ROCKFORD AND CHICAGO
THOUGH CONFIDENCE THERE IS LOW BASED ON PROBABLE MORNING/EARLY
AFTERNOON CONVECTION. HAVE MENTIONED HEAVY RAIN IN THE FORECAST
FOR TUE AND TUE NIGHT GIVEN THE ATMOSPHERIC SETUP AND DO HAVE CHC
SEVERE MENTIONED IN FAR NORTHERN IL GIVEN THE CONSISTENT SIGNAL
AND PATTERN SUPPORT FOR AT THE LEAST A NEARBY MCS.
CONFIDENCE...OVERALL MEDIUM.
WEDNESDAY...THE COOL FRONT...OR AT LEAST THE WIND SHIFT IS MAINLY
AGREED ON BY GUIDANCE TO BE MOVING SOUTHEAST THROUGH THE AREA
EARLY WED. THE COOLER TEMPERATURES IN THE MIX DOWN LAYER LOOK TO
ARRIVE LATE IN THE AFTERNOON INTO THE EVE...SO HIGHS IN THE MID TO
UPPER 80S ARE STILL FORECAST. SOME ONGOING CONVECTION IS LIKELY
IN THE SOUTHEAST CWA AT LEAST ON WED MORNING...THOUGH COVERAGE IS
TOUGH TO TELL AT THIS POINT. DEW POINTS LOOK TO FALL BY WED EVE.
CONFIDENCE...HIGH.
EXTENDED...HAVE NOT MADE TOO MANY CHANGES FROM A SMART BLEND OF
GUIDANCE WITH GOING FORECAST. THIS PERIOD LOOKS MAINLY QUIET AS
THE PATTERN EVOLVES THROUGH THE WEEKEND TO ONCE AGAIN A BLOCKED
SETUP. SURFACE HIGH PRESSURE LOOKS TO PREVAIL WITH ONSHORE FLOW
INTO CHICAGOLAND AND NORTHWEST INDIANA. THIS SHOULD OFFER ONLY
MINIMAL COOLING THOUGH WITH BASICALLY TEMPERATURES AT OR JUST
BELOW SEASONAL NORMALS IN MOST PLACES.
CONFIDENCE...HIGH.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* RE-ORGANIZING LINE OF TSRA AFFECTING AREA TIL 18/19Z. PERIODIC
IFR VSBY POSSIBLE...MAINLY AT MDW.
* SOUTH-SOUTHWEST WINDS TURNING MORE SOUTHWEST EARLY THIS
AFTERNOON.
* LOW CHANCE FOR ADDITIONAL SHRA/TSRA LATER THIS AFTERNOON.
* ANOTHER ROUND OF TSRA POSSIBLE EARLY TUESDAY MORNING.
MDB
//DISCUSSION...UPDATED 16Z...
NARROW LINE OF TSRA HAS DEVELOPED FROM JUST NE OF DKB AND EXTENDS
ACROSS MDW AND GYY. CELLS CONTINUE TO BUILD ON THE WESTERN TAIL OF
THE LINE SUGGESTING THAT THE LINE WILL BE IN THE AREA FOR A FEW
HOURS AS IT TRAINS EASTWARD. MDW/DPA/GYY LOOK TO REMAIN IN CLOSE
PROXIMITY OR UNDERNEATH THE LINE WITH PERIODIC IFR VSBY AND HEAVY
DOWNPOURS. ORD LOOKS TO REMAIN TO THE NORTH OF THE LINE BUT WITH
THE NORTHWARD ARC BACK NEAR DKB AM CONCERNED THAT THEY MAY HAVE THE
TAIL OF THE LINE CROSS THE TERMINAL IN ANOTHER HOUR OR TWO IF IT
MAINTAINS ITSELF. WINDS HAVE BECOME STEADIER FROM THE SSW AND
EXPECT A TRANSITION TO SW EARLY THIS AFTERNOON. LOW CHANCES FOR
ADDITIONAL SHRA/TSRA CONTINUE THIS AFTERNOON.
MDB
FROM 12Z...
SHOWERS WITH ISOLATED TS CURRENTLY PUSHING ACROSS TERMINALS THIS
MORNING AS LARGE AREA OF PRECIP SPANNING MUCH OF THE REGION SHIFTS
EAST. ALTHOUGH COVERAGE OF THIS PRECIP HAS HELD TOGETHER...THE
OVERALL CONVECTIVE NATURE OF THIS SYSTEM HAS DIMINISHED OVER THE
LAST ONE TO TWO HOURS WITH LIGHTNING BECOMING MORE LIMITED.
NONETHELESS...HAVE OBSERVED A PERIODIC LIGHTNING STRIKE WITH THIS
AREA OF PRECIP OVER THE LAST HOUR...AND SO HAVE MAINTAINED THE
TEMPO GROUP FOR TS OVER THE NEXT COUPLE OF HOURS BEFORE THIS
PRECIP CONTINUES TO SHIFT EAST OF THE TERMINALS. ALTHOUGH A BRIEF
DRY PERIOD WILL BE OBSERVED WITH THE DEPARTURE OF THIS MORNINGS
PRECIP...DO THINK THAT SCATTERED DEVELOPMENT WILL REMAIN POSSIBLE
THIS AFTERNOON BUT WITH CONFIDENCE LOWER WITH REGARDS TO COVERAGE
AS WELL AS INTENSITY. MOST OF THIS EVENING AND OVERNIGHT SHOULD
REMAIN DRY...BUT WILL NEED TO CONTINUE MONITORING ANY DEVELOPMENT
WEST OF THE REGION TONIGHT AS THIS PRECIP WILL BE CAPABLE OF
SHIFTING EAST TOWARDS THE TERMINALS LATE TONIGHT EARLY TUESDAY
MORNING AND COULD HAVE IMPACTS FOR THE TERMINALS.
SOUTHWEST WEST WINDS WILL BE LIKELY TODAY WITH GUSTS INCREASING TO
THE UPPER TEENS TODAY...BEFORE DIMINISHING THIS EVENING. THERE HAS
BEEN A SLIGHT INCREASE IN GUSTS TO AROUND 20 KT MORE FROM A
WESTERLY DIRECTION WITH THESE SHOWERS THIS MORNING. HAVE ADJUSTED
THE TAFS TO REFLECT THIS POSSIBILITY AND TRENDS...BUT WITH THIS
REMAINING BRIEF.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN TSRA CONTINUING WITH PERIODIC IFR
VSBY...MEDIUM CONFIDENCE IN END TIME.
* HIGH CONFIDENCE IN WIND DIRECTION TRENDS BUT MEDIUM CONFIDENCE
IN TIMING OF CHANGES.
* MEDIUM HIGH CONFIDENCE THAT POTENTIAL FOR ADDITIONAL SHRA/TSRA
LATER THIS AFTERNOON IS LOW.
* LOW CONFIDENCE IN SHRA/TSRA TIMING/COVERAGE TUESDAY MORNING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...LIKELY TSRA. MVFR/GUSTY WINDS POSSIBLE.
WEDNESDAY...CHANCE OF TSRA...OTHERWISE VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
RODRIGUEZ
&&
.MARINE...
425 AM CDT
AS AN AREA OF LOW PRESSURE OVER THE UPPER MISSISSIPPI VALLEY
SHIFTS EAST TOWARDS THE LAKE THIS MORNING...SOUTH TO SOUTHEAST
WINDS OF 10 TO 20 KT ARE BEING OBSERVED ACROSS THE LAKE. WITH THIS
LOW CONTINUING ACROSS THE LAKE TODAY...EXPECT FAIRLY DIFFERENT
CONDITIONS FROM THE NORTH HALF TO THE SOUTH HALF. WITH THIS LOW
MOVING THROUGH AND A BOUNDARY LEFT OVER THE LAKE...THE NORTHERN
HALF OF THE LAKE WILL OBSERVE WINDS SHIFTING TO THE NORTHEAST AND
EAST TODAY/TONIGHT WHILE THE SOUTHERN HALF REMAINS SOUTHWEST AND
WEST. AN EASTERLY COMPONENT TO THE WIND LATE TONIGHT INTO TUESDAY
WILL ONCE AGAIN TURN MORE SOUTHERLY AS NEW LOW PRESSURE DEVELOPS
TO THE WEST. SPEEDS WILL INCREASE TO 10 TO 20 KT ON TUESDAY BEFORE
TURNING TO THE SOUTHWEST AND WEST TUESDAY NIGHT...BEFORE A PERIOD
OF NORTHERLY WINDS SETTLES IN ON WEDNESDAY THROUGH THE REMAINDER
OF THE FORECAST PERIOD.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
652 PM EDT MON JUL 8 2013
.SYNOPSIS...
ISSUED AT 651 PM EDT MON JUL 8 2013
SHOWER AND THUNDERSTORM COVERAGE WILL INCREASE THROUGH THE EVENING
AND INTO THE OVERNIGHT HOURS TONIGHT WITH LOW TEMPERATURES IN THE
LOW 70S. THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS AGAIN ON
TUESDAY WITH HIGH TEMPERATURES IN THE UPPER 80S. A FEW OF THE
THUNDERSTORMS COULD BE STRONG TO SEVERE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 314 PM EDT MON JUL 8 2013
COMPLICATED FCST PERIOD WRT CONVECTIVE POTENTIAL THIS EVENING AND
AGAIN ON TUESDAY.
AREA OF SHOWERS AND THUNDERSTORMS THAT DEVELOPED THIS MORNING ACROSS
NE IL HAVE ADVECTED INTO THE NW CWA THIS AFTERNOON. THIS AREA OF
SHOWERS APPEARS TO BE IN A DECAYING STATE...AND HAS WORKED OVER THE
ENVIRONMENT ACROSS MUCH OF THE AREA. THE DEGREE OF RECOVERY LATE
THIS AFTERNOON AND EARLY THIS EVENING WILL BE CRITICAL TO ANY
CONVECTIVE POTENTIAL GOING FORWARD INTO THE OVERNIGHT.
HI RES MODELS HAVE DONE A POOR JOB WITH THE CONVECTIVE EVOLUTION
OVER THE PAST 6 HOURS. HRRR AND 12Z SPC 4KM RUNS HAVE INDICATED A
W-E ORIENTED LINE OF CONVECTION DEVELOPING ACROSS THE LOWER GREAT
LAKES REGION AND SINKING SOUTHWARD ACROSS THE AREA...COINCIDENT WITH
SHORTWAVE ENERGY ADVECTING SOUTHEAST ACROSS THE LOWER GREAT LAKES
PER W/V. THE COVERAGE AND EXTENT OF THIS POTENTIAL CONVECTION WILL
BE HIGHLY DEPENDENT ON ATMOSPHERIC RECOVERY. RECENT RAP13 RUNS DO
INDICATED A STRONG LOW LVL THETA E POOLING ACROSS NRN IL...ADVECTING
INTO NRN IN THROUGH 00Z. THIS OPTIMISTIC SCENARIO WOULD ALLOW
MLCAPES TO RECOVER TO 1000-2000 J/KG. MODEST 0-6 KM BULK SHEAR
VALUES OF 25-30 KTS...AND 850-500 MB LAPSE RATES OF 5.5-6 C/KM WILL
KEEP SEVERE POTENTIAL LOW TO MARGINAL AT THIS POINT....HOWEVER AN
ISOLATED STORM PRODUCING STRONG TO SEVERE WIND GUSTS IS POSSIBLE.
GIVEN ALL OF THESE FACTORS...DECIDED TO LEAVE POPS IN THE SCATTERED
CATEGORY TONIGHT...WITH THE BEST POTENTIAL FOR CONVECTION BETWEEN
22Z AND 04Z.
CONVECTIVE OUTFLOW SHOULD PUSH PRECIP POTENTIAL SOUTHWARD THROUGH
THE OVERNIGHT HOURS...AND HAVE CONFINED SLIGHT CHANCE POPS TO THE
SOUTH. WARM AND MUGGY CONDITIONS ARE EXPECTED AGAIN ON TUESDAY WITH
HIGHS TOPPING OUT IN THE MID TO UPPER 80S...WITH HEAT INDICES IN THE
LOW TO MID 90S. REMNANT CONVECTIVE BOUNDARY MAY BE A FOCUS FOR
SHOWER AND THUNDERSTORM ACTIVITY TOMORROW WITH A JUICED ENVIRONMENT.
UPSTREAM SHORTWAVE EXPECTED TO ADVECT INTO THE REGION LATE TUESDAY
AFTERNOON...WHICH WILL PROVIDE MORE SUPPORT FOR CONVECTION. GIVEN
UNCERTAINTY WITH EVOLUTION OF CONVECTION THIS EVENING...AND
RESULTING BOUNDARY LOCATION...AS WELL AS UNCERTAINTY WITH THE
EVOLUTION OF CONVECTIVELY INDUCED SHORTWAVE...HAVE OPTED TO KEEP
POPS IN THE CHANCE RANGE...WITH THE HIGHEST IN THE AFTERNOON.
POTENTIAL FOR SEVERE WIND GUSTS TOMORROW DOES EXIST GIVEN HIGHLY
UNSTABLE ENVIRONMENT...BUT MODEST BULK SHEAR VALUES OF 25-30 KTS MAY
BE A LIMITING FACTOR FOR STORM ORGANIZATION.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 314 PM EDT MON JUL 8 2013
SHARPENING MID LVL TROUGH SWEEPING THROUGH SRN CANADA SHRT TERM WILL
PROPEL A VIGOROUS CDFNT THROUGH CWA ON WED. IN LIGHT OF DISPARATE
MODEL GUIDANCE WILL GENERALLY RELAY ON HIGHRES CONSENSUS OF FASTER
FROPA ESP WITHIN GUISE OF TUE NIGHT CONVN/MCS AND LIKELY OUTFLW
REMNANT COMPOSITING MORE EFFECTIVE DY3 FORCING MECHANISM SWD TWD THE
OH VALLEY. AS SUCH HAVE SHARPLY CURTAILED POPS ON WED.
AFT THAT...HIGH PRES TO RIDGE SWD ACRS THE LAKES AS MID LVL TROUGH
AMPLIFIES THROUGH NEW ENGLAND BRINGING SEASONABLE TEMPS TO THE
REGION AND DRY WX.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 114 PM EDT MON JUL 8 2013
COMPLICATED TAF FCST GIVEN ONGOING CONVECTIVE ACTIVITY ACROSS THE
REGION...AND MODEL GUIDANCE PROVIDING LITTLE INSIGHT ATTM.
REMNANTS OF CONVECTION HAVE DEVOLVED INTO LITTLE MORE THAN
SPRINKLES ACROSS MUCH OF THE AREA...WITH RENEWED CONVECTION SOUTH
OF KORD AND KMDW TO KVPZ. THIS WILL BRING RAIN SHOWER ACTIVITY TO
KSBN...BUT CONDITIONS WILL LIKELY REMAIN VFR. MODELS HINTING AT
CONVECTION FIRING ACROSS SRN LWR MI AND NRN IN BY 22Z AND SINKING
SOUTHWARD ACROSS TAF SITES THROUGH 04Z TIMEFRAME. LITTLE
CONFIDENCE IN EXACT EVOLUTION RESULTING IN ONLY VCSH MENTION AT
KFWA...HOWEVER MORE CONFIDENT THAT CONVECTION WILL IMPACT KSBN
FROM 22Z TO 02Z TIMEFRAME. WILL CONTINUE TO MONITOR CONVECTIVE
TRENDS THROUGH THE AFTERNOON AND AMMEND AS NEEDED. ADDED HIGH END
MVFR CONDS NEAR DAYBREAK TUESDAY GIVEN GUIDANCE TRENDS...HOWEVER
AS MENTION BEFORE WELL MIXED BOUNDARY LAYER SHOULD LIMIT ANY LOW
END MVFR/IFR CONDS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...BENTLEY
SHORT TERM...NG
LONG TERM...T
AVIATION...NG
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
315 PM EDT MON JUL 8 2013
.SYNOPSIS...
ISSUED AT 1049 AM EDT MON JUL 8 2013
WARMER AND MORE UNSTABLE AIR ACROSS THE REGION WILL LIKELY PROVIDE
FOR RENEWED SCATTERED AFTERNOON AND EVENING THUNDERSTORMS TODAY AS
AN UPPER LEVEL WAVE ACROSS THE UPPER MISSISSIPPI VALLEY SHIFTS
INTO THE SOUTHERN GREAT LAKES. AFTERNOON HIGH TEMPERATURES WILL BE
A FEW DEGREES WARMER THAN YESTERDAY...WELL INTO THE MID 80S. MUGGY
CONDITIONS COULD MAKE IT FEEL LIKE THE LOWER 90S. RAIN CHANCES
WILL DIMINISH OVERNIGHT...AS LOW TEMPERATURES ONLY FALL INTO THE
UPPER 60S AND LOW 70S.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 314 PM EDT MON JUL 8 2013
COMPLICATED FCST PERIOD WRT CONVECTIVE POTENTIAL THIS EVENING AND
AGAIN ON TUESDAY.
AREA OF SHOWERS AND THUNDERSTORMS THAT DEVELOPED THIS MORNING ACROSS
NE IL HAVE ADVECTED INTO THE NW CWA THIS AFTERNOON. THIS AREA OF
SHOWERS APPEARS TO BE IN A DECAYING STATE...AND HAS WORKED OVER THE
ENVIRONMENT ACROSS MUCH OF THE AREA. THE DEGREE OF RECOVERY LATE
THIS AFTERNOON AND EARLY THIS EVENING WILL BE CRITICAL TO ANY
CONVECTIVE POTENTIAL GOING FORWARD INTO THE OVERNIGHT.
HI RES MODELS HAVE DONE A POOR JOB WITH THE CONVECTIVE EVOLUTION
OVER THE PAST 6 HOURS. HRRR AND 12Z SPC 4KM RUNS HAVE INDICATED A
W-E ORIENTED LINE OF CONVECTION DEVELOPING ACROSS THE LOWER GREAT
LAKES REGION AND SINKING SOUTHWARD ACROSS THE AREA...COINCIDENT WITH
SHORTWAVE ENERGY ADVECTING SOUTHEAST ACROSS THE LOWER GREAT LAKES
PER W/V. THE COVERAGE AND EXTENT OF THIS POTENTIAL CONVECTION WILL
BE HIGHLY DEPENDENT ON ATMOSPHERIC RECOVERY. RECENT RAP13 RUNS DO
INDICATED A STRONG LOW LVL THETA E POOLING ACROSS NRN IL...ADVECTING
INTO NRN IN THROUGH 00Z. THIS OPTIMISTIC SCENARIO WOULD ALLOW
MLCAPES TO RECOVER TO 1000-2000 J/KG. MODEST 0-6 KM BULK SHEAR
VALUES OF 25-30 KTS...AND 850-500 MB LAPSE RATES OF 5.5-6 C/KM WILL
KEEP SEVERE POTENTIAL LOW TO MARGINAL AT THIS POINT....HOWEVER AN
ISOLATED STORM PRODUCING STRONG TO SEVERE WIND GUSTS IS POSSIBLE.
GIVEN ALL OF THESE FACTORS...DECIDED TO LEAVE POPS IN THE SCATTERED
CATEGORY TONIGHT...WITH THE BEST POTENTIAL FOR CONVECTION BETWEEN
22Z AND 04Z.
CONVECTIVE OUTFLOW SHOULD PUSH PRECIP POTENTIAL SOUTHWARD THROUGH
THE OVERNIGHT HOURS...AND HAVE CONFINED SLIGHT CHANCE POPS TO THE
SOUTH. WARM AND MUGGY CONDITIONS ARE EXPECTED AGAIN ON TUESDAY WITH
HIGHS TOPPING OUT IN THE MID TO UPPER 80S...WITH HEAT INDICES IN THE
LOW TO MID 90S. REMNANT CONVECTIVE BOUNDARY MAY BE A FOCUS FOR
SHOWER AND THUNDERSTORM ACTIVITY TOMORROW WITH A JUICED ENVIRONMENT.
UPSTREAM SHORTWAVE EXPECTED TO ADVECT INTO THE REGION LATE TUESDAY
AFTERNOON...WHICH WILL PROVIDE MORE SUPPORT FOR CONVECTION. GIVEN
UNCERTAINTY WITH EVOLUTION OF CONVECTION THIS EVENING...AND
RESULTING BOUNDARY LOCATION...AS WELL AS UNCERTAINTY WITH THE
EVOLUTION OF CONVECTIVELY INDUCED SHORTWAVE...HAVE OPTED TO KEEP
POPS IN THE CHANCE RANGE...WITH THE HIGHEST IN THE AFTERNOON.
POTENTIAL FOR SEVERE WIND GUSTS TOMORROW DOES EXIST GIVEN HIGHLY
UNSTABLE ENVIRONMENT...BUT MODEST BULK SHEAR VALUES OF 25-30 KTS MAY
BE A LIMITING FACTOR FOR STORM ORGANIZATION.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 314 PM EDT MON JUL 8 2013
SHARPENING MID LVL TROUGH SWEEPING THROUGH SRN CANADA SHRT TERM WILL
PROPEL A VIGOROUS CDFNT THROUGH CWA ON WED. IN LIGHT OF DISPARATE
MODEL GUIDANCE WILL GENERALLY RELAY ON HIGHRES CONSENSUS OF FASTER
FROPA ESP WITHIN GUISE OF TUE NIGHT CONVN/MCS AND LIKELY OUTFLW
REMNANT COMPOSITING MORE EFFECTIVE DY3 FORCING MECHANISM SWD TWD THE
OH VALLEY. AS SUCH HAVE SHARPLY CURTAILED POPS ON WED.
AFT THAT...HIGH PRES TO RIDGE SWD ACRS THE LAKES AS MID LVL TROUGH
AMPLIFIES THROUGH NEW ENGLAND BRINGING SEASONABLE TEMPS TO THE
REGION AND DRY WX.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 114 PM EDT MON JUL 8 2013
COMPLICATED TAF FCST GIVEN ONGOING CONVECTIVE ACTIVITY ACROSS THE
REGION...AND MODEL GUIDANCE PROVIDING LITTLE INSIGHT ATTM.
REMNANTS OF CONVECTION HAVE DEVOLVED INTO LITTLE MORE THAN
SPRINKLES ACROSS MUCH OF THE AREA...WITH RENEWED CONVECTION SOUTH
OF KORD AND KMDW TO KVPZ. THIS WILL BRING RAIN SHOWER ACTIVITY TO
KSBN...BUT CONDITIONS WILL LIKELY REMAIN VFR. MODELS HINTING AT
CONVECTION FIRING ACROSS SRN LWR MI AND NRN IN BY 22Z AND SINKING
SOUTHWARD ACROSS TAF SITES THROUGH 04Z TIMEFRAME. LITTLE
CONFIDENCE IN EXACT EVOLUTION RESULTING IN ONLY VCSH MENTION AT
KFWA...HOWEVER MORE CONFIDENT THAT CONVECTION WILL IMPACT KSBN
FROM 22Z TO 02Z TIMEFRAME. WILL CONTINUE TO MONITOR CONVECTIVE
TRENDS THROUGH THE AFTERNOON AND AMMEND AS NEEDED. ADDED HIGH END
MVFR CONDS NEAR DAYBREAK TUESDAY GIVEN GUIDANCE TRENDS...HOWEVER
AS MENTION BEFORE WELL MIXED BOUNDARY LAYER SHOULD LIMIT ANY LOW
END MVFR/IFR CONDS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MURPHY/KG
SHORT TERM...NG
LONG TERM...T
AVIATION...NG
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AREA FORECAST DISCUSSION
NWS MARQUETTE MI
147 PM EDT MON JUL 8 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 508 AM EDT MON JUL 8 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE NRN CONUS AND SRN CANADA. AT THE SFC...A FRONTAL BOUNDARY
EXTENDED ACROSS NRN WI THROUGH SRN UPPER MI. A SHORTWAVE TROUGH FROM
NRN ONTARIO THROUGH WRN LAKE SUPERIOR INTO NW WI SUPPORTED A LARGE
AREA OF SHOWERS AND THUNDERSTORMS ACROSS CNTRL UPPER MI INTO NE WI
AND NRN LAKE MICHIGAN. EVEN THOUGH THE GREATER MUCAPE VALUES OF
500-1000 J/KG AND STRONGER TSRA WERE LOCATED ALONG AND SOUTH OF THE
FRONT...FORCING ASSOCIATED WITH THE SHRTWV WAS STRONG ENOUGH TO
SUPPORT TSRA OVER N CNTRL UPPER MI. MANY LOCATIONS FROM GOGEBIC
COUNTY THROUGH SRN UPPER MI HAVE RECEIVED RAINFALL AMOUNTS IN THE 1
TO 2 INCH RANGE...PER RADAR ESTIMATES.
TODAY...EXPECT THAT AS THE SHRTWV MOVES OFF TO THE EAST THIS
MORNING...THE SHRA/TSRA WILL ALSO SHIFT INTO THE ERN CWA. WITH SOME
CLEARING IN THE AFTERNOON...TEMPS COULD AGAIN REBOUND TO
THE LOWER 80S OVER THE SOUTH HALF OF UPPER MICHIGAN. EVEN THOUGH THIS
WOULD BOOST MLCAPE VALUES BACK INTO THE 1K-2K J/KG RANGE...WITH MID
LEVEL RIDGING AND WEAK QVECTOR DIV BUILDING INTO THE AREA IN THE WAKE
OF THE SHORTWAVE....PCPN CHANCES WILL BE MINIMAL. NEVERTHELESS...SOME
ISOLD SHRA/TSRA WILL STILL BE POSSIBLE...MAINLY OVER THE S CNTRL CWA
WHERE MODELS SUGGEST A WEAK SFC TROUGH AXIS WOULD MAXIMIZE LOW LEVEL
CONVERGENCE.
TONIGHT...WEAK MID-LEVEL RIDGING SHOULD AND LOSS OF DAYTIME HEATING
SHOULD BRING AN END TO ANY LINGERING PCPN. MID LEVEL DRYING AND A
DEVELOPING SUBSIDENCE INVERSION ABOVE LINGERING LOW-LEVEL MOISTURE
WILL FAVOR ANOTHER ROUND OF FOG ACROSS INTERIOR LOCATIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 508 AM EDT MON JUL 8 2013
THE MODELS CONTINUE TO AGREE ON THE GENERAL IDEA THAT AN MCS WILL BE
ONGOING AT THE START OF THE PERIOD NEAR THE NOSE OF THE 40-45KT LLJ
OVER THE UPPER MISSISSIPPI VALLEY. HOWEVER...THERE TENDS TO BE SOME
MODEL DISAGREEMENT ON THE EXACT PLACEMENT OF THE MCS...WHICH WILL
PROVE CRITICAL IN THE PRECIPITATION AND POP FORECAST ESPECIALLY
TUESDAY AFTERNOON INTO TUESDAY EVENING. IN GENERAL...THE MODELS HAVE
TRENDED NORTHWARD WITH THE NOSE OF THE LOW LEVEL JET. THE REGIONAL
GEM IS THE MOST AGGRESSIVE...WITH THE BEST LOW LEVEL JET ENERGY
FOCUSED WELL INTO NRN MN AND WESTERN LAKE SUPERIOR TUESDAY...WHILE
THE NAM AND GFS SUPPRESS IT FURTHER SOUTH INTO CENTRAL WI AND
SOUTH-CENTRAL UPPER MI RESPECTIVELY. DUE TO CONVECTIVE FEEDBACK FROM
BOTH THE MODELS...IT IS UNCLEAR WHERE THIS MCS WILL TRACK ON
TUESDAY...HOWEVER CLIMATOLOGY...PAST EXPERIENCE AND MODEL FORWARD
PROPAGATING CORFIDI VECTORS WOULD SUGGEST THAT ANY MCS OVER
SOUTHERN/CENTRAL MN TUE MORNING WOULD LIKELY STAY NEAR OR JUST SOUTH
OF THE WI/MI BORDER AND PERHAPS CLIP MENOMINEE COUNTY LATER TUESDAY
AFTERNOON. THIS SCENARIO WOULD POTENTIALLY LEAVE MUCH OF UPPER
MICHIGAN DRY ON TUESDAY OR JUST WITH RESIDUAL STRATIFORM RAIN AND
EMBEDDED THUNDER TUE AFTN INTO THE EVENING. IN ADDITION...THIS MCS
MAY HELP DISRUPT THE MOISTURE INFLOW INTO THE MAIN SYSTEM AND COLD
FRONT OVER THE NRN PLAINS/NW ONTARIO LATER TUESDAY INTO TUESDAY
NIGHT. RESIDUAL CLOUD COVER BLOWOFF FROM THE MCS MAY ALSO ALLOW FOR
DIMINISHED INSTABILITY ACROSS THE REGION AS THE COLD FRONT
APPROACHES FROM THE NORTHWEST TUESDAY NIGHT. AS SUCH...AS PREVIOUS
FORECASTS HAVE INDICATED...CONFIDENCE REMAINS RATHER LOW REGARDING
THE POP/QPF FORECAST TUESDAY AFTERNOON INTO TUESDAY NIGHT. FOR
NOW...HAVE MAINTAINED LIKELY POPS ACROSS THE SOUTH CENTRAL TUE AFTN
WITH CHANCE POPS ELSEWHERE. FOR TUESDAY NIGHT...HAVE OPTED TO GO
WITH LIKELY POPS NEAR LAKE MICHIGAN WITH CHANCE POPS ELSEWHERE AS
THE MAIN UPPER WAVE AND ASSOCIATED COLD FRONT PASS THROUGH.
MUCH LESS HUMID AND MORE SEASONABLE TEMPS ON WEDNESDAY BEHIND THE
COLD FRONT. CANNOT RULE OUT A PASSING SHOWER EARLY ACROSS THE
EASTERN HALF OF UPPER MI EARLY WED MORNING AS THE UPPER TROUGH AXIS
WILL HAVE YET TO PASS THROUGH. OTHERWISE...HIGH PRESSURE WILL BUILD
ACROSS THE AREA WED NIGHT-THURSDAY LEADING TO VERY SEASONABLE AND
DRY CONDITIONS. UPPER HEIGHTS BUILD ON FRIDAY ACROSS THE WESTERN
LAKES...GIVING SOME WARMER TEMPS BUT DRY CONDITIONS WILL CONTINUE.
ON SATURDAY...THE GFS AND 00Z ECMWF ARE IN BETTER AGREEMENT IN
SHOWING A WEAK DISTURBANCE MOVING OVER THE RIDGE AXIS. ALTHOUGH
MOISTURE WILL BE LACKING...CANNOT TOTALLY RULE OUT SHOWERS/STORMS
ACROSS THE WEST SAT AFTN AS AS SUCH HAVE ADDED A 30 PCT CHANCE ON
SATURDAY. NEXT SYSTEM MOVES INTO THE WESTERN LAKES LATE IN THE
WEEKEND OR EARLY MONDAY. STILL SOME TIMING ISSUES WITH THE ECMWF
BEING FASTER THAN THE GFS. WITH THIS IN MIND...HAVE KEPT ANY MENTION
OF PRECIPITATION OUT OF THE FORECAST FOR SUNDAY...BUT MAY NEED TO BE
INTRODUCED IN LATER FORECASTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 146 PM EDT MON JUL 8 2013
VLIFR CONDITIONS EXPECTED TO DEVELOP AT ALL SITES OVERNIGHT. PLENTY
OF LOW-LEVEL MOISTURE HAS BEEN HANGING AROUND TODAY...WITH ALL SITES
FINALLY STARTING TO MIX ENOUGH TO BREAK OUT OF IFR STRATUS. TO MAKE
THINGS COMPLICATED...ALL SITES ARE CURRENTLY EXPOSED TO UPSLOPE
FLOW...WHICH IS KEEPING LOW STATUS VERY NEAR THE TERMINALS. BELIEVE
THAT CMX WILL STAY WITH BKN MVFR CIGS THROUGHOUT THE DAY...WHILE IWD
SHOULD SCATTER OUT. AS FOR SAW...THEY HAVE SCATTERED OUT EARLY THIS
AFTERNOON...BUT REDEVELOPMENT OF MVFR STRATOCUMULUS SHOULD COMMENCE
BY MID-AFTERNOON.
A MID-LEVEL RIDGE MOVING OVERHEAD TONIGHT WILL CLEAR OUT MID TO
HIGH-LEVEL CLOUDS AND ALLOW FOR DECENT RADIATIONAL COOLING. IF LAST
NIGHT IS ANY INDICATION OF HOW THINGS WILL GO TONIGHT...ALL SITES
CAN BE EXPECTED TO REACH LANDING MINS BY AROUND 05Z. SAW COULD SEE
THIS HAPPEN EARLIER GIVEN EXTRA MOISTURE AROUND FROM RAINFALL THIS
MORNING. DO NOT SEE ANY REASON THINGS WILL CLEAR OUT TOO QUICK
TUESDAY MORNING...SO HELD ON TO LOWER CIGS AND VIS UNTIL LATE
MORNING AT ALL SITES. BY THE END OF THE PERIOD...MIXING SHOULD ERODE
MUCH OF THE CLOUD COVER. THOUGH OUTSIDE OF THE PERIOD...IWD HAS THE
POTENTIAL TO SEE SOME CONVECTION DEVELOP BY LATE AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 508 AM EDT MON JUL 8 2013
A DENSE FOG ADVISORY REMAINS TODAY FOR ALL OF LAKE SUPERIOR GIVEN SEVERAL
SHIP REPORTS OF NEAR ZERO VISIBILITY AND VERY HUMID AIR OVER
RELATIVELY CHILLY LAKE SUPERIOR WATERS. THE FOG MAY ALSO LINGER INTO
TONIGHT BEFORE DISSIPATING TUESDAY. A SURFACE FRONT MOVING ACROSS
LAKE SUPERIOR TUESDAY EVENING WILL ALLOW WINDS TO SHIFT TO THE
NORTHWEST AT 15 TO 25 KNOTS FOR A SHORT TIME LATE TUESDAY NIGHT INTO
WEDNESDAY. HIGH PRESSURE WILL SETTLE BACK OVER THE LAKE FOR THE
LATER HALF OF THE WEEK WITH WINDS LESS THAN 15 KNOTS EXPECTED INTO
NEXT WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 11 AM EDT /10 AM CDT/ TUESDAY FOR
LSZ162-240>251-263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...KLUBER
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GLASGOW MT
430 PM MDT MON JUL 8 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY...
430PM UPDATE...
SEVERE THUNDERSTORM WATCH WAS JUST EXTENDED TO INCLUDE DANIELS AND
SHERIDAN COUNTIES UNTIL 7PM. FORECAST APPEARS ON TRACK SO NO OTHER
CHANGES AT THIS TIME. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO
PUSH FROM WEST TO EAST ACROSS THE CWA THIS EVENING AND TONIGHT.
SOME STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL...VERY LARGE
HAIL...AND STRONG WINDS. REPORTS OF GOLF BALL TO BASEBALL SIZED
HAIL HAVE COME IN THIS EVENING WITH A STORM THAT PUSHED THROUGH
NORTHEASTERN GARFIELD COUNTY AND INTO SOUTHERN MCCONE COUNTY. THIS
STORM IS CURRENTLY THE STRONGEST STORM IN THE FORECAST REGION AND
WILL BE MOVING SOUTHEAST INTO SOUTHERN DAWSON AND NORTHERN PRAIRIE
COUNTIES. ADDITIONAL SHOWERS AND STORMS EXIST IN A LINE FROM JUST
WEST OF THE PORT OF OPHEIM EXTENDING DOWN THROUGH PETROLEUM
COUNTY. SOME OF THESE STORMS MAY BECOME SEVERE AS WELL AS THEY
MARCH EASTWARD THROUGH THE EVENING. WILL UPDATE AS NEEDED.
MALIAWCO
MAIN FOCUS FOR THE SHORT TERM PERIOD IS A STRONG UPPER LEVEL
SHORTWAVE FEATURE PUSHING INTO WESTERN MONTANA THIS AFTERNOON. OUT
AHEAD OF THIS WAVE THERE IS ENOUGH INSTABILITY TO GENERATE SOME
SHOWERS AND THUNDERSTORMS. FORECAST SOUNDINGS SHOW VERY GOOD
CAPE/DIRECTIONAL WIND SHEAR PROFILES THROUGH TONIGHT AND
PRECIPITABLE WATER VALUES OF GREATER THAN ONE INCH. ALSO GIVEN
SEVERE THUNDERSTORM WATCH UNTIL 7PM FOR MOST OF THE CWA EXCEPT FOR
DANIELS AND SHERIDAN COUNTIES...WILL NEED TO MONITOR FOR SOME
STORMS TO PRODUCE LARGE HAIL...STRONG WINDS...AND VERY HEAVY
RAINFALL. SPC STORM SCALE ENSEMBLE OF OPPORTUNITY PRODUCT SHOWS
CONSISTENCY WITH LATEST HRRR AND NAM MODEL SOLUTIONS. EXPECT MOST
OF THE ACTIVITY TO OCCUR PRIOR TO MIDNIGHT. BEYOND
MIDNIGHT...CANNOT RULE OUT SHOWERS AND STORMS BUT THEY SHOULD
REDUCE IN COVERAGE AND SEVERE POTENTIAL WILL LIKELY BE LIMITED BY
THAT TIME.
TUESDAY AND WEDNESDAY...ANY LEFTOVER SHOWERS AND THUNDERSTORMS
WILL EXIT THE CWA DURING THE MORNING HOURS ON TUESDAY.
THEREAFTER...MODELS DEPICT AN UPPER LEVEL RIDGE BUILDING INTO THE
CWA WHICH WILL LEAD TO AN ABUNDANCE OF SUNSHINE...DRIER
CONDITIONS...AND WARMING TEMPERATURES UNDER A REGIME OF LARGE
SCALE SUBSIDENCE. DID NOT MAKE MANY CHANGES TO THIS PORTION OF THE FORECAST
DUE TO THE PRIMARY CONCENTRATION ON THE SEVERE WEATHER POTENTIAL
FOR THIS AFTERNOON INTO TONIGHT. WILL MAKE UPDATES AS NEEDED AS
CONDITIONS WARRENT. MALIAWCO
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
SYNOPTIC SET UP... LONG TERM BEGINS WITH A LARGE HEAT DOME OVER
THE DESERT SOUTHWEST AND INTERMOUNTAIN WEST. A RIDGE SPUR IS
ANTICIPATED TO JUT OUT OF THE DOME OVER THE HIGH PLAINS OF MONTANA
AND ALBERTA. A CLOSED LOW IS EXPECTED OVER THE COAST OF BRITISH
COLUMBIA AND THE PACIFIC NORTHWEST.
WEDNESDAY NIGHT INTO THURSDAY... DRY CONDITIONS ARE ANTICIPATED
UNTIL THURSDAY AS NORTHEAST MONTANA COMES UNDER THE FULL OF AND
INCREASING RIDGE. THURSDAY... THE AXIS OF THE RIDGE WILL PASS
THROUGH AND ALLOW FOR A ISOLATED THUNDERSTORMS TO DEVELOP ON THE
AXIS. THURSDAY ALSO LOOKS TO BE VERY WARM AHEAD OF THE AXIS WITH
UPPER 90S AND POSSIBLE AS 850 MB TEMPERATURES REACH INTO THE 30*
CELSIUS RANGE.
THURSDAY NIGHT INTO SATURDAY...CLOSED LOW OVER THE PACIFIC
NORTHWEST IS ANTICIPATED TO MOVE EAST THROUGH WEST MONTANA INTO
THE HIGH PLAINS... EXITING THE RIDGE ALOFT OVER THE GREAT PLAINS.
THIS WILL PLACE NORTHEAST MONTANA IN A SOUTHWEST FLOW WITH A WEAK
TROUGHS AND SHORTWAVES MOVING THROUGH THE FLOW. A SHORTWAVE IS
CURRENTLY TIMED ON FRIDAY WITH THE BASE OF THE LARGE TROUGH
MOVING THROUGH SATURDAY HOWEVER... TIMING OF THESE WAVES COULD
EASILY SHIFT AS THE LAST COUPLE RUNS HAVE ALREADY MOVED THEM
AROUND.
SATURDAY NIGHT ONWARD... THE TROUGH IS ANTICIPATED TO PASS OFF TO
THE EAST AND REPRESS THE HEAT TO THE SOUTH WHILE A NEW RIDGE
BUILDS OVER THE PACIFIC NORTHWEST. THIS WILL GENERATE ZONAL TO
NORTHWEST FLOW ACROSS NORTHEAST MONTANA. CONDITIONS WILL BE DRY
SLIGHTLY WITH A WEAK WARMING TREND. GAH
&&
.AVIATION...
VFR. ISOLATED THUNDERSTORMS CAN BE EXPECTED OFF AND ON THROUGH THE
DAY WITH FEW SIGNIFICANT IMPACTS THROUGH 18Z. 21Z-06Z...HOWEVER A
LINE OR COMPLEX OF SEVERE THUNDERSTORMS IS EXPECTED TO ROLL ACROSS
NORTHEAST MONTANA. 23-01Z FOR KGGW... 00Z-02Z FOR KOLF... AND
01-03Z FOR KSDY/KGDV BASED ON THE CURRENT GUIDANCE. DO EXPECT
SIGNIFICANT IMPACTS TO FLIGHT OPERATIONS LATE THIS AFTERNOON AND
THROUGH THE EVENING HOURS WITH THESE THUNDERSTORMS. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
234 PM MDT MON JUL 8 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY...
MAIN FOCUS FOR THE SHORT TERM PERIOD IS A STRONG UPPER LEVEL
SHORTWAVE FEATURE PUSHING INTO WESTERN MONTANA THIS AFTERNOON. OUT
AHEAD OF THIS WAVE THERE IS ENOUGH INSTABILITY TO GENERATE SOME
SHOWERS AND THUNDERSTORMS. FORECAST SOUNDINGS SHOW VERY GOOD
CAPE/DIRECTIONAL WIND SHEAR PROFILES THROUGH TONIGHT AND
PRECIPITABLE WATER VALUES OF GREATER THAN ONE INCH. ALSO GIVEN
SEVERE THUNDERSTORM WATCH UNTIL 7PM FOR MOST OF THE CWA EXCEPT FOR
DANIELS AND SHERIDAN COUNTIES...WILL NEED TO MONITOR FOR SOME
STORMS TO PRODUCE LARGE HAIL...STRONG WINDS...AND VERY HEAVY
RAINFALL. SPC STORM SCALE ENSEMBLE OF OPPORTUNITY PRODUCT SHOWS
CONSISTENCY WITH LATEST HRRR AND NAM MODEL SOLUTIONS. EXPECT MOST
OF THE ACTIVITY TO OCCUR PRIOR TO MIDNIGHT. BEYOND
MIDNIGHT...CANNOT RULE OUT SHOWERS AND STORMS BUT THEY SHOULD
REDUCE IN COVERAGE AND SEVERE POTENTIAL WILL LIKELY BE LIMITED BY
THAT TIME.
TUESDAY AND WEDNESDAY...ANY LEFTOVER SHOWERS AND THUNDERSTORMS
WILL EXIT THE CWA DURING THE MORNING HOURS ON TUESDAY.
THEREAFTER...MODELS DEPICT AN UPPER LEVEL RIDGE BUILDING INTO THE
CWA WHICH WILL LEAD TO AN ABUNDANCE OF SUNSHINE...DRIER
CONDITIONS...AND WARMING TEMPERATURES UNDER A REGIME OF LARGE
SCALE SUBSIDENCE. DID NOT MAKE MANY CHANGES TO THIS PORTION OF THE FORECAST
DUE TO THE PRIMARY CONCENTRATION ON THE SEVERE WEATHER POTENTIAL
FOR THIS AFTERNOON INTO TONIGHT. WILL MAKE UPDATES AS NEEDED AS
CONDITIONS WARRENT. MALIAWCO
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
SYNOPTIC SET UP... LONG TERM BEGINS WITH A LARGE HEAT DOME OVER
THE DESERT SOUTHWEST AND INTERMOUNTAIN WEST. A RIDGE SPUR IS
ANTICIPATED TO JUT OUT OF THE DOME OVER THE HIGH PLAINS OF MONTANA
AND ALBERTA. A CLOSED LOW IS EXPECTED OVER THE COAST OF BRITISH
COLUMBIA AND THE PACIFIC NORTHWEST.
WEDNESDAY NIGHT INTO THURSDAY... DRY CONDITIONS ARE ANTICIPATED
UNTIL THURSDAY AS NORTHEAST MONTANA COMES UNDER THE FULL OF AND
INCREASING RIDGE. THURSDAY... THE AXIS OF THE RIDGE WILL PASS
THROUGH AND ALLOW FOR A ISOLATED THUNDERSTORMS TO DEVELOP ON THE
AXIS. THURSDAY ALSO LOOKS TO BE VERY WARM AHEAD OF THE AXIS WITH
UPPER 90S AND POSSIBLE AS 850 MB TEMPERATURES REACH INTO THE 30*
CELSIUS RANGE.
THURSDAY NIGHT INTO SATURDAY...CLOSED LOW OVER THE PACIFIC
NORTHWEST IS ANTICIPATED TO MOVE EAST THROUGH WEST MONTANA INTO
THE HIGH PLAINS... EXITING THE RIDGE ALOFT OVER THE GREAT PLAINS.
THIS WILL PLACE NORTHEAST MONTANA IN A SOUTHWEST FLOW WITH A WEAK
TROUGHS AND SHORTWAVES MOVING THROUGH THE FLOW. A SHORTWAVE IS
CURRENTLY TIMED ON FRIDAY WITH THE BASE OF THE LARGE TROUGH
MOVING THROUGH SATURDAY HOWEVER... TIMING OF THESE WAVES COULD
EASILY SHIFT AS THE LAST COUPLE RUNS HAVE ALREADY MOVED THEM
AROUND.
SATURDAY NIGHT ONWARD... THE TROUGH IS ANTICIPATED TO PASS OFF TO
THE EAST AND REPRESS THE HEAT TO THE SOUTH WHILE A NEW RIDGE
BUILDS OVER THE PACIFIC NORTHWEST. THIS WILL GENERATE ZONAL TO
NORTHWEST FLOW ACROSS NORTHEAST MONTANA. CONDITIONS WILL BE DRY
SLIGHTLY WITH A WEAK WARMING TREND. GAH
&&
.AVIATION...
VFR. ISOLATED THUNDERSTORMS CAN BE EXPECTED OFF AND ON THROUGH THE
DAY WITH FEW SIGNIFICANT IMPACTS THROUGH 18Z. 21Z-06Z...HOWEVER A
LINE OR COMPLEX OF SEVERE THUNDERSTORMS IS EXPECTED TO ROLL ACROSS
NORTHEAST MONTANA. 23-01Z FOR KGGW... 00Z-02Z FOR KOLF... AND
01-03Z FOR KSDY/KGDV BASED ON THE CURRENT GUIDANCE. DO EXPECT
SIGNIFICANT IMPACTS TO FLIGHT OPERATIONS LATE THIS AFTERNOON AND
THROUGH THE EVENING HOURS WITH THESE THUNDERSTORMS. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
504 PM CDT MON JUL 8 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 455 PM CDT MON JUL 8 2013
PLENTY OF THINGS TO PONDER DURING THE NEXT 24 HOURS...INCLUDING AT
LEAST ONE CONDITIONAL RISK FOR SEVERE STORMS THIS EVENING...AND
MAYBE ANOTHER SEVERE RISK ON TUESDAY AFTERNOON/EVENING...ALTHOUGH
CONFIDENCE IS QUITE LOW ON THE LIKELIHOOD/EVOLUTION OF THE LATTER.
IN OTHER DEPARTMENTS...TOMORROW IS CURRENTLY EXPECTED TO BE THE
OVERALL-HOTTEST AFTERNOON OF THE SUMMER SO FAR FOR MOST OF THE
CWA...AND A HEAT ADVISORY HAS BEEN ISSUES FOR SEVERAL
SOUTHERN/SOUTHEAST COUNTIES.
21Z OBJECTIVE SURFACE ANALYSIS HIGHLIGHTS A SOMEWHAT SUBTLE-BUT
EVIDENT EAST-WEST QUASI STATIONARY GENERALLY STRETCHED ACROSS THE
SOUTHERN HALF OF NEBRASKA. IN THE WIND-FIELD...THIS BOUNDARY
SEPARATES A STEADY 15+ MPH SOUTHERLY BREEZE IN NORTH CENTRAL
KANSAS...FORM A LIGHTER...GENERALLY EAST-SOUTHEAST BREEZE WITHIN
MOST OF THE NEBRASKA CWA. ITS ALSO SOMEWHAT OF A MOISTURE
BOUNDARY...WITH MID-50S TO LOW 60S DEWPOINTS RESIDING IN THE
DEEPLY MIXED AIRMASS TO THE SOUTH...AND HIGHER DEWPOINTS MID-60S
TO NEAR 70 MOST AREAS ALONG/NORTH OF I-80. AS DISCUSSED EARLIER
TODAY...NEAR-CRITICAL FIRE DANGER WILL PERSIST FOR A FEW MORE
HOURS ESPECIALLY IN THE PHILLIPS/ROOKS COUNTY AREA IN KS. HIGH
TEMPS THIS AFTERNOON WORKED OUT PRETTY WELL ACROSS THE
SOUTHWESTERN 2/3 OF THE CWA RANGING GENERALLY 95-104
DEGREES...WHILE SOME NORTHEAST AREAS ARE STRUGGLING TO REACH 90
THANKS IN PART TO A BATCH OF MID LEVEL CLOUDS THAT FORMED ON THE
BACK-SIDE OF AN MCV THAT HAS MOVED WELL EAST INTO WESTERN IA.
ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA CONFIRM
CONTINUED QUASI-ZONAL FLOW ACROSS THE LOCAL AREA...BETWEEN THE
LARGER-SCALE MID LEVEL RIDGE AXIS STRETCHED WEST-EAST FROM AZ TO
OK...AND A VIGOROUS SHORTWAVE TROUGH MAKING ITS WAY ACROSS THE
ID/MT/CANADA BORDER AREA. THE MAIN LOW-AMPLITUDE SHORTWAVE TROUGH
OF INTEREST FOR THIS EVENING IS CURRENTLY LIFTING OUT OF WY INTO
WESTERN NEB/SD.
LATE THIS AFTERNOON INTO THIS EVENING...THE PRIMARY FOCUS IS ON
HOW MUCH THUNDERSTORM COVERAGE THE CWA WILL SEE...AND WHETHER SOME
OF THIS ACTIVITY COULD BECOME SEVERE. AT PRESENT TIME...RADAR
INDICATES A FEW WEAK-ISH/HIGH-BASED STORMS NEAR THE STATE LINE IN
THE SOUTHWESTERN CWA...LARGELY A RESULT OF VERY STEEP LOW-LEVEL
LAPSE RATES IN THE HOT/DEEPLY MIXED AIRMASS OVER KS.
MEANWHILE...OFF TO THE NORTHWEST...A FEW STRONG TO SEVERE STORMS
HAVE TAKEN OFF IN NORTH CENTRAL/WESTERN NEB...IN AN ENVIRONMENT
CHARACTERIZED BY AROUND 2000+ J/KG MLCAPE AND 30+ KNOTS OF 0-6KM
DEEP LAYER SHEAR. LOCALLY...WITH THE EXCEPTION OF THE HIGH-BASED
STORMS IN OUR SOUTH...MODEL SOUNDINGS SUGGEST THERE IS JUST ENOUGH
OF A CAP IN PLACE TO KEEP CONVECTION FROM DEVELOPING OVERHEAD IN
MOST OF THE CENTRAL/NORTHERN CWA...AIDED IN PART BY SUBSIDENCE
BEHIND THE DEPARTING MCV. AS HAS BEEN THE CASE FOR DAYS
NOW...CONFIDENCE IN THE DETAILS IS LOW IN THIS WEAKLY FORCED
PATTERN...BUT TAKING CUE FROM THE LATEST RAP/HRRR AND 12Z 4KM WRF-
NMM...THE GENERAL EXPECTATION IS FOR MOST OF THE CWA TO REMAIN
STORM FREE THROUGH AT LEAST 00Z/7PM...BEFORE STORM CHANCES
GRADUALLY INCREASE THROUGH THE EVENING HOURS ESPECIALLY NEAR/NORTH
OF I-80...AND LIKELY MAINLY AS A FUNCTION OF ACTIVITY MOVING IN
FROM WESTERN NEBRASKA...ALTHOUGH LOCAL INITIATION NEAR THE SURFACE
BOUNDARY CANNOT BE RULED OUT EITHER. BOTH THE WRF-NMM AND HRRR ARE
FAIRLY AGGRESSIVE BRINGING A CLUSTER OF STORMS...POSSIBLY A SEMI-
ORGANIZED MCS ACROSS ESPECIALLY THE NORTHERN 1/2 OF THE CWA THIS
EVENING...BUT A SIMILAR MODEL DEPICTION YESTERDAY ENDED UP BEING A
BIT OVERDONE...AND THUS HAVE CAPPED POPS AT NO HIGHER THAN 50
PERCENT AT LEAST FOR NOW. WITH MLCAPE REMAINING 1000+ J/KG WELL
INTO THE EVENING HOURS AND WITH AT LEAST MODEST SHEAR...AT LEAST A
LOCALIZED LARGE HAIL AND ESPECIALLY A WIND THREAT IS QUITE
POSSIBLE ESPECIALLY IF STORMS TO THE WEST CAN ORGANIZE AND DEVELOP
A COLD POOL. AGREE WITH SPC IN HIGHLIGHTING THE NORTHERN 1/2 OF
THE CWA FOR THE GREATEST SEVERE THREAT...BUT JUST CANNOT RULE OUT
A STRONG TO SEVERE STORM ANYWHERE IN THE CWA THIS EVENING.
ALTHOUGH THE MAIN SEVERE THREAT SHOULD BE ON THE WANE BY
MIDNIGHT...LINGERED LOW POPS THROUGH THE NIGHT ESPECIALLY ACROSS
THE EASTERN 2/3 OF THE CWA TO ACCOUNT FOR ACTIVITY PERSISTING OR
NEWLY-DEVELOPING WITHIN THE LOW LEVEL JET AXIS...AND JUST AHEAD ON
APPROACHING COLD FRONT. IF NOTHING ELSE...HOPEFULLY PARTS OF THE
CWA CAN RECEIVE SOME MUCH-NEEDED RAINS TONIGHT...BECAUSE THIS MAY
BE ONE OF THE BETTER CHANCES FOR AWHILE. TEMPERATURE-WISE...MADE
ONLY MINOR TWEAKS TO LOWS...WITH THE PREVALENT LIGHT SOUTHERLY
BREEZE HOLDING MOST AREAS UP INTO THE 70-75 RANGE. ALTHOUGH AT
LEAST LIGHT FOG DEVELOPMENT CANNOT BE RULED OUT LATE TONIGHT
ESPECIALLY IN AREAS THAT RECEIVE RAIN...THE PROBABILITY/MAGNITUDE
SEEMED LOW ENOUGH TO OMIT FROM THE FORECAST.
TURNING TO TUESDAY DAYTIME...REALLY DON/T THINK SEVERE STORMS ARE
GOING TO END UP BEING MUCH OF A STORY...AT LEAST THROUGH THE VAST
MAJORITY OF THE DAY. ALOFT...QUASI-ZONAL FLOW WILL START TO TURN A
BIT MORE NORTHWESTERLY IN RESPONSE TO THE PASSAGE OF A FAIRLY
VIGOROUS SHORTWAVE TROUGH FROM EASTERN MT TOWARD NORTHERN MN. AT
THE SURFACE...A FAIRLY WEAK COLD FRONT...MORE EVIDENT IN THE WIND
FIELD THAN ON A THERMOMETER...WILL WORK SOUTHWARD ACROSS THE CWA
AS THE DAY WEARS ON...WITH MOST AREAS SEEING A FEW HOURS OF
LIGHT/VARIABLE WINDS BEFORE A SLIGHTLY MORE STEADY NORTHERLY
BREEZE SETTLES IN. ALONG AND ESPECIALLY JUST AHEAD OF THIS
BOUNDARY...A LOW LEVEL THERMAL RIDGE WILL EXTEND INTO THE CWA FROM
THE SOUTHWEST...PROMOTING WHAT SHOULD BE THE HIGHEST HEAT-INDEX
READINGS OF THE SUMMER SO FAR FOR MOST ALL OF THE CWA...AND IN
SOME SPOTS THE HOTTEST ACTUAL AIR TEMPERATURES. THE ONLY CAVEATS
WOULD BE AN UNEXPECTEDLY STRONG OUTFLOW BOUNDARY FROM CONVECTION
TONIGHT THAT MIGHT HELP ACCELERATE THE COLD FRONT SOUTHWARD
FASTER...AND MAYBE A DENSER-THAN-EXPECTED COVERAGE OF MID LEVEL
CLOUDS OR LINGERING WEAK CONVECTION. BUT ASSUMING NEITHER ONE OF
THESE CAVEATS PLAY OUT...HAVE AIMED FOR ACTUAL HIGH TEMPS RANGING
FROM MID 90S NORTH...UPPER 90S CENTRAL...AND 100-106 NEAR AND
SOUTH OF THE STATE LINE. HEAT INDEX VALUES OF 100+ ARE FORECAST
ACROSS MUCH OF THE SOUTHERN AND EASTERN HALVES OF THE CWA...AND
HAVE ISSUED A HEAT ADVISORY FOR ALL KS ZONES ALONG WITH WEBSTER-
NUCKOLLS-THAYER IN NEBRASKA...WHICH HAVE THE HIGHEST LIKELIHOOD OF
REACHING OR EXCEEDING A 105 HEAT INDEX. FORTUNATELY FOR FIRE
WEATHER CONCERNS IN THE FAR SOUTHWEST COUNTIES...SUSTAINED
WINDS/GUSTS DO NOT LOOK TO EXCEED 20 MPH DURING THE PEAK OF
AFTERNOON HEATING. AS FOR CONVECTIVE CHANCES...FORECAST SOUNDINGS
SUGGEST THAT A FAIRLY STRONG CAP SHOULD PREVAIL THROUGH THE DAY AS
VERY WARM MID LEVEL TEMPS OVERSPREAD THE AREA. AS A RESULT...OTHER
THAN A LINGERING SLIGHT CHANCE OF MORNING STORMS IN EASTERN
COUNTIES RIGHT AWAY IN THE MORNING...WILL AIM FOR A DRY MAJORITY
OF THE DAY...BEFORE BRINGING BACK SLIGHT STORM CHANCES POST-
21Z/4PM. THERE ARE AT LEAST TWO POSSIBLE FOCUSES FOR LATE
AFTERNOON DEVELOPMENT...THE MAIN COLD FRONT WHICH SHOULD BE VERY
NEAR THE FAR SOUTHEAST CORNER OF THE CWA...AND ALSO FORCING FROM
THE SOUTHERN EDGE OF THE NORTHERN PLAINS SHORTWAVE TROUGH...WHICH
COULD KICK OFF CONVECTION CLOSER TO THE NORTHERN EDGE OF THE CWA.
HOWEVER...MODELS SUCH AS THE 12Z 4KM WRF-NMM ADVERTISE ESSENTIALLY
NO LATE AFTERNOON STORMS ANYWHERE IN THE CWA...SO THUS ONLY THE
SLIGHT POPS. IF STORMS WOULD MANAGE TO FORM...A CONDITIONAL SEVERE
THREAT COULD EXIST ALMOST ANYWHERE IN THE CWA...POTENTIALLY EVEN
WEST OF THE SPC DAY 2 SLIGHT RISK AREA. PLENTY OF UNCERTAINTY FOR
SURE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 455 PM CDT MON JUL 8 2013
MAIN FORECAST CONCERNS
WILL BE CHANCES FOR THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY NIGHT
AND AGAIN SATURDAY NIGHT THROUGH MONDAY AND TEMPERATURES.
MODELS ARE FAIRLY SIMILAR IN BUILDING AN UPPER LEVEL RIDGE ACROSS
THE AREA DURING THE PERIOD...BUT THE DETAILS OF THE TIMING MAINLY
WEAK UPPER LEVEL WAVES THROUGH THE AREA ARE SOMEWHAT DIFFERENT
BETWEEN THE MODELS. THIS BRINGS SOME UNCERTAINTY IN WHEN THERE WILL
BE SOME CHANCES FOR THUNDERSTORMS.
A SURFACE COLD FRONT WILL MOVE TO THE SOUTH ACROSS THE SOUTHERN PART
OF THE FORECAST AREA DURING THE EVENING. AN UPPER LEVEL WAVE WILL
ALSO BE MOVING THROUGH THE AREA. EXPECT SOME THUNDERSTORMS ALONG
THAT BOUNDARY DURING THE EVENING...BUT OVERNIGHT THEY SHOULD MOVE
OUT OF THE AREA. MUCAPE IS THE HIGHEST DURING THE EARLY EVENING
HOURS AND DIMINISHES SOME LATER IN THE EVENING...BUT STILL REMAINS
AROUND 2500 J/KG. EXPECT THAT THERE COULD BE SOME SEVERE WEATHER
DURING THE EVENING.
A COOL SURFACE HIGH PRESSURE SYSTEM SETTLES INTO THE AREA ON
WEDNESDAY. HIGH TEMPERATURES WILL BE AROUND 10 DEGREES COOLER THAN
ON TUESDAY. WEDNESDAY SHOULD REMAIN DRY...BUT AN UPPER LEVEL WAVE
MOVES ACROSS THE RIDGE AND THERE COULD BE SOME ISOLATED SHOWERS AND
THUNDERSTORMS THAT MOVE OFF THE HIGH PLAINS DURING THE NIGHT TIME
HOURS.
THE SURFACE HIGH MOVES OFF TO THE EAST ON THURSDAY AND THE SURFACE
PRESSURE GRADIENT TIGHTENS. WINDS AT 850MB ARE ONLY 20 TO 25 KTS SO
EXPECT SOME BREEZY CONDITIONS. WITH WINDS FROM THE SOUTH THE
TEMPERATURES WILL WARM UP.
THE UPPER LEVEL RIDGE CONTINUES TO BUILD ACROSS THE AREA FOR THE
PERIOD THURSDAY THROUGH SATURDAY. EXPECT TEMPERATURES TO WARM A
LITTLE EACH DAY THROUGH THE PERIOD.
THE UPPER LEVEL RIDGE REMAINS IN PLACE FOR SATURDAY NIGHT THROUGH
MONDAY...BUT IT IS MORE OF AN UPPER LEVEL HIGH PRESSURE SYSTEM
ACROSS THE AREA. IT IS FAIRLY BROAD AND THERE ARE A FEW UPPER LEVEL
WAVES THAT MOVE THROUGH THE AREA. SIMILAR TO THE PAST WEEK OR SO
EACH OF THESE UPPER LEVEL WAVES HAS A CHANCE FOR SOME THUNDERSTORMS.
DO NOT EXPECT THAT IT WILL BE WIDESPREAD OR THAT EVERYONE WILL HAVE
SOME PRECIPITATION. THE TIMING AND THE LOCATION OF ANY PRECIPITATION
IS IN QUESTION. WITH A FEW MORE CLOUDS AND THE CHANCE FOR SOME
PRECIPITATION THE TEMPERATURES WILL BE A LITTLE COOLER.
&&
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1250 PM CDT MON JUL 8 2013
FOR NOW...VFR CEILING/VISIBILITY IS FORECAST THROUGH THE NEXT 24
HOURS...ALTHOUGH THERE A FEW CAVEATS TO SPEAK OF THAT COULD LEAD
TO AT LEAST BRIEF DETERIORATION. THE FIRST CAVEAT IS THE POTENTIAL
FOR THUNDERSTORMS...POTENTIALLY STRONG TO SEVERE...TO MOVE IN FROM
THE WEST THIS EVENING. ALTHOUGH THIS SEEMS TO BE AN INCREASING
BET...WILL CONTINUE TO KEEP IT SIMPLE FOR NOW WITH ONLY A VICINITY
THUNDERSTORM MENTION FROM 01Z-09Z...AND DEFER TO LATER FORECASTS
TO BETTER PIN DOWN POTENTIAL TIMING AND IMPACT TO THE TERMINAL IF
NEED BE. ONCE THE STORM CHANCE ENDS...THE LATE NIGHT/EARLY MORNING
HOURS COULD SEE ANOTHER ROUND OF MVFR VISIBILITY RESTRICTION IN
LIGHT FOG...BUT GIVEN LOW CONFIDENCE IN THIS OCCURRING WILL ONLY
HINT AT IT FOR NOW WITH A LOW-END VFR VISIBILITY RESTRICTION
BETWEEN 09Z-15Z. ITS POSSIBLE THAT ANY PRECEDING RAINFALL COULD
ENHANCE THE PROBABILITY OF FOG. OTHERWISE...THERE COULD ALSO BE A
PERIOD OF LOW LEVEL WIND SHEAR TONIGHT AS WINDS BETWEEN 1 AND 2
THOUSAND FEET ACCELERATE BETWEEN 40-45KT FROM THE SOUTHWEST...BUT
AT THIS TIME THE MAGNITUDE AND DURATION OF SHEAR APPEARS SMALL
ENOUGH TO LEAVE OUT OF THE TAF...WITH THUNDERSTORM-RELATED WIND
ISSUES POTENTIALLY BEING A BIGGER ISSUE. AT THE SURFACE...AND
APART FROM ANY THUNDERSTORM-MODIFIED EFFECTS...BREEZES ARE
EXPECTED TO AVERAGE UNDER 12KT THROUGH THE PERIOD...INITIALLY
SOUTHERLY BEFORE BECOMING MORE WESTERLY AHEAD OF AN INVADING COLD
FRONT TUESDAY MORNING. A SWITCH TO NORTHERLY BREEZES COULD OCCUR
TOWARD THE VERY END OF THE PERIOD...BUT WILL DEFER TO NEXT
FORECAST TO INTRODUCE THIS WIND SHIFT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM NOON TO 7 PM CDT TUESDAY FOR NEZ085>087.
KS...HEAT ADVISORY FROM NOON TO 7 PM CDT TUESDAY FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...JCB
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1257 PM CDT MON JUL 8 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 312 AM CDT MON JUL 8 2013
ANOTHER ACTIVE SEVERE WEATHER DAY IS EXPECTED BEGINNING THIS
AFTERNOON THROUGH THE OVERNIGHT HOURS TONIGHT. THE FOCUS FOR STORM
DEVELOPMENT REVOLVES AROUND A STRONG UPPER LEVEL DISTURBANCE MOVING
THROUGH THE DAKOTAS. A WEAKER DISTURBANCE WILL APPROACH SWRN NEB
LATE THIS AFTERNOON PERHAPS FOCUSING ANOTHER CLUSTER OF STRONG TO
SEVERE STORMS. THE DISTURBANCE MOVING THROUGH THE DAKOTAS IS
EXPECTED TO LIFT A 700 MB WARM FRONT THROUGH SWRN NEB...PERHAPS
CAPPING THE ATMOSPHERE THIS EVENING. IT WOULD APPEAR THERE IS A
WINDOW FOR SEVERE STORM DEVELOPMENT ACROSS SWRN NEB LATE THIS
AFTERNOON BEFORE THE ATMOSPHERE BECOMES CAPPED THIS EVENING. THERE
ARE NO HOLDS BARRED ACROSS NCNTL AND NW NEB LATE THIS AFTN AND
THIS EVENING WHERE THE CAP WILL BE WEAKER AND JUST AS UNSTABLE AS
THE SOUTHWEST.
THE RAP SUGGESTS STORMS COULD FIRE ACROSS NCNTL NEB LATE THIS AFTN
JUST AHEAD OF THE MID LEVEL WARM FRONT. AT THE SFC A WARM FRONT WILL
LIE ALONG INTERSTATE 80 PROVIDING AN OPPORTUNITY FOR STORM
DEVELOPMENT THERE. THUS THE FCST USES A MULTIMODEL BLEND FOR HIGHEST
POPS...40S...ACROSS THE NORTH AND ISOLATED POPS ACROSS SWRN NEB.
HIGHS TODAY SHOULD REACH WELL INTO THE 90S ALONG AND SOUTH OF THE
SFC FRONT NEAR INTERSTATE 80 AND 80S ACROSS NCNTL NEB. LOWS TONIGHT
FALL INTO THE 60S TO AROUND 70.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 312 AM CDT MON JUL 8 2013
A COLD FRONT WILL BE DRIVEN SOUTH THROUGH THE AREA TUESDAY...AS A
STRONG SHORT WAVE TROUGH SKIRTS EAST ACROSS THE NORTHERN PLAINS
AND SOUTHERN CANADA. THIS WILL BRING A TEMPORARY REST FROM T-STORM
ACTIVITY...AS THE BEST FOCUS WILL SHIFT SOUTH AND EAST OF THE AREA
ALONG THE FRONT. WEDNESDAY THE FRONT WILL BEGIN TO LIFT BACK NORTH
AS A WARM FRONT...WITH A WARM MOIST EASTERLY UPSLOPE FLOW LIKELY
TO IGNITE T-STORMS ACROSS THE PANHANDLE WEDNESDAY AFTERNOON. THESE
SHOULD MOVE EAST INTO CENTRAL/SOUTHWEST NEBRASKA WEDNESDAY
EVENING.
THE UPPER LEVEL RIDGE OF HIGH PRESSURE IS STILL EXPECTED TO BUILD
NORTH OVER THE AREA THURSDAY INTO FRIDAY. WARMING MID LEVEL
TEMPERATURES WILL LIKELY CAP THE ATMOSPHERE...AND T-STORM CHANCES
WILL DIMINISH. HOT WEATHER CAN ALSO BE ANTICIPATED AS THE RIDGE
BUILDS IN...WITH HIGHS IN THE MID 90S TO AROUND 100 DEGREES.
ANOTHER STRONG SHORTWAVE TROUGH WILL PUSH EAST ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA SATURDAY AND SUNDAY. THIS APPEARS TO
DRIVE ANOTHER COLD FRONT SOUTH INTO THE AREA...WITH RETURNING
CHANCES FOR T-STORMS AND SOMEWHAT COOLER TEMPERATURES BY SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1255 PM CDT MON JUL 8 2013
VFR CONDITIONS EARLY THIS AFTERNOON...HOWEVER EXPECT ANOTHER
ROUND OF THUNDERSTORMS TO DEVELOP OVER WESTERN NEBRASKA AND MOVE
ACROSS THE AREA THIS EVENING. IMPACT IS EXPECTED AT BOTH TERMINAL
SITES...WITH STORMS CAPABLE OF GUSTY WINDS POSSIBLY SOME HAIL.
OVERNIGHT...FOLLOWING THE CONVECTION...AS SKIES RETURN TO VFR AND
TEMPS COOL...RICH BOUNDARY LAYER MOISTURE MAY RESULT IN THE
DEVELOPMENT OF FOG...LOCALLY LESS THAN 1SM. DID NOT GO THAT LOW
IN THE TAF YET...AS SOME UNCERTAINTY TO HOW WIDESPREAD THE FOG
WILL BE. ANY FOG THAT DOES DEVELOP SHOULD QUICKLY BURN OFF WITH
VFR CONDITIONS RETURNING FOR THE MID AND LATE MORNING HOURS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
354 PM CDT MON JUL 8 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CDT MON JUL 8 2013
THE MAIN FORECAST ISSUE DURING THE SHORT TERM IS STORM
COVERAGE/TIMING/SEVERITY THROUGH TONIGHT. SCATTERED STORMS ARE
EXPECTED TO DEVELOP AND/OR MOVE INTO THE WEST LATE THIS AFTERNOON.
MORE FAVORABLE DEEP LAYER SHEAR IS CONFINED TO THE WEST THROUGH
LATE AFTERNOON. SOME ISOLATED SEVERE STORMS ARE POSSIBLE...WITH
LARGE HAIL THE MAIN THREAT. THE HRRR IS STILL FOCUSING ON THE SOUTHWEST
FOR INITIATION...WHILE THE 12Z WRF FOCUSES ON A FRONT STRETCHING
FROM WEST CENTRAL INTO NORTH CENTRAL NORTH DAKOTA. WILL CONTINUE
TO MONITOR CLOSELY FOR INITIATION. AN INTENSE SUPERCELL IS MOVING
THROUGH NORTHEAST MONTANA...AND WOULD IMPACT THE FORECAST AREA
AFTER 00Z IF IT HOLDS TOGETHER. A BIGGER CONCERN WILL BE A
THUNDERSTORM COMPLEX THAT WILL LIKELY TRACK FROM WEST TO EAST
ACROSS THE FORECAST AREA AFTER AROUND 9 PM CDT. DAMAGING STRAIGHT
LINE WINDS WILL BE THE BIGGEST THREAT. FAST STORM MOTIONS SHOULD
PRECLUDE WIDESPREAD FLASH FLOODING. A MULTI- MEDIA WEATHER BRIEFING
HAS BEEN POSTED AT WWW.WEATHER.GOV/BIS. THE SEVERE THREAT MAY
PERSIST AFTER MIDNIGHT TONIGHT BEFORE STORMS WEAKEN. ADDITIONAL
NON-SEVERE STORMS WILL BE LIKELY THROUGH AT LEAST MIDDAY TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CDT MON JUL 8 2013
MAIN HIGHLIGHT FOR THE LONG TERM IS SHORTWAVE TROUGH AND
ASSOCIATED COLD FRONT ENTERING NORTHERN PLAINS THURSDAY/FRIDAY.
THE PERSISTENT HIGH AMPLITUDE RIDGING TO THE WEST WILL CONTINUE TO
BE BOMBARDED BY SHORTWAVE TROUGHS DIVING DOWN OUT OF WESTERN
CANADA. THIS WILL FORCE THE RIDGE TO TRANSLATE EASTWARD OVER THE
CENTRAL STATES. THIS WILL IN TURN ALLOW NORTH DAKOTA TO BE
INFLUENCED BY SOUTHWESTERLY FLOW AND LEE CYCLOGENESIS. BOTH THE
12 UTC ECMWF AND THE 12 UTC GFS BOTH HAVE A SHORTWAVE TROUGH
DRAPED ACROSS THE NORTHERN PLAINS AND SURFACE LOW OVER
NORTHWESTERN SOUTH DAKOTA EARLY FRIDAY MORNING. THIS WILL ALLOW
FOR MOIST SOUTHERLY FLOW AHEAD OF THE COLD FRONT. WITH INCREASING
MOISTURE...SURFACE LOW PRESSURE...AND UPPER LEVEL DIFFLUENCE
WIDESPREAD THUNDERSTORM DEVELOPMENT IS POSSIBLE FRIDAY AFTERNOON
AND EVENING. IN ADDITION TO THOSE INGREDIENTS THE 12 UTC ECMWF IS
FORECASTING 50+ KNOTS OF 0-6 KM SHEAR...2000+ MUCAPE...AND DEW
POINTS IN THE MID TO UPPER 60S. IF THIS VERIFIES...SEVERE WEATHER
IS POSSIBLE FRIDAY AFTERNOON AND EVENING.
OTHERWISE...THE EXTENDED PERIOD LOOKS ACTIVE WITH CHANCES FOR
PRECIP THROUGHOUT THE PERIOD AS SHORTWAVES RIDE ALONG THE
NORTHERN PERIPHERY OF THE RIDGE TO OUR SOUTH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 341 PM CDT MON JUL 8 2013
THE MAIN FOCUS THROUGH THE TAF PERIOD IS THUNDERSTORMS.
OTHERWISE...EXPECT VFR CONDITIONS. SCATTERED STORMS ARE EXPECTED
THIS AFTERNOON THROUGH EARLY EVENING...BUT TOUGH TO PINPOINT FAVORED
AREA FOR DEVELOPMENT AND TIMING. LATER TONIGHT...AFTER 02Z...ENHANCED
WINDS WILL BE POSSIBLE WITH FAST MOVING LINES OF THUNDERSTORMS.
ALTHOUGH THESE SEVERE WEATHER ELEMENTS WILL BE POSSIBLE..TOO
UNCERTAIN IN TIMING TO INCLUDE IN TAF FORECAST. AVIATION PLANNERS
SHOULD ANTICIPATE MULTIPLE LINES OF THUNDERSTORMS MOVING WEST TO
EAST ACROSS THE STATE AFTER 02Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM...AJ
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
118 PM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 1258 PM CDT MON JUL 8 2013
UPDATE MAINLY FOR HOURLY POPS THIS AFTERNOON AND TONIGHT.
SCATTERED STORMS ARE EXPECTED TO DEVELOP ACROSS THE WEST AND
PERHAPS INTO CENTRAL COUNTIES THIS AFTERNOON. MORE FAVORABLE DEEP
LAYER SHEAR WILL BE CONFINED TO THE WEST THROUGH LATE AFTERNOON.
SOME ISOLATED SEVERE STORMS ARE POSSIBLE...WITH LARGE HAIL THE
MAIN THREAT. THE HRRR IS FOCUSING ON THE SOUTHWEST FOR
INITIATION...WHILE THE 12Z WRF FOCUSES ON A FRONT STRETCHING FROM
WEST CENTRAL INTO NORTH CENTRAL NORTH DAKOTA. EITHER LOCATION IS
PLAUSIBLE. THE BIGGER CONCERN WILL BE A THUNDERSTORM COMPLEX THAT
WILL LIKELY TRACK FROM WEST TO EAST ACROSS THE FORECAST AREA AFTER
AROUND 9 PM CDT. DAMAGING STRAIGHT LINE WINDS WILL BE THE BIGGEST
THREAT. FAST STORM MOTIONS SHOULD PRECLUDE WIDESPREAD FLASH
FLOODING. WILL HAVE AN UPDATED MULTI-MEDIA WEATHER BRIEFING UP
SHORTLY AT WWW.WEATHER.GOV/BIS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT MON JUL 8 2013
THE MAIN CONCERN IN THE SHORT TERM WILL BE THE CHANCE OF
THUNDERSTORMS...SOME POSSIBLY SEVERE. EARLY MORNING RADAR MOSAIC
SHOWS THUNDERSTORMS MOVING ACROSS NORTHEAST MONTANA INTO NORTHWEST
NORTH DAKOTA. THE HRRR CAPTURES THIS ACTIVITY AND MOVES IT INTO
THE NORTH CENTRAL PART OF THE STATE LATER THIS MORNING. MUCAPE
FROM THE SPC MESOSCALE ANALYSIS PAGE SHOWS VALUES NEAR 1000 J/KG
THIS MORNING ACROSS NORTHWEST / NORTH CENTRAL NORTH DAKOTA...SO AN
ISOLATED STRONG STORM IS POSSIBLE.
ATTENTION THIS AFTERNOON SHIFTS TO A BOUNDARY THAT IS EXPECTED TO
BECOME ESTABLISHED FROM SOUTHWEST NORTH DAKOTA INTO THE NORTH
CENTRAL PART OF THE STATE. THE LATEST RAP SHOWS CONVECTION
DEVELOPING ALONG THE BOUNDARY BY EARLY AFTERNOON. THERE WILL BE
GOOD INSTABILITY IN PLACE WITH MLCAPE VALUES OF 1500-2500
J/KG...AND DEEP LAYER SHEAR OF 40 KTS SHOULD SUPPORT SUPERCELLS.
THE MAIN THREATS ARE EXPECTED TO BE LARGE HAIL AND DAMAGING
WINDS...THOUGH AN ISOLATED TORNADO IS ALSO POSSIBLE.
LATER TONIGHT...A STRONG H5 WAVE IS EXPECTED TO MOVE ACROSS MONTANA
INTO NORTH DAKOTA. THIS WILL HELP INCREASE THUNDERSTORM
COVERAGE...WITH THE POTENTIAL DEVELOPMENT OF AN EASTWARD
PROPAGATING MCS. THIS WILL GRADUALLY SHIFT THE PRIMARY
THUNDERSTORM THREATS TO DAMAGING WINDS AND HEAVY RAIN LATER
TONIGHT. SEE THE HYDRO SECTION BELOW WHICH DISCUSSES THE HEAVY
RAIN POTENTIAL.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT MON JUL 8 2013
THE CHALLENGE IN THE EXTENDED WILL BE ENDING THE PRECIPITATION
CHANCES TUESDAY AS THE SHORTWAVE EXITS THE REGION. BELIEVE RESIDUAL
SHOWERS AND THUNDERSTORMS WILL BE IN THE NORTH AND EAST TUESDAY
MORNING...WITH ONLY A SLIGHT CHANCE SOUTH. THE PRECIPITATION WILL
LIKELY BE EXITING THE REGION BY EARLY AFTERNOON...SO BY EVENING
TUESDAY IT SHOULD BE DRY ACROSS THE REGION. THIS WILL BE FOLLOWED BY
A RELATIVELY QUIET PERIOD WEDNESDAY AND THURSDAY AS AN H500 RIDGE
BUILDS INTO THE REGION. HOWEVER...MUCH WARMER TEMPERATURES
ASSOCIATED WITH THE RIDGE WILL ALSO ARRIVE IN THE WEST ON THURSDAY
AND CONTINUE INTO FRIDAY. BOTH GFS AND ECMWF MODELS SUPPORT THIS
SCENARIO. EXPECT HIGH TEMPERATURES WEDNESDAY INTO THE LOW TO MIDDLE
90S WEST...UPPER 80S TO AROUND 90 CENTRAL. AS THE RIDGE MOVES EAST
ON FRIDAY INTO THE WEEKEND...WILL BE PICKING UP MORE CHANCES FOR
THUNDERSTORMS AS SHORTWAVE ENERGY WILL AGAIN BE MOVING THROUGH THE
NORTHERN PLAINS. THAT BEING 5 TO 7 DAYS OUT...AND WITH MODELS
DIFFERING IN THE FLOW ALOFT...JUST MENTIONED SLIGHT CHANCE FOR
THUNDERSTORMS FRIDAY INTO WEEKEND. GFS HAS BUILDING HEIGHTS FOR THIS
PERIOD ALOFT WHILE THE EUROPEAN IS MORE ACTIVE WITH SHORTWAVE ENERGY
MOVING THROUGH....ALTHOUGH BOTH MODELS WOULD SUPPORT SOME
THUNDERSTORMS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1258 PM CDT MON JUL 8 2013
THE MAIN FOCUS THROUGH THE TAF PERIOD IS THUNDERSTORMS.
OTHERWISE...EXPECT VFR CONDITIONS. SCATTERED STORMS ARE EXPECTED
THIS AFTERNOON THROUGH EARLY EVENING...BUT TOUGH TO PINPOINT FAVORED
AREA FOR DEVELOPMENT AND TIMING. LATER TONIGHT...AFTER 02Z...ENHANCED
WINDS WILL BE POSSIBLE WITH FAST MOVING LINES OF THUNDERSTORMS.
ALTHOUGH THESE SEVERE WEATHER ELEMENTS WILL BE POSSIBLE..TOO
UNCERTAIN IN TIMING TO INCLUDE IN TAF FORECAST. AVIATION PLANNERS
SHOULD ANTICIPATE MULTIPLE LINES OF THUNDERSTORMS MOVING WEST TO
EAST ACROSS THE STATE AFTER 02Z.
&&
.HYDROLOGY...
ISSUED AT 325 AM CDT MON JUL 8 2013
HEAVY RAIN IS POSSIBLE WITH MULTIPLE ROUNDS OF THUNDERSTORMS TODAY
INTO TONIGHT. PRECIPITABLE WATER VALUES AROUND 1.5 INCHES ARE
EXPECTED TONIGHT ACROSS MUCH OF THE FORECAST AREA. THE HEAVIEST
RAIN POTENTIAL APPEARS TO BE ALONG AND NORTH OF HIGHWAY 200...WHERE
AN EASTWARD PROPAGATING THUNDERSTORM COMPLEX IS POSSIBLE. 1 HOUR
FLASH FLOOD GUIDANCE VALUES ARE AT LEAST 1.5 INCHES...AND 3 HOUR
VALUES ARE GENERALLY IN THE 1.5 - 3.0 INCH RANGE. DECIDED TO HOLD
OFF ON ANY FLASH FLOOD WATCHES FOR NOW DUE TO THE RELATIVELY HIGH
FLASH FLOOD GUIDANCE VALUES AND EXPECTED PROGRESSIVE STORM
MOTIONS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM/HYDROLOGY...CK
LONG TERM...WAA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1250 PM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 1242 PM CDT MON JUL 8 2013
ISOLD SHRA HAVE PRETTY MUCH DISSIPATED OR MOVED OUT OF FORECAST
AREA WITH DEPARTING WAVE. WEAK BOUNDARY REMAINS IN PLACE ACROSS N
CENTRAL INTO PARTS OF NE ND HOWEVER CAPE AND INSTABILITY WEAK.
KEPT SOME LOW POPS ALONG BOUNDARY HOWEVER CONFIDENCE LOW ON ANY
OTHER CONVECTION DEVELOPING REMAINDER OF AFTERNOON SO TRIMMED POPS
ACCORDINGLY ELSEWHERE. WITH CLOUDS LINGERING LONGER OVER THE NW FA
DID LOWER TEMPERATURES SLIGHTLY OTHERWISE TEMPERATURES LOOKING OK.
UPDATE ISSUED AT 931 AM CDT MON JUL 8 2013
SHORTWAVE RIDING ALONG INTERNATIONAL BORDER AND WEAK SURFACE
BOUNDARY JUST NORTH OF HIGHWAY 2 ENOUGH TO SUSTAIN ISOLD
CONVECTION PROPAGATING INTO FAR WESTERN FA WEST OF DVL. CELLS
WEAKENING AND SHORT RANGE MESOSCALE MODELS GENERALLY DISSIPATE
CONVECTION BY NOON. TRIMMED BACK ON POPS TO COVER JUST THE FAR
WEST AND IF TRENDS CONTINUE WILL LIKELY BE ABLE TO PULL POPS REST
OF TODAY. ADJUSTED SKY CONDITION OTHERWISE NO OTHER CHANGES FOR
THIS UPDATE PERIOD.
UPDATE ISSUED AT 643 AM CDT MON JUL 8 2013
STORMS OVER NORTHWESTERN ND HAVE BEEN HOLDING A BIT BETTER THAN
EXPECTED. IN ADDITION...LATEST RUNS OF THE RAP HAVE A FEW REMNANTS
OF CONVECTION REACHING THE FAR NORTHWESTERN CWA THIS MORNING.
THUS...INCLUDED SOME 20 POPS IN THAT AREA STARTING AT 15Z.
OTHERWISE...THINK THAT MORE SIGNIFICANT ACTIVITY WILL HOLD OFF
UNTIL TONIGHT SO WILL KEEP HIGHEST POPS FOR THAT TIME PERIOD.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 302 AM CDT MON JUL 8 2013
CONVECTION TIMING WILL BE THE MAIN HEADACHE FOR THE SHORT TERM.
WV LOOP SHOWS NEAR ZONAL FLOW OVER THE NORTHERN PLAINS...WITH
VARIOUS WEAK SHORTWAVES APPROACHING FROM THE WEST. WEAK SFC HIGH
PRESSURE REMAINS IN PLACE OVER THE CWA...AND MODELS ARE IN FAIRLY
GOOD AGREEMENT ON IT MOVING TO THE EAST TODAY AS LOW PRESSURE
DEVELOPS IN THE LEE OF THE ROCKIES. SPC MESOANALYSIS HAS THE CWA
UNDER A RELATIVELY STABLE AND DRIER AIRMASS THAN THE SURROUNDING
AREAS. WILL HAVE TO MONITOR CONVECTION CURRENTLY ENTERING FAR
NORTHWESTERN ND. AT THIS POINT IT SEEMS LIKE IT WILL DISSIPATE
BEFORE APPROACHING OUR CWA LATER THIS MORNING WHICH THE
RAP...GFS...ECMWF...AND GEM SHOW. A FEW OF THE MODELS SUCH AS NAM
AND HRR HOWEVER HAVE IT HOLDING TOGETHER ENOUGH TO ENTER THE
DEVILS LAKE BASIN LATER ON THIS MORNING. AT THIS POINT THINK THE
STORMS WILL OUTRUN THEIR SUPPLY OF ELEVATED INSTABILITY AND DIE
OUT BUT WILL KEEP AN EYE ON RADAR TRENDS BEFORE SENDING EVERYTHING
OUT. JUST HAVE SOME LOW POPS IN THE FAR WEST THIS AFTERNOON
BETWEEN 18-00Z FOR ANYTHING DRIFTING INTO THE AREA FROM CENTRAL ND.
THINK THAT THE MAIN THREAT WILL BE LATER TONIGHT AS A MORE
SIGNIFICANT UPPER SHORTWAVE COMES OUT INTO THE NORTHERN PLAINS.
THE SFC LOW WILL MOVE OUT INTO THE EASTERN DAKOTAS...AND THERE
SHOULD BE A GOOD AMOUNT OF BULK SHEAR TO WORK WITH AS THE SYSTEM
COMES OUT. SOME OF THE MODELS SHOW MORE THAN 1500 J/KG OF CAPE IN
THE WESTERN CWA...BUT OTHERS HAVE ONLY SOME LIMITED ELEVATED CAPE
THIS EVENING. THE GFS HAS A STRONGER CONVECTIVE COMPLEX OVER SD
WHILE THE NORTHERN ACTIVITY IS A BIT LESS. ON THE OTHER
HAND...THINK THERE COULD BE ENOUGH INSTABILITY TO GET STORMS GOING
OVER WESTERN ND THIS AFTERNOON AND THEN COME EASTWARD AS AN MCS
LATER TONIGHT. KEPT FAIRLY HIGH POPS GOING FOR TONIGHT AND WILL
MENTION HAIL AND DAMAGING WIND THREAT IN THE HWO.
HOW TUESDAY PLAYS OUT WILL DEPEND SOMEWHAT ON HOW CONVECTION
BEHAVES TONIGHT. THE UPPER SHORTWAVE TROUGH WILL MOVE INTO THE
CWA...BUT THE SFC LOW WILL BE WELL TO OUR SOUTHEAST AND THE COLD
FRONT MAY BE THROUGH MOST OF THE CWA BY PEAK HEATING. WILL
CONTINUE TO KEEP POPS FAIRLY HIGH BUT THE COLDER AIR BUILDING IN
AS WELL AS ANY CONVECTIVE DEBRIS FROM EARLY MORNING ACTIVITY COULD
PUT A DAMPER ON ANY STRONGER STORMS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 302 AM CDT MON JUL 8 2013
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT SHOULD BE FAIRLY QUIET WITH
NORTHWESTERLY FLOW ALOFT AND SFC HIGH PRESSURE OVER THE AREA. COLD
AIR ADVECTION BEHIND THE EARLY WEEK SYSTEM SHOULD KNOCK BACK TEMPS
A BIT. HIGHS ON WEDNESDAY WILL BE IN THE 70S TO LOW 80S WITH LOWS
MAINLY IN THE 50S.
THURSDAY-SUNDAY...THE UPPER RIDGE WILL AMPLIFY ACROSS THE ROCKIES
AND HIGH PLAINS ON THURSDAY. RETURN FLOW WILL ENSUE AS THE SFC HIGH
DRIFTS EAST TOWARDS THE WESTERN GREAT LAKES. 925 MB WARM A BIT FROM
WEDNESDAY...WHICH SHOULD ALLOW TEMPS TO RISE INTO THE LOW TO MID 80S.
THE 00Z GFS/ECMWF INDICATE A STRONGER UPPER WAVE/JET STREAK
PROPAGATING INTO CENTRAL CANADA ON FRIDAY...DRAGGING A SFC BOUNDARY
INTO THE REGION...AND PROVIDING SOME POSSIBLE FOCUS FOR CONVECTION
FRI/FRI NIGHT. KEPT HIGH TEMPS ON FRIDAY IN THE LOW TO MID 80S. THE ECMWF
NOSES THE THERMAL RIDGE ACROSS THE AREA AHEAD OF THE FRONT...AND
WOULD SUGGEST A BIT WARMER TEMPS...BUT MUCH WILL DEPEND ON THE
TIMING OF THE WAVE AND ORIENTATION OF THE FLOW FIELDS.
FORECAST CONFIDENCE IS LOW FOR NEXT WEEKEND. BOTH THE GFS/ECMWF KEEP
THE UPPER RIDGE ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH
MORE ZONAL FLOW ACROSS THE NORTHERN PLAINS AS EMBEDDED SHORTWAVES
HELP TO FLATTEN THE RIDGE. THERE ARE SIGNIFICANT DIFFERENCES BETWEEN
THE GFS/ECMWF IN THE POSITION OF SURFACE AND UPPER FEATURES...WITH
THE ECMWF THE COOLER AND MORE PROGRESSIVE SOLUTION. AS SUCH...WILL
CONTINUE TO MENTION LOW POPS WITH FAIRLY SEASONABLE TEMPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1242 PM CDT MON JUL 8 2013
THE MAIN CHALLENGE WILL BE INCREASING CHANCES FOR SHOWERS AND STORMS
FROM WEST TO EAST LATE TONIGHT INTO TUE MORNING. WILL MENTION SOME
-TSRA IN THE WEST LATER TONIGHT...AND IN THE EAST TUE MORNING.
WINDS SHOULD REMAIN SOUTHERLY TONIGHT BEFORE SHIFTING TO THE N/NW
LATE TONIGHT AND TUE MORNING. WINDS COULD BE LOCALLY GUSTY WITH
STRONG WINDS POSSIBLE WITH A THUNDERSTORM COMPLEX LATE
TONIGHT/TUE...BUT WON/T MENTION ANY HIGHER GUSTS YET.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...DK
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
356 PM CDT MON JUL 8 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM CDT MON JUL 8 2013
ATTENTION IN THE SHORT TERM IS ON THE CONVECTIVE DEVELOPMENT.
OUTFLOW/FRONTAL HYBRID REMAINS DISTINCT ACROSS WESTERN IOWA JUST
ALONG THE SOUTHERN EDGE OF THE CWA...BUT MORE DIFFUSE HEADING WEST
INTO NEBRASKA. MCV PASSING SOUTH OF CWA...AND RECENTLY HAVE SEEN
LONE CONVECTIVE CELL DEVELOP ALONG THIS BOUNDARY NEAR CWA BORDER...
AND NOT SURPRISED WITH RAP ANALYSIS INDICATING WEAKENED /MORE LIKELY
WEAKENING/ CAP. LIKELY THAT MOST AREAS AT LEAST A WEAK CAP REMAINS
/ON ORDER OF A SKINNY 20-40 J/KG/ IF SOME PRECONVECTED MODELS USED
FOR GUIDANCE. NO QUESTION ATMOSPHERE IS CERTAINLY LOADING UP ON
POTENTIAL ENERGY THIS AFTERNOON...BUT SOMEWHAT LESS OUT IN THE FAR
WEST WHERE HAVE BEEN ALONG EDGE OF NAGGING CIRRUS SHIELD FROM
EARLIER DAY ACTIVITY. THE AREA ACROSS NORTHWEST IOWA WILL BE ONE
AREA OF CONVECTIVE THREAT FOR THE LATE AFTERNOON AND EARLY EVENING...
AND THREATS THERE WILL BALANCE BETWEEN QUARTER TO HALF DOLLAR HAIL...
AND DAMAGING WIND GUSTS. ALSO MUST NOT FORGET THAT FAIRLY WEAK WINDS
ALONG WITH RIGHT MOVING SUPERCELL MOTION OF 5 TO 10 KNOTS MAXIMUM
THROUGH EARLY EVENING...WITH WARM CLOUD DEPTHS OVER 12 KFT...FLASH
FLOODING IS A RISK.
EFFECTIVELY SHEAR IS IN THAT 30-40 KNOT RANGE...AND CERTAINLY IN THE
REALM WHERE SUERCELLS WOULD CERTAINLY BE POSSIBLE...OR AT LEAST
HYBRID WITH LINEAR/BOWING STRUCTURE. LOWER TO MID LEVEL STORM
RELATIVE INFLOW FAIRLY BALANCED...SO MAY END UP WITH A FAIRLY STABLE
BOWING STRUCTURE...AND SOMETHING TOWARD A HIGHER END DAMAGING WIND
EVENT IS NOT OUT OF THE QUESTION. MOST HIGH RESOLUTION GUIDANCE IS
SUPPORTIVE OF THIS MODE...AND LITTLE REASON TO DOUBT IT. FOR NOW...
MOST LIKELY AREA WOULD APPEAR TO BE NEAR/SOUTH OF INTERSTATE 90 FROM
THE EARLY EVENING HOURS NEAR 9V9...AROUND MIDNIGHT CLOSER TO
I29...AND A BIT LATER THROUGH NW IA.
IN THE WAKE OF THE MCS...WILL AGAIN BE POTENTIAL FOR SOME PATCHY FOG
WHERE SKIES CAN CLEAR...AND ADDED SMALL MENTION FOR AREAS GENERALLY
NEAR/SOUTH OF I90 AND NEAR/WEST OF I29.
AFTER THE ATMOSPHERE BEING WORKED OVER TONIGHT...VEERING LOW LEVEL
JET SHOULD QUICKLY END EARLY DAY ACTION EAST...WITH TEMPS CONTINUING
TO WARM ALOFT AHEAD OF FAIRLY STRONG UPPER ENERGY...WHICH WILL SWING
SOUTHEAST ACROSS THE AREA ON TUESDAY AFTERNOON. AT THE SURFACE...
OUTFLOW/CONVERGENCE BOUNDARY SHOULD BE LEADING THE AREA ACROSS
NORTHWEST IOWA BY MIDDAY... HOWEVER...THE STRONGER BOUNDARY/MOISTURE
DISCONTINUITY WILL BE TIED TO THE UPPER ENERGY. AREAS BETWEEN THE
BOUNDARIES WILL CONTINUE STIFLING HUMIDITY AND HAVE MUCH OF NW IA
REACHING HEAT INDEX VALUES FROM 100 TO 105 FROM MIDDAY TOMORROW
THROUGH MUCH OF THE AFTERNOON. LIKELY TO REMAIN FAIRLY CAPPED UNTIL
LIFT FROM APPROACHING FRONT AND COOLING TEMPS ALOFT WITH UPPER WAVE.
EFFECTIVE SHEAR LOOKS TO BE A BIT STRONGER AND QUITE LINEAR...AND A
SEVERE RISK OVER THE SOUTHEASTERN 2/3 OF THE AREA LOOKS WARRANTED
GIVEN THE DEGREE OF POTENTIAL INSTABILITY AND EFFECTIVE SHEAR.
THREAT WOULD AGAIN BE PRIMARILY HAIL AND DAMAGING WIND.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 353 PM CDT MON JUL 8 2013
THE SHORTWAVE AND FRONTAL BOUNDARY WILL TRACK OFF TO THE EAST BY
TUESDAY EVENING...WITH ANY LINGERING THUNDERSTORM ACTIVITY FOLLOWING
SUIT. WITH DECENT COLD AIR ADVECTION AND DRYING BEHIND THE EXITING
SYSTEM...IT WILL BE A COOLER NIGHT WITH LOWERING DEW POINTS. LOWS
WILL BOTTOM OUT IN THE UPPER 50S TO LOWER 60S BY EARLY WEDNESDAY
MORNING.
A SURFACE RIDGE SLIDES SOUTHWARD THROUGH THE REGION ON
WEDNESDAY...PROVIDING FOR A PLEASANT DAY WITH LIGHT WINDS AND DEW
POINTS DOWN INTO THE 50S. HIGHS WILL BE SEASONABLE FOR THIS TIME OF
YEAR WITH READINGS IN THE UPPER 70S TO LOWER 80S.
THURSDAY ALSO LOOKS TO BE A DECENT DAY...ALBEIT WARMER AS HIGH
PRESSURE BEGINS TO MOVE OFF TO THE EAST AND A SOUTHERLY FLOW
RETURNS TO THE REGION. WITH 850 MB TEMPERATURES CLIMBING AROUND 3
DEGREES OVER WEDNESDAY...HIGHS WILL RISE INTO THE LOWER 80S EAST TO
NEAR 90 THROUGH SOUTH CENTRAL SOUTH DAKOTA.
IN THE EXTENDED...UPPER LEVEL RIDGE BUILDS INTO THE REGION THROUGH
THE END OF THE WEEK...TRANSITIONING TO A MORE WEST-EAST FLOW BY THE
START OF NEXT WEEK. THIS WILL BRING A CONTINUED WARM UP INTO
SUNDAY...THEN SOME COOLING POSSIBLE BY MONDAY. AS LOW LEVEL MOISTURE
AND INSTABILITY INCREASE THROUGH THE PERIOD...CONVECTION CHANCES
WILL INCREASE FOR THE WEEKEND...WITH TYPICAL MODEL DIFFERENCES IN
TIMING/PLACEMENT OF CONVECTION. HIGHS INTO THE WEEKEND LOOK TO
GENERALLY BE IN THE MID 80S TO LOWER 90S...WITH LOWS UPPER 60S TO
LOWER 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 112 PM CDT MON JUL 8 2013
MAIN AVIATION CONCERN FOR THE MIDDAY PACKAGE IS THE DEVELOPMENT OF
CONVECTION. EXPECTATIONS ARE FOR MOST SIGNIFICANT CONVECTION WILL
DEVELOP ACROSS WESTERN SOUTH DAKOTA AND PROGRESS EASTWARD THROUGH
THE EVENING AND EARLY OVERNIGHT HOURS...PRESENTING GENERALLY A
DAMAGING WIND AND MARGINALLY LARGE HAIL THREAT SOUTH OF INTERSTATE
90. OTHER MORE ISOLATED STORMS MAY DEVELOP BY LATE AFTERNOON IN
PROXIMITY TO CUMULUS FIELD DEVELOPING SOUTH OF INTERSTATE 90...
AND EXTENDING INTO NW IA. THESE STORMS WOULD BRING A LARGE HAIL
AND DAMAGING WIND THREAT. DAMAGING WIND GUSTS UP TO 80 MPH WILL BE
POSSIBLE WITH ORGANIZED BOWING SYSTEM...A MODE SUGGESTED BY
SEVERAL HIGH RESOLUTION MODELS. THUNDERSTORMS WILL LIKELY CONTAIN
PERIODS OF MVFR TO IFR CONDITIONS.
POSSIBILITY FOR SOME AREAS IN WAKE OF MCS TO DEVELOP SOME MVFR FOG
LATE NIGHT OR EARLY MORNING...BUT FOR NOW MENTIONED ONLY A LITTLE
AROUND KFSD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...JM
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
229 PM CDT MON JUL 8 2013
.DISCUSSION...
AN UPPER LEVEL DISTURBANCE PASSING BY TO THE SOUTH ACROSS THE BIG
BEND COULD GENERATE ISOLATED THUNDERSTORMS THIS EVENING ACROSS
WEST TEXAS PER CUMULUS FIELD AND LATEST RUC GUIDANCE. ANY ACTIVITY
SHOULD DIE THIS EVENING WITH LOSS OF HEATING. THIS DISTURBANCE
IS FORECAST TO CONTINUE TO SLOWLY TRACK WESTWARD ACROSS NORTHERN
MEXICO TUESDAY AND TUESDAY EVENING WITH ISOLATED TO WIDELY SCATTERED
SHOWERS AND THUNDERSTORMS POSSIBLE AGAIN ACROSS THE BIG BEND...DAVIS
MOUNTAINS AND LOWER TRANS PECOS REGION CLOSEST TO THE TRACK OF
DISTURBANCE. BEYOND TUESDAY A SPRAWLING UPPER LEVEL HIGH PRESSURE
AREA ACROSS THE PLAINS AND ROCKIES SHOULD REGAIN FIRM CONTROL OF
THE REGION AND PRECIPITATION CHANCES WILL BE VERY LOW. THE NEXT
CHANCE OF CONVECTION APPEARS TO BE NEXT SUNDAY AND MONDAY AS
ANOTHER DISTURBANCE TRACKS WESTWARD ACROSS THE GULF AND MEXICO.
HIGH TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL THROUGH WEDNESDAY
WITH ABOVE NORMAL TEMPERATURES EXPECTED THURSDAY THROUGH SATURDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
ANDREWS TX 68 94 71 96 / 10 10 0 0
BIG SPRING TX 70 94 72 96 / 10 10 0 0
CARLSBAD NM 67 95 68 97 / 10 10 0 0
DRYDEN TX 72 94 71 96 / 10 20 10 0
FORT STOCKTON TX 71 93 72 96 / 10 10 10 10
GUADALUPE PASS TX 66 86 67 88 / 10 10 10 10
HOBBS NM 65 93 70 95 / 10 0 0 0
MARFA TX 63 86 59 88 / 10 20 10 20
MIDLAND INTL AIRPORT TX 71 94 71 96 / 10 10 0 0
ODESSA TX 70 94 72 96 / 10 10 0 0
WINK TX 72 96 73 99 / 10 10 10 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
44/12
AREA FORECAST DISCUSSION
NWS SPOKANE WA
227 PM PDT Mon Jul 8 2013
.SYNOPSIS...
A weather system passing through the Inland Northwest today will
promote scattered showers and thunderstorms across the northern
mountains of Washington and Idaho, as well as southeast
Washington. Tuesday and Wednesday will be the warmest days this
week with high temperatures in the upper 80s to mid 90s. Thursday
through Saturday will be occasionally breezy with temperatures
pretty close to average, or slightly below. Low shower and
thunderstorms chances will linger near the mountains, especially
closer to the Canadian border, but otherwise conditions will be
dry. Temperatures begin to warm up again slightly going into early
next week.
&&
.DISCUSSION...
This Afternoon and Evening: The weather over northeast Washington
and the Idaho Panhandle will be active. Scattered thunderstorms
are expected through early this evening. Our concern area extends
from the Okanogan Highlands through northeast Washington into the
northern and central Idaho Panhandle. The 2 PM visible imagery
shows a mid-level atmospheric circulation in far southeast British
Columbia slowly moving east. Around this circulation the
atmosphere has become increasingly unstable with the RUC analysis
indicating 500 to 1000 J/KG of surface based CAPE from Republic to
Sandpoint to Spokane to Kellogg. Very little convective inhibition
remains, so look for convection to continue to develop through
late afternoon. Shear and buoyancy values suggest the potential
for organized multi-cell thunderstorms. Our main threat through 6
PM will be the potential for hail, heavy rain, and gusty winds. A
couple severe thunderstorm warnings may be needed, but most of the
cells through early evening will probably pulse up, produce hail
up to dime size, then pulse down. The threat for thunderstorms
should dissipate quickly early this evening as the upper level
support (upper low in SE BC) moves east of the region focusing the
threat over Montana.
Tuesday: A shortwave ridge of high pressure will replace the
trough over the Inland Northwest for Tuesday. Look for relatively
light winds, clear skies and temperatures 5 to 8 degrees above
average. /GKoch
Tuesday night through Thursday evening...General long-wave trof
lingers overhead but the air-mass contained in it is not very
unstable and does not have much moisture tied to any discrete
feature traversing through it. As thus for the most part a dry
forecast remains, with exception being minimal chance for
afternoon/evening mountain thunderstorms up North and over the
Idaho Panhandle Thursday afternoon and evening. Forecast
temperatures remain just slightly on the warm side of what would
be considered normal for this time of year. Other shortwave
features of note will be a dry disturbance passage on Wednesday
afternoon and evening which will increase the wind some but only
to low breezy category at most. /Pelatti
Thursday night through Monday: The Inland Northwest remains in a
more active pattern through the week`s end, before high pressure
starts to nudge in Sunday and Monday. A shortwave system continues
to slip through Idaho into Montana Thursday night, even as a
second shortwave begins to move toward the Cascades. That second
shortwave slips across eastern Washington and north Idaho through
Friday, with a third wave slipping by Saturday before high
pressure begins to nudge in Saturday night. Models continue to
disagree over some of the details. Yet the progression of these
features will bring some shower and thunderstorm chances to the
region. The main chances remain around the northern mountains.
Smaller chances will be found across the Blue Mountains through
the Central Panhandle, including the Palouse as the wave is
exiting Thursday night. While some of these waves are depicted as
being somewhat dynamic/strong, models still do not depict
significant instability and keep the deeper moisture southeast of
the region. So regardless of timing and track, fuel for showers is
not impressive. Thus over PoPs remain slight or isolated in
nature. Look for occasional breezy conditions, especially Friday,
with the passage of these waves. Although a couple models skim
another wave by southern BC, near the WA/ID border early next
week, drier conditions are forecast going into Sunday and Monday.
Look for slightly cooler than normal conditions around the end of
the work week, before temperatures warm closer to or slightly
above seasonal norms going into early next week. /J. Cote`
&&
.AVIATION...
18Z TAFS: Showers and thunderstorms will be the main aviation impact
this afternoon. A weak surface pressure trough currently lays over
the Spokane/Coeur D`Alene areas and should be the focus for
afternoon convection. RUC analysis of surface based CAPE and
convective inhibition compares favorably with the 12z NAM prog. It
looks like the convective temperature will be reached around 20-21z.
The window of opportunity for thunderstorms is relatively brief as
the upper trough will shift into western Montana shortly after 00z
putting the Idaho Panhandle and eastern Washington in a region of
subsidence. Instability and shear are marginal for organized
multicell thunderstorms. Hail up to dime size and gusts to 40 mph
look to be the upper end of what we can expect with the strongest
cells this afternoon. /GKoch
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 58 89 60 89 59 83 / 0 0 0 0 0 10
Coeur d`Alene 56 87 58 87 58 83 / 10 0 0 0 0 10
Pullman 53 87 55 88 55 82 / 0 0 0 10 10 10
Lewiston 62 95 64 95 63 90 / 0 0 0 10 10 10
Colville 53 90 56 92 56 86 / 10 0 0 0 0 10
Sandpoint 50 85 53 86 54 82 / 20 0 0 0 0 10
Kellogg 54 87 57 87 58 82 / 10 0 0 0 10 10
Moses Lake 60 94 62 94 60 87 / 0 0 0 0 0 0
Wenatchee 64 92 65 91 62 85 / 0 0 0 0 0 0
Omak 60 94 60 92 59 86 / 0 0 0 0 0 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1140 AM PDT Mon Jul 8 2013
.SYNOPSIS...
A weather system passing through the Inland Northwest today will
promote scattered showers and thunderstorms across the northern
mountains of Washington and Idaho, as well as southeast
Washington. Tuesday and Wednesday will be the warmest days this
week with high temperatures in the upper 80s to mid 90s. Thursday
through the upcoming weekend will be occasionally breezy with
temperatures pretty close to average.
&&
.DISCUSSION...
The morning forecast has been updated to remove showers and
thunderstorms from southeast Washington and the Kamiah/Lewiston
areas. The high-based activity that occurred early this morning
over northeast Oregon and the southern Idaho Panhandle was driven
by mid-level instability and warm advection processes, and has
pushed east of the Spokane forecast area.
Further north in the Bonners Ferry, Colville and Wilbur areas,
clusters of showers and thunderstorms are occurring in the
vicinity of a slow moving upper level trough. Look for these
clusters to migrate eastward through the morning and afternoon.
The 06z and 12z NAM suggest that thunderstorms may develop as far
south as Spokane and far northern Whitman counties this afternoon.
This idea is supported by the high resolution HRRR. This scenario
makes sense given the presence of a weak surface trough currently
located over Spokane, Latah and southern Shoshone counties. Some
thunderstorms this afternoon will have the potential to produce
brief heavy rain and possibly some hail. /GKoch
&&
.AVIATION...
18Z TAFS: Showers and thunderstorms will be the main aviation impact
this afternoon. A weak surface pressure trough currently lays over
the Spokane/Coeur D`Alene areas and should be the focus for
afternoon convection. RUC analysis of surface based CAPE and
convective inhibition compares favorably with the 12z NAM prog. It
looks like the convective temperature will be reached around 20-21z.
The window of opportunity for thunderstorms is relatively brief as
the upper trough will shift into western Montana shortly after 00z
putting the Idaho Panhandle and eastern Washington in a region of
subsidence. Instability and shear are marginal for organized
multicell thunderstorms. Hail up to dime size and gusts to 40 mph
look to be the upper end of what we can expect with the strongest
cells this afternoon. /GKoch
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 83 58 90 60 89 59 / 40 0 0 0 0 0
Coeur d`Alene 80 55 87 58 87 58 / 40 10 0 0 0 0
Pullman 82 52 88 55 88 55 / 10 0 0 0 10 10
Lewiston 90 61 96 64 95 63 / 10 0 0 0 10 10
Colville 84 52 92 56 92 56 / 60 10 0 0 0 0
Sandpoint 77 49 86 53 86 54 / 60 20 0 0 0 0
Kellogg 78 54 88 57 87 58 / 50 10 0 0 0 10
Moses Lake 91 59 94 62 94 60 / 0 0 0 0 0 0
Wenatchee 88 63 93 65 91 62 / 0 0 0 0 0 0
Omak 88 58 94 60 92 59 / 20 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1225 PM CDT MON JUL 8 2013
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 353 AM CDT MON JUL 8 2013
WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWING A MID-LEVEL
SHORTWAVE TROUGH EXTENDING FROM WESTERN LAKE SUPERIOR THROUGH
APPROXIMATELY SIOUX FALLS SD. PUSH OF 850MB MOIST TRANSPORT AND A
CONVERGENCE/WINDSHIFT LINE AT THE SURFACE WAS SUPPORTING A BROKEN
BAND OF SHOWERS AND THUNDERSTORMS EXTENDING FROM NORTHERN WI THROUGH
EASTERN IA/WESTERN IL. MODELS SHOW THIS MID-LEVEL TROUGH AND SURFACE
CONVERGENCE/WINDSHIFT LINE MOVING EAST AND SOUTHEAST OF THE AREA
THIS MORNING ALONG WITH ANY 850MB MOISTURE TRANSPORT. THIS WILL
BRING AN END TO THE SHOWER/THUNDER CHANCES TODAY AS MID-LEVEL
RIDGING BUILDS IN BEHIND THIS DEPARTING WAVE. THERE LOOKS TO BE A
CHANCE OF CONVECTION REDEVELOPING ALONG THIS SURFACE BOUNDARY JUST
TO OUR SOUTH...BUT BELIEVE THIS ACTION WILL REMAIN OUT OF OUR AREA.
OTHERWISE...LOOK FOR ANOTHER VERY WARM AND MUGGY DAY WITH HIGHS IN
THE 80S...WITH PERHAPS A FEW SPOTS ACROSS FAR SOUTHWEST WI/NORTHEAST
IA POKING AT THE 90 DEGREE MARK. WITH DEW POINTS SITTING IN THE
LOWER 70S...PLAN ON HEAT INDICES IN THE MID 90S ALONG AND SOUTH OF
THE I-94 CORRIDOR...WITH A FEW SPOTS IN THE 95 TO 100 DEGREE RANGE
ACROSS NORTHEAST IA.
FOCUS THEN SHIFTS TO MCS LIKELY DEVELOPING OVER SOUTH DAKOTA THIS
EVENING IN RESPONSE TO INCREASING LOW LEVEL JET/850MB MOISTURE
TRANSPORT AHEAD OF A SW U.S. MONSOONAL MID-LEVEL TROUGH AND LOW
PRESSURE OVER THE ROCKY MOUNTAIN FRONT OF WY. GFS/NAM IN FAIRLY GOOD
AGREEMENT THAT THIS MCS WILL PROPAGATE EASTWARD ACROSS SOUTHERN MN
AFTER MIDNIGHT. TRENDED POPS TOWARD THIS SOLUTION WITH BULK OF
SHOWER/THUNDER CHANCES STAYING WEST OF THE MISSISSIPPI THROUGH 12Z
MONDAY.
MODELS THEN DIVERGE A BIT TUESDAY ON THE PATH OF THE MCS. THE GFS
WANTS TO TAKE IT ALONG AND NORTH OF THE I-94 CORRIDOR WHEREAS THE
NAM TAKES IT MORE ACROSS THE I-90 CORRIDOR. ONE THING IS FOR
SURE...THE MODELS HAVE BEEN VERY CONSISTENT WITH THIS MCS SIGNATURE.
AND...WITH HIGHER-END PRECIPITABLE WATER VALUES IN THE 2-2.5 INCH
RANGE WHICH IS SOME 200 PERCENT ABOVE NORMAL...VERY HEAVY RAINFALL
WILL BE A REAL THREAT FOR SOMEWHERE IN OUR AREA. USED A BLEND
APPROACH FOR NOW...WHICH WOULD PUT THE HIGHEST LIKELIHOOD OF
HEAVIEST RAINFALL ALONG/NORTH OF THE I-90 CORRIDOR. SEE HYDROLOGY
SECTION BELOW FOR EXPECTED IMPACT OF THIS HEAVY RAIN.
OTHERWISE...LOOKS LIKE IF THE MCS/DEBRIS CLOUDS CLEAR THE AREA BY
LATER IN THE AFTERNOON...SEVERE THUNDERSTORMS COULD ERUPT AS A
RATHER VIGOROUS MID-LEVEL TROUGH DROPS SOUTHEAST OUT OF THE NORTHERN
PLAINS AND PUSHES A COLD FRONT INTO THE REGION. NAM/GFS SHOW THE
POTENTIAL FOR 0-1ML MUCAPE TO BUILD INTO THE 3500-5500J/KG RANGE BY
LATE AFTERNOON WITH AMPLE 0-3KM BULK SHEAR IN THE 30-50KT RANGE.
THIS COULD LEAD TO EXPLOSIVE DEEP CONVECTION MAINLY SOUTH OF THE
I-90 CORRIDOR. DAMAGING WIND/LARGE HAIL/LOCALIZED FLASH FLOODING/
ISOLATED TORNADO ALL A THREAT.
LINGERING SHOWER/THUNDERSTORM CHANCES WILL EXIST GOING INTO TUESDAY
NIGHT IN ASSOCIATION WITH THE MID-LEVEL TROUGH DROPPING SOUTHEAST
THROUGH THE AREA.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 353 AM CDT MON JUL 8 2013
DRIER/COOLER WEATHER EXPECTED WEDNESDAY THROUGH THURSDAY AS HIGH
PRESSURE DROPS IN FROM THE NORTHERN PLAINS. LOOK FOR HIGHS IN THE
76-81 DEGREE RANGE WEDNESDAY AND 78-82 ON THURSDAY...WITH DEW POINTS
IN THE MID-UPPER 50S.
MID-UPPER LEVEL RIDGING/INCREASING SOUTHERLY FLOW BRINGS WARMING AND
HIGHER HUMIDITY LEVELS BACK INTO THE AREA FRIDAY AND SATURDAY. WILL
HAVE TO WATCH FRIDAY NIGHT THROUGH SUNDAY FOR A CHANCE OF SHOWERS AND
THUNDERSTORMS AS THE EC/GFS SHOW A MID-LEVEL TROUGH/WEAK COLD FRONT
TOPPING THE RIDGE AND TOWARD THE AREA. OTHERWISE...LOOK FOR HIGHS IN
THE LOWER 80S FRIDAY AND SATURDAY THEN LOWERING SOME BACK INTO THE UPPER
70S/AROUND 80 ON SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1225 PM CDT MON JUL 8 2013
MVFR/IFR CIGS/VSBYS CONTINUED TO ERODE/IMPROVE WITH DIURNAL WARMING/
MIXING THRU THE MID-LATE MORNING HOURS. THESE CLOUDS DECKS WILL
CONTINUE TO ERODE THRU THE EARLY AFTERNOON HOURS AS WELL AS
IMPROVING VSBYS AS WEAK NORTHWEST FLOW BEHIND A COOL FRONT SPREADS
SOME SLIGHTLY DRIER AIR INTO THE AREA. VFR CONDITIONS EXPECTED FOR
THE MID AFTERNOON THRU EVENING HOURS. WITH THE MOIST LOW LEVEL
AIRMASS OVER THE AREA...LIGHT WINDS AND PARTLY CLOUDY SKIES THIS
EVENING...MVFR VSBYS IN BR EXPECTED AFTER MIDNIGHT.
MOISTURE/FORCING/LIFT START TO RETURN AFTER MIDNIGHT...WITH AN
UNSTABLE AND VERY MOIST AIRMASS BEING LIFTED NORTH/EAST OVER THE
FRONTAL BOUNDARY RETURNING NORTH AS A WARM FRONT. TREND HAS BEEN
SLIGHTLY SLOW WITH THE WARM FRONT...FORCING AND MOISTURE LIFTING
NORTHEAST...NOW LOOKING TO IMPACT THE TAF SITES MORE ON TUESDAY INTO
TUE NIGHT. ONCE THE FORCING/MOISTURE ARRIVE...A BROAD BAND OF
SHRA/TSRA IS EXPECTED TO LIFT NORTHEAST ACROSS THE TAF SITES. SPREAD
VCTS/CB AND MVFR CIGS INTO THE TAF SITE IN THE 09-11Z TIME-FRAME
THEN PREVAILED -SHRA AND VCTS/CB AFTER 11-13Z. THERE MAY BE A BREAK
DURING THE LATE MORNING/ EARLY AFTERNOON HOURS...WITH A COLD FRONT
LOOKING TO BRING MORE SHRA/TSRA TO THE AREA FOR THE LATER AFTERNOON
AND EVENING HOURS OF TUESDAY.
&&
.HYDROLOGY...(TUESDAY)
ISSUED AT 353 AM CDT MON JUL 8 2013
SIGNAL REMAINS HIGH FOR A COMPLEX OF THUNDERSTORMS TO ROLL THROUGH
THE AREA TUESDAY. CONFIDENCE IS INCREASING THAT THIS COMPLEX WILL
MOVE THROUGH THE AREA SOMEWHERE IN THE 7 AM TO NOON TIME
FRAME...THEN MOVE EAST OF THE AREA AFTER THAT. HOWEVER...CONFIDENCE
IS LOWER WITH EXACT TRACK OF THE COMPLEX OF STORMS. RIGHT NOW...THE
HIGHEST POTENTIAL FOR HEAVIER RAINFALL LOOKS TO BE ALONG AND NORTH
OF THE I-90 CORRIDOR. WITH PRECIPITABLE WATER VALUES IN THE 2-2.5
INCH RANGE WHICH IS SOME 200 PERCENT ABOVE NORMAL...LOOK FOR THE
POTENTIAL OF VERY HEAVY RAINFALL WITH THIS COMPLEX OF STORMS. TWO
POSITIVE FACTORS TO LOOK AT. 1. THE COMPLEX WILL BE TRANSITORY IN
NATURE AND 2. 6-HOUR FLASH FLOOD GUIDANCE IS IN THE 3-5 INCH RANGE.
HOWEVER...IF DOWNPOURS ARE TORRENTIAL ENOUGH...LITTLE WILL BE
ABSORBED IMMEDIATELY IN THE GROUND AND COULD CAUSE SOME LOCALIZED
PONDING IN POUR DRAINAGE AREAS AND RUNOFF INTO AREA RIVERS. THIS
WILL LIKELY CAUSE SOME WITHIN BANK RISES...BUT NOT CONFIDENT ON ANY
WIDESPREAD FLOODING AT THIS POINT. AS A COLD FRONT DROPS THROUGH THE
AREA TUESDAY AFTERNOON...ANOTHER BATCH OF HEAVIER RAINFALL COULD
FALL. THIS AGAIN SHOULD BE TRANSITORY IN NATURE...BUT COULD CAUSE
SOME LOCALIZED PONDING/RUNOFF OF WATER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RRS
HYDROLOGY....DAS