Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/16/15


AREA FORECAST DISCUSSION
NWS PHOENIX AZ
950 PM MST TUE JAN 13 2015 .SYNOPSIS... AN EXITING WEATHER SYSTEM WILL AFFECT EASTERN ARIZONA THROUGH EARLY WEDNESDAY...KEEPING CHANCES FOR SHOWERS ACROSS HIGHER TERRAIN AREAS EAST OF PHOENIX. BEHIND THIS SYSTEM...MUCH DRIER AIR AND LOCALLY BREEZY CONDITIONS WILL FILTER SOUTH INTO THE AREA. HOWEVER AFTER THIS SYSTEM PASSES...HIGH PRESSURE WILL RETURN WITH SLOWLY INCREASING TEMPERATURES THROUGH THE WEEKEND. && .DISCUSSION... UPPER LOW CENTERED OVER THE COLORADO PLATEAU THIS EVENING. CLOUDS AND SHOWERS ARE CURRENTLY LIMITED TO ROUGHLY THE NORTHEAST HALF OF ARIZONA. SHOWER ACTIVITY HAS PRETTY MUCH ENDED OVER OUR FORECAST AREA AS DRIER AIR MOVES IN. MADE SOME UPDATES TO DECREASE THE POPS SIGNIFICANTLY THE REST OF THE NIGHT...REMOVING SLIGHT CHANCES FROM PHOENIX AREA. OF NOTE...RAP AND HRRR APPEAR TO HAVE OVERDONE THE PRECIP OVER MARICOPA COUNTY FOR THIS EVENING...ESPECIALLY THE HRRR. HELD ON TO SLIGHT CHANCE OVER SOUTHERN GILA COUNTY AND FAR NORTHEAST MARICOPA COUNTY DUE TO CLOSE PROXIMITY OF THE UPPER LOW CENTER AND THE PASSAGE OF AT LEAST ONE MORE VORT LOBE PER LATEST MODELS. ALSO HELD ON TO SLIGHT CHANCES THERE FOR DAY TIME WEDNESDAY DUE TO INSTABILITY ASSOCIATED WITH PASSAGE OF UPPER LOW CENTER. MODELS AGREE IT WILL BE ONLY AREA IN OUR CWA FOR QPF. MADE ANOTHER ADJUSTMENT TO THE FORECASTS FOR TONIGHT AND WEDNESDAY MORNING TO ADD MENTION OF PATCHY FOG FOR SOUTH-CENTRAL ARIZONA SINCE A NUMBER OF PLACES HAD MORE THAN TWO-TENTHS OF AN INCH OF PRECIP...SKIES WILL BE MOSTLY CLEAR...AND WINDS WILL BE LIGHT. HOWEVER...LARGE SCALE SUBSIDENCE WILL NOT BE UNDERWAY YET AND THERE MAY BE JUST ENOUGH MIXING TO PRECLUDE FOG DEVELOPMENT. THUS ANTICIPATE THAT IT WILL MOSTLY BE HAZE WITH VISIBILITY ABOVE 3 MILES BUT ISOLATED SPOTS...EVEN IN PHOENIX METRO...THAT WILL HAVE LOWER VIS. OTHERWISE...ANTICIPATE COLDER TEMPS TONIGHT/WEDNESDAY MORNING FOLLOWED BY SOME CUMULUS DEVELOPMENT DURING THE DAY BUT WITH ANY PRECIP CONFINED TO THE HIGHER MOUNTAINS. && .PREVIOUS DISCUSSION ISSUED 202 PM MST/102 PM PST... A FAIRLY IMPRESSIVE RAIN BAND WITH EMBEDDED MODERATE TO EVEN HEAVY SHOWERS MOVED OUT OF CENTRAL ARIZONA THIS MORNING INTO THE PHOENIX AREA LATE IN THE MORNING...AND NOW IS PUSHING INTO THE MOUNTAINS TO THE EAST. RAINFALL AMOUNTS WERE GENERALLY AROUND A TENTH OF AN INCH...BUT THERE WERE A FEW LOCALIZED AMOUNTS OF A QUARTER INCH OR MORE. THE UPPER TROUGH RESPONSIBLE FOR THIS RAIN IS NOW CENTERED OVER NORTHWEST ARIZONA...BUT THE MAJORITY OF THE VERTICAL ASCENT IS NOW SITUATED OVER SOUTHEAST ARIZONA NEAR A 120 KT UPPER JET STREAK. DRY AIR ALOFT CAN BE SEEN ON WATER VAPOR IMAGERY TO THE SOUTH OF THE UPPER LOW CENTER OVER SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA. THIS DRY AIR ALONG WITH GRADUALLY INCREASING SUBSIDENT FLOW ALOFT SHOULD KEEP OUR RAIN CHANCES FOR THE REST OF TODAY MAINLY LIMITED TO HIGHER TERRAIN AREAS EAST OF PHOENIX. HOWEVER...VISIBLE IMAGERY DOES SHOW A GOOD AMOUNT OF SUNSHINE TO THE WEST OF PHOENIX AND SOME CU DEVELOPMENT OVER THE PAST HOUR. MAY SEE A FEW SHOWERS FORM IN THESE SUNNY AREAS THROUGH THE REST OF THE AFTERNOON...BUT WITH VERY LIMITED INSTABILITY...ANY DEVELOPMENT SHOULD REMAIN ISOLATED. THE LATEST HI-RES HRRR AND WRF4KM RUNS SHOWS THE BULK OF THE RAIN ENDING BY EARLY EVENING. THERE WILL BE A LINGERING CHANCE OF SOME SHOWERS ACROSS EASTERN ARIZONA DURING THE OVERNIGHT HOURS AS THE MAIN VORT MAX AND PVA ANOMALY CURRENTLY OVER NORTHWEST ARIZONA SLIDES SOUTHEASTWARD. NOT WORRIED ABOUT THE CHANCES FOR MUCH SNOW TONIGHT AS THE SYSTEM IS NOT UNUSUALLY COLD OR DEEP AND HEIGHTS/THICKNESSES ALOFT INDICATE FREEZING LEVEL REMAINING AOA 7K FT. THEREFORE...SNOW LEVELS SHOULD REMAIN WELL ABOVE POPULATION CENTERS/TRANSPORTATION CORRIDORS WITH ONLY A DUSTING ON THE PEAKS OF SRN GILA COUNTY LATER TONIGHT. AS THE LOW CENTER AND COLD CORE SHIFTS OVER EAST-CENTRAL ARIZONA DURING THE DAYTIME HOURS WEDNESDAY...WE SHOULD SEE SOME DIURNALLY FORCED SCT RAIN/SNOW SHOWER REDEVELOPMENT WITHIN THE COLD CORE...BUT PRIMARILY LIMITED TO THE WHITE MOUNTAINS OF ERN ARIZONA. OPERATIONAL AND ENSEMBLE MEMBERS ARE IN VERY GOOD AGREEMENT THAT STRONGER ZONAL PACIFIC JET ENERGY WILL FORCE A SIGNIFICANT DOWNSTREAM PATTERN SHIFT OVER THE WESTERN HEMISPHERE DURING THE LATTER HALF OF THIS WEEK INTO NEXT WEEK...UNLOCKING THE PREVAILING BLOCKED FLOW INTO A MORE PROGRESSIVE QUASI-ZONAL PATTERN. SHORTWAVE FEATURES OVER THE CONUS WILL BE EXCLUSIVELY LOW AMPLITUDE AND RELEGATED TO THE NORTHERN STREAM WITH FLAT RIDGING PREDOMINATING THE SWRN REGION. AS A RESULT...ENSEMBLE GUIDANCE EXHIBITS VERY LOW FORECAST SPREAD WITH H5 HEIGHTS OSCILLATING AROUND A 580DM RANGE AND H8 TEMPERATURES NEAR +10C. BASED ON HISTORICAL BIASES DURING SIMILAR PATTERN EVOLUTION...HAVE HEDGED TOWARDS THE WARMEST GUIDANCE PACKAGES YIELDING FORECAST HIGHS AT LEAST 5F ABOVE AVERAGE. EVEN THIS APPROACH MAY BE CONSERVATIVE GIVEN A DRY ENVIRONMENT AND POTENTIALLY SEVERAL DAYS OF FULL INSOLATION. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL... THE UPPER LOW...CENTERED OVER COLORADO PLATEAU AS OF 04Z...WILL SLOWLY MOVE SOUTH-SOUTHEASTWARD. HOWEVER SHOWERS AND CEILINGS PRETTY MUCH DONE FOR THE NIGHT AS DRIER AIR HAS STARTED TO MOVE IN...EXCEPT POSSIBLY NEAR HIGHER MOUNTAINS AND FOOTHILLS MAINLY NORTH AND EAST OF PHOENIX AREA. ANTICIPATE HIGHER MOUNTAIN TOPS TO BE OBSCURED. LINGERING LOW LEVEL MOISTURE...MOSTLY CLEAR SKIES...AND LIGHT WINDS MAY LEAD TO AREAS OF HAZE/MIST AFTER 08Z LOWERING VISIBILITIES BELOW 10SM AND POSSIBLY BELOW 5SM. SOME ISOLATED SPOTS COULD DIP BELOW 3SM. IF THIS OCCURS...SLANT VISIBILITIES WILL ALSO BE REDUCED EVEN IF SURFACE VIS IS AOA 6SM. THIS SCENARIO MAY VERY WELL NOT MATERIALIZE DUE TO LACK OF STRONG DISTINCT SUBSIDENCE. SURFACE WINDS WILL REMAIN LIGHT WITH LOWER LEVEL WINDS TRENDING TOWARD EASTERLY DIRECTIONS OVERNIGHT. THERE MAY BE SOME CUMULUS REDEVELOPMENT DURING THE DAY WEDNESDAY BUT EXPECT ANY CEILINGS TO BE OVER HIGHER TERRAIN WELL EAST OF PHOENIX AREA. SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... EXPECT NORTHERLY SURFACE WINDS TO CONTINUE TRANSITIONING TO FAVORED NOCTURNAL DIRECTIONS 06Z. ANTICIPATE MODERATE NORTHERLY SURFACE WINDS CONTINUING IN THE LOWER LEVELS ABOVE THE INVERSION OVERNIGHT WITH RESUMPTION OF NORTHERLY SURFACE WINDS BY 18Z WEDNESDAY...GUSTS REMAINING BELOW 15 KTS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... FRIDAY THROUGH TUESDAY... UPPER LEVEL RIDGING WILL TAKE SHAPE ACROSS THE REGION BY FRIDAY AND REMAIN LARGELY IN PLACE THROUGH EARLY NEXT WEEK. THIS WILL RESULT IN INCREASED TEMPERATURES WITH DAILY HIGH TEMPERATURES SEVERAL DEGREES OR MORE ABOVE SEASONAL NORMALS EACH DAY. DESPITE THE PRESENCE OF HIGH PRESSURE...HUMIDITIES WILL STAY A BIT ELEVATED EACH DAY WITH MINIMUM RH VALUES MOSTLY BETWEEN 15 AND 25 PERCENT ACROSS THE DESERTS. WINDS THROUGH THE PERIOD WILL BE LIGHT AND GENERALLY DIURNAL IN NATURE. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...AJ PREVIOUS DISCUSSION...KUHLMAN/MO AVIATION...AJ FIRE WEATHER...CB
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
324 AM MST WED JAN 14 2015 .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 320 AM MST WED JAN 14 2015 NLY FLOW ALOFT WILL BE OVER THE AREA TODAY THRU TONIGHT. SOME LINGERING LOW LVL MOISTURE WILL CONTINUE TO AFFECT THE HIGHER TERRAIN AND ALONG THE FRONT RANGE THIS MORNING HOWEVER DO NOT EXPECT ANY PCPN. ALSO THERE MAY BE SOME FOG IN THE HIGHER VALLEYS AND IN THE FOOTHILLS WITH PATCHY AREAS OVER THE PLAINS. AS FOR HIGHS 850- 700 MB TEMPS RISE A DEGREE OR TWO FM TUE SO EXPECT HIGHS MAINLY IN THE 30S OVER NERN CO. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 320 AM MST WED JAN 14 2015 MODELS HAVE AN UPPER RIDGE WITH WEAK ZONAL FLOW FOR THE CWA ON THURSDAY. THERE IS A FLATTER UPPER RIDGE AROUND ON FRIDAY. AN UPPER TROUGH MOVES ACROSS FRIDAY NIGHT. THE SYNOPTIC SCALE ENERGY IS NEUTRAL TO WEAK DOWNWARD THURSDAY THROUGH FRIDAY NIGHT. THE BOUNDARY LAYER FLOW THROUGH THE FOUR PERIODS IS MOSTLY DOWNSLOPING. MOISTURE IS QUITE SPARSE THURSDAY THROUGH FRIDAY...WITH SOME INCREASE FRIDAY NIGHT...MOSTLY OVER THE MOUNTAINS. THE QPF FIELDS HAVE NO MEASURABLE PRECIPITATION OVER THE CWA THURSDAY THROUGH FRIDAY...THEN A TAD OVER THE MOUNTAINS FRIDAY NIGHT. NO POPS THROUGH FRIDAY EVENING...THEN A TAD IN THE MOUNTAINS OVERNIGHT. IT IS PRETTY DRY. FOR TEMPERATURES...THURSDAY`S HIGHS ARE UP 3-7 C FROM WEDNESDAY`S. FRIDAY`S HIGHS ARE UP ANOTHER 1.0-2.5 C FROM THURSDAY`S. FOR THE LATER DAYS...SATURDAY THROUGH TUESDAY...THERE IS NORTHWESTERLY FLOW ALOFT ON SATURDAY WITH AN UPPER RIDGE TO THE WEST. THE RIDGE MOVES ACROSS COLORADO SUNDAY WITH ZONAL FLOW SUNDAY AND MONDAY. THERE IS ANOTHER WEAK UPPER TROUGH MONDAY NIGHT INTO TUESDAY. THE MOISTURE IS NOT GREAT WITH THE TROUGH. A COLD FRONT MOVES IN TUESDAY. NOT MUCH IN THE WAY OF POPS...AND ONLY FOR THE MOUNTAINS...NOTHING FOR THE PLAINS. TEMPERATURES WILL BE ABOVE SEASONAL NORMALS SUNDAY AND MONDAY. && .AVIATION...(FOR THE TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 320 AM MST WED JAN 14 2015 CEILINGS IN THE 3000-3500 FT RANGE CONTINUE EARLY THIS MORNING. BASED ON STRATUS BREAKOUT PROGRAM THEY MAY LINGER THRU ABOUT 14Z. MEANWHILE LATEST HRRR WANTS TO DVLP SOME FOG BY 13Z WITH IT LINGERING THRU THE EARLY AFTN HOURS WHILE THE RAP HAS NOTHING. AT THIS POINT FOG LOOKS UNLIKELY SO WILL NOT MENTION IT IN THE TAF. FOR THIS AFTN THRU TONIGHT WILL KEEP CONDITIONS VFR. AS FOR WINDS THEY WILL BE LIGHT SSE THIS MORNING AND THEN BECOME LIGHT NELY BY EARLY AFTN. FOR TONIGHT THEY SHOULD GRADUALLY BECOME DRAINAGE DURING THE EARLY EVENING HOURS. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RPK LONG TERM...RJK AVIATION...RPK
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
913 PM MST TUE JAN 13 2015 .UPDATE... ISSUED AT 912 PM MST TUE JAN 13 2015 UPPER CLOSED LOW IS SINKING INTO CENTRAL AZ. WEAK JET STREAK ON THE NNE SIDE OF THE LOW SINKS THROUGH UTAH OVERNIGHT. THIS IS PRODUCING SOME DEFORMATION OVER THE CENTRAL FORECAST AREA THIS EVENING WITH MILD CONVECTIVE CELLS AND SHOWERS POPPING MAINLY OVER THE CENTRAL CWA HIGHER TERRAIN. OTHERWISE LIGHT SHOWERS WILL CONTINUE OVER THE SOUTHERN ZONES TONIGHT WHERE THE DEEPER MOISTURE LINGERS. FOG MAY BE A CONCERN ESPECIALLY ALONG THE SLOPES OF THE SOUTHERN AND CENTRAL MTNS INTO WEDNESDAY MORNING. EXPECT MILD LOW TEMPERATURES TONIGHT FOR THE SOUTHERN AND CENTRAL ZONES BUT COLDER THAN NORMAL ACROSS THE DRIER NORTH. UPDATE ISSUED AT 616 PM MST TUE JAN 13 2015 ALLOWED ALL WARNINGS AND ADVISORIES TO EXPIRE AT 6 PM LOCAL TIME. LIGHT ACCUMULATIONS MAY CONTINUE THIS EVENING OVER THE SWRN SAN JUAN MOUNTAINS...BUT THE BRUNT OF THE HEAVY SNOW HAS ENDED. THE OTHER FORECAST QUESTION THAT NEEDS TO BE MONITORED IS FOG FORMATION. MAY BE SUFFICIENT CLOUD COVER OR WIND CIRCULATION TO PREVENT WIDESPREAD LOW LYING FOG...BUT THE TREND WILL BE FOR CLEARING SKIES OVERNIGHT. && .SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT) ISSUED AT 253 PM MST TUE JAN 13 2015 UPPER LEVEL LOW HAS JUST DROPPED BELOW THE UTAH STATE LINE INTO ARIZONA AS MOIST SWLY FLOW CONTINUES TO PUMP MOISTURE INTO THE REGION. ALONG AND JUST N OF INTERSTATE 70...FLOW HAS TURNED EASTERLY WITH RADAR SHOWING RETURNS THAT ARE MORE CONVECTIVE IN NATURE. ALL MODELS CONTINUE TO HIGHLIGHT A RATHER BROAD AREA OF DEFORMATION THAT APPEARS TO BE PANNING OUT WITH SOME DISTINCT BANDS OF PRECIP HAVING SET UP OVER THE REGION. UNDER THESE BANDS...EXPECT PRECIP TO PICK UP SOME BUT COVERAGE LOOKS TO BE SOMEWHAT LIMITED SO DO NOT ANTICIPATE MUCH OF AN INCREASE TO RAIN AND SNOW TOTALS. SPEAKING OF...MANY REPORTS OF DECENT SNOWFALL WITH MONTEZUMA COUNTY REPORTING 6 TO 8 INCHES...LA PLATA COUNTY CAME IN WITH 6 TO 10 INCHES AND ARCHULETA COUNTY REPORTS 8 TO 12 INCHES IN SOME SPOTS. NAM12 CONTINUES TO SHOW RATHER WIDESPREAD PRECIP FOR THE SAN JUANS AND AREAS SOUTH THROUGH TONIGHT BUT THIS LOOKS WAY OVERDONE. HRRR IS MUCH MORE CONSERVATIVE AND ALSO SHIFTS THE BEST PRECIP SOUTHWARD INTO NEW MEXICO. VISIBLE SATELLITE DOES SHOW PLUME OF MOISTURE STEADILY DROPPING EAST AND SOUTH SO THINK HRRR HAS THE BEST HANDLE ON CURRENT SITUATION. FOR THE REMAINDER OF THE DAY THEN...A FEW MORE INCHES...1 TO 3...FOR THE MOUNTAINS WITH VALLEYS POSSIBLY SEEING ANOTHER INCH OR TWO. CURRENT HIGHLIGHTS CONTINUE THROUGH 6PM SO WILL KEEP THEM GOING. FOR WEDNESDAY...HIGH PRESSURE BUILDS IN WITH LESS CLOUDS UP NORTH AND MORE DOWN SOUTH WITH CONDITIONS IMPROVING THROUGH THE DAY. ONLY BIG QUESTION MARK WILL BE FOG AND HOW THICK AND HOW WIDESPREAD IT WILL BE AS AMPLE MOISTURE WILL REMAIN IN THE ATMOSPHERE DUE TO THE EVAPORATING SNOWFALL ESPECIALLY SOUTH. TEMPS WILL STAY NEAR NORMAL THROUGH THE PERIOD WITH A WARMUP TOWARDS THE END OF THE WEEK. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 253 PM MST TUE JAN 13 2015 A PROGRESSIVE FLOW WILL BRING A SERIES OF RIDGES AND TROUGHS ACROSS THE CONUS DURING THE LONG TERM PERIOD. FOR THE MOST PART...OUR FORECAST AREA WILL BE SOUTH OF...OR ON THE SOUTHERN EDGE AT BEST OF ANY WEATHER ASSOCIATED WITH ANY DISTURBANCE THAT PASSES. ALSO TIMING WILL REMAIN DIFFICULT FOR THESE FAST MOVING WAVES. ON THU AT THE START OF THE PERIOD. THE AREA WILL BE UNDER A FLATTENING RIDGE THAT WASHES OUT AS IT GETS PUSHED EAST THU NIGHT. A SHORTWAVE TROUGH WILL MOVE INTO THE PACIFIC NORTHWEST ON FRIDAY...THEN WILL BRUSH OUR FORECAST AREA FRI NIGHT INTO SAT. EXCEPT FOR THE LATEST/12Z ECMWF...THE MODELS HAVE INDICATED THAT THIS WAVE WILL JUST BARELY BRUSH OUR NORTHEAST CORNER...WITH THE FLOW MAINLY STAYING ZONAL. THE 12Z EC HOWEVER IS MORE AMPLIFIED THAN EARLIER RUNS WHICH COULD MEAN A BETTER CHANCE OF SNOW...STILL STAYING MAINLY OVER THE NORTH AND CENTRAL CO MOUNTAINS. WILL KEEP THE GENERALLY DRY FORECAST FOR NOW BEFORE BUYING OFF ON THIS STRENGTHENING TREND. A RIDGE WILL BUILD BEHIND THIS WAVE ON SUN...THEN FLATTEN AGAIN DURING THE EARLY PART OF THE WORK WEEK AS WAVES MOVES INTO WESTERN NOAM. EXPECT TEMPERATURES TO RUN JUST A LITTLE ABOVE NORMAL FOR THE MOST PART. THE MEX AND ECE GUIDANCE NUMBERS SHOW RATHER BIG DIFFERENCES...WITH THE MEX PROBABLY TOO WARM AND ECE TOO COOL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 912 PM MST TUE JAN 13 2015 LOW CIGS WITH AREAS OF SNOW PERSIST FROM THE I-70 CORRIDOR SOUTHWARD. THESE CONDITIONS WILL IMPROVE TONIGHT AS SHOWER COVERAGE CONTINUES TO DECREASE. TAF SITES IN ERN UTAH AND NW COLORADO WILL BE AT VFR TONIGHT...THOUGH KDRO CIGS MAY BE AT OR BELOW ILS APPROACH HEIGHT AT TIMES THROUGH 15Z. LOCAL FOG MAY LIMIT VISIBILITY ALONG RIVER VALLEYS AND LOW LYING AREAS LATE TONIGHT. CLOUD COVER OR WIND CIRCULATIONS MAY BE SUFFICIENT TO KEEP TAF SITES FREE FROM FOG...BUT THIS NEEDS TO BE MONITORED. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ UPDATE...JOE SHORT TERM...TGR LONG TERM...EH AVIATION...PF/JOE
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
638 PM EST THU JAN 15 2015 .SYNOPSIS... RAIN WILL MOVE ACROSS THE REGION THIS EVENING AND EARLY TONIGHT...THEN PUSH OFF THE COAST BY FRIDAY MORNING. A PRESSURE RIDGE MOVING INTO THE FORECAST AREA FROM THE WEST WILL EXTEND THROUGH THE AREA FRIDAY NIGHT AND SATURDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... PATCHY LIGHT RAIN MOVING ACROSS THE REGION EARLY THIS EVENING AHEAD OF SHORT WAVE TROUGH. BULK OF RAIN MOVING ACROSS EASTERN GEORGIA AND COASTAL CAROLINA. RAINFALL AMOUNTS IN THE MIDLANDS/CSRA QUITE LIGHT. POPS HIGH HOWEVER ACROSS THE SOUTHEAST CWA EARLY THIS EVENING...RAIN MORE PATCHY TO THE NORTH WHERE MOISTURE LIMITED. RAIN MAY LINGER INTO THE EVENING UNTIL SHORT WAVE TROUGH MOVES THROUGH...BUT LATEST RAP INDICATES LIFT WEAKENING BY 04Z AND THIS IS SUPPORTED BY RADAR TRENDS. DIMINISHING CLOUDINESS LATE TONIGHT MAY LEAD TO FOG DEVELOPMENT TOWARD MORNING DUE TO HIGH LOW-LEVEL MOISTURE AND LIGHT WINDS. GUIDANCE TEMPS APPEAR OK WITH CLEARING LATE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... HIGH PRESSURE ALONG WITH DRIER AIR WILL RIDGE INTO THE FORECAST AREA FRIDAY AND FRIDAY NIGHT THEN MOVE EAST OF THE AREA SATURDAY AFTERNOON. CLOUDS WILL BEGIN DEVELOPING OVER THE AREA SATURDAY NIGHT AS THE NEXT DISTURBANCE MOVES INTO THE REGION. WITH THE HIGH PRESSURE OVER THE AREA EXPECT MOSTLY CLEAR SKIES WITH AFTERNOON HIGH TEMPERATURES IN THE MIDDLE 50S TO AROUND 60. OVERNIGHT LOWS WILL BE IN THE LOWER 30S FRIDAY NIGHT WITH UPPER 30S TO LOWER 40S SATURDAY NIGHT. && .LONG TERM /SUNDAY THROUGH THURSDAY/... MODELS ARE IN RELATIVELY GOOD AGREEMENT THROUGH THE LONG TERM WITH SOME DIFFERENCES IN TIMING AND INTENSITY WITH THE SYSTEM FOR SUNDAY INTO SUNDAY NIGHT. UPPER LEVEL TROUGH OVER THE EASTERN US WILL PROGRESS FROM THE MS RIVER VALLEY SUNDAY MORNING THROUGH THE FORECAST AREA SUNDAY NIGHT WITH ZONAL FLOW RETURNING TO THE AREA MONDAY THROUGH THE END OF THE LONG TERM. AT THE SURFACE LOW PRESSURE OVER THE GREAT LAKES SUNDAY WILL PUSH A FRONTAL BOUNDARY THROUGH THE FORECAST AREA SUNDAY LATE AFTERNOON/EVENING WITH A SECONDARY LOW CENTER DEVELOPING ALONG THE VA COAST SUNDAY EVENING. DRIER AIR WILL MOVE IN FOR MONDAY AND MONDAY NIGHT WITH A FRONTAL BOUNDARY SAGGING TOWARD THE AREA TUESDAY INTO THURSDAY. WITH VERY LIMITED DYNAMICS AND MOISTURE ASSOCIATED WITH THE FRONTAL BOUNDARY HAVE KEPT THE FORECAST DRY MONDAY THROUGH THURSDAY. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY ABOVE NORMAL. && .AVIATION /23Z THURSDAY THROUGH TUESDAY/... MVFR CEILINGS WITH PERIODS OF LIGHT RAIN THIS EVENING...THEN FOG POSSIBLE...LATE TONIGHT INTO EARLY FRIDAY MORNING. APPROACHING UPPER ENERGY AND ASSOCIATED AREAS OF LIGHT RAIN WILL CONTINUE TO SHIFT EAST ACROSS THE TERMINALS EARLY TONIGHT...THEN SHIFT EAST OF THE TERMINALS AFTER MIDNIGHT. MVFR CIGS/VSBYS EXPECTED TO CONTINUE AT LEAST THROUGH EARLY TONIGHT. QUESTION INVOLVES POSSIBILITY OF CLEARING LATE TONIGHT...WITH DRY AIR ALOFT AND GENERALLY LIGHT SURFACE WINDS...WHICH COULD PROMOTE FOG DEVELOPMENT IF CLOUDS CLEAR OUT. WILL GENERALLY TAKE A BLEND OF GUIDANCE WHICH INDICATES MVFR TO IFR CONDITIONS LATE TONIGHT INTO EARLY THURSDAY MORNING. AFTER ANY MORNING CIG/VSBY RESTRICTIONS...VFR EXPECTED FRIDAY. EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS TO AVIATION EXPECTED FRIDAY AFTERNOON THROUGH SATURDAY. CIG RESTRICTIONS POSSIBLE LATE SAT NT/EARLY SUNDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
608 AM EST WED JAN 14 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 359 AM EST WED JAN 14 2015 COLD CONDITIONS WILL PERSIST UNDER THE INFLUENCE OF SURFACE HIGH PRESSURE THROUGH TONIGHT BEFORE A STEADY WARM UP BEGINS FOR THE LATTER PORTION OF THE WEEK AND INTO THE WEEKEND WITH ARCTIC AIR MODERATING SIGNIFICANTLY ACROSS THE AREA. && .NEAR TERM /TODAY/... ISSUED AT 359 AM EST WED JAN 14 2015 TEMPERATURES ARE THE ONLY MAJOR FORECAST VARIABLE TODAY AS WHILE A VERY WEAK UPPER WAVE PASSES TO OUR NORTH...DRY MID LEVEL AIR AND A NEAR TOTAL LACK OF LIFT ASSOCIATED WITH THE WAVE WILL PREVENT ANY PRECIPITATION FROM OCCURRING. TEMPERATURES ARE TRICKY AS SOME LOW LEVEL CLOUD HAS BUILT BACK INTO CENTRAL INDIANA OVERNIGHT AND HIGH LEVEL CLOUD WILL BE ON THE INCREASE LATER IN THE DAY. HOWEVER...WITH SOME MINOR ADJUSTMENTS NORTH WHERE TEMPERATURES WILL BE STARTING THE DAY NEAR OR BELOW ZERO...BLEND OF AVAILABLE GUIDANCE PROVIDES AN ADEQUATE STARTING POINT...WITH THE MID TO UPPER TEENS ACROSS THE NORTH AND LOW TO MID 20S ACROSS THE SOUTH. APPARENT TEMPERATURES WILL BE COLD THROUGH THE MORNING BUT WELL ABOVE ADVISORY CRITERIA. && .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... ISSUED AT 359 AM EST WED JAN 14 2015 DRY WEATHER WILL PERSIST THROUGH THE SHORT TERM AS DRY MID LEVELS WILL CONTINUE TO INHIBIT PRECIPITATION CHANCES EVEN WITH A WEAK WAVE PASSING NEAR THE AREA THURSDAY. THIS LEAVES TEMPERATURES AGAIN AS THE ONLY MAJOR FORECAST VARIABLE. CANNOT PARTICULARLY QUIBBLE WITH MODEL CONSENSUS EXCEPT ACROSS THE NORTH WHERE SOME LINGERING SNOW COVER PERSISTS. HAVE GENERALLY TIGHTENED THE FORECAST TEMP GRADIENT ACROSS THE AREA A BIT. APPARENT TEMPERATURES WILL AGAIN APPROACH OR BRIEFLY GO BELOW ZERO ACROSS THE NORTH TONIGHT INTO THURSDAY MORNING...BUT REMAIN AGAIN WELL ABOVE ADVISORY CRITERIA. && .LONG TERM /SATURDAY THROUGH TUESDAY/... ISSUED AT 253 AM EST WED JAN 14 2015 DRY WEATHER IS EXPECTED DURING THIS PERIOD ALONG WITH MODERATING TEMPERATURES. GFS AND ECMWF AGREE THAT A QUICK MOVING SHORT WAVE WILL PUSH THROUGH THE GREAT LAKES ON SATURDAY NIGHT AND SUNDAY...HOWEVER THIS SYSTEM LOOKS TO REMAIN RATHER MOISTURE STARVED AS BEST FORCING REMAINS WELL NORTH OF CENTRAL INDIANA. NORTHWEST FLOW PERSISTS ON SUNDAY NIGHT INTO MONDAY IN THE WAKE OF THE PASSING SHORT WAVE...CONTINUING THE FLOW OF DRY...BUT MILD PACIFIC AIR. && .AVIATION /DISCUSSION FOR THE 141200 TAFS/... ISSUED AT 609 AM EST WED JAN 14 2015 SCT MVFR CIGS AT HUF AND BMG WILL LINGER FOR A COUPLE OF HOURS THIS MORNING BEFORE A RETURN TO VFR CONDITIONS. SATELLITE SHOWS THE MVFR CIGS OVER SOUTHERN INDIANA. RUC INDICATES THESE CLOUDS WILL ADVECT EAST AS HIGH PRESSURE TO THE NORTHWEST SLOWLY BUILDS ACROSS CENTRAL INDIANA. SOME HIGHER CLOUDS...VFR...OVR THE MISSISSIPPI RIVER VALLEY AREA EXPECTED TO ADVECT ACRS THE TAF SITES LATER THIS MORNING. FORECAST SOUNDINGS DRY OUT OVERNIGHT AS WEAK SUBSIDENCE RESUMES...FORECAST SOUNDINGS DRY OUT AND CONDITIONS REMAIN VFR. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...NIELD NEAR TERM...NIELD SHORT TERM...NIELD LONG TERM...PUMA AVIATION...JP VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
640 PM EST Thu Jan 15 2015 ...Updated Aviation Discussion... .SHORT TERM (Now through Friday Night)... Issued at 240 PM EST Thu Jan 15 2015 Latest water vapor imagery combined with 500 mb heights shows a broad trough moving across the eastern CONUS with shortwaves moving across the TN Valley and the Great Lakes region. This is the wave that brought a band of snow to central and south Kentucky earlier this morning. Much of this activity has now weakened and pushed east of the LMK forecast area. Latest satellite shows the back edge of the cloud deck extending from around Lexington/Louisville southwest toward Padaucah. We`ll see the clearing line push slowly east/south during the evening and should make it the Cumberland region late in the evening. The overnight period has become a bit more interesting as models have latched onto the idea that we could be dealing with low stratus and/or fog. Time height and cross sections show much of this moisture residing below 975 mb, very shallow but likely due to the residual moisture from today`s melting snow. Boundary layer winds are expected to be less than 5 kts. The melting snow, residual moisture combined with light boundary layer winds is a recipe for fog/stratus. Hi-res models such as the NSSL WRF fog product, SREF probs for less than 3 SM, HRRR and RAP simulated visibility show patches developing toward midnight across the southwest forecast area and then spreading east toward BWG, Elizabethtown and the rest of south-central Kentucky overnight. Have introduced areas of fog to the forecast, mainly where snow fell today, though if it does form, it could advect further north/east. We`ll have to watch this closely as it may be locally dense. For Friday, we`ll begin to get a push of southwest flow as high pressure builds into the region. Any morning stratus/fog that does develop should begin to scatter out and plan on highs right around normal. Near normal lows ranging from the mid 20s to near 30 degrees. .LONG TERM (Saturday through Thursday)... Issued at 300 PM EST Thu Jan 15 2015 Progressive upper pattern expected through the long term. SW return flow on Saturday will bring a dry and mild day, perhaps one of the more pleasant days all winter. Max temp forecast splits the difference between GFS MOS and cooler NAM MOS, but puts most locations into the 50s. Longwave trof will swing through Saturday night and Sunday, bringing low-end chances for precipitation. QPF looks on the light side with most of the forcing well up over the Great Lakes, and quite a weak tap of Gulf moisture. Precip type has been a concern, but at this time it looks too warm for anything wintry with temps ranging from the mid 30s to mid 40s through the event, and moisture not deep enough for much ice in the clouds. Mon-Tue looks to be a zonal pattern, with some uncertainty over just how mild we get under a Pacific high. GFS takes us back into the 50s, but will go with a wait-and-see approach until this shows up in more than one run. Next shot for precip is Tuesday night into Wednesday with a shortwave trof scooting through the Great Lakes. Forcing looks even weaker so will limit it to slight chance. However, with temps just either side of freezing on Wednesday morning, precip type is uncertain. Will just keep vague mention of rain/snow mix. Current forecast for Thursday is dry with temps near climo, but confidence is fairly low given the large run-to-run fluctuations of the ECMWF. Some indication of a southern stream system from the Euro, but at this point it looks to remain suppressed beyond day 7. && .AVIATION (00Z TAF Update)... Issued at 639 PM EST Thu Jan 15 2015 A complicated forecast in store for the overnight period. The snow that fell earlier today helped to saturate the atmosphere across south-central KY, including KBWG. This has brought much higher dewpoints in this area, helping to limit dewpoint depressions. The main forecast challenge is whether these higher dewpoints will be enough to cause fog/stratus, and if this fog/stratus will slowly develop northeastward given the weak southwesterly winds expected overnight. Fuel-alternate cigs will remain in KBWG and KLEX for the next few hours, but should clear out later tonight. If this clearing occurs as forecast, then fog/stratus will likely bring cigs/vsbys into IFR thresholds, perhaps even LIFR. While KSDF and KLEX did not receive snowfall today, the pool of better moisture remains just off to the southwest. With southwest winds staying up slightly, this better moisture could advect into the terminals. Will hit the stratus potential more than the fog potential given the winds expected to stay around 4-6 knots. Either way, think restrictions, again possibly IFR or even LIFR, will be possible at mainly KSDF, with a lesser chance at KLEX. These scenarios may not pan out if the current stratus does not clear out over the higher dewpoints across south-central KY as currently anticipated. We will continue to monitor trends overnight and amend as needed. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Short Term........ZBT Long Term.........RAS Aviation..........KJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
715 PM EST THU JAN 15 2015 .SYNOPSIS... MOSTLY CLOUDY AND COOL CONDITIONS EXPECTED THROUGH TONIGHT... FOLLOWED BY A GRADUAL WARMING AND DRYING TREND FRIDAY AND SATURDAY. AN APPROACHING COLD FRONT ON SUNDAY WILL ALLOW FOR INCREASED RAIN CHANCES SATURDAY NIGHT THROUGH SUNDAY NIGHT. DRY AND GRADUAL WARMING RETURNS EARLY INTO NEXT WEEK AS HIGH PRESSURE BUILDS IN. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM THURSDAY...THE AXIS OF AN UPPER LEVEL DISTURBANCE IN THE WEST SOUTHWESTERLY FLOW HAS REACHED ALABAMA AND CONTINUES TO PRESS EASTWARD TOWARD THE CAROLINAS. THE 12 UTC MODELS ARE SHOWING THE DISTURBANCE SHIFTING OFF THE COAST AROUND 06 UTC FRIDAY. THE CURRENT RADAR SHOWS THE LEADING EDGE OF PRECIPITATION IS JUST WEST OF THE SOUTH CAROLINA BORDER WITH GEORGIA. THE 300K ISENTROPIC SURFACE IS SHOWING THE BEST LIFT IS AROUND 00 UTC IN OUR AREA. THE LATEST HRRR IS NOT AS OPTIMISTIC ON WIDESPREAD PRECIPITATION ESPECIALLY OVER THE NORTHERN HALF OF THE FORECAST AREA BUT IT IS SHOWING THE BETTER COVERAGE IN GEORGETOWN AND WILLIAMSBURG AREAS. WILL KEEP A 50 TO 70% POP OVERNIGHT BUT THIS WILL BE FOR LIGHT RAIN. THE QPF TOTALS ARE EXPECTED TO BE LESS THAN A TENTH OF AN INCH. WITH THE CLOUD COVER AND INCREASE OF WINDS OVERNIGHT...IT IS EXPECTED TO BE OVERCAST ALL NIGHT THE LOWS ARE EXPECTED TO RANGE IN THE MID 30 WITH UPPER 30S ALONG THE SOUTHERN TIER OF COUNTIES. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 PM THURSDAY...HIGH PRESSURE WILL CONTROL AREA WEATHER FRIDAY AND SATURDAY...BEFORE CONDITIONS DETERIORATE SATURDAY NIGHT AS A COASTAL FRONT AFFECTS THE AREA. EXPECT SKIES TO BECOME MOSTLY CLEAR FRIDAY AND REMAIN SO INTO SATURDAY AFTERNOON. HIGHS FRIDAY SHOULD REACH THE LOW TO MID 50S WITH MID TO UPPER 50S...PERHAPS 60 SOUTH...ON SATURDAY. LOWS FRIDAY NIGHT SHOULD RANGE FROM 30 TO 35 WITH MID TO UPPER 20S POSSIBLE IN NORMALLY COOLER LOCATIONS. SATURDAY NIGHT...WEATHER CONDITIONS WILL GO DOWNHILL AS AN APPROACHING H5 SHORT WAVE INTERACTS WITH A DEVELOPING COASTAL FRONT TO BRING CLOUDS AND A GOOD CHANCE FOR RAIN TO THE AREA...MAINLY AFTER MIDNIGHT. LOWS ARE FORECAST TO RANGE FROM AROUND 40 NW TO THE MID TO UPPER 40S SOUTH AND EAST. HOWEVER...THIS IS A SCENARIO WHERE WE COULD SEE TEMPERATURES RISE OVERNIGHT IF THE COASTAL FRONT MOVES ASHORE. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 3 PM THURSDAY...COLD FRONT AND FAIRLY STRONG UPPER WAVE TO CROSS THE REGION ON SUNDAY. IT MAY BE TOO EARLY IN THE DAY FOR MUCH INSTABILITY TO DEVELOP SO WHILE SHOWERS LOOK A GOOD BET THUNDER MAY BE HARD TO COME BY. COOL AND DRY ADVECTION ON MONDAY WILL BE FOLLOWED BY ANOTHER DAY OF SUN TUESDAY WITH SOME RECOVERY IN BOUNDARY LAYER TEMPERATURES. A COLD FRONT PUSHES THROUGH ON WEDNESDAY BUT WITH NEARLY ZONAL FLOW ALOFT THERE WILL LIKELY BE TOO LITTLE MOISTURE TO SUPPORT MEANINGFUL PRECIP CHANCES. MOISTURE MAY BE STREAMING INTO THE REGION ON THURSDAY AS A VERY BROAD AREA OF LOW PRESSURE DEVELOPS ACROSS THE GULF OF MEXICO AND FLORIDA. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... AS OF 00Z...THE STRATUS DECK IS SLOWLY ERODING FROM WEST TO EAST. KFLO IS VFR AND KLBT JUST WENT FROM IFR TO VFR. THE COASTAL TERMINALS ARE MVFR EXCEPT KCRE/KMYR ARE FLIRTING WITH IFR WITH CIGS AT 1K. VERY LIGHT RAIN IS APPROACHING FROM THE WEST AHEAD OF AN UPPER DISTURBANCE. THE DISTURBANCE WILL MOVE ACROSS THE TERMINALS THIS EVENING AND OFFSHORE AROUND MIDNIGHT. CURRENT CIGS WILL LIKELY CONTINUE TO PERSIST THIS EVENING WITH LOW CIGS SCATTERING AR THE COASTAL TERMINALS AROUND 05Z. MID LEVEL CIGS WILL PERSIST FOR AWHILE AFTER THE DISTURBANCE PASSES. BR WILL BEGIN TO DEVELOP AS SUBSIDENCE SETTLES IN BUT MID LEVEL CLOUDS SHOULD KEEP VSBYS FROM DROPPING TOO MUCH. ONCE MID LEVEL CLOUDS SCATTER THERE WILL BE AN INCREASE LIKELIHOOD FOR IFR FOG DEVELOPMENT AND LIFR CIGS. ANY FOG/STRATUS SHOULD RAPIDLY DISSIPATE A FEW HOURS AFTER SUNRISE. VFR WILL PREVAIL FRIDAY WITH DRY NW FLOW AOB 10 KT AND SCT SKIES. EXTENDED OUTLOOK...VFR FRI AND SAT. RAIN AND MVFR/TEMPO IFR POSSIBLE ON SUN. VFR ON MON AND TUE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM...LIGHT WEST-NORTHWEST WINDS ARE BLOWING OVER THE COASTAL WATERS AT SPEEDS LESS THAN 10 KNOTS. AS A UPPER-LEVEL DISTURBANCE PASSES ACROSS THE WATERS OVERNIGHT THE WINDS WILL BACK TO THE NORTHWEST AND WILL INCREASE TO 10 TO 15 KNOTS. SEA HEIGHTS ARE RUNNING BETWEEN 2 AND 3 FEET WITH A FEW 4 FOOTERS 15 TO 20 MILES OFF THE POINT OF CAPE FEAR. WITH THE INCREASE IN THE WINDS THE SEAS WILL RESPOND WITH MORE 4 FOOTERS 15 TO 20 MILES OFF THE COAST FROM FRYING PAN NORTHWARD AND IN MOST SOUTHWEST PORTION OF AMZ256. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 PM THURSDAY...NORTHWESTERLY WINDS ON FRIDAY WILL BECOME MORE NORTHERLY LATE FRIDAY NIGHT. WINDS WILL TURN TO THE NORTHEAST SATURDAY AND VEER TO SE TO S SATURDAY NIGHT. SPEEDS WILL REMAIN AOB 15 KT THROUGH THE PERIOD. SEAS OVER THE OPEN WATERS WILL RUN 3 TO 4 FEET THROUGH MUCH OF THE PERIOD...THOUGH 1 TO 2 FOOTERS ARE EXPECTED CLOSER TO SHORE FRIDAY INTO SATURDAY MORNING. AFTER WINDS TURN TOWARD THE SOUTHEAST SATURDAY NIGHT...5 FOOTERS ARE POSSIBLE AT 20 NM OVER THE NORTHERN WATERS. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 3 PM THURSDAY...PREFRONTAL FLOW INCREASES ON SUNDAY POSSIBLY TO THE POINT WHERE ANY ADVISORIES OR CAUTIONARY HEADLINES WILL BE NEEDED. THE POST-FRONTAL FLOW REGIME WILL FEATURE STRONGER FLOW AND THE ADVISORY MAY CONTINUE DUE TO WINDS EVEN AS THE ABRUPT TURN TO OFFSHORE PUSHES THE LARGEST SEAS OUT OF THE 20NM MARKER. HIGH PRESSURE BUILDS INTO THE FLORIDA BIG BEND ON MONDAY KEEPING THE WINDS OFFSHORE BUT WITH A MUCH LESSER GRADIENT. THE FLOW WILL ALSO ACQUIRE A SOUTHERLY COMPONENT LATER IN THE DAY AS SURFACE RIDGE AXIS MOVES OFF THE COAST. LIGHT SWRLY FLOW CONTINUES ON TUESDAY AS THE HIGH MOVES INTO THE WESTERN ATLANTIC. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DRH SHORT TERM...31 LONG TERM...MBB AVIATION...MRR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1255 AM EST WED JAN 14 2015 .SYNOPSIS... COLD HIGH PRESSURE WILL EXTEND SOUTH INLAND FROM THE COAST THROUGH WEDNESDAY AS WEAK LOW PRESSURE DEVELOPS AND LIFTS NORTHEAST WELL OFFSHORE. HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE WEST LATE IN THE WEEK AND INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1250 AM WEDNESDAY...LIGHT PRECIPITATION SHIELD CONTINUES TO LIFT NORTHEAST ACROSS THE CENTRAL AND NORTHERN COASTAL PLAINS AND SOUND COUNTIES. TEMPERATURES HAVE DROPPED TO 32 DEGREES AT KPGV...KISO AND KDPL...BUT THE REMAIN OF THE REGION REMAINS AT 34 DEGREES OR HIGHER. SURFACE OBSERVATIONS HAVE INDICATED SOME LIGHT FREEZING RAIN/SLEET AT THESE LOCATIONS. SOME CHANGES MADE TO THE FORECAST IN TERMS OF TIMING AND EXTENT OF PRECIPITATION PER LATEST 3KM HRRR AND 4KM NSSL WRF MODELS...WHICH SHOW BULK OF THE PRECIPITATION SHOULD DIMINISH OVER THE WINTER WEATHER ADVISORY AREA OVER THE NEXT FEW HOURS...WITH ADDITIONAL PRECIPITATION LATE TONIGHT BEING CONFINED TO NEAR THE COAST WHERE TEMPERATURES ARE IN THE UPPER 30S TO MID 40S. WILL MAKE NO CHANGES TO THE ADVISORY AT THIS TIME HOWEVER...AS FAR WESTERN AREAS MAY SEE SOME ADDITIONAL LIGHT FREEZING RAIN/SLEET THROUGH 08Z OR SO AND WILL CONTINUE TO MONITOR. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TODAY/... AS OF 245 PM TUESDAY...WIDESPREAD PRECIP WILL TAPER OF AND END FROM SW TO NE WED MORN INTO EARLY AFTN. WILL CONT WINTER WX ADVISORY INLAND THRU LATE MORN AS TEMPS WILL STRUGGLE TO RISE GIVEN PERSISTENT NRLY FLOW AND CLOUDS. DURING AFTN PATCHY LIGHT RAIN OR DRIZZLE WILL BE POSS ESPCLY NE SECTIONS. HIGHS MAINLY MID/UPR 30S INLAND TO NEAR 50 CAPE HAT. WITH WEAK LOW OFFSHORE NRLY WINDS WILL REMAIN GUSTY ALONG THE COAST. && .LONG TERM /TONIGHT THROUGH TUESDAY/... AS OF 250 PM TUE...LOW PRESSURE WELL OFFSHORE WILL CONTINUE TO PUSH NE WED NIGHT WITH LIGHT RAIN/DRIZZLE TAPERING OFF FROM WEST TO EAST. LINGERING MOISTURE ON ROADWAYS COULD LEAD RE-FREEZING AND ICY SPOTS WED NIGHT INTO THURSDAY MORNING. WILL CONTINUE SC PRECIP FOR THU...BUT OVERALL EXPECT LIMITED COVERAGE. LOW LEVEL THICKNESS VALUES AND CLOUDS SUPPORT HIGHS IN THE 40S THU. SHORTWAVE WILL MOVE THROUGH THE REGION THU NIGHT...PUSHING OFF THE SE COAST EARLY FRIDAY WITH SKIES GRADUALLY CLEARING. SFC HIGH WILL BUILD IN FROM THE WEST THU NIGHT THROUGH THE WEEKEND...WITH AREA DRYING OUT AND GRADUAL WARM UP. BY SAT/SUN HIGHS IN THE MID 50S TO AROUND 60. HIGH PRESSURE WILL MOVE OFF THE COAST SAT NIGHT SUNDAY. NEXT FRONTAL SYSTEM IS EXPECTED TO MOVE THROUGH THE AREA LATE SUN. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM /THROUGH 06Z THURSDAY/... AS OF 1250 AM WEDNESDAY...IFR CEILINGS AT ALL TAF SITES WITH LIGHT PRECIPITATION OCCURRING. THIS PRECIPITATION SHOULD GRADUALLY END OVER THE NEXT SEVERAL HOURS...BUT IFR CEILINGS WILL PREVAIL THROUGH THE DAY ALONG WITH MODERATE NORTHERLY WINDS. EXPECT SOME PATCHES OF FOG TO RETURN BY TONIGHT ACCOMPANIED BY CEILINGS AROUND 500-700 FEET OR SO. .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 250 PM TUE...SUB-VFR CONDITIONS EXPECTED TO PERSIST WEDNESDAY NIGHT THEN GRADUALLY IMPROVE TO VFR THROUGH THE DAY THU WITH CIGS LIFTING. HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE WEST THU NIGHT INTO THE WEEKEND...WITH PRED VFR CONDITIONS. && .MARINE... SHORT TERM /THROUGH WEDNESDAY/... AS OF 1255 AM WEDNESDAY...GUSTY NORTH WINDS CONTINUE ON THE COASTAL WATERS AND SOUNDS AND NO CHANGES TO THE CURRENT ADVISORIES AS DUCK IS GUSTING TO 32 KNOTS AND CAPE LOOKOUT TO 25 KNOTS AT THIS TIME. ALSO PICKING UP 27 KNOT WINDS ON THE ALBEMARLE SOUND. SEAS CONTINUE IN THE 9 TO 11 FOOT RANGE. .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 250 PM TUE...GUSTY NLY WINDS 15-25KT WILL CONTINUE WED NIGHT THEN GRADUALLY TAPERING OFF AS LOW PRESSURE WELL OFFSHORE CONTINUES TO MOVE NE. ELEVATED SEAS 5-9FT CONTINUE WED NIGHT SUBSIDING TO 4-7FT THU AFTERNOON. MAIN CHANGE TO FORECAST WAS TO END SCA EARLIER THAN PREVIOUS FORECAST BASED ON LATEST GUIDANCE...WITH SEAS SUBSIDING BELOW 6FT THURSDAY NIGHT. SFC HIGH PRESSURE WILL GRADUALLY BUILD INTO THE WATERS FROM THE WEST THU NIGHT THROUGH THE WEEKEND. NWLY WINDS 10-20KT THU NIGHT INTO FRI...BECOMING SE 10KT OR LESS SAT AFTERNOON. HIGH PRESSURE WILL MOVE OFFSHORE SAT NIGHT...WITH SWLY FLOW 10-20KT DEVELOPING ACROSS THE WATERS SUN. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR NCZ029-044-045-079-080-090>093-098. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ130- 131-135. SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR AMZ150-152-154. SMALL CRAFT ADVISORY UNTIL 7 PM EST THURSDAY FOR AMZ156-158. && $$ SYNOPSIS...RF NEAR TERM...CTC SHORT TERM...RF LONG TERM...CQD AVIATION...CTC/CQD MARINE...CTC/CQD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1234 AM EST WED JAN 14 2015 .SYNOPSIS... FREEZING LIGHT RAIN AND PATCHY ICY SURFACES ARE POSSIBLE OVERNIGHT AND EARLY WEDNESDAY FOR PARTS OF INTERIOR SOUTHEAST NORTH CAROLINA AND NORTHEAST SOUTH CAROLINA. DESPITE A COLD DAY ON WEDNESDAY...A SLOW WARMING SHOULD MELT ANY ICE THAT FORMS BY LATE MORNING. WEAK HIGH PRESSURE WILL BRING A DRYING TREND THURSDAY. A GULF OF MEXICO DISTURBANCE COULD BRING PATCHY LIGHT RAIN EARLY ON FRIDAY. FAIR AND MILDER CONDITIONS ARE EXPECTED THIS WEEKEND BEFORE A COLD FRONT MOVES THROUGH SUNDAY NIGHT. BUILDING HIGH PRESSURE FROM THE NORTH WILL BRING A COOLING TREND EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 12:30 AM WEDNESDAY...CONTINUED WITH NO CHANGES NEEDED FOR THE CURRENT WINTER WX ADVISORY IN EFFECT FOR MUCH OF THE INLAND PORTIONS OF THE ILM CWA. THE FA IS STILL LOOKING AT A STRATUS TYPE LIGHT PCPN EVENT...WITH THE POSSIBILITY OF FREEZING RAIN AND/OR DRIZZLE OCCURRING...IF ENOUGH COLD AIR GETS FUNNELED SOUTHWARD BEFORE THE PCPN EVENT ENDS COME MID TO LATE WED MORNING. ONCE AGAIN...THE LATEST SFC TEMP/DEWPT READINGS ACROSS THE FA WERE UPDATED INTO THE CURRENT FORECAST SCHEME...AND APPLIED TO THE LATEST HOURLY RUC MODEL. THE RESULTS STILL KEEP THE SOUTHERNMOST EXTENT OF THE SFC 32 DEGREE TEMP ISOTHERM AND LOW 30S DEWPOINTS OCCURRING BETWEEN 4AM-8AM WED. AT 1ST LOOK...THE LATEST 00Z MODEL DATA GUIDANCE INDICATES THAT SFC DEWPOINTS ARE PROGGED NOT TO DROP INTO THE 20S BUT STAY AT 30 DEGREES OR HIGHER IN THE ADVISORY AREA. THIS IS NOT ENOUGH TO FORCE A CHANGE IN THE CONFIGURATION OF THE FREEZING RAIN ADV AT THIS TIME. BUT...IF ADDITIONAL 00Z MODELS INDICATE A MILDER ATM PROFILE OR COLUMN IN THE LOWER LEVELS...THEN A CHANGE WOULD LIKELY BE DEEMED NECESSARY. ON A SIDE NOTE...THE 21Z SREF MODEL DATA CONTINUES TO ILLUSTRATE THAT BLADEN AND/OR ROBESON COUNTIES HAVE THE HIGHEST PROBABILITY TO OBSERVE MEASURABLE FREEZING RAIN WITHIN THE ILM CWA DURING THIS EVENT. DUE TO MORE OF A STRATUS TYPE EVENT...THE LATEST QPF ACROSS THE FA WAS LOWERED TO ROUGHLY BETWEEN 0.1 TO 0.5 INCHES. HOWEVER...STILL LOOKING AT SEVERAL ONE-HUNDREDTHS OF AN INCH TO LESS THAN ONE TENTH OF AN INCH OF TOTAL ICE ACCUMULATION POSSIBLE WITHIN THE FREEZING RAIN ADVISORY AREA. THEREFORE...THE CURRENT WWA LOOKS AOK WITH NO NEEDED UPDATES FOR RE-CONFIGURATION. PREVIOUS DISCUSSION.................................... AS OF 3 PM TUESDAY...A VERY LIGHT FREEZING RAIN SETUP STILL APPEARS TO TAKE SHAPE TOWARDS THE VERY END OF THE PERIOD BUT SOME NAGGING UNCERTAINTIES REMAIN. HIGH PRESSURE WILL PROGRESS EAST TONIGHT MOVING FROM GREAT LAKES TO NEW ENGLAND STATES, WITH RIDGE AXIS DEVELOPING INTO THE CAROLINAS. RIGHT AWAY THIS LEADS TO THE FIRST FORECAST UNCERTAINTY AND THAT IS HOW COOL AND DRY THIS AIRMASS BECOMES LOCALLY BY DAYBREAK WEDNESDAY AS THE CORE OF THE AIRMASS REMAINS WELL TO OUR NORTH AND DEWPOINTS SEEMINGLY THE LIMITING FACTOR. NOT PRESENT ARE THE VERY LOW DEWPOINTS OFTEN ASSOCIATED WITH ARCTIC AIR AND FREEZING RAIN EVENTS, THE FORMER SERVING AS A CONSTANT SOURCE OF LOWER DEWPOINTS AND THUS WETBULBS TO SUPPORT THE LATTER. RATHER OVERNIGHT DEWPOINTS JUST A FEW DEGREES F LAZILY OOZE INTO FAR NORTHWESTERN ZONES FOR A SETUP ABOUT AS MARGINAL AS CAN BE. THE STRENGTH AND DEPTH OF THE WARM NOSE (MAXING OUT AT 8-9C AT A HEIGHT OF 3500FT WITHIN AN ABOVE- FREEZING LAYER SPANNING 2000FT- 9000FT) WILL PRECLUDE ANY PTYPES OTHER THAN RAIN AND FREEZING RAIN. ANOTHER POINT OF UNCERTAINTY IS MODEL QPF. BOTH GFS AND WRF SHOWING ALMOST AS MUCH AS 0.25 OVER PART OF THE AREA BUT GIVEN OVERALL WEAK FORCING AND DRY MID AND UPPER LEVELS THIS MAY BE HARD TO COME BY. THIS IDEA SUPPORTED BY THE LATEST/15Z SREF WHICH SHOWS PROBS OF .25" STRUGGLING TO MAX OUT AT 50 PERCENT OVER A SMALL PART OF THE REGION. LASTLY THE AREA MOST FAVORED FOR FZRA MAY BORDER WHERE THE HIGHEST PRECIP OCCURS AND ANY TINY ADJUSTMENT OF THAT BATTLE LINE COULD HAVE BIG IMPLICATIONS FOR THE FORECAST. TOP-DOWN METHODOLOGY WITH A SLIGHT HAT TIP TO THE SREF PTYPE ALGORITHM ACTUALLY CALLED FOR NO CHANGES TO THE CURRENT ADVISORY WHERE SEEMINGLY UP TO JUST A FEW HUNDREDTH OF AN INCH TO AT WORST ABOUT A TENTH OF AN INCH OF FREEZING RAIN MAY OCCUR. WITH THE COOL AIR SO SLOW TO ARRIVE DO NOT EXPECT ANY APPRECIABLE SUB-FREEZING TEMPS TIL 09Z. NON- ELEVATED SURFACES LIKELY ABOVE FREEZING AND WILL HAVE TROUBLE ACCRETING MUCH ICE AT ALL. THERE WAS SEEMINGLY LITTLE VALUE OR INCENTIVE TO TRIM THE ADVISORY AS ITS IT QUITE UNDESIRABLE TO HAVE TO RE-RAISE ONE BUT DO SUSPECT THAT EVENING SHIFT MAY BE ABLE TO REMOVE A SMALL PART OF THE SOUTHERN PERIPHERY OF THE ADVISORY...ROUGHLY LINING UP WITH WPC`S 40-50% LINE OF 0.01" OR MORE OF FZRA. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...EARLY WEDNESDAY LINGERING ICE/-FZRA COULD POSE COMMUTE HAZARDS BUT BY MIDDAY...DESPITE A COLD DAY OVERALL...MELTING OF ANY ICE IS ANTICIPATED AS TEMPERATURES RISE ABOVE FREEZING. THE PROBABILITY OF PCPN WILL WANE FROM SW TO NE ACROSS NE SC AND SE NC THROUGH MORNING...LIKELY ENDING AS PATCHY BUT CHILLY LIGHT RAIN OVER SE NC APPROACHING AFTERNOON. NO CHANGES TO ENDING TIME OR THE GEOGRAPHY OF THE FZRA ADVISORY ON WEDNESDAY...AND NOON EXPIRATION WAS RETAINED. DRYING TREND THURSDAY AS WEAK HIGH SETS IN ACCOMPANIED BY MID-LVL SUBSIDENCE. THE PROGRESSIVE PATTERN USHERS APPROACH OF AN UPPER TROUGH LATE THURSDAY...HELPING TO LIFT AN IMPULSE OUT OF THE NORTHERN GULF OF MEXICO LATE THU/EARLY FRI AND A SLIGHT CHANCE OF PCPN. DURING THE PEAK OF MOISTURE LATE THU/EARLY FRI...TEMPS AT THIS TIME APPEAR TO WARM TO SUPPORT FROZEN PCPN. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...A DEEP LONG-WAVE TROUGH WILL BE EAST OF THE FORECAST AREA BY THE START OF THE PERIOD. HIGH PRESSURE...SURFACE AND ALOFT...WILL MOVE INTO THE EASTERN CAROLINAS FROM THE WEST ON FRI. A LARGE N-S RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS THE AREA ON SAT...MOVING OFFSHORE SAT NIGHT AND SUN. STILL SOME UNCERTAINTY WITH REGARDS TO THE DEVELOPMENT OF A COASTAL TROUGH AND A WAVE OF LOW PRESSURE MOVING UP THE COAST LATE IN THE WEEKEND. IF THIS TROUGH DOES DEVELOP...THERE MAY BE A PERIOD OF SHOWERS ALONG THE COAST AND OFFSHORE SUN. A COLD FRONT WILL SWEEP ACROSS THE AREA SUN NIGHT/ EARLY MONDAY. STILL UNCLEAR GIVEN MODEL SPREAD WHETHER ANY SHOWERS WILL ACCOMPANY THE COLD FRONT. COOL HIGH PRESSURE WILL BUILD DOWN THE EAST COAST ON TUE. THE FORECAST PERIOD WILL LARGELY BE DRY...AND AT THIS TIME...NO RAINFALL IS FORECAST EXCEPT FOR POSSIBLY THE IMMEDIATE COAST LATER IN THE WEEKEND. A GOOD DEAL OF SUNSHINE WILL HELP TO FINALLY BRING ABOVE NORMAL TEMPS TO THE REGION. TEMPS WILL WARM EACH DAY WITH SUN BEING THE WARMEST...UPPER 50S AND LOWER 60S. TEMPS WILL THEN FALL BACK MON AND TUE OF NEXT WEEK...BUT NO COOLER THAN NORMAL FOR MID JANUARY. LOWS FRI NIGHT MAY DIP BELOW FREEZING INLAND LATE... OTHERWISE WE DO NOT EXPECT FREEZING TEMPS OVER THE WEEKEND. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 06Z...IFR/LIFR IS OCCURRING EARLY THIS MORNING WITH LIGHT RAIN/DRIZZLE/BR. AT KLBT CIGS ARE HOVERING AROUND 1K. THE RAIN IS CURRENTLY ABATING...BUT SATELLITE IMAGES SHOW AN UPPER IMPULSE APPROACHING FROM THE WEST. LIGHT DRIZZLE AND/OR LIGHT RAIN WILL CONTINUE TO BE LIKELY THROUGH SUNRISE. WITH COLD AIR ADVECTION TEMPERATURES WILL FALL TO NEAR FREEZING AT KLBT 09-10Z. LIGHT FREEZING DRIZZLE AND/OR POSSIBLY LIGHT FREEZING RAIN WILL BE POSSIBLE AT KLBT...ESPECIALLY ON ELEVATED SURFACES...UNTIL THE TEMPERATURE WARMS ABOVE FREEZING AROUND 13Z. PRECIPITATION SHOULD SHORTLY AFTER SUNRISE. IFR/LIFR CIGS WILL SLOWLY LIFT DURING THE DAY. HIGH PRESSURE BUILDING IN SHOULD ALLOW FOR CIGS TO LIFT TO MVFR AT KFLO/KLBT IN THE LATE MORNING/EARLY AFTERNOON. CIGS AT KCRE/KMYR SHOULD ALSO REACH TEMPO MVFR LEVELS IN THE EARLY AFTERNOON. AT KILM NEAREST THE OFFSHORE LOW IFR CIGS APPEAR MOST LIKELY TO PERSIST INTO THE AFTERNOON. EXTENDED OUTLOOK...MVFR/IFR CIGS WILL PREVAIL THROUGH THU MORNING AS A COLD WEDGE OF HIGH PRESSURE REMAINS IN PLACE. VFR THU AFTN-SUN. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 12:30 AM WEDNESDAY...SMALL CRAFT ADVISORY REMAINS IN EFFECT. FORECAST REMAINS UNCHANGED FOR THE EARLY MORNING HOURS. PREVIOUS DISCUSSIONS FOLLOW: CURRENT/LATEST WINDS AND SIGNIFICANT SEAS CONDITIONS REPORTED ACROSS THE LOCAL WATERS...AND JUST OFFSHORE IE. FRYING PAN SHOALS BUOY...ARE RUNNING SLIGHTLY HIGHER THAN THE LATEST WAVEWATCH 3 WIND AND SEAS FCST. AS A RESULT...THE OVERNIGHT WIND AND SEAS FCST WAS TWEAKED GIVEN THESE LATEST TRENDS. THIS KEEPS THE ILM WATERS WITHIN A STRONG SCA OVERNIGHT. ONCE THE LOW BEGINS ITS AMPLIFICATION/INTENSIFICATION OFFSHORE AND ENE OF CAPE FEAR...WIND DIRECTIONS WILL BACK FROM NE TO NNE OR DUE N...AT SPEEDS OF 20 TO 25 KT WITH G30 KT. THIS BACKING WILL HELP CUT DOWN SIGNIFICANT SEAS ESPECIALLY NEARSHORE GIVEN THE REDUCED FETCH FOR WHICH TO BUILD SEAS ACROSS THE ILM LOCAL WATERS. MUCH OF THIS BACKING WILL LIKELY OCCUR AFTER THIS NEAR TERM PERIOD. AS A RESULT...HAVE TWEAKED SIGNIFICANT SEAS A FOOT TO POSSIBLY 2 HIGHER DURING THE OVERNIGHT PERIOD. AVERAGE PERIODS WILL RUN 4.0 TO 5.0 SECONDS. PREVIOUS DISCUSSION............................ AS OF 3 PM TUESDAY...FRYING PAN SHOALS BUOY ALREADY UP TO 9 FT DESPITE WINDS HAVING PRETTY MUCH LEVELED OFF. DOMINANT PERIOD OF 8 SECONDS SUGGESTING THAT NORTHEASTERLY SWELL ENERGY TEAMING UP WITH THE AGITATED WINDS TO BLAME. THE PINCHED GRADIENT AND FETCH WILL NOT CHANGE MUCH THROUGH THE PERIOD AND A SMALL INCREASE IN SEAS WILL LARGELY OCCUR OUTSIDE OF THE FORECAST ZONES IN THE LARGELY COAST-PARALLEL FLOW. SOLID SMALL CRAFT ADVISORY THUS CONTINUES THROUGH THE PERIOD AND BEYOND. LOW PRESSURE DEVELOPS WELL OFF THE COAST LATE IN THE PERIOD AND IT MAY ADD A FEW KTS OF WIND BUT THE OVERALL POOR ALIGNMENT OF FLOW IN THE VERTICAL, OR EVEN THE LACK OF MUCH WIND ABOVE THE SURFACE LAYER AT ALL FOR THAT MATTER, SHOULD PRECLUDE GALES. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...UNFRIENDLY MARINE ENVIRONMENT TO KICK OFF WED WITH LINGERING SEA-HEIGHTS OF 5-7 FEET AWAY FROM SHORE. AS WINDS BECOME NW AND AND ABATE MORE IN EARNEST...ADVISORIES WILL LIKELY BE DROPPED SOMETIME LATE THURSDAY NIGHT AS A COASTAL LOW PULLS AWAY FROM THE 0-20 NM WATERS...AND SEA HEIGHT DAMPEN. NW WINDS WILL HOLD THROUGH FRIDAY AS HIGH PRESSURE EDGES IN FROM THE WEST BUT BELOW ADVISORY LEVELS. MODERATE N AND NW CHOP WILL EASE FRIDAY ACCOMPANIED BY E WAVE 2-3 FEET RUNNING IN 9-10 SECONDS INTERVALS. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...HIGH PRESSURE WILL PUSH EASTWARD AND ACROSS THE WATERS FRI WITH A LARGE RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE WATERS SAT. THIS RIDGE WILL THEN PULL OFFSHORE SAT NIGHT AND SUN WITH A COASTAL TROUGH POSSIBLY DEVELOPING IN ITS WAKE. CONDITIONS ARE EXPECTED TO REMAIN BELOW ADVISORY CRITERIA DURING THIS PERIOD. WIND SPEEDS WILL BE UP TO 15 TO 20 KT FRI...OTHERWISE 10 TO 15 KT OR LESS. SEAS WILL BE 3 TO 5 FT FRI...OTHERWISE 2 TO 4 FT THROUGH THE WEEKEND. THE WIND DIRECTION WILL BE N FRI...VEERING TO NE FRI NIGHT...E TO SE SAT...AND S TO SW ON SUN AS HIGH PRESSURE MOVES PROGRESSIVELY OFFSHORE. LOW PRESSURE MAY DEVELOP ON THE TROUGH LATE SAT AND IF THE LOW DOES DEVELOP...A TIGHTER PRESSURE GRADIENT WILL BE REALIZED...RESULTING IN HIGHER WINDS AND POSSIBLY SEAS BY THE END OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR SCZ017-023-024- 032-033-053. NC...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NCZ087-096-099- 105. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ250-252- 254-256. && $$ SYNOPSIS...MJC NEAR TERM...DCH/REK/MBB SHORT TERM...MJC LONG TERM...RJD AVIATION...MRR MARINE...DCH/REK/RJD/MBB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1146 PM EST TUE JAN 13 2015 .SYNOPSIS... FREEZING LIGHT RAIN AND PATCHY ICY SURFACES ARE POSSIBLE LATE TONIGHT AND EARLY WEDNESDAY FOR PARTS OF INTERIOR SOUTHEAST NORTH CAROLINA AND NORTHEAST SOUTH CAROLINA. DESPITE A COLD DAY ON WEDNESDAY...A SLOW WARMING SHOULD MELT ANY ICE THAT FORMS BY LATE MORNING. WEAK HIGH PRESSURE WILL BRING A DRYING TREND THURSDAY. A GULF OF MEXICO DISTURBANCE COULD BRING PATCHY LIGHT RAIN EARLY ON FRIDAY. FAIR AND MILDER CONDITIONS ARE EXPECTED THIS WEEKEND BEFORE A COLD FRONT MOVES THROUGH SUNDAY NIGHT. BUILDING HIGH PRESSURE FROM THE NORTH WILL BRING A COOLING TREND EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 1115 PM TUESDAY...CONTINUED WITH NO CHANGES NEEDED FOR THE CURRENT WINTER WX ADVISORY IN EFFECT FOR MUCH OF THE INLAND PORTIONS OF THE ILM CWA. THE FA IS STILL LOOKING AT A STRATUS TYPE LIGHT PCPN EVENT...WITH THE POSSIBILITY OF FREEZING RAIN AND/OR DRIZZLE OCCURRING...IF ENOUGH COLD AIR GETS FUNNELED SOUTHWARD BEFORE THE PCPN EVENT ENDS COME MID TO LATE WED MORNING. ONCE AGAIN...THE LATEST SFC TEMP/DEWPT READINGS ACROSS THE FA WERE UPDATED INTO THE CURRENT FORECAST SCHEME...AND APPLIED TO THE LATEST HOURLY RUC MODEL. THE RESULTS STILL KEEP THE SOUTHERNMOST EXTENT OF THE SFC 32 DEGREE TEMP ISOTHERM AND LOW 30S DEWPOINTS OCCURRING BETWEEN 4AM-8AM WED. AT 1ST LOOK...THE LATEST 00Z MODEL DATA GUIDANCE INDICATES THAT SFC DEWPOINTS ARE PROGGED NOT TO DROP INTO THE 20S BUT STAY AT 30 DEGREES OR HIGHER IN THE ADVISORY AREA. THIS IS NOT ENOUGH TO FORCE A CHANGE IN THE CONFIGURATION OF THE FREEZING RAIN ADV AT THIS TIME. BUT...IF ADDITIONAL 00Z MODELS INDICATE A MILDER ATM PROFILE OR COLUMN IN THE LOWER LEVELS...THEN A CHANGE WOULD LIKELY BE DEEMED NECESSARY. ON A SIDE NOTE...THE 21Z SREF MODEL DATA CONTINUES TO ILLUSTRATE THAT BLADEN AND/OR ROBESON COUNTIES HAVE THE HIGHEST PROBABILITY TO OBSERVE MEASURABLE FREEZING RAIN WITHIN THE ILM CWA DURING THIS EVENT. DUE TO MORE OF A STRATUS TYPE EVENT...THE LATEST QPF ACROSS THE FA WAS LOWERED TO ROUGHLY BETWEEN 0.1 TO 0.5 INCHES. HOWEVER...STILL LOOKING AT SEVERAL ONE-HUNDREDTHS OF AN INCH TO LESS THAN ONE TENTH OF AN INCH OF TOTAL ICE ACCUMULATION POSSIBLE WITHIN THE FREEZING RAIN ADVISORY AREA. THEREFORE...THE CURRENT WWA LOOKS AOK WITH NO NEEDED UPDATES FOR RE-CONFIGURATION. PREVIOUS DISCUSSION................................................ AS OF 3 PM TUESDAY...A VERY LIGHT FREEZING RAIN SETUP STILL APPEARS TO TAKE SHAPE TOWARDS THE VERY END OF THE PERIOD BUT SOME NAGGING UNCERTAINTIES REMAIN. HIGH PRESSURE WILL PROGRESS EAST TONIGHT MOVING FROM GREAT LAKES TO NEW ENGLAND STATES, WITH RIDGE AXIS DEVELOPING INTO THE CAROLINAS. RIGHT AWAY THIS LEADS TO THE FIRST FORECAST UNCERTAINTY AND THAT IS HOW COOL AND DRY THIS AIRMASS BECOMES LOCALLY BY DAYBREAK WEDNESDAY AS THE CORE OF THE AIRMASS REMAINS WELL TO OUR NORTH AND DEWPOINTS SEEMINGLY THE LIMITING FACTOR. NOT PRESENT ARE THE VERY LOW DEWPOINTS OFTEN ASSOCIATED WITH ARCTIC AIR AND FREEZING RAIN EVENTS, THE FORMER SERVING AS A CONSTANT SOURCE OF LOWER DEWPOINTS AND THUS WETBULBS TO SUPPORT THE LATTER. RATHER OVERNIGHT DEWPOINTS JUST A FEW DEGREES F LAZILY OOZE INTO FAR NORTHWESTERN ZONES FOR A SETUP ABOUT AS MARGINAL AS CAN BE. THE STRENGTH AND DEPTH OF THE WARM NOSE (MAXING OUT AT 8-9C AT A HEIGHT OF 3500FT WITHIN AN ABOVE- FREEZING LAYER SPANNING 2000FT- 9000FT) WILL PRECLUDE ANY PTYPES OTHER THAN RAIN AND FREEZING RAIN. ANOTHER POINT OF UNCERTAINTY IS MODEL QPF. BOTH GFS AND WRF SHOWING ALMOST AS MUCH AS 0.25 OVER PART OF THE AREA BUT GIVEN OVERALL WEAK FORCING AND DRY MID AND UPPER LEVELS THIS MAY BE HARD TO COME BY. THIS IDEA SUPPORTED BY THE LATEST/15Z SREF WHICH SHOWS PROBS OF .25" STRUGGLING TO MAX OUT AT 50 PERCENT OVER A SMALL PART OF THE REGION. LASTLY THE AREA MOST FAVORED FOR FZRA MAY BORDER WHERE THE HIGHEST PRECIP OCCURS AND ANY TINY ADJUSTMENT OF THAT BATTLE LINE COULD HAVE BIG IMPLICATIONS FOR THE FORECAST. TOP-DOWN METHODOLOGY WITH A SLIGHT HAT TIP TO THE SREF PTYPE ALGORITHM ACTUALLY CALLED FOR NO CHANGES TO THE CURRENT ADVISORY WHERE SEEMINGLY UP TO JUST A FEW HUNDREDTH OF AN INCH TO AT WORST ABOUT A TENTH OF AN INCH OF FREEZING RAIN MAY OCCUR. WITH THE COOL AIR SO SLOW TO ARRIVE DO NOT EXPECT ANY APPRECIABLE SUB-FREEZING TEMPS TIL 09Z. NON- ELEVATED SURFACES LIKELY ABOVE FREEZING AND WILL HAVE TROUBLE ACCRETING MUCH ICE AT ALL. THERE WAS SEEMINGLY LITTLE VALUE OR INCENTIVE TO TRIM THE ADVISORY AS ITS IT QUITE UNDESIRABLE TO HAVE TO RE-RAISE ONE BUT DO SUSPECT THAT EVENING SHIFT MAY BE ABLE TO REMOVE A SMALL PART OF THE SOUTHERN PERIPHERY OF THE ADVISORY...ROUGHLY LINING UP WITH WPC`S 40-50% LINE OF 0.01" OR MORE OF FZRA. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...EARLY WEDNESDAY LINGERING ICE/-FZRA COULD POSE COMMUTE HAZARDS BUT BY MIDDAY...DESPITE A COLD DAY OVERALL...MELTING OF ANY ICE IS ANTICIPATED AS TEMPERATURES RISE ABOVE FREEZING. THE PROBABILITY OF PCPN WILL WANE FROM SW TO NE ACROSS NE SC AND SE NC THROUGH MORNING...LIKELY ENDING AS PATCHY BUT CHILLY LIGHT RAIN OVER SE NC APPROACHING AFTERNOON. NO CHANGES TO ENDING TIME OR THE GEOGRAPHY OF THE FZRA ADVISORY ON WEDNESDAY...AND NOON EXPIRATION WAS RETAINED. DRYING TREND THURSDAY AS WEAK HIGH SETS IN ACCOMPANIED BY MID-LVL SUBSIDENCE. THE PROGRESSIVE PATTERN USHERS APPROACH OF AN UPPER TROUGH LATE THURSDAY...HELPING TO LIFT AN IMPULSE OUT OF THE NORTHERN GULF OF MEXICO LATE THU/EARLY FRI AND A SLIGHT CHANCE OF PCPN. DURING THE PEAK OF MOISTURE LATE THU/EARLY FRI...TEMPS AT THIS TIME APPEAR TO WARM TO SUPPORT FROZEN PCPN. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...A DEEP LONG-WAVE TROUGH WILL BE EAST OF THE FORECAST AREA BY THE START OF THE PERIOD. HIGH PRESSURE...SURFACE AND ALOFT...WILL MOVE INTO THE EASTERN CAROLINAS FROM THE WEST ON FRI. A LARGE N-S RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS THE AREA ON SAT...MOVING OFFSHORE SAT NIGHT AND SUN. STILL SOME UNCERTAINTY WITH REGARDS TO THE DEVELOPMENT OF A COASTAL TROUGH AND A WAVE OF LOW PRESSURE MOVING UP THE COAST LATE IN THE WEEKEND. IF THIS TROUGH DOES DEVELOP...THERE MAY BE A PERIOD OF SHOWERS ALONG THE COAST AND OFFSHORE SUN. A COLD FRONT WILL SWEEP ACROSS THE AREA SUN NIGHT/ EARLY MONDAY. STILL UNCLEAR GIVEN MODEL SPREAD WHETHER ANY SHOWERS WILL ACCOMPANY THE COLD FRONT. COOL HIGH PRESSURE WILL BUILD DOWN THE EAST COAST ON TUE. THE FORECAST PERIOD WILL LARGELY BE DRY...AND AT THIS TIME...NO RAINFALL IS FORECAST EXCEPT FOR POSSIBLY THE IMMEDIATE COAST LATER IN THE WEEKEND. A GOOD DEAL OF SUNSHINE WILL HELP TO FINALLY BRING ABOVE NORMAL TEMPS TO THE REGION. TEMPS WILL WARM EACH DAY WITH SUN BEING THE WARMEST...UPPER 50S AND LOWER 60S. TEMPS WILL THEN FALL BACK MON AND TUE OF NEXT WEEK...BUT NO COOLER THAN NORMAL FOR MID JANUARY. LOWS FRI NIGHT MAY DIP BELOW FREEZING INLAND LATE... OTHERWISE WE DO NOT EXPECT FREEZING TEMPS OVER THE WEEKEND. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 00Z...MOSTLY IFR CIGS ARE OCCURRING THIS EVENING WITH LIGHT RAIN BREAKING OUT FROM KFLO/KLBT. OCCASIONALLY CIGS ARE LOW MVFR AT KLBT/KFLO. TEMPO MVFR CIGS SHOULD BECOME LESS LIKELY AS THE LOW LEVELS BECOME MORE SATURATED FROM LIGHT RAIN/DRIZZLE THROUGH THE OVERNIGHT HOURS. WITH COLD AIR ADVECTION TEMPERATURES WILL REACH FREEZING AT KLBT 09-10Z. LIGHT FREEZING RAIN OR DRIZZLE/MAYBE FROZEN PRECIPITATION WILL BE POSSIBLE ESPECIALLY ON ELEVATED SURFACES UNTIL THE TEMPERATURE WARMS ABOVE FREEZING AROUND 13Z. PRECIPITATION SHOULD END AROUND SUNRISE. IFR/LIFR CIGS WILL SLOWLY LIFT WEDNESDAY. HIGH PRESSURE BUILDING IN AT KFLO/KLBT SHOULD ALLOW CIGS TO IMPROVE TO MVFR IN THE LATE MORNING AFTERNOON. CIGS AT KCRE/KMYR SHOULD ALSO REACH TEMPO MVFR LEVELS IN THE AFTERNOON. AT KILM NEAREST THE OFFSHORE LOW IFR CIGS APPEAR MOST LIKELY TO PERSIST INTO THE AFTERNOON. EXTENDED OUTLOOK...MVFR/IFR CIGS WILL PREVAIL THROUGH THU MORNING AS A COLD WEDGE OF HIGH PRESSURE REMAINS IN PLACE. VFR THU AFTN-SUN. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1115 PM TUESDAY...CURRENT/LATEST WINDS AND SIGNIFICANT SEAS CONDITIONS REPORTED ACROSS THE LOCAL WATERS...AND JUST OFFSHORE IE. FRYING PAN SHOALS BUOY...ARE RUNNING SLIGHTLY HIGHER THAN THE LATEST WAVEWATCH 3 WIND AND SEAS FCST. AS A RESULT...THE OVERNIGHT WIND AND SEAS FCST WAS TWEAKED GIVEN THESE LATEST TRENDS. THIS KEEPS THE ILM WATERS WITHIN A STRONG SCA OVERNIGHT. ONCE THE LOW BEGINS ITS AMPLIFICATION/INTENSIFICATION OFFSHORE AND ENE OF CAPE FEAR...WIND DIRECTIONS WILL BACK FROM NE TO NNE OR DUE N...AT SPEEDS OF 20 TO 25 KT WITH G30 KT. THIS BACKING WILL HELP CUT DOWN SIGNIFICANT SEAS ESPECIALLY NEARSHORE GIVEN THE REDUCED FETCH FOR WHICH TO BUILD SEAS ACROSS THE ILM LOCAL WATERS. MUCH OF THIS BACKING WILL LIKELY OCCUR AFTER THIS NEAR TERM PERIOD. AS A RESULT...HAVE TWEAKED SIGNIFICANT SEAS A FOOT TO POSSIBLY 2 HIER DURING THE OVERNITE PERIOD. AVERAGE PERIODS WILL RUN 4.0 TO 5.0 SECONDS. PREVIOUS DISCUSSION..................................... AS OF 3 PM TUESDAY...FRYING PAN SHOALS BUOY ALREADY UP TO 9 FT DESPITE WINDS HAVING PRETTY MUCH LEVELED OFF. DOMINANT PERIOD OF 8 SECONDS SUGGESTING THAT NORTHEASTERLY SWELL ENERGY TEAMING UP WITH THE AGITATED WINDS TO BLAME. THE PINCHED GRADIENT AND FETCH WILL NOT CHANGE MUCH THROUGH THE PERIOD AND A SMALL INCREASE IN SEAS WILL LARGELY OCCUR OUTSIDE OF THE FORECAST ZONES IN THE LARGELY COAST-PARALLEL FLOW. SOLID SMALL CRAFT ADVISORY THUS CONTINUES THROUGH THE PERIOD AND BEYOND. LOW PRESSURE DEVELOPS WELL OFF THE COAST LATE IN THE PERIOD AND IT MAY ADD A FEW KTS OF WIND BUT THE OVERALL POOR ALIGNMENT OF FLOW IN THE VERTICAL, OR EVEN THE LACK OF MUCH WIND ABOVE THE SURFACE LAYER AT ALL FOR THAT MATTER, SHOULD PRECLUDE GALES. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...UNFRIENDLY MARINE ENVIRONMENT TO KICK OFF WED WITH LINGERING SEA-HEIGHTS OF 5-7 FEET AWAY FROM SHORE. AS WINDS BECOME NW AND AND ABATE MORE IN EARNEST...ADVISORIES WILL LIKELY BE DROPPED SOMETIME LATE THURSDAY NIGHT AS A COASTAL LOW PULLS AWAY FROM THE 0-20 NM WATERS...AND SEA HEIGHT DAMPEN. NW WINDS WILL HOLD THROUGH FRIDAY AS HIGH PRESSURE EDGES IN FROM THE WEST BUT BELOW ADVISORY LEVELS. MODERATE N AND NW CHOP WILL EASE FRIDAY ACCOMPANIED BY E WAVE 2-3 FEET RUNNING IN 9-10 SECONDS INTERVALS. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...HIGH PRESSURE WILL PUSH EASTWARD AND ACROSS THE WATERS FRI WITH A LARGE RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE WATERS SAT. THIS RIDGE WILL THEN PULL OFFSHORE SAT NIGHT AND SUN WITH A COASTAL TROUGH POSSIBLY DEVELOPING IN ITS WAKE. CONDITIONS ARE EXPECTED TO REMAIN BELOW ADVISORY CRITERIA DURING THIS PERIOD. WIND SPEEDS WILL BE UP TO 15 TO 20 KT FRI...OTHERWISE 10 TO 15 KT OR LESS. SEAS WILL BE 3 TO 5 FT FRI...OTHERWISE 2 TO 4 FT THROUGH THE WEEKEND. THE WIND DIRECTION WILL BE N FRI...VEERING TO NE FRI NIGHT...E TO SE SAT...AND S TO SW ON SUN AS HIGH PRESSURE MOVES PROGRESSIVELY OFFSHORE. LOW PRESSURE MAY DEVELOP ON THE TROUGH LATE SAT AND IF THE LOW DOES DEVELOP...A TIGHTER PRESSURE GRADIENT WILL BE REALIZED...RESULTING IN HIGHER WINDS AND POSSIBLY SEAS BY THE END OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...FREEZING RAIN ADVISORY UNTIL NOON EST WEDNESDAY FOR SCZ017-023- 024-032-033-053. NC...FREEZING RAIN ADVISORY UNTIL NOON EST WEDNESDAY FOR NCZ087-096- 099-105. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST WEDNESDAY NIGHT FOR AMZ250-252-254-256. && $$ SYNOPSIS...MJC NEAR TERM...DCH/MBB SHORT TERM...MJC LONG TERM...RJD AVIATION...MRR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
711 AM EST WED JAN 14 2015 .SYNOPSIS... HIGH PRESSURE ACROSS THE REGION WILL STAY IN PLACE THROUGH THURSDAY. A COLD FRONT WILL SINK SOUTH ACROSS THE GREAT LAKES THURSDAY NIGHT INTO FRIDAY...THEN RETREAT BACK NORTH AS A WARM FRONT ON SATURDAY. LOW PRESSURE WILL MOVE ACROSS THE NORTHERN LAKES AND TAKE A COLD FRONT ACROSS THE LOCAL AREA SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... PESKY STRATUS AND FLURRIES CONTINUE THIS MORNING ACROSS NW OHIO. THE STRATUS HAS BEEN DRIFTING FOR 24 HRS NOW...SHRINKING AND EXPANDING DIURNALLY. SO THIS MORNING IT IS OVER TOL/FDY. IT IS ENTIRELY POSSIBLE THAT LOCATIONS COULD GET A COATING OF DRY SNOW THIS MORNING. ALL OTHERS WILL BE DRY. FORECAST WILL LEAN TOWARD SOME BREAKS THIS AFTERNOON/PARTLY CLOUDY...BUT STRATUS MAY VERY WELL STILL BE LINGERING IN THE AREA OR DRIFT EAST AGAIN. HAVE MADE MINOR SKY GRID MODIFICATIONS WITH THIS EARLY MORNING UPDATE TO ACCOUNT FOR AN EASTWARD DRIFT. PATCHY FOG HAS BECOME MORE WIDESPREAD OVER THE LAST COUPLE OF HOURS. HAVE ADDED THAT TO THE FORECAST FOR FIRST THING THIS MORNING. ANOTHER AREA OF STRATUS WILL HUG THE SOUTHEAST BORDER SO EXPECT A CLOUDY PERIOD WITH BREAKS LATER. WITH HIGH PRESSURE OVERHEAD WINDS WILL BE LIGHT. COLD TO START WITH A NUMBER OF SUB- ZERO READINGS. SEE NO REASON TO STRAY FAR FROM GUIDANCE TODAY WHICH GIVES TEENS WEST TO LOWER 20S EAST. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... TONIGHT WILL BE THE LAST SUPER COLD NIGHT WITH TEMPERATURES MODIFYING THROUGH THE END OF THE WEEK. THE HIGH WILL STILL BE OVERHEAD/CENTERED TO OUR EAST BUT EXPECT A FEW CLOUDS WITH A MINOR SHORTWAVE MOVING ACROSS THE REGION. WINDS WILL BE LIGHT FROM THE SOUTHWEST. WITH THAT WILL ONLY TAKE LOWS INTO THE POSITIVE SINGLE DIGITS. EVEN WITH THE SOUTHWEST FLOW THURSDAY WE DO NOT GET A BIG PUSH OF WARM AIR...MID/UPPER 20S WILL BE ALL WE CAN DO BUT THIS IS AN IMPROVEMENT ON THE RECENT PAST. LOW PRESSURE WILL TRACK ACROSS SOUTHERN CANADA...THE NORTHERN LAKES...AND INTO QUEBEC. THE BEST PUSH WITH THE COLD FRONT WILL STAY TO OUR NORTH AND WE WILL SEE IN INCREASE IN CLOUDS AND SOME SNOW SHOWERS TOWARD FRIDAY MORNING...MORE SO WHEN THE FLOW COMES AROUND TO THE WEST- NORTHWEST. GFS IS STILL A LITTLE MORE AGGRESSIVE WITH COLDER AIR. WITH A LAKE THAT IS INCREASINGLY ICE COVERED AND LIMITED ENVIRONMENTAL MOISTURE NOT TOO CONCERNED ABOUT DECENT LAKE EFFECT. WILL CONTINUE TO GO WITH A CHANCE OF SNOW SHOWERS FOR NE OH/NW PA. RIDGE MOVES IN QUICKLY FRIDAY AFTERNOON AND ANY PRECIP WOULD BE COMING TO AN END. WITH THE COLD AIR ADVECTION FRIDAY MAY SEE TEMPS JUST HOLD STEADY IN THE LOWER 20S/AROUND 20. SO CHILLY AGAIN FRIDAY NIGHT ESPECIALLY ACROSS THE EAST...BUT WESTERN AREAS WILL BE BETTER OFF WITH THE APPROACH OF A WARM FRONT AND SOUTHERLY FLOW. GENERALLY TEENS WITH SOME SINGLE DIGITS FOR NW PA. THE WARM FRONT LIFTS NORTH ACROSS THE AREA ON SATURDAY AND TEMPERATURES WILL WARM...ENOUGH TO GET US ABOVE AVERAGE. WILL GO WITH UPPER 30S/AROUND 40 AFTER THE COOL START. LOW PRESSURE WILL BE MOVING ACROSS THE NORTHERN LAKES SATURDAY NIGHT...BUT THE LOCAL AREA WILL STILL BE IN THE WARM SECTOR SO TEMPERATURES WILL ONLY FALL BACK TO AROUND FREEZING. && .LONG TERM /SUNDAY THROUGH TUESDAY/... A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY. ALL THE MODELS ARE IN AGREEMENT...EXCEPT THE ECMWF IS DRIER WITH THIS FEATURE. NONE THE LESS IT WILL BE A LIGHT SNOW EVENT WITH CHANCE POPS AT THIS TIME...THEY MIGHT NEED TO BE RAISED. SOME SNOW COULD LINGER OVER THE SNOW BELT SUNDAY NIGHT IN THE NORTHWEST FLOW WITH A LAKE AND 850 MB TEMPERATURE DIFFERENCE OF 13C. THE POPS MAY HAVE TO BE RAISED AS THE TRENDS BECOME CLEARER. DRY MONDAY WITH A RIDGE ACROSS THE AREA AND THEN ANOTHER LOW WILL BE APPROACHING THE AREA FOR TUESDAY. SOME TIMING ISSUES AT THIS TIME...WILL KEEP TUESDAY DRY AND CONTINUE THE CHANCE TUESDAY NIGHT. USED A BLEND OF GUIDANCE FOR THE TEMPERATURE FORECAST. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... A RIDGE WILL BE BUILDING INTO THE AREA TODAY AND THEN IT WILL SHIFT SOUTH THURSDAY. STRATUS DEVELOPED OVER NW OHIO AND IT WILL BE SOMEWHAT SLOW TO BURNOFF. THE HRRR AND RUC MODELS MOVES LOW CLOUDS FROM WEST TO EAST...NONE OF THE OTHER MODELS DO THIS. THIS SEEMS REASONABLE...SO WENT ALONG WITH IT. THE LOW CLOUDS WILL DECREASE SLOWLY FROM THE WEST STARTING LATE THIS AFTERNOON. SOME MID CLOUDS WILL BE OVER THE AREA TONIGHT ASSOCIATED WITH A WEAK TROF ALOFT. .OUTLOOK...NON VFR POSSIBLE ACROSS NE OH/NW PA THURSDAY NIGHT INTO FRIDAY AND AGAIN LATE SATURDAY NIGHT INTO SUNDAY. && .MARINE... AT THIS TIME NOT EXPECTING GALE FORCE WINDS THROUGH THE PERIOD...IT COULD BE CLOSE AT TIMES AS SEVERAL WEATHER SYSTEMS WILL MOVE THROUGH. A RIDGE WILL BE BUILDING ACROSS THE LAKE TODAY AND THEN IT WILL SHIFT EAST TONIGHT AND A WEAK FRONT WILL MOVE THROUGH THURSDAY NIGHT. SUSTAINED WINDS OF 30 KNOTS ARE LIKELY AND THEN A RIDGE WILL BUILD IN QUICKLY BY LATE FRIDAY. STRONG SOUTHWEST WINDS WILL DEVELOP ON SATURDAY IN THE WARM ADVECTION...HOWEVER...THEY WILL NOT MIX DOWN TOTALLY. A COLD FRONT WILL MOVE THROUGH ON SUNDAY WITH WINDS BELOW GALE FORCE. THIS WILL HAVE TO BE WATCHED. NOT MUCH WIND ON MONDAY AS A RIDGE WILL BRIEFLY MOVE ACROSS THE LAKE. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...OUDEMAN NEAR TERM...OUDEMAN SHORT TERM...OUDEMAN LONG TERM...KIELTYKA AVIATION...KIELTYKA MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS TULSA OK
1152 PM CST TUE JAN 13 2015 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. MID CLOUDS...CURRENTLY JUST WEST OF A BVO/TUL/MLC LINE WILL SLOWLY SPREAD EAST OVERNIGHT INTO WEDNESDAY MORNING. STILL COULD SEE AREAS OF LIGHT SNOW SPREAD ACROSS NORTHEAST OKLAHOMA INTO THE DAY WEDNESDAY WITH A LIMITED/PROB30 CHANCE FOR MVFR CONDITIONS AT BVO. OTHERWISE...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE FORECAST PERIOD. && .PREV DISCUSSION... /ISSUED 938 PM CST TUE JAN 13 2015/ ..UPDATE... DISCUSSION... UPDATED FORECAST THIS EVENING TO INCLUDE SOME LOW CHANCE POPS ACROSS NORTHEAST OKLAHOMA LATE TONIGHT INTO THE DAY WEDNESDAY. LOCAL WRF AND HRRR HINTING AT THE POTENTIAL FOR WIDELY SCATTERED AREAS OF LIGHT SNOW/SLEET DURING THIS TIME. LATEST 00Z NAM ALSO DEVELOPS SOME LIGHT PRECIP DURING THE DAY WEDNESDAY NORTH OF INTERSTATE 44 AS MAIN UPPER LEVEL JET STREAK SHIFTS INTO THE REGION. ANY SNOW ACCUMULATIONS WOULD BE LIGHT AND FAIRLY LOCALIZED WITH NO WIDESPREAD IMPACTS. THIS WILL CONTINUE TO BE MONITORED AS ADDITIONAL DATA BECOMES AVAILABLE. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...12
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
657 AM EST WED JAN 14 2015 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE STRETCHED FROM THE MID MISSISSIPPI VALLEY TO THE NEW ENGLAND STATES WILL MAINTAIN CONTROL OF OUR LOCAL WEATHER THROUGH MUCH OF THURSDAY. A VIGOROUS UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT WILL PUSH SOUTHEAST FROM THE GREAT LAKES AND CROSS THE STATE THURSDAY NIGHT AND EARLY FRIDAY. THIS RELATIVELY MOISTURE STARVED SYSTEM WILL BE ACCOMPANIED BY SOME SNOW SHOWERS AND FOLLOWED BY ANOTHER SHOT OF COLDER AIR FOR FRIDAY AND ON INTO THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A RELATIVELY THICK SHIELD OF MID AND HIGH CLOUDS COVERS ALL BUT THE NW MTNS OF PA EARLY TODAY AS A RELATIVELY WEAK AND FAST MOVING UPPER TROUGH HEADS ENE ACROSS THE CENTRAL APPALACHIANS. A SHALLOW LAYER OF MOIST AND ANOMALOUS EASTERLY FLOW OFF THE ATLANTIC WAS COMBINING WITH A BROAD AREA OF MODERATELY STRONG 850-700 MB FGEN AND UVVEL OVER THE MID ATLANTIC PIEDMONT REGION... TO PRODUCE A BLOSSOMING AREA OF WINTRY PRECIP /FALLING MAINLY AS PERIODS OF LIGHT SNOW ALONG AND JUST TO THE NW OF I95 IN NRN VA AND MD/. WHILE CLOUDS ACROSS SOUTHERN PENN KEEP MIN TEMPS IN THE TEENS THERE...MAINLY CLEAR SKIES...VERY DRY TEMPS AND ESSENTIALLY CALM AIR WILL LEAD TO FRIGID TEMPS IN THE -5 TO -15F RANGE NEAR AND TO THE WEST OF KBFD THROUGH SUNRISE. 00Z HI RES ARW AND NMM...ALONG WITH THE 07Z HRRR AND RAP PRECIP DEPICTION IS ALREADY TOO FAR SOUTH BY NEARLY 50 NM /AND BARELY BRUSHES THE DC AREAS WITH ANY MEASURABLE SNOW THIS MORNING/. 00Z 12KM NAM AND 03Z SREF ARE THE FURTHER NORTH WITH THE LEADING EDGE OF THE LIGHT SNOW AND APPEAR TO BE MORE ON TARGET WITH ITS PRESENT LOCATION. ANOMALOUS EASTERLY 925 MB FLOW SHOULD HELP TO MAINTAIN SOME VERY LIGHT SNOW AS IT APPROACHES THE MASON DIXON LINE AROUND OR SHORTLY AFTER DAYBREAK. RATHER THICK MID-LEVEL CLOUDS WILL LIKELY BE AFFECTING AT LEAST THE SOUTHERN PORTION OF THE FORECAST AREA TO START THE DAY TODAY. SOME LIGHT SNOW AND A DUSTING IS POSSIBLE TO THE SOUTH OF A KTHV TO KLNS LINE LATE THIS MORNING AS THE AXIS OF STRONGEST EASTERLY LLVL FLOW AND A FEW EAST/WEST BANDS OF WEAK 850-700 MB FRONTOGENESIS AND UVVEL BRUSHES THAT AREA. MADE SOME MINOR TWEAKS TO CLOUDS/TEMPS/POPS...AND LIGHT SNOW AMOUNTS ACROSS THE FAR SE ZONES TODAY. ANY LIGHT SNOW ACCUM TO THE SOUTH OF A KTHV TO KLNS LINE SHOULD BE LIMITED TO UNDER 0.5 OF AN INCH. AND WILL MAKE JUST SOME MINOR ADJUSTMENTS TO THE ALREADY VERY LIGHT QPF/SNOW FORECAST FOR OUR EXTREME SE CWA...NEAR AND TO THE SOUTH OF STATE RT 30 FROM YORK TO LANCASTER. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... AS THE SFC LOW LOCATED OFFSHORE STARTS TO BECOME BETTER ORGANIZED ALONG THE FRONTAL ZONE...GEOSTROPHIC FLOW SHOULD TURN BACK MORE TO THE NORTH ONCE AGAIN AND FORCE THE CLOUDS BACK OUT OF THE AREA FROM NW TO SE LATE TODAY. RIDGE OF HIGH PRESSURE WILL SLIDE EAST FROM THE OHIO VALLEY AND CROSS OUR FCST AREA LATE TONIGHT AND EARLY THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... A BROADENING LONGWAVE TROF OVER THE EASTERN HALF OF THE CONUS WILL LEAD TO COLD AND GENERALLY DRY WEATHER ACROSS THE REGION THROUGH THE REMAINDER OF THE WEEK. UPPER FLOW IS FORECAST TO BECOME ZONAL FOR A SHORT PERIOD OVER THE WEEKEND BEFORE ANOTHER TROF REDEVELOPS FROM THE OHIO VALLEY EASTWARD NEXT WEEK. THE PATTERN THROUGH THIS WEEK SHOULD SEE SEVERAL WEAK AND MAINLY DRY SHORTWAVES IN THE NRN STREAM THAT COULD BRING A SLIGHT CHANCE OF LIGHT PCPN...MAINLY FRIDAY AFTN IN THE NW MTNS...AND LATE THIS UPCOMING WEEKEND. CONSIDERING THE PHASE SHIFT AND INCONSISTENCIES OF THE ENSEMBLES...HAVE LEFT ONLY CHANCE POPS. TEMPS SHOULD SEE A GENERAL RISE AS THE WEEK CONTINUES INTO THE WEEKEND...WITH HIGHS CLIMBING INTO THE 40S ALONG THE SOUTHERN TIER POSSIBLE BY LATE IN THE WEEKEND. THE RENEWED TROFFING WILL SEND TEMPS BACK DOWN NEXT WEEK...BUT AT THIS POINT NOT LOOKING AS COLD AS THIS WEEK. CHANCES OF PCPN REMAIN LOW FOR NEXT WEEK AS WELL WITH LITTLE TO NO ROOM FOR AMPLIFICATION OF SHORTWAVE ENERGY. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... IN THE WAKE OF A WEAK SHORTWAVE EXITING THE SOUTHERN MID ATLANTIC STATES THIS MORNING...AN EXPANSIVE AREA OF LOW CLOUDS WILL MOVE INTO THE AIRSPACE FROM THE SW. MEDIUM-HIGH CONFIDENCE IN WDSPRD LOW END VFR TO MVFR CIGS DEVELOPING BY AFTN AND LASTING THROUGH TONIGHT. LOW LEVEL MSTR ASCENDING THE SW MTNS VIA WEAK UPSLOPE FLOW SUGGESTS IFR IS POSSIBLE AT JST...WITH FCST SOUNDINGS INDICATING FAVORABLE SET-UP FOR -FZDZ. LOW CLOUDS SHOULD GET TRAPPED BENEATH INVERSION AND MAINTAIN LOW/REDUCED CIGS OVERNIGHT INTO THURSDAY MORNING. OUTLOOK... THU...VFR/NO SIG WX. FRI...MVFR CIGS/-SHSN POSSIBLE N/W. VFR ELSEWHERE. NW WIND GUSTS 20-30KTS. SAT..VFR/NO SIG WX. SUN...IFR RESTRICTIONS POSSIBLE WITH CHANCE OF SNOW. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/GARTNER AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
546 AM EST WED JAN 14 2015 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE STRETCHED FROM THE MID MISSISSIPPI VALLEY TO THE NEW ENGLAND STATES WILL MAINTAIN CONTROL OF OUR LOCAL WEATHER THROUGH MUCH OF THURSDAY. A VIGOROUS UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT WILL PUSH SOUTHEAST FROM THE GREAT LAKES AND CROSS THE STATE THURSDAY NIGHT AND EARLY FRIDAY. THIS RELATIVELY MOISTURE STARVED SYSTEM WILL BE ACCOMPANIED BY SOME SNOW SHOWERS AND FOLLOWED BY ANOTHER SHOT OF COLDER AIR FOR FRIDAY AND ON INTO THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A RELATIVELY THICK SHIELD OF MID AND HIGH CLOUDS COVERS ALL BUT THE NW MTNS OF BENN EARLY TODAY AS A RELATIVELY WEAK AND FAST MOVING UPPER TROUGH HEADS ENE ACROSS THE CENTRAL APPALACHIANS. A SHALLOW LAYER OF MOIST AND ANOMALOUS EASTERLY FLOW OFF THE ATLANTIC WAS COMBINING WITH A BROAD AREA OF MODERATELY STRONG 850-700 MB FGEN AND UVVEL OVER THE MID ATLANTIC PIEDMONT REGION... TO PRODUCE A BLOSSOMING AREA OF WINTRY PRECIP /FALLING MAINLY AS PERIODS OF LIGHT SNOW ALONG AND JUST TO THE NW OF I95 IN NRN VA AND MD/. WHILE CLOUDS ACROSS SOUTHERN PENN KEEP MIN TEMPS IN THE TEENS THERE...MAINLY CLEAR SKIES...VERY DRY TEMPS AND ESSENTIALLY CALM AIR WILL LEAD TO FRIGID TEMPS IN THE -5 TO -15F RANGE NEAR AND TO THE WEST OF KBFD THROUGH SUNRISE. 00Z HI RES ARW AND NMM...ALONG WITH THE 07Z HRRR AND RAP PRECIP DEPICTION IS ALREADY TOO FAR SOUTH BY NEARLY 50 NM /AND BARELY BRUSHES THE DC AREAS WITH ANY MEASURABLE SNOW THIS MORNING/. 00Z 12KM NAM AND 03Z SREF ARE THE FURTHER NORTH WITH THE LEADING EDGE OF THE LIGHT SNOW AND APPEAR TO BE MORE ON TARGET WITH ITS PRESENT LOCATION. ANOMALOUS EASTERLY 925 MB FLOW SHOULD HELP TO MAINTAIN SOME VERY LIGHT SNOW AS IT APPROACHES THE MASON DIXON LINE AROUND OR SHORTLY AFTER DAYBREAK. RATHER THICK MID-LEVEL CLOUDS WILL LIKELY BE AFFECTING AT LEAST THE SOUTHERN PORTION OF THE FORECAST AREA TO START THE DAY TODAY. SOME LIGHT SNOW AND A DUSTING IS POSSIBLE TO THE SOUTH OF A KTHV TO KLNS LINE LATE THIS MORNING AS THE AXIS OF STRONGEST EASTERLY LLVL FLOW AND A FEW EAST/WEST BANDS OF WEAK 850-700 MB FRONTOGENESIS AND UVVEL BRUSHES THAT AREA. MADE SOME MINOR TWEAKS TO CLOUDS/TEMPS/POPS...AND LIGHT SNOW AMOUNTS ACROSS THE FAR SE ZONES TODAY. ANY LIGHT SNOW ACCUM TO THE SOUTH OF A KTHV TO KLNS LINE SHOULD BE LIMITED TO UNDER 0.5 OF AN INCH. AND WILL MAKE JUST SOME MINOR ADJUSTMENTS TO THE ALREADY VERY LIGHT QPF/SNOW FORECAST FOR OUR EXTREME SE CWA...NEAR AND TO THE SOUTH OF STATE RT 30 FROM YORK TO LANCASTER. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... AS THE SFC LOW LOCATED OFFSHORE STARTS TO BECOME BETTER ORGANIZED ALONG THE FRONTAL ZONE...GEOSTROPHIC FLOW SHOULD TURN BACK MORE TO THE NORTH ONCE AGAIN AND FORCE THE CLOUDS BACK OUT OF THE AREA FROM NW TO SE LATE TODAY. RIDGE OF HIGH PRESSURE WILL SLIDE EAST FROM THE OHIO VALLEY AND CROSS OUR FCST AREA LATE TONIGHT AND EARLY THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... A BROADENING LONGWAVE TROF OVER THE EASTERN HALF OF THE CONUS WILL LEAD TO COLD AND GENERALLY DRY WEATHER ACROSS THE REGION THROUGH THE REMAINDER OF THE WEEK. UPPER FLOW IS FORECAST TO BECOME ZONAL FOR A SHORT PERIOD OVER THE WEEKEND BEFORE ANOTHER TROF REDEVELOPS FROM THE OHIO VALLEY EASTWARD NEXT WEEK. THE PATTERN THROUGH THIS WEEK SHOULD SEE SEVERAL WEAK AND MAINLY DRY SHORTWAVES IN THE NRN STREAM THAT COULD BRING A SLIGHT CHANCE OF LIGHT PCPN...MAINLY FRIDAY AFTN IN THE NW MTNS...AND LATE THIS UPCOMING WEEKEND. CONSIDERING THE PHASE SHIFT AND INCONSISTENCIES OF THE ENSEMBLES...HAVE LEFT ONLY CHANCE POPS. TEMPS SHOULD SEE A GENERAL RISE AS THE WEEK CONTINUES INTO THE WEEKEND...WITH HIGHS CLIMBING INTO THE 40S ALONG THE SOUTHERN TIER POSSIBLE BY LATE IN THE WEEKEND. THE RENEWED TROFFING WILL SEND TEMPS BACK DOWN NEXT WEEK...BUT AT THIS POINT NOT LOOKING AS COLD AS THIS WEEK. CHANCES OF PCPN REMAIN LOW FOR NEXT WEEK AS WELL WITH LITTLE TO NO ROOM FOR AMPLIFICATION OF SHORTWAVE ENERGY. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... 14/09Z UPDATE...MVFR CIGS HAS DEVELOPED ON NRN PERIPHERY OF WINTRY PCPN ZONE CURRENTLY EXPANDING NEWD BTWN THE I-81 AND I-95 CORRIDORS. AMENDED MDT/LNS TO LOWER CIGS WHICH SHOULD PERSIST THROUGH AT LEAST MIDDAY. OBS TRENDS SUGGEST JST WILL BE THE NEXT SITE TO DROP TO MVFR AS LOW CIGS SHIFT NWD FROM THE NRN WV/MD PNHDL. EXTRAPOLATION OF RADAR TRENDS NOW SUGGESTS -SN MAY CLIP MDT/LNS WITH BETTER CHANCE AT LNS VS. MDT. 14/06Z...A WEAK SHORTWAVE LIFTING NEWD FROM THE TN VALLEY/CENTRAL APPALACHIANS WILL CROSS THE SOUTHERN MID-ATLANTIC STATES EARLY TODAY. THE ENERGY IS EXPECTED TO INVIGORATE AN AREA OF LOW PRESSURE EAST OF THE NC OUTER BANKS WHICH IS THEN FORECAST TO EXIT NORTHEAST WELL OFF THE EAST COAST. WHILE THE BULK OF THE PRECIPITATION WITH THIS SYSTEM IS FORECAST TO REMAIN S/E OF THE AIRSPACE...SOME LOWER CIGS ARE A GOOD BET...AT LEAST AOB 5KFT OVER THE SOUTH-CENTRAL/SE TERMINALS. HIGHEST CONFIDENCE IN POTENTIAL IFR CONDITIONS WOULD BE AT JST GIVEN UPSLOPE FLOW AND SUPPORT FROM GUIDANCE. OUTLOOK... THU...VFR/NO SIG WX. FRI...MVFR CIGS/-SHSN POSSIBLE N/W. VFR ELSEWHERE. NW WIND GUSTS 20-30KTS. SAT..VFR/NO SIG WX. SUN...IFR RESTRICTIONS POSSIBLE WITH CHANCE OF SNOW. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/GARTNER AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
509 AM EST WED JAN 14 2015 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE STRETCHED FROM THE MID MISSISSIPPI VALLEY TO THE NEW ENGLAND STATES WILL MAINTAIN CONTROL OF OUR LOCAL WEATHER THROUGH MUCH OF THURSDAY. A VIGOROUS UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT WILL PUSH SOUTHEAST FROM THE GREAT LAKES AND CROSS THE STATE THURSDAY NIGHT AND EARLY FRIDAY. THIS RELATIVELY MOISTURE STARVED SYSTEM WILL BE ACCOMPANIED BY SOME SNOW SHOWERS AND FOLLOWED BY ANOTHER SHOT OF COLDER AIR FOR FRIDAY AND ON INTO THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... HIGH CLOUDS CONTINUE TO SPREAD NORTH AND GRADUALLY THICKEN-UP ACROSS THE SOUTHERN HALF OF PENN...WHILE MAINLY CLEAR SKIES ACROSS THE NORTHERN MTNS HAVE ALLOWED TEMPS TO DROP TO FRIGID LEVELS OF 5-10 BELOW ZERO IN SOME RURAL VALLEY LOCATIONS OF ELK...MCKEAN AND POTTER COUNTIES. SCHOOL/MESO OBS FROM THAT AREA SHOW A -14F INVOF MT JEWETT IN SOUTHERN MCKEAN COUNTY...AND -11F IN THE CITY OF BRADFORD. TEMPS SHOULD FALL UP TO ANOTHER FEW DEG F ACROSS THE NRN TIER...WHILE THE INCREASING CLOUDS FURTHER SOUTH LEVEL OFF THE TEMPS. THE SOUTHERN THIRD OF THE STATE SHOULD SEE TEMPS HOLDING STEADY IN THE MID TO UPPER TEENS...OR FALL JUST A FEW DEG F UNDER THE THICKEST CLOUD COVER. WILL BE CLOSELY MONITORING THE PROGRESSION OF THE NRN EDGE OF LIGHT SNOW MAKING IT/S WAY NNE ALONG THE I-95 CORRIDOR /AND NOW OVERSPREADING THE D.C. AREA. 00Z HI RES ARW AND NMM...ALONG WITH THE 07Z HRRR AND RAP PRECIP DEPICTION IS ALREADY TOO FAR SOUTH BY NEARLY 50 NM /AND BARELY BRUSHES THE DC AREAS WITH ANY MEASURABLE SNOW THIS MORNING/. 00Z 12KM NAM AND 03Z SREF ARE THE FURTHER NORTH WITH THE LEADING EDGE OF THE LIGHT SNOW AND APPEAR TO BE MORE ON TARGET WITH ITS PRESENT LOCATION. ANOMALOUS EASTERLY 925 MB FLOW SHOULD HELP TO MAINTAIN SOME VERY LIGHT SNOW AS IT APPROACHES THE MASON DIXON LINE AROUND OR SHORTLY AFTER DAYBREAK. WILL MAKE JUST SOME MINOR ADJUSTMENTS TO THE ALREADY VERY LIGHT QPF/SNOW FORECAST FOR OUR EXTREME SE CWA...NEAR AND TO THE SOUTH OF STATE RT 30 FROM YORK TO LANCASTER. && .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM THURSDAY/... RATHER THICK MID-LEVEL CLOUDS WILL LIKELY BE AFFECTING AT LEAST THE SOUTHERN PORTION OF THE FORECAST AREA TO START THE DAY TODAY. SOME LIGHT SNOW AND A DUSTING IS POSSIBLE TO THE SOUTH OF A KTHV TO KLNS LINE LATE THIS MORNING AS THE AXIS OF STRONGEST EASTERLY LLVL FLOW AND A FEW EAST/WEST BANDS OF WEAK 850-700 MB FRONTOGENESIS AND UVVEL BRUSHES THAT AREA. AS THE SFC LOW OFFSHORE STARTS TO BECOME BETTER ORGANIZED ALONG THE FRONTAL ZONE...GEOSTROPHIC FLOW SHOULD TURN BACK MORE TO THE NORTH ONCE AGAIN AND FORCE THE CLOUDS BACK OUT OF THE AREA FROM NW TO SE. IT WILL REMAIN COLD TODAY AND HIGHS IN THE 20S WILL BE WELL BELOW NORMAL. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... A BROADENING LONGWAVE TROF OVER THE EASTERN HALF OF THE CONUS WILL LEAD TO COLD AND GENERALLY DRY WEATHER ACROSS THE REGION THROUGH THE REMAINDER OF THE WEEK. UPPER FLOW IS FORECAST TO BECOME ZONAL FOR A SHORT PERIOD OVER THE WEEKEND BEFORE ANOTHER TROF REDEVELOPS FROM THE OHIO VALLEY EASTWARD NEXT WEEK. THE PATTERN THROUGH THIS WEEK SHOULD SEE SEVERAL WEAK AND MAINLY DRY SHORTWAVES IN THE NRN STREAM THAT COULD BRING A SLIGHT CHANCE OF LIGHT PCPN...MAINLY FRIDAY AFTN IN THE NW MTNS...AND LATE THIS UPCOMING WEEKEND. CONSIDERING THE PHASE SHIFT AND INCONSISTENCIES OF THE ENSEMBLES...HAVE LEFT ONLY CHANCE POPS. TEMPS SHOULD SEE A GENERAL RISE AS THE WEEK CONTINUES INTO THE WEEKEND...WITH HIGHS CLIMBING INTO THE 40S ALONG THE SOUTHERN TIER POSSIBLE BY LATE IN THE WEEKEND. THE RENEWED TROFFING WILL SEND TEMPS BACK DOWN NEXT WEEK...BUT AT THIS POINT NOT LOOKING AS COLD AS THIS WEEK. CHANCES OF PCPN REMAIN LOW FOR NEXT WEEK AS WELL WITH LITTLE TO NO ROOM FOR AMPLIFICATION OF SHORTWAVE ENERGY. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... 14/09Z UPDATE...MVFR CIGS HAS DEVELOPED ON NRN PERIPHERY OF WINTRY PCPN ZONE CURRENTLY EXPANDING NEWD BTWN THE I-81 AND I-95 CORRIDORS. AMENDED MDT/LNS TO LOWER CIGS WHICH SHOULD PERSIST THROUGH AT LEAST MIDDAY. OBS TRENDS SUGGEST JST WILL BE THE NEXT SITE TO DROP TO MVFR AS LOW CIGS SHIFT NWD FROM THE NRN WV/MD PNHDL. EXTRAPOLATION OF RADAR TRENDS NOW SUGGESTS -SN MAY CLIP MDT/LNS WITH BETTER CHANCE AT LNS VS. MDT. 14/06Z...A WEAK SHORTWAVE LIFTING NEWD FROM THE TN VALLEY/CENTRAL APPALACHIANS WILL CROSS THE SOUTHERN MID-ATLANTIC STATES EARLY TODAY. THE ENERGY IS EXPECTED TO INVIGORATE AN AREA OF LOW PRESSURE EAST OF THE NC OUTER BANKS WHICH IS THEN FORECAST TO EXIT NORTHEAST WELL OFF THE EAST COAST. WHILE THE BULK OF THE PRECIPITATION WITH THIS SYSTEM IS FORECAST TO REMAIN S/E OF THE AIRSPACE...SOME LOWER CIGS ARE A GOOD BET...AT LEAST AOB 5KFT OVER THE SOUTH-CENTRAL/SE TERMINALS. HIGHEST CONFIDENCE IN POTENTIAL IFR CONDITIONS WOULD BE AT JST GIVEN UPSLOPE FLOW AND SUPPORT FROM GUIDANCE. OUTLOOK... THU...VFR/NO SIG WX. FRI...MVFR CIGS/-SHSN POSSIBLE N/W. VFR ELSEWHERE. NW WIND GUSTS 20-30KTS. SAT..VFR/NO SIG WX. SUN...IFR RESTRICTIONS POSSIBLE WITH CHANCE OF SNOW. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...DEVOIR/LAMBERT SHORT TERM...LA CORTE/LAMBERT LONG TERM...LAMBERT/GARTNER AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
300 AM EST WED JAN 14 2015 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE STRETCHED FROM THE MID MISSISSIPPI VALLEY TO THE NEW ENGLAND STATES WILL MAINTAIN CONTROL OF OUR LOCAL WEATHER THROUGH MUCH OF THURSDAY. A VIGOROUS UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT WILL PUSH SOUTHEAST FROM THE GREAT LAKES AND CROSS THE STATE THURSDAY NIGHT AND EARLY FRIDAY. THIS RELATIVELY MOISTURE STARVED SYSTEM WILL BE ACCOMPANIED BY SOME SNOW SHOWERS AND FOLLOWED BY ANOTHER SHOT OF COLDER AIR FOR FRIDAY AND ON INTO THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... HIGH CLOUDS CONTINUE TO SPREAD NORTH AND GRADUALLY THICKEN-UP ACROSS THE SOUTHERN HALF OF PENN...WHILE MAINLY CLEAR SKIES ACROSS THE NORTHERN MTNS HAVE ALLOWED TEMPS TO DROP TO FRIGID LEVELS OF 5-10 BELOW ZERO IN SOME RURAL VALLEY LOCATIONS OF ELK...MCKEAN AND POTTER COUNTIES. SCHOOL/MESO OBS FROM THAT AREA SHOW A -14F INVOF MT JEWETT IN SOUTHERN MCKEAN COUNTY...AND -11F IN THE CITY OF BRADFORD. TEMPS SHOULD FALL UP TO ANOTHER FEW DEG F ACROSS THE NRN TIER...WHILE THE INCREASING CLOUDS FURTHER SOUTH LEVEL OFF THE TEMPS. THE SOUTHERN THIRD OF THE STATE SHOULD SEE TEMPS HOLDING STEADY IN THE MID TO UPPER TEENS...OR FALL JUST A FEW DEG F UNDER THE THICKEST CLOUD COVER. WILL BE CLOSELY MONITORING THE PROGRESSION OF THE NRN EDGE OF LIGHT SNOW MAKING IT/S WAY NNE ALONG THE I-95 CORRIDOR /AND NOW OVERSPREADING THE D.C. AREA. 00Z HI RES ARW AND NMM...ALONG WITH THE 07Z HRRR AND RAP PRECIP DEPICTION IS ALREADY TOO FAR SOUTH BY NEARLY 50 NM /AND BARELY BRUSHES THE DC AREAS WITH ANY MEASURABLE SNOW THIS MORNING/. 00Z 12KM NAM AND 03Z SREF ARE THE FURTHER NORTH WITH THE LEADING EDGE OF THE LIGHT SNOW AND APPEAR TO BE MORE ON TARGET WITH ITS PRESENT LOCATION. ANOMALOUS EASTERLY 925 MB FLOW SHOULD HELP TO MAINTAIN SOME VERY LIGHT SNOW AS IT APPROACHES THE MASON DIXON LINE AROUND OR SHORTLY AFTER DAYBREAK. WILL MAKE JUST SOME MINOR ADJUSTMENTS TO THE ALREADY VERY LIGHT QPF/SNOW FORECAST FOR OUR EXTREME SE CWA...NEAR AND TO THE SOUTH OF STATE RT 30 FROM YORK TO LANCASTER. && .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM THURSDAY/... RATHER THICK MID-LEVEL CLOUDS WILL LIKELY BE AFFECTING AT LEAST THE SOUTHERN PORTION OF THE FORECAST AREA TO START THE DAY TODAY. SOME LIGHT SNOW AND A DUSTING IS POSSIBLE TO THE SOUTH OF A KTHV TO KLNS LINE LATE THIS MORNING AS THE AXIS OF STRONGEST EASTERLY LLVL FLOW AND A FEW EAST/WEST BANDS OF WEAK 850-700 MB FRONTOGENESIS AND UVVEL BRUSHES THAT AREA. AS THE SFC LOW OFFSHORE STARTS TO BECOME BETTER ORGANIZED ALONG THE FRONTAL ZONE...GEOSTROPHIC FLOW SHOULD TURN BACK MORE TO THE NORTH ONCE AGAIN AND FORCE THE CLOUDS BACK OUT OF THE AREA FROM NW TO SE. IT WILL REMAIN COLD TODAY AND HIGHS IN THE 20S WILL BE WELL BELOW NORMAL. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... A BROADENING LONGWAVE TROF OVER THE EASTERN HALF OF THE CONUS WILL LEAD TO COLD AND GENERALLY DRY WEATHER ACROSS THE REGION THROUGH THE REMAINDER OF THE WEEK. UPPER FLOW IS FORECAST TO BECOME ZONAL FOR A SHORT PERIOD OVER THE WEEKEND BEFORE ANOTHER TROF REDEVELOPS FROM THE OHIO VALLEY EASTWARD NEXT WEEK. THE PATTERN THROUGH THIS WEEK SHOULD SEE SEVERAL WEAK AND MAINLY DRY SHORTWAVES IN THE NRN STREAM THAT COULD BRING A SLIGHT CHANCE OF LIGHT PCPN...MAINLY FRIDAY AFTN IN THE NW MTNS...AND LATE THIS UPCOMING WEEKEND. CONSIDERING THE PHASE SHIFT AND INCONSISTENCIES OF THE ENSEMBLES...HAVE LEFT ONLY CHANCE POPS. TEMPS SHOULD SEE A GENERAL RISE AS THE WEEK CONTINUES INTO THE WEEKEND...WITH HIGHS CLIMBING INTO THE 40S ALONG THE SOUTHERN TIER POSSIBLE BY LATE IN THE WEEKEND. THE RENEWED TROFFING WILL SEND TEMPS BACK DOWN NEXT WEEK...BUT AT THIS POINT NOT LOOKING AS COLD AS THIS WEEK. CHANCES OF PCPN REMAIN LOW FOR NEXT WEEK AS WELL WITH LITTLE TO NO ROOM FOR AMPLIFICATION OF SHORTWAVE ENERGY. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... A WEAK SHORTWAVE LIFTING NEWD FROM THE TN VALLEY/CENTRAL APPALACHIANS WILL CROSS THE SOUTHERN MID-ATLANTIC STATES EARLY TODAY. THE ENERGY IS EXPECTED TO INVIGORATE AN AREA OF LOW PRESSURE EAST OF THE NC OUTER BANKS WHICH IS THEN FORECAST TO EXIT NORTHEAST WELL OFF THE EAST COAST. WHILE THE BULK OF THE PRECIPITATION WITH THIS SYSTEM IS FORECAST TO REMAIN S/E OF THE AIRSPACE...SOME LOWER CIGS ARE A GOOD BET...AT LEAST AOB 5KFT OVER THE SOUTH-CENTRAL/SE TERMINALS. HIGHEST CONFIDENCE IN POTENTIAL IFR CONDITIONS WOULD BE AT JST GIVEN UPSLOPE FLOW AND SUPPORT FROM GUIDANCE. RESTRICTIONS ARE STILL A TOUGH CALL TOWARD THE SERN AIRFIELDS MDT/LNS -- AND FOR NOW WILL GO WITH LOW VFR CIGS BLW 5KFT AND MONITOR CIG TRENDS TO THE SOUTH. CONFIDENCE IS EVEN LOWER IN LIGHT SNOW POTENTIAL AS PRECIPITATION AREA CURRENTLY MOVG NWD ACRS CENTRAL VA INTO SRN MD CONTINUES TO LIFT NEWD THIS MORNING. OUTLOOK... THU...VFR/NO SIG WX. FRI...MVFR CIGS/-SHSN POSSIBLE N/W. VFR ELSEWHERE. NW WIND GUSTS 20-30KTS. SAT..VFR/NO SIG WX. SUN...IFR RESTRICTIONS POSSIBLE WITH CHANCE OF SNOW. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT/LA CORTE NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/GARTNER AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
309 AM CST WED JAN 14 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 308 AM CST WED JAN 14 2015 NOT A LOT GOING ON TODAY AND TONIGHT AS A NORTHWEST FLOW ALOFT CONTINUES TO DOMINATE THE AREAS WEATHER. THE REMAINING STRATUS ACROSS OUR FORECAST AREA EARLY THIS MORNING WILL EXIT...ONLY TO BE REPLACED BY MID AND HIGH LEVEL CLOUDS MOVING IN FROM THE NORTHWEST. BUT TODAY WILL MARK THE BEGINNING OF A WARMING TREND...WITH HIGHS FINALLY CLOSER TO SEASONAL NORMALS WITH 20S ALONG AND EAST OF THE JAMES RIVER VALLEY...AND LOWER 30S IN OUR SOUTH CENTRAL SD ZONES. TONIGHT...A SURFACE TROUGH OF LOW PRESSURE WILL MOVE THROUGH. AHEAD OF THE TROUGH...TEMPERATURES WILL LIKELY BE COOLER THAN READINGS BEHIND THE TROUGH. THEREFORE TEMPERATURES MAY STEADY OUT OR EVEN SLIGHTLY RISE AFTER MIDNIGHT FOR MANY LOCATIONS. BECAUSE OF THIS... LOWS SHOULD BOTTOM OUT IN THE MID TEENS TO LOWER 20S. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 308 AM CST WED JAN 14 2015 EXTENDED CONTINUES TO APPEAR RELATIVELY MILD FOR THIS TIME OF YEAR WITH WEST TO NORTHWEST FLOW PREVAILING ACROSS THE PLAINS. WITH WEST TO NORTHWEST FLOW PREVAILING...DO NOT THINK LOW LYING STRATUS WILL BE AN ISSUE...BUT MODELS SUGGESTING THAT A FAIR AMOUNT OF MID AND UPPER LEVEL CLOUDS WILL BE AROUND LATE THIS WEEK INTO THIS WEEKEND. RAISED CLOUD COVER. MIXING TO 925 HPA ALONE WOULD SUGGEST WARMER TEMPERATURES THAT THE CURRENT FORECAST...HOWEVER...WITH FAIRLY DEEP SNOWCOVER UPSTREAM...WAS NOT OVERLY AGGRESSIVE IN RAISING TEMPERATURES. ON FRIDAY...MODELS SHOW WINDS INCREASING ACROSS THE EASTERN THIRD AHEAD OF A TROUGH APPROACHING FROM THE WEST. WITH STRONG SOUTHWEST FLOW ALOFT...SOUTHWEST MINNESOTA MAY BE ABLE TO WARM MORE THAN THEY WOULD OTHERWISE. SURFACE TROUGH PASSES TO THE NORTH OF THE FORECAST AREA FRIDAY NIGHT. COLD FRONT MOVES THROUGH THE AREA LATE IN THE OVERNIGHT PERIOD...WITH LITTLE IN THE WAY OF COLD AIR BEHIND THE FRONT. HOWEVER...THE PRESSURE GRADIENT IS QUITE STRONG BEHIND THE FRONT WITH 40-45 KNOTS AT 925 HPA PREVAILING THROUGH THE DAY ON SATURDAY. HAVE INCREASED WINDS FAIRLY SUBSTANTIALLY DURING THE DAY ON SATURDAY...AS IT LOOKS LIKE A SOLID WIND ADVISORY. WINDS ARE SLOW TO SUBSIDE SATURDAY NIGHT...BUT WITH LACK OF COLD AIR ADVECTION WAS UNSURE HOW LONG TO KEEP THEM STRONG. FOR NOW...SIDED CLOSE TO CONS MOS NUMBERS THROUGH THE EVENING HOURS. LOOKS LIKE A SLIGHT COOL DOWN ON SUNDAY INTO MONDAY BUT TEMPERATURES STILL REMAIN ABOVE NORMAL. MODELS ARE IN REMARKABLY GOOD AGREEMENT ON OPEN WAVE TRANSLATING FROM THE PACIFIC NORTHWEST EASTWARD INTO THE PLAINS. THIS WAVE WOULD AFFECT THE FORECAST AREA MONDAY NIGHT INTO TUESDAY. WITH GOOD AGREEMENT IN TERMS OF PLACEMENT AND TIMING...INCREASED POPS OVER INITIAL GUIDANCE MONDAY NIGHT INTO TUESDAY. PRECIPITATION TYPE WITH THIS SYSTEM COULD BE A LITTLE TRICKY ACROSS THE SOUTHERN EDGE OF THE FORECAST AREA WITH TEMPERATURES AT OR SLIGHTLY ABOVE FREEZING. FOR NOW...LEFT PRECIP TYPE AS RAIN OR SNOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1044 PM CST TUE JAN 13 2015 AREA OF MVFR STRATUS WILL MOVE ACROSS THE AREA TONIGHT. USED THE RAP AND HRRR FOR TIMING...AS BOTH MATCH CURRENT OBS PRETTY WELL. EXPECT A RETURN TO VFR FROM NORTHWEST TO SOUTHEAST LATER TONIGHT INTO THE MORNING. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...MJ LONG TERM... AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1046 PM CST TUE JAN 13 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 332 PM CST TUE JAN 13 2015 LIFT ASSOCIATED WITH THE SHORT WAVE...SOME INSTABILITY ALOFT...AND LIFT LARGELY IN THE DENDRITIC ZONE WILL CONTINUE TO TRIGGER SNOW SHOWERS OVER THE NORTHERN COUNTIES LATE THIS AFTERNOON WITH ACTIVITY PASSING INTO THE NORTHEAST AND EAST CENTRAL AREA...THAT IS SOUTHWEST MN TO THE IA GREAT LAKES...THIS EVENING BEFORE PASSING EAST SOUTHEAST OF THE AREA DURING THE NIGHT. VISIBILITIES HAVE LOWERED TO AS LOW AS A QUARTER MILE THIS AFTERNOON AND THIS COULD CONTINUE FOR SEVERAL HOURS. ACCUMULATIONS WILL BE LIMITED BY DURATION AND STILL DO NOT EXPECT MORE THAN AN INCH ANYWHERE...THOUGH WE WILL HAVE TO WATCH THE FAR NORTHEAST INCLUDING MARSHALL MN AREA AROUND SUNSET. LITTLE OR NOTHING IS EXPECTED SOUTH OF INTERSTATE 90 EXCEPT PERHAPS IN NORTHWEST IA DOWN TO SPENCER FOR THE EVENING. AS THE WAVE PASSES...THE SEMI STIFF SOUTHERLY SURFACE FLOW WILL EASE AND START TO TURN MORE WESTERLY TONIGHT. CLOUD COVER PRESENTS SOME PROBLEMS WITH MODELS INDICATING SOME LOW LEVEL MOISTURE BANDS BEHIND THE WAVE. ENOUGH CLEARING SHOULD OCCUR SO THAT WITH THE LIGHT WINDS...WE WILL HAVE A LITTLE SURFACE TEMPERATURE DROP TONIGHT... THOUGH OF COURSE LOWS WILL BE MUCH WARMER THAN THOSE LAST NIGHT...MAINLY 5 TO 10 ABOVE ZERO EXCEPT 10 TO 15 SOUTHWEST. DO NOT EXPECT ANY FOG...IT IS THE KIND OF PATTERN WHERE WE MIGHT EXPECT A LITTLE AS THE WINDS GOT LIGHT IF WE HAD GOTTEN ABOVE FREEZING TODAY. WEDNESDAY WILL BE UNEVENTFUL...WITH STILL SOME QUESTIONS ON CLOUD COVER...BUT DO NOT EXPECT EITHER CLEAR OR SOLID OVERCAST. TEMPERATURES LOOK IN LINE WITH WHAT WE HAVE BEEN GOING FOR WITH 20S NORTH AND EAST TO LOWER 30S SOUTHWEST. WINDS WILL BE LIGHTER THAN TODAY...PEAKING AT AROUND 10 MPH WITH SOME SORT OF WESTERLY COMPONENT...AND IN VIEW OF RECENT COLD IT SHOULD FEEL PLEASANT FOR ANYONE WHO DID NOT JUST FLY IN FROM FLORIDA. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 332 PM CST TUE JAN 13 2015 PROLONGED PERIOD OF MUCH MILDER TEMPERATURES AND DRY WEATHER IS EXPECTED THROUGH THE BULK MIDDLE AND LONG RANGE. PREDOMINATELY NORTHWEST UPPER LEVEL FLOW WILL REIGN. WHILE A FEW WEAK SHORTWAVES TRACK INTO THE NORTHERN PLAINS... WE ARE NOT EXPECTING ANY PRECIPITATION THROUGH MONDAY. THE FIRST WEAK SHORTWAVE DROPS ALONG THE NORTHWEST FLOW ON WEDNESDAY NIGHT AND THURSDAY MORNING. MID AND HIGH CLOUDS WILL BLANKET THE REGION WEDNESDAY EVENING THEN CLEAR OUT FROM WEST TO EAST OVERNIGHT. 925 MB TEMPERATURES WILL BE MILD AT AROUND 0 TO +3C THURSDAY MORNING...BUT COOL SLIGHTLY THURSDAY AFTERNOON. WEST TO NORTHWEST WINDS LOW LEVEL WINDS SHOULD MIX DOWN SOME MUCH WARMER TEMPERATURES IN THE 30S...WITH THE LOWER 40S IN THE LOWER BRULE. A LITTLE MORE UNCERTAINTY ARRIVES ON FRIDAY MORNING AS ANOTHER WEAK AND FAST MOVING SHORTWAVE DIVES SOUTHEAST. MODELS VARY IN THE STRENGTH AND TRACK OF THIS FEATURE...BUT ONLY IMPACT WILL BE SOME PASSING HIGH CLOUDS. TEMPERATURES SHOULD REMAIN MILD WITH SIMILAR READINGS TO THURSDAY. BEHIND THE WAVE...WINDY CONDITIONS DEVELOP FRIDAY NIGHT AND SATURDAY. MIXY CONDITIONS AND WARM LOW AND MID LEVELS WILL RESULT IN EVEN MILDER TEMPERATURES ON SATURDAY. HIGHS WILL IMPROVE A FEW MORE DEGREES IN OUR NORTHEAST...REACHING THE MID 30S TO LOWER 40S AREAWIDE. A MORE SUBSTANTIAL TROUGH BREAKS DOWN THE RIDGE EARLY NEXT WEEK. THIS LOOKS LIKE THE BEST SHOT FOR ANY PRECIPITATION DURING THE FORECAST PERIOD...WITH THE BEST CHANCES MONDAY NIGHT INTO TUESDAY. WILL GO WITH LOW END CHANCES OF SNOW FOR NOW...PERHAPS MIXING WITH RAIN IN THE FAR SOUTH. TEMPERATURES REMAIN ABOVE NORMAL EARLY NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1044 PM CST TUE JAN 13 2015 AREA OF MVFR STRATUS WILL MOVE ACROSS THE AREA TONIGHT. USED THE RAP AND HRRR FOR TIMING...AS BOTH MATCH CURRENT OBS PRETTY WELL. EXPECT A RETURN TO VFR FROM NORTHWEST TO SOUTHEAST LATER TONIGHT INTO THE MORNING. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM... LONG TERM... AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
605 AM CST WED JAN 14 2015 .DISCUSSION... 12Z TAF DISCUSSION IN AVIATION SECTION BELOW. && .AVIATION... TOUGH START FOR THE TAF THIS MORNING. CIGS HAVE SCT TO VFR ACROSS A LOT OF THE AREA WITH AN OVC 6000-8000FT CEILING. MVFR CIGS HAVE FILLED BACK IN OVER KGLS AND KSGR. IT LOOKS LIKE THIS MIGHT BE THE EXTENT AT WHICH DRIER AIR AROUND 925MB HAS MOVED INTO THE REGION MIXING OUT THE MVFR CIGS. INITIAL THOUGHTS HAVE BEEN THAT NAM/HRRR WAS ON RIGHT TRACK WITH PESSIMISTIC MVFR CIGS WITH DZ/RA BUT THINK RAP/GFS HAS BEEN BETTER SHOWING THE DRIER AIR AT 925MB. CHANGED TAF TO THIS THINKING OF THE RAP WITH VFR FOR THE NEXT 5-8HRS WITH MVFR CIGS DEVELOPING AGAIN. WITH KSGR BECOMING MVFR AGAIN...MAY SEE MVFR CIGS COME BACK TO KIAH/KHOU SOONER THAN EXPECTED. STILL THINK IT WILL TAKE ISENTROPIC LIFT OVER THE FRONTAL BOUNDARY SOME TIME FOR DZ TO DEVELOP. SHORT WAVE TROUGH SHOULD MOVE OVER THE AREA SO THINK FORECAST IS ON TRACK WITH RA TONIGHT WITH MVFR CIGS. MODELS DO BRING IN DRIER AIR ON THUR SO HOPEFULLY SEE CEILINGS LIFT WITH IF ANYTHING SOME HIGH CLOUDS FOR THUR AFTERNOON. 39 && .PREV DISCUSSION... /ISSUED 423 AM CST WED JAN 14 2015/ DISCUSSION... AN ACTIVE SUBTROPICAL JET WILL HELP KEEP CHANCES OF RAIN ACROSS SE TEXAS THROUGH THURSDAY. AN UPPER TROUGH OVER THE SOUTHERN PLAINS AND SOUTHERN ROCKIES WILL SHEAR OUT AS IT MOVES EASTWARD...BUT SHORTWAVE TROUGHS MOVING ALONG THE UPPER FLOW WILL HELP PROVIDE CHANCES FOR RAIN INTO THURSDAY MORNING. HOWEVER...THE UNSEASONABLY COOL DAYTIME CONDITIONS WILL PERSIST FOR ANOTHER DAY. HIGH PRESSURE AT THE SURFACE WILL KEEP NORTHERLY WINDS IN PLACE WHILE THE CLOUD COVER WILL KEEP THE DIURNAL TEMPERATURE RANGE UNDER 10 DEGREES BETWEEN TODAY AND TONIGHT. THE PASSAGE OF THE SHORTWAVE TROUGH ACROSS THE AREA WILL SCATTER OUT THE CLOUD DECK...ALTHOUGH HIGH CLOUDINESS MAY LINGER DUE TO THE POSITION OF THE SUBTROPICAL JET. STILL FELT THAT ENOUGH SUN WILL OCCUR TO HELP BRING HIGH TEMPERATURES ON THURSDAY INTO THE 50S. THIS WILL MEAN THAT THURSDAY WILL BE THE FIRST DAY WITH THE HIGH TEMPERATURES ABOVE THE 40S SINCE THE 7TH. DRIER CONDITIONS ARE EXPECTED INTO THE WEEKEND AS THE UPPER TROUGH MOVES EAST OF THE AREA AND A RIDGE BUILDS OVER THE WESTERN PART OF THE COUNTRY. THIS WILL ALSO MEAN A WARMING TREND WITH DAYTIME HIGHS INTO THE 60S OVER THE WEEKEND. THE MODELS DIFFER A BIT ON THE EVOLUTION OF A SHORTWAVE TROUGH MOVING THROUGH THE SOUTHERN PLAINS SATURDAY NIGHT AND SUNDAY. A COLD FRONT SHOULD ALSO MOVE THROUGH SE TEXAS. HOWEVER...THE CONSENSUS IS FOR RAIN CHANCES TO REMAIN LOW AHEAD OF THE FRONT. HIGH PRESSURE WILL THEN KEEP DRY CONDITIONS IN PLACE THROUGH TUESDAY. 40 MARINE... HIGH PRESSURE WILL REMAIN OVER THE PLAINS THE NEXT COUPLE OF DAYS WHICH WILL SUPPORT NORTHERLY OFFSHORE WINDS. WINDS DO WEAKEN OVER THE UPPER TX COAST FRI INTO SAT AS AN AREA OF LOW PRESSURE FORMS IN THE PLAINS. SW WINDS DEVELOP SAT INTO SUN AHEAD OF THE NEXT COLD FRONT. GFS AND ECMWF HAVE THE FRONT PUSHING OFF THE COAST SAT NIGHT INTO SUN MORNING. GFS IS A BIT SLOWER THAN THE ECMWF BUT NOT BY MUCH. GFS IS ALSO STRONGER WITH WINDS BEHIND THE FRONT. FORECAST WINDS WERE INCREASED A BIT BEHIND THE FRONT. HIGH PRESSURE THEN BUILDS OVER THE AREA FOR EARLY NEXT WEEK. WINDS BEHIND THE FRONT MAY BE STRONG ENOUGH FOR SCA/SCEC TO POSSIBLY BE NEEDED. 39 AVIATION... RIGHT NOW THERE IS A MIX OF MVFR/VFR CIGS WITH MAINLY AN OVC 8000FT CEILING. DO THINK MVFR CIGS WILL DEVELOP BACK AGAIN AS ISENTROPIC LIFT INCREASES OVER THE FRONT DURING THE LATE MORNING. RADAR SHOWS SOME ISO AREAS OF DZ WITH SHRA OFF THE COAST SO AT LEAST SOME LIFT IS OCCURRING. LATEST NAM/HRRR CONTINUE WITH RA DEVELOPING OVER THE AREA. RAP/GFS/ECMWF KEEP MORE OF THE PRECIP OFFSHORE AND JUST INLAND. MAY NEED TO REVISIT HOW WIDESPREAD -RA/DZ WILL BE FOR 12Z TAF. LIKELY TO CONTINUE TO MENTION MVFR CIGS THROUGH MUCH OF THE TAF PERIOD. MODELS DO INCREASE RA OVER THE AREA WED NIGHT INTO THUR MORNING AS SHORT WAVE TROUGH ROTATES THROUGH. IN WAKE OF THE SHORTWAVE THERE MAY BE...WAIT FOR IT...CLEARING! 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 43 36 53 34 58 / 20 30 10 0 0 HOUSTON (IAH) 45 38 53 36 58 / 20 50 10 0 0 GALVESTON (GLS) 46 41 52 43 55 / 30 60 30 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...40 AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
513 AM CST WED JAN 14 2015 .AVIATION... MOST OF THE AREA IS UNDER MVFR CONDITIONS WITH IFR PRIMARILY WEST OF I-35 INTO THE HILL COUNTRY. AUS/SAT/SSF COULD ALSO TOUCH IFR CIGS EARLY THIS MORNING WITH A COMBINATION OF SLIGHTLY LOWER CEILINGS AND/OR LOWERING VSBY DUE TO LIGHT DRIZZLE FALLING IN PORTIONS OF THE AREA. RADAR IS SHOWING WAVES OF VERY LIGHT PRECIP BUT MOST METAR SITES ARE NOT REPORTING ANY DRIZZLE. THIS TOO WILL BE FAIRLY SPOTTY THROUGH THE MORNING. THE ISENTROPIC LIFT WILL CONTINUE AS MID LEVEL WINDS INCREASE WITH THE APROACH OF UPPER LEVEL SYSTEM TO THE WEST. WILL LIKELY SEE A REPEAT OF YESTERDAY WITH SOME SITES GOING UP TO VFR BY LATE IN THE AFTERNOON. HAVE DRT HITTING THE VFR FIRST AROUND 23Z, FOLLOWED BY AUS/SAT/SSF SHORTLY AFTER 00Z TONIGHT. HRRR SHOWS SOME VFR WORKING IN FROM THE NORTHEAST BY EARLY AFTERNOON WITH GFS MOS SHOWING THE CIGS RISING BY THE EVENING. NAM IS MUCH MORE PESSIMISTIC WITH IFR AND EVEN LIFR MUCH OF THE DAY TODAY. WENT MORE WITH THE GFS/HRRR SOLUTION. WHILE TODAY WILL BE CHALLENGING...ALL THE MODELS SHOW BIG IMPROVEMENTS ON THURSDAY AS WAVE MOVES EAST ALLOWING FOR OVERALL CLOUDCOVER TO DECREASE DRASTICALLY BY THU AFTERNOON. && .PREV DISCUSSION... /ISSUED 319 AM CST WED JAN 14 2015/ SHORT TERM (TODAY THROUGH THURSDAY)... GOES-WEST WATER VAPOR CHANNEL SHOWS AN UPPER LEVEL LOW SYSTEM OVER NORTHERN ARIZONA. THIS SYSTEM IS FORECAST TO PUSH TO THE SOUTHEAST THROUGHOUT THE DAY AND BECOME AN OPEN-WAVE THIS EVENING. UPPER LEVEL MOISTURE ASSOCIATED WITH THE OPEN-WAVE WILL MOVE ACROSS THE AREA THIS MORNING AND CONTINUE THROUGH LATE TONIGHT. AT THE SURFACE...A SHALLOW COOL LAYER REMAINS WITH NORTHERLY WINDS IN CONTROL. EXPECT MOSTLY CLOUDY TO CLOUDY SKIES WITH LIGHT RAIN/DRIZZLE ACROSS MUCH OF THE AREA AS PULSES OF UPPER LEVEL MOISTURE AND ISENTROPIC LIFT PREVAILS. A BIT COOLER THIS MORNING...ESPECIALLY OVER THE HILL COUNTRY WITH LOWER 30S AND UPPER 30S ELSEWHERE. TODAY`S HIGHS WILL REACH THE LOWER TO MID 40S DUE TO THE CLOUD COVERAGE. RAIN CHANCES COME TO AN END BY NOON THURSDAY ACROSS MUCH OF THE AREA AS THE UPPER LEVEL WAVE PUSHES TO EAST-SOUTHEAST...LEAVING BEHIND A ZONAL FLOW ALOFT THROUGH THE WEEKEND. LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)... CLOUDS WILL NOT DISAPPEAR COMPLETELY FOR THE LATTER PART OF THE WEEK AS MID TO UPPER LEVEL MOISTURE ARRIVES FROM THE WEST. HOWEVER...A WARMING TREND IS IN STORE FOR FRIDAY INTO THE UPCOMING WEEKEND AS SURFACE SOUTHERLY FLOW RETURNS. HIGHS ARE FORECAST TO REACH MID 60S BOTH SATURDAY AND SUNDAY. A DRY PACIFIC FRONT IS EXPECTED TO PUSH ACROSS THE AREA SATURDAY. IT MAY BRING SUNDAY`S HIGHS DOWN A DEGREE OR TWO FROM THOSE OBSERVED SATURDAY. BY MONDAY...SOUTHERLY FLOW RESUMES AND BRINGS HIGHS BACK TO THE LOWER 60S. CAN`T RULE OUT FEW PASSING SHOWERS MONDAY AS AN UPPER LEVEL SHORT WAVE RUSHES OVER THE REGION. NEXT RAIN CHANCES COULD COME MID WEEK AS AN UPPER LEVEL DISTURBANCE PUSHES ACROSS THE AREA AND A SURFACE LOW DEVELOPS ACROSS THE NORTHWEST GULF OF MEXICO. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 43 37 54 34 62 / 20 10 - 0 0 AUSTIN BERGSTROM INTL AIRPORT 43 36 54 31 61 / 20 20 - 0 0 NEW BRAUNFELS MUNI AIRPORT 44 38 54 34 62 / 20 20 - 0 0 BURNET MUNI AIRPORT 41 31 53 31 61 / 20 - - 0 0 DEL RIO INTL AIRPORT 48 38 56 37 62 / 20 - - 0 0 GEORGETOWN MUNI AIRPORT 42 32 52 31 61 / 20 - - 0 0 HONDO MUNI AIRPORT 46 38 57 33 62 / 20 - - 0 0 SAN MARCOS MUNI AIRPORT 44 37 53 33 61 / 20 20 - 0 0 LA GRANGE - FAYETTE REGIONAL 44 38 54 34 60 / 20 30 10 - 0 SAN ANTONIO INTL AIRPORT 45 38 56 35 62 / 20 10 - 0 0 STINSON MUNI AIRPORT 45 39 56 36 62 / 20 10 - 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...09 SYNOPTIC/GRIDS...17
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
311 AM MST WED JAN 14 2015 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 310 AM MST WED JAN 14 2015 PATCHY FOG AND WIDESPREAD LOW STRATUS ARE STILL AN ISSUE EARLY THIS MORNING PER WEB CAMS AND 11-3.9 MICROMETER SATELLITE IMAGERY. MAINLY CONCERNED ABOUT AREAS ALONG AND WEST OF THE LARAMIE RANGE...ALTHOUGH INCREASING LOW-LEVEL MOISTURE HAS ALLOWED SOME OF THIS TO CREEP INTO CHEYENNE IN THE LAST HOUR. ADDED AREAS OF DENSE FOG TO THE GRIDS FOR THE INTERSTATE 80 SUMMIT AS WEAK UPSLOPE COMBINED WITH GOOD BOUNDARY LAYER MOISTURE IS CONTRIBUTING TO VISIBILITY REDUCTIONS DOWN TO LESS THAN A HALF MILE. SINCE THIS APPEARS TO BE CONFINED PRIMARILY TO THE HIGHEST ELEVATIONS ALONG INTERSTATE 80...DECIDED AGAINST A DENSE FOG ADVISORY ATTM. GFS/NAM BUFKIT SOUNDINGS SUGGEST ENOUGH DRYING IN THE LOW LEVELS TO HELP SCATTER THINGS OUT BY AROUND 15Z...BUT WOULD NOT BE SURPRISED TO SEE CLOUDS LINGER THROUGH THE AFTERNOON FOR WESTERN AREAS. INCREASED CLOUD COVER FOR TODAY TO COMPENSATE FOR THE STRATUS AND POTENTIAL FOR A FEW CIRRUS LATER ON. MIGHT SEE A REPEAT OF THIS TONIGHT IN SOUTHWEST CARBON COUNTY BASED ON FORECAST SOUNDINGS...SO ADDED PATCHY FOG DURING THAT TIME AS WELL. NO CONCERNS ELSEWHERE. HEIGHT RISES WITH UPPER-LEVEL RIDGING OVER THE NEXT 24-48 HOURS WILL SIGNAL A TRANSITION TO A MUCH WARMER AND DRIER WEATHER PATTERN THRU THE END OF THE WEEK. 700-300 MILLIBAR MOISTURE FIELDS ARE RATHER DRY AND SUBSIDENCE ALOFT SHOULD ELIMINATE ANY POTENTIAL FOR PRECIP OVER THE NEXT FEW DAYS. AFTER A RELATIVELY COOL DAY TODAY...EXCELLENT LOW LEVEL DOWNSLOPE WILL BECOME ESTABLISHED ON THU AND FRI. H7 TEMPS ARE PROGGED IN THE +2 TO +4 DEG C RANGE OVER THE PLAINS AND MOS GUIDANCE IS SHOWING MAX TEMPERATURES WELL INTO THE 50S. SHOULD BE WELL ABOVE SEASONAL NORMALS WITH A FEW NEAR RECORD HIGHS POSSIBLE BY THE END OF THE WEEK. PRESSURE FALLS ALREADY OBSERVED FROM CENTRAL MT INTO PARTS OF NORTHEAST WY ARE EXPECTED TO EXPAND THROUGH THE REST OF THE WEEK IN RESPONSE TO MID LEVEL ENERGY EMANATING FROM THE NEXT LARGE SCALE SHORTWAVE CURRENTLY OFF THE PACIFIC COAST. THIS WILL STRENGTHEN LOW LEVEL GRADIENTS...AND ULTIMATELY LEAD TO AN UPTICK IN WINDS FOR THU AND FRI. MAY BE A LITTLE GUSTY TODAY FOR THE WIND PRONE AREAS...BUT THE H85 CAG-CPR GRADIENT ONLY TOPS OUT AROUND 20 METERS AT 21Z. DO NOT EXPECT ANYTHING MUCH MORE THAN 30-40 MPH. BIGGER CONCERNS FOR LATE THU NIGHT THROUGH FRI. THE NAM H85 CAG-CPR GRADIENT INCREASES TO 50-60 METERS BY 06Z FRI AND REMAINS HIGH INTO THE AFTERNOON AND EVENING. THIS RESULTS IN A BELT OF 50 TO 60 KT H75 FLOW OVER THE PRIMARY WIND CORRIDOR OF SOUTHEAST WY. THE MODELS SHOW STRONG SUBSIDENCE IN THE 700-500 MILLIBAR LAYER...SO A MARGINAL HIGH WIND EVENT FOR THE GAP AREAS LOOKS PROBABLE. DID NOT ISSUE ANY WIND HEADLINES THIS MORNING AS WE ARE STILL 4TH TO 5TH PERIOD...BUT LATER SHIFTS WILL MORE THAN LIKELY NEED TO HOIST WATCHES FOR THE ARLINGTON AND BORDEAUX AREAS. DO NOT THINK THIS WILL SPREAD INTO THE PLAINS IN THE SHORT TERM...BUT A LITTLE CONCERNED THAT THE GFS SHOWS FAVORABLE DOWNWARD MOTION SPREADING INTO CENTRAL LARAMIE COUNTY BY 18Z WITH 50 KT AVAILABLE UPSTAIRS. ALWAYS TOUGH TO HIT WARNING CRITERIA WITH LOW LEVEL WARM ADVECTION...BUT WILL CERTAINLY NEED TO WATCH THOSE ZONES JUST EAST OF THE LARAMIE RANGE ON FRI AFTERNOON FOR STRONG CHINOOK WINDS APPROACHING 60 MPH. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 300 AM MST WED JAN 14 2015 THERE ARE MINOR DIFFERENCES WITH THE 00Z/06Z MEDIUM RANGE DETERMINISTIC MODEL GUIDANCE...THEREFORE A BLEND OF OPERATIONAL GFS/ECMWF/GEM WILL BE APPLIED. PROGRESSIVE FLOW WEST TO EAST FLOW ALOFT WILL DOMINATE THE LONG TERM. SHORTWAVE TROUGH WILL TRACK EAST FROM THE PACIFIC NORTHWEST FRIDAY NIGHT ACROSS THE FRONT RANGE AND NORTH/CENTRAL GREAT PLAINS SATURDAY. ACCOMPANYING PACIFIC COLD FRONT AND MID/UPPER LEVEL MOISTURE WILL PRODUCE INCREASING CLOUDS FRIDAY NIGHT AND SATURDAY MORNING. LIGHT RAIN/SNOW WILL IMPACT NORTHEAST WY/WESTERN SD. ISOLATED LIGHT OROGRAPHIC SNOW SHOWERS MAY DEVELOP OVER THE SOUTH CENTRAL WY MOUNTAINS. ALBEIT COOLER COMPARED TO FRIDAY...DOWNSLOPE WEST-NORTHWEST WINDS WILL TEMPERATURES TO RISE INTO THE 40S OVER THE SOUTHEAST WY PLAINS AND SOUTHERN NE PANHANDLE SATURDAY AFTERNOON. STRONG WESTERLY WINDS WITH GUSTS TO 60 MPH WILL BE POSSIBLE FOR WIND PRONE AREAS OF SOUTHEAST WY PRIOR TO FROPA SATURDAY MORNING...THEN DIMINISH TO 25-40 MPH ALONG AND EAST OF THE LARAMIE RANGE DURING THE AFTERNOON. UPPER RIDGE OVER THE INTERMOUNTAIN WEST FLATTENS SOMEWHAT SUNDAY AS SHORTWAVE ENERGY PASSES EAST ALONG THE U.S.-CANADIAN BORDER. RESULTING NEAR ZONAL FLOW ALOFT AND DOWNSLOPE FLOW LEE OF THE LARAMIE RANGE WILL PROVIDE ABOVE NORMAL TEMPERATURES IN THE 40S. LIGHT OROGRAPHIC SNOW SHOWERS WILL BE POSSIBLE OVER THE SIERRA MADRE/MEDICINE BOW RANGES. ANOTHER UPPER TROUGH TRACKS EAST ACROSS THE PACIFIC NORTHWEST MONDAY MORNING THEN SOUTHEAST THROUGH WY MONDAY NIGHT. THIS SYSTEM WILL BE ACCOMPANIED BY A COLD FRONT. MID/UPPER LEVEL DYNAMICS AND MOISTURE APPEAR MORE ORGANIZED FOR SOME LIGHT PRECIPITATION OVER SOUTH/EAST CENTRAL WY AND NORTHERN NE PANHANDLE. WEST-NORTHWEST DOWNSLOPE WILL KEEP SOUTHEAST WY AND SOUTHERN NE PANHANDLE DRY. IT WILL BE BREEZY MONDAY AND MONDAY NIGHT PRIOR TO AND AFTER FROPA. LIGHT SNOW WILL GRADUALLY END DURING THE DAY TUESDAY FOLLOWING THE PASSAGE OF THE UPPER TROUGH. IT WILL TURN COOLER TUESDAY WITH HIGH TEMPERATURES CLOSER TO SEASONAL NORMALS IN THE 20S AND 30S. BREEZY NORTHWEST WINDS WILL PREVAIL AS WELL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 230 AM MST WED JAN 14 2015 PER LATEST HRRR MODEL GUIDANCE...MVFR TO LIFR CIGS WILL LINGER THIS MORNING WEST OF THE LARAMIE RANGE. OCCASIONAL MVFR CIGS WILL OCCUR FROM LARAMIE TO CHEYENNE AS WELL. VSBYS MAY BRIEFLY DROP TO MVFR AT RAWLINS AND SARATOGA...WITH IFR TO LIFR VSBYS OVER THE SOUTHERN LARAMIE RANGE. ELSEWHERE...EXPECT VFR CONDITIONS THROUGH THE FORECAST PERIOD. LIGHT AND VARIABLE WINDS EARLY THIS MORNING WILL BECOME SOUTHWESTERLY 10-15 KT...WITH GUSTS TO 20 KT LATE THIS MORNING ALONG AND WEST OF THE LARAMIE RANGE. && .FIRE WEATHER... ISSUED AT 230 AM MST WED JAN 14 2015 NO FIRE WEATHER CONCERNS. WITH SNOW STILL ON THE GROUND ACROSS MUCH OF THE AREA...OVERALL CONDITIONS WILL NOT SUPPORT NOTABLE FIRE GROWTH OVER THE NEXT FEW DAYS. MUCH WARMER TEMPERATURES ARE EXPECTED BY LATE IN THE WEEK...WITH WINDY CONDITIONS ALONG AND WEST OF THE LARAMIE RANGE. AFTERNOON RELATIVE HUMIDITY VALUES WILL REMAIN ABOVE 25 PERCENT THROUGH THE END OF THE WEEK. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...CLH LONG TERM...MAJ AVIATION...MAJ FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1004 PM MST TUE JAN 13 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 233 PM MST TUE JAN 13 2015 WEATHER CONDITIONS WILL BE TRANSITIONING TO SLIGHTLY WARMER TEMPS AND LESS LOW CLOUD COVER THROUGH WED. WATER VAPOR IMAGERY SHOWS AN UPPER LOW SPINNING ACROSS NORTHERN ARIZONA WITH LARGE SCALE ASCENT ACROSS SOUTHWESTERN COLORADO. LOW CLOUDS HAVE BEEN PERSISTENT OVER MUCH OF THE CWA...HOWEVER BEGINNING TO SEE SOME RAISING CIGS AS THE LLVLS ARE STARTING TO DRY. SFC PRESSURES ARE RISING AND A COLD FRONT IS MOVING OVER THE SOUTHERN ZONES RIGHT NOW WITH CHEYENNE GETTING NORTHERLY WIND GUSTS TO 30 MPH. LLVL RH PROGS AND SOUNDINGS INDICATE THAT LOW CLOUDS WILL CONTINUE TO CLEAR THROUGH THE EVENING AND EARLY NIGHT. ADDED SOME PATCHY FOG OVER PORTIONS OF CARBON COUNTY AS WINDS ARE REALLY LIGHT AND RUC SOUNDINGS SHOULD A GOOD LLVL INVERSION AND SATURATION. IT WILL BE ANOTHER CHILLY NIGHT ESPECIALLY WITH CLEARING SKIES. HEIGHTS ALOFT RISE ON WED WITH LIGHT WESTERLY SFC WINDS OVER MUCH OF THE REGION. STARTING TO GET SOME WEAK PRESSURE FALLS TO THE EAST OF THE LARAMIE RANGE HOWEVER THE CAG-CPR GRADIENT REMAINS BELOW 30 METERS. TEMPS WILL MODERATE SOME COMPARED TO TODAY (5-10 DEGREES WARMER) HOWEVER THE PRONOUNCED DOWNSLOPING AND WARMING WILL NOT ARRIVE UNTIL THURS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 233 PM MST TUE JAN 13 2015 WEDNESDAY NIGHT/THURSDAY...NORTH NORTHWEST FLOW ALOFT TRANSITIONS TO NORTHWEST. MILD WEATHER ENTHUSIASTS WILL ENJOY THURSDAY AS DOWNSLOPE WARMING AND A MODERATING AIRMASS HELPS HIGH TEMPERATURES TO SOAR WELL INTO THE 40S AND LOWER 50S EAST OF I-25 AND 30S WEST OF I-25. FRIDAY...FLOW ALOFT BACKS EVEN MORE TO WEST...INDUCING EVEN MORE DOWNSLOPE WARMING AND WITH PROGGED THICKNESSES AND 700 MB TEMPERATURES...WE EXPECT MAXIMUM TEMPERATURES TO SOAR WELL INTO THE 40S TO MID 50S AT LOWER ELEVATIONS ASSUMING MIDDLE AND HIGH CLOUD OPACITY...THICKNESS...IS MINIMAL. OUR WIND PRONE LOCATIONS MAY BE NEAR HIGH WIND CRITERIA BASED ON THE PROGGED LOW AND MID LEVEL GRADIENTS. SATURDAY...POTENT ALBERTA CLIPPER SHORTWAVE TROUGH ALOFT SWEEPS ACROSS THE NORTHERN PLAINS STATES WITH THE ASSOCIATED COLD FRONT SLIDING ACROSS OUR COUNTIES EARLY IN THE DAY...USHERING IN WINDY CONDITIONS ALONG WITH HIGH TEMPERATURES BACK INTO THE 30S TO MID 40S AT LOWER ELEVATIONS. COULD SEE A FEW LOCATIONS NEAR HIGH WIND CRITERIA IN THE FEW HOURS AFTER COLD FRONTAL PASSAGE DUE TO A BORA EVENT. SUNDAY...THE ROLLER COASTER CONTINUES WITH THE FLOW ALOFT TURNING WEST NORTHWEST...INDUCING MORE SURFACE LEE TROUGHING AND AIDING WARMING TEMPERATURES INTO THE 40S AND LOWER 50S AT LOWER ELEVATIONS. MONDAY...ANOTHER FAST MOVING SHORTWAVE TROUGH ALOFT SWEEPS ACROSS THE NORTHERN ROCKIES SENDING ANOTHER COLD FRONT INTO OUR COUNTIES IN THE AFTERNOON AND PRODUCING A COOLING TREND. WILL SEE SCATTERED OROGRAPHIC SNOWS OVER THE SNOWY AND SIERRA MADRE RANGES...DRY ELSEWHERE. TUESDAY...WINDY AND COLD WITH A FEW MOUNTAIN SNOW SHOWERS...AS A BROAD TROUGH ALOFT PREVAILS OVER THE NORTHERN PLAINS STATES SENDING REINFORCING COLD AIR SOUTHWARD ACROSS OUR COUNTIES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1001 PM MST TUE JAN 13 2015 LATEST 11-3.9U SATELLITE IMAGERY SHOWING LOW CLOUDS FILLING IN OVER CARBON COUNTY LATE THIS EVENING. DO BELIEVE THERE IS A CHANCE FOR KRWL TO GO DOWN ONCE AGAIN OVERNIGHT IN NORTHEAST FLOW. CONCERNS FOR KLAR AS WELL...BUT CONFIDENCE IS NOT THERE FOR THEM TO GO DOWN AS THEY STAY IN A NORTHEAST DOWNSLOPE WIND FLOW. ELSEWHERE...VFR CONDITIONS SHOULD PREVAIL. && .FIRE WEATHER... ISSUED AT 233 PM MST TUE JAN 13 2015 NO CRITICAL FIRE WEATHER CONDITIONS OVER THE NEXT FEW DAYS. WIDESPREAD SNOW COVER REMAINS ON THE GROUND. TEMPERATURES WILL WARM TO AROUND NORMAL BY THURSDAY...HOWEVER MINIMUM AFTERNOON HUMIDITY VALUES WILL STILL BE ABOVE 30 PERCENT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...ZF LONG TERM...RUBIN AVIATION...GCC FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1015 AM EST FRI JAN 16 2015 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION TODAY. HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT AND THEN SLIDE ACROSS THE REGION ON SATURDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE CAROLINA COAST AND LIFT NORTHWARD INTO OUR AREA SUNDAY NIGHT INTO MONDAY. MEANWHILE, A LOW PRESSURE SYSTEM WILL CROSS SOUTHERN CANADA AND ENTER THE GREAT LAKES REGION OVER THE WEEKEND. THESE TWO LOWS WILL MERGE, THEN DEEPEN AND MOVE NORTHWARD. HIGH PRESSURE WILL PUSH ACROSS THE REGION EARLY IN THE WEEK. A CLIPPER SYSTEM WILL APPROACH THE REGION WHILE ANOTHER LOW PRESSURE SYSTEM MAY DEVELOP NEAR THE CAROLINAS AROUND MIDWEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... VERY FEW CHANGES ON THE MID MORNING UPDATE. LATE MORNING TEMPERATURES AND DEWPOINTS WERE UPDATED WITH LATEST LAV GUIDANCE. BASED ON RADAR TRENDS, EXTENDED THREAT OF SNOW SHOWERS FURTHER SOUTHEAST DURING THE DAY. PREVIOUS DISCUSSION FOLLOWS.. TODAY...A WELL DEFINED COLD FRONT WITH STRONG COLD AIR ADVECTION BEHIND IT MOVES SEWD ACROSS THE FORECAST AREA THIS AFTERNOON WITH A WIND SHIFT TO THE NORTHWEST. THIS FRONT WILL BE MOISTURE STARVED BUT STILL WILL PROVIDE A PERIOD OF PARTLY TO MOSTLY CLOUDY SKIES OVER THE NW 2/3RDS OF OUR FCST AREA BETWEEN 11 AM AND 4 PM EST. ELEVATION AND FLOW OFF THE GREAT LAKES EARLY THIS AFTERNOON SHOULD PERMIT FLURRIES AND SNOW SHOWERS TO CROSS THE EXTREME NORTHWEST PORTION OF THE FORECAST AREA...POCONOS AND SUSSEX COUNTY NJ HIGH TERRAIN. ISOLATED SMALL AMOUNTS OF SNOW UNDER ONE HALF INCH ARE POSSIBLE...ESPECIALLY POCONOS. LAPSE RATES AND CONVERGENCE ALONG THE COLD FRONT PLUS LAKE EFFECT SNOW TRANSPORTED EASTWARD IN BANDS AHEAD OF THE FRONT ARE THE MAIN REASONS FOR THE FORECAST OF SNOW SHOWERS THERE. YOU CAN SEE THAT BAND ON THE 630 AM RADAR IMAGERY FROM SW NYS THROUGH KITH. PRIMARY TIMING FOR THE SNOW APPEARS TO BE NOON TO 2 PM. NSSL WRF HAS SLIGHTLY MORE EXTENSIVE SNOW FLURRIES IN NE PA THAN WE DO ATTM. THE SPC WRF AND HRRR WERE NOT THAT IMPRESSIVE AT LAST CHECK THROUGH 08Z. USUALLY 20F T/DEWPOINT SPREADS TAKE POTENTIAL SNOW SHOWERS AND LEAVE THEM AS VIRGA FLYING BY OVERHEAD...THE MILKY WHITE SKY LOOK AS I EXPECT TO SEE VIRGA IN NORTHERN AND CENTRAL NJ AND NE PA TODAY DOWN TO I78. FALLING TEMPERATURES A BIT SOONER THAN USUAL THIS AFTERNOON WITH MAX TEMPS EXPECTED 11 AM TO 1 PM PRIOR TO WIDESPREAD SC FORMATION. WEST WINDS WILL BECOME INCREASINGLY GUSTY THIS MORNING AND THEN NORTHWEST GUSTS 25-35 MPH THIS AFTERNOON. FORECAST TEMPS/DEWS/WINDS ARE A 50 50 BLEND OF THE 00Z/16 NCEP MOS GUIDANCE WITH THE TEMPS ON THE WARMER SIDE OF THE BLEND. THESE MAXIMUM TEMPERATURES TODAY ARE FORECAST AT OR UP TO 3 DEGREES ABOVE NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... COLDER BY 5 TO 15 DEGREES..DEPENDING ON LOCATION.. AS COMPARED TO THIS MORNING, ESPECIALLY WITH A WIND CHILL! GUSTY NORTHWEST WINDS 20 TO POSSIBLY 25 MPH CONTINUE TILL ABOUT MIDNIGHT WITH DECENT LOW LEVEL LAPSE RATES. WINDS TEND TO DECOUPLE IN THE COUNTRYSIDE LATE. WIND CHILL INDEX IS FORECAST TO BOTTOM OUT BETWEEN -10 AND -13 AT KMPO BETWEEN 4 AM AND 7 AM SATURDAY. FORECAST TEMPS/DEWS/WIND ARE A 50 50 BLEND OF THE 00Z/16 NCEP MOS GUIDANCE. THESE LOWS WILL RANGE FROM ABOUT 5 DEGREES BELOW NORMAL IN SOUTHERN DELAWARE TO ALMOST 15 DEGREES BELOW NORMAL IN THE POCONOS. && .LONG TERM /SATURDAY THROUGH THURSDAY/... AT THE SURFACE...HIGH PRESSURE SLIDES ACROSS THE REGION ON SATURDAY. A DEVELOPING COASTAL LOW WILL MOVE UP THE MIDDLE ATLANTIC COAST AND THEN MERGE WITH A LOW MOVING THROUGH THE GREAT LAKES REGION/ACROSS SOUTHERN CANADA. HIGH PRESSURE RETURNS FOR THE EARLY PART OF THE WEEK. A CLIPPER SYSTEM WILL APPROACH THE REGION WHILE ANOTHER LOW PRESSURE SYSTEM MAY DEVELOP NEAR THE CAROLINAS AROUND MIDWEEK. IN THE MID LEVELS...ZONAL FLOW ON SATURDAY WILL TRANSITION TO TROUGHING AS A DEEP MID LEVEL TROUGH MOVES INTO THE AREA ON SUNDAY. THE TROUGH BECOME NEGATIVELY TILTED BEFORE STARTING TO LIFT NORTHWARD ON MONDAY. ZONAL FLOW RETURNS FOR THE MID WEEK PERIOD. A FEW SHORTWAVES WILL ROTATE THROUGH THE MID LEVEL FLOW THROUGH THE PERIOD. SATURDAY...HIGH PRESSURE WILL SLIDE ACROSS THE REGION AND THIS SHOULD KEEP US NICE AND DRY TO START OFF THE WEEKEND. AS THE HIGH MOVES OFFSHORE, WE WILL SEE A SOUTHERLY FLOW DEVELOP. THIS SOUTHERLY FLOW SHOULD USHER IN A BIT MORE MOISTURE AND WE SHOULD TEMPERATURES START TO WARM UP JUST A BIT, AS WELL. SUNDAY...A COASTAL LOW STARTS TO DEVELOP NEAR THE CAROLINAS. MEANWHILE, ANOTHER LOW PRESSURE SYSTEM WILL BE CROSSING THE GREAT LAKES REGION AND CROSSING SOUTHERN CANADA. IN ADDITION, A DEEP MID LEVEL TROUGH WILL MOVING INTO THE AREA. THE DEVELOPING COASTAL LOW WILL START TO OVERSPREAD PRECIPITATION INTO OUR AREA SUNDAY MORNING AND THEN CONTINUE INTO THE AFTERNOON AND EVENING. THE TROUGH WILL CREATE ADDITIONAL LIFT AS IT STARTS TO NEGATIVELY TILT DURING THE EVENING AND THIS HAS THE POTENTIAL TO ENHANCE THE PRECIPITATION FOR A PERIOD OF TIME. THE SOUTHERN LOW WILL TAKE OVER AND ABSORB THE NORTHERN LOW. THE COMBINED LOW WILL DEEPEN AS IT PULLS TO THE NORTHEAST OF OUR AREA LATE SUNDAY INTO MONDAY. TEMPERATURES ON SUNDAY WILL BE COLD AT THE START BUT AS WE SEE SOME WARM ADVECTION OCCURRING, WE WILL START TO SEE TEMPERATURES RISE. MUCH OF THE AREA WILL BE BELOW FREEZING TO START THE DAY AND MIXED PRECIPITATION CAN BE EXPECTED. AS THE LOW LIFTS NORTHWARD, TEMPERATURES WILL RISE ABOVE FREEZING AND A CHANGEOVER TO RAIN CAN EXPECTED FROM SOUTH TO NORTH. A MIX MAY REMAIN ACROSS THE FAR NORTHERN PARTS OF OUR FORECAST AREA. THERE REMAINS SOME UNCERTAINTY TO HOW MUCH COLD AIR WILL BE IN PLACE WHEN THE PRECIPITATION ARRIVES ON SUNDAY. SHOULD COLD AIR BE STUBBORN AT THE SURFACE AS THE WARMER AIR MOVES IN, WE COULD SEE PRECIPITATION FALL AS FREEZING RAIN BEFORE THE TEMPERATURES AT THE SURFACE RISE ABOVE THE FREEZING MARK. FOR NOW, WE KEEP SNOW/RAIN IN THE FORECAST AND WILL ALLOW FOR ANOTHER ROUND OF DATA TO COME IN BEFORE WE FINALIZE THE DETAILS. MONDAY...AS THE LOW PULLS FURTHER TO THE NORTH, THE MID LEVEL TROUGH WILL GET PULLED TO THE NORTH DURING MONDAY MORNING. THE COLD FRONT FROM THE ABSORBED LOW WILL CROSS THE AREA. HOWEVER, IT WILL HAVE LOST MOST OF ITS OOMPH FROM HAVING BEEN ABSORBED INTO THE COASTAL LOW. WHILE THIS TYPICALLY WOULD MAKE FOR A DRY FRONTAL PASSAGE IN OUR AREA, THE STRONG NORTHWESTERLY WINDS SHOULD ALLOW FOR SOME LAKE EFFECT SNOWS TO MAKE INTO OUR AREA. IN ADDITION, WE WILL SEE A PUSH OF SOME COLDER AIR MOVE BACK ACROSS THE REGION. TUESDAY...A WEAK HIGH PRESSURE SYSTEM TRIES TO BUILD ACROSS THE AREA BUT LOOKS MORE LIKE A BRIEF RIDGE FOR OUR AREA. AS THE NEXT SYSTEM APPROACHES THE AREA, SOME PRECIPITATION MIGHT ARRIVE DURING TUESDAY NIGHT. WEDNESDAY AND THURSDAY...A CLIPPER SYSTEM LOOKS LIKE IT WILL APPROACH THE AREA ON WEDNESDAY BUT IT DOES NOT APPEAR TO BE ALL THAT STRONG. IN ADDITION, THERE IS THE POTENTIAL FOR ANOTHER LOW PRESSURE SYSTEM TO DEVELOP NEAR THE CAROLINAS. A FEW STRONG SHORTWAVES IN THE MID LEVELS LOOK TO CROSS OUR AREA DURING THIS TIME AS WELL. OVERALL, IT LOOKS LIKE WE WILL SEE SOME KIND OF STORM AFFECTING OUR AREA DURING THE MIDWEEK TIME FRAME BUT THERE IS A DIFFERENCE BETWEEN THE MODELS WITH RESPECT TO TIMING AND STRENGTH OF THESE ITEMS. WEDNESDAY LOOKS TO BE THE DAY WE SEE OUT NEXT ROUND OF MIXED PRECIPITATION WITH ANOTHER, SMALLER, CHANCE OF MORE ON THURSDAY. NEEDLESS TO SAY, THIS PART OF THE EXTENDED LOOKS UNSETTLED AND CONFIDENCE IS NOT HIGH. SATURDAY WILL BE A FAIRLY COLD DAY AND BELOW NORMAL. SUNDAY WILL WARM UP APPRECIABLY IN THE WAA AND TEMPS WILL RISE ABOVE NORMAL. THE REMAINDER OF THE WEEK LOOKS TO BE NEAR OR SLIGHTLY ABOVE NORMAL. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...VFR. SCT-BKN AOA 4500 FT. WEST WINDS GUST 20 KT THIS MORNING SHIFT NW AND GUST 25-33 KT DURING THE AFTERNOON. BRIEF IFR CONDS EXPECTED IN SCT SNOW SHOWERS OVER THE POCONOS 16Z- 21Z TODAY. ELSEWHERE... VIRGA EARLY THIS AFTN...POSSIBLE FLURRY DOWN TO KRDG AND KABE BUT TEMP DEW SPREADS OF 20F MAY PREVENT FLURRY OCCURRENCE THERE. TONIGHT...VFR CLEAR. NW WIND GUSTY AROUND 20 KT THROUGH 06Z THEN DIMINISH LATE. OUTLOOK... SATURDAY...VFR CONDITIONS EXPECTED. SUNDAY...VFR CONDITIONS EARLY...BECOMING MVFR, POSSIBLY IFR, IN RAIN/SNOW SHOWERS. SOUTH WINDS 5 TO 10 KNOTS. MONDAY...MAINLY VFR CONDITIONS EXPECTED. A CHANCE FOR SOME SNOW/RAIN SHOWERS EARLY NORTH AND WEST OF KPHL. GUSTY NORTHWEST WINDS 10 TO 15 KNOTS WITH GUSTS AROUND 20 TO 25 KNOTS, HIGHER TOWARDS THE EAST. TUESDAY...VFR CONDITIONS EXPECTED. LIGHT WESTERLY WINDS. && .MARINE... SCA PRIMARILY THIS AFTERNOON/EARLY TONIGHT. NW WIND GUSTS MAY TOUCH 34 KT FOR 2 OR 3 HOURS OVER ANZ450 - THE NORTHERN NEW JERSEY COASTAL WATERS...SOMETIME BETWEEN 5 PM AND 10 PM THIS EVENING. FOR NOW HAVE CAPPED GUSTS AT 32 KT AND NO GALE WARNING. 00Z/16 WW3 SEAS RAISED 1 FT AT 00Z AND 06Z/17. LIGHT FREEZING SPRAY IS FORECAST TO DEVELOP TONIGHT BY OUR TOOL AND AUTOMATED GUIDANCE FROM THE GFS MODEL. WINDS AND SEAS SLOWLY DIMINISH BEGINNING AROUND 06Z/17. OUTLOOK... SATURDAY...SEAS AND WINDS WILL DIMINISH BELOW SMALL CRAFT ADVISORY CRITERIA. SATURDAY NIGHT...WINDS WILL INCREASE THROUGH THE EVENING AND OVERNIGHT PERIOD AND MAY NEAR SMALL CRAFT ADVISORY CONDITIONS. SUNDAY AND MONDAY...SEAS WILL START TO BUILD SUNDAY AND WILL EXCEED 5 FEET BY SUNDAY AFTERNOON/EVENING. SEAS WILL REMAIN ELEVATED THROUGH MONDAY NIGHT BEFORE FALLING BELOW SMALL CRAFT ADVISORY LEVELS. WINDS WILL BECOME GUSTY, ESPECIALLY MONDAY, AND GUST ABOVE 25 KNOTS. WINDS WILL START TO DIMINISH LATE ON MONDAY. TUESDAY...BOTH WINDS AND SEAS SHOULD FALL BELOW SMALL CRAFT ADVISORY CRITERIA. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SATURDAY FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 2 AM EST SATURDAY FOR ANZ430-431. && $$ SYNOPSIS...MEOLA NEAR TERM...DRAG/SZATKOWSKI SHORT TERM...DRAG LONG TERM...MEOLA AVIATION...DRAG/SZATKOWSKI/MEOLA MARINE...DRAG/SZATKOWSKI/MEOLA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1045 AM EST FRI JAN 16 2015 .SYNOPSIS... HIGH PRESSURE BUILDING INTO THE REGION TODAY WILL MOVE OFFSHORE SATURDAY. AN UPPER LEVEL DISTURBANCE AND COLD FRONT CROSSING THE AREA SATURDAY NIGHT INTO SUNDAY WILL BRING ANOTHER CHANCE FOR SHOWERS. DRY WEATHER AND SEASONABLE TEMPERATURES ARE EXPECTED FOR THE BEGINNING OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... LOW CLOUDS OVER THE MIDLANDS ARE DECREASING AND SKIES SHOULD BE MOSTLY CLEAR OVER CENTRAL SC BY NOON AS HIGH PRESSURE SLOWLY BUILDS INTO THE AREA. OVER THE CSRA IT IS A DIFFERENT STORY. SAT IMAGES SHOW CLOUDS HOLDING TIGHT AS WEAK PRESSURE GRADIENT AND ABUNDANT LOW LEVEL MOISTURE KEEP THE CLOUDS IN. CLOUDS IN CSRA SHOULD START TO DECREASE DURING THE EARLY AFTERNOON HOURS. EXPECT AFTERNOON HIGHS IN THE LOWER TO MIDDLE 50S. SHOULD SEE CLEAR SKIES AND LIGHT WINDS TONIGHT AS SURFACE HIGH PRESSURE AND WEAK UPPER LEVEL RIDGING MOVES OVER THE AREA. OVERNIGHT LOWS SHOULD BE AT OR JUST BELOW THE FREEZING MARK. DO NOT EXPECT FOG TO BE AN ISSUE EXCEPT IN VERY LOW LYING AREAS WHERE THERE MAY BE SUFFICIENT POOLED MOISTURE TO SUPPORT PATCHY GROUND FOG. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... SURFACE HIGH PRESSURE AND WEAK UPPER LEVEL RIDGING WILL MOVE OFF THE COAST SATURDAY AFTERNOON. CLOUDS WILL BEGIN DEVELOPING OVER THE AREA SATURDAY NIGHT AS THE NEXT DISTURBANCE MOVES INTO THE REGION FROM THE WEST. AFTERNOON HIGHS SHOULD BE A DEGREE OR TWO HIGHER THAN ON FRIDAY. WE KEPT HIGHS IN THE MID 50S NORTH TO LOWER 60S SOUTH. GIVEN INCREASING CLOUDS...OVERNIGHT LOWS IN THE UPPER 30S AND LOWER 40S....WHICH AGREE WITH GUIDANCE CONSENSUS. && .LONG TERM /SUNDAY THROUGH THURSDAY/... MODELS ARE IN RELATIVELY GOOD AGREEMENT THROUGH THE LONG TERM WITH SOME DIFFERENCES IN TIMING AND INTENSITY WITH THE SYSTEM FOR SUNDAY INTO SUNDAY NIGHT. UPPER LEVEL TROUGH OVER THE EASTERN US WILL PROGRESS FROM THE MS RIVER VALLEY SUNDAY MORNING THROUGH THE FORECAST AREA SUNDAY NIGHT WITH ZONAL FLOW RETURNING TO THE AREA MONDAY THROUGH THE END OF THE LONG TERM. AT THE SURFACE LOW PRESSURE OVER THE GREAT LAKES SUNDAY WILL PUSH A FRONTAL BOUNDARY THROUGH THE FORECAST AREA SUNDAY LATE AFTERNOON/EVENING WITH A SECONDARY LOW CENTER DEVELOPING ALONG THE VA COAST SUNDAY EVENING. DRIER AIR WILL MOVE IN FOR MONDAY AND MONDAY NIGHT WITH A FRONTAL BOUNDARY SAGGING TOWARD THE AREA TUESDAY INTO THURSDAY. WITH VERY LIMITED DYNAMICS AND MOISTURE ASSOCIATED WITH THE FRONTAL BOUNDARY HAVE KEPT THE FORECAST DRY MONDAY THROUGH THURSDAY. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY ABOVE NORMAL. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... AT CAE...CUB...AND OGB...REMAINING LOW LEVEL CLOUDS WILL QUICKLY DISSIPATE BY AROUND 16Z AND EXPECT VFR CONDITIONS THROUGH THE PERIOD WITH LIGHT LOW LEVEL WINDS AS DRY HIGH PRESSURE BUILDS OVER THE AREA. AT AGS AND DNL...POOLED LOW LEVEL MOISTURE AND A WEAK PRESSURE GRADIENT ARE ALLOWING THE STRATUS DECK TO PERSIST. MODELS HOLD THE STRATUS DECK WITH THE HRRR SHOWING THE DECK BREAKING BY 19-20Z. CURRENT FORECAST IS FOR IFR TO MVFR CONDITIONS UNTIL 18Z...BECOMING VFR AFTER THAT TIME AS THE CLOUD DECK STARTS TO DISSIPATE. FOG MAY BE AN ISSUE AT AGS IN THE MORNING DUE TO POOLED LOW LEVEL MOISTURE NEAR THE RIVER AND STRONG RADIATION COOLING. EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS TO AVIATION EXPECTED FRIDAY AFTERNOON THROUGH SATURDAY. CIG RESTRICTIONS POSSIBLE LATE SAT NT/EARLY SUNDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS BISMARCK ND
847 AM CST FRI JAN 16 2015 .UPDATE... ISSUED AT 831 AM CST FRI JAN 16 2015 FOG/LOW CLOUDS REMAIN PARKED OVER CENTRAL INTO PARTS OF WESTERN NORTH DAKOTA THIS MORNING. LATEST GUIDANCE TRIES TO RETRACT THIS LATER THIS MORNING INTO THE AFTERNOON...THOUGH STILL SOME QUESTION ON HOW MUCH THIS ERODES. HIGH TEMPERATURE FORECAST REMAINS TRICKY AS THE POSITION OF THE CLOUD COVER WILL HAVE A GREAT INFLUENCE ON IT. FOR MORNING UPDATE HAVE INCREASED FOG COVERAGE A BIT...PARTICULARLY ON THE LEADING EDGE WHERE A BROAD AREA OF REDUCED VISIBILITIES ARE BEING REPORTED. UPDATE ISSUED AT 639 AM CST FRI JAN 16 2015 CLOUDS AND AREAS OF FOG CLOSELY FOLLOWS THE LATEST HRRR LOW CLOUD FRACTION FORECAST. THIS MODEL ERODES THE CLOUDS SLOWLY FROM THE WEST IN WARM ADVECTION BY NOON. WILL MAINTAIN THE FOG AND FREEZING DRIZZLE FORECAST AS HAVE HAD SEVERAL REPORTS EARLIER ACROSS THE NORTH CENTRAL AS THE CLOUDS WEE MOVING IN. BELIEVE ITS SOMEWHAT PATCHY BUT APPEARS REASONABLE. && .SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON) ISSUED AT 422 AM CST FRI JAN 16 2015 MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE LOW CLOUDS...AND POSSIBLE FLURRIES AND FREEZING DRIZZLE TODAY OVER MUCH OF CENTRAL AND PARTS OF NORTHWESTERN NORTH DAKOTA. THE FOCUS THEN SHIFTS TO TONIGHT AND SATURDAY AS A LOW PRESSURE SYSTEM BRINGS A CHANCE OF PRECIPITATION FRIDAY NIGHT INTO SATURDAY MORNING AND STRONG WINDS LATE FRIDAY NIGHT AND SATURDAY. CURRENTLY...SATELLITE INDICATES IFR STRATUS ALONG AND EAST OF A LINE FROM CROSBY TO TIOGA...TO HAZEN AND BISMARCK...TO NEAR WISHEK. LATEST HRRR/RAP CONTINUE TO SHOW THIS BAND SLOWING ITS PROGRESSION SOUTHWESTWARD...AND GRADUALLY RETREATING EASTWARD DURING THE DAY. THIS OCCURS AS WARM ADVECTION TAKES HOLD FROM THE WEST AHEAD OF THE LOW PRESSURE SYSTEM. NO HIGHER CLOUDS ABOVE THE LOW STRATUS...AND THIS AREA REMAINS UNDER THREAT OF FREEZING DRIZZLE ALONG WITH THE FOG. WILL KEEP A MENTION OF PATCHY FREEZING DRIZZLE THIS MORNING...GRADUALLY ENDING FROM WEST TO EAST. WARM ADVECTION AND PARTLY CLOUDY SKIES WEST WITH HIGHS IN THE MID 30S TO MID 40S. HOWEVER...EXPECT STRATUS CLOUDS TO BE SLOW TO RETREAT IN THE TURTLE MOUNTAINS AND JAMES RIVER VALLEY - WITH HIGHS TODAY ONLY REACHING INTO THE 20S. FRIDAY NIGHT AND SATURDAY AN UPPER LEVEL SHORTWAVE WITH AN ASSOCIATED SURFACE LOW AND FRONT TRAVERSES THE NORTHERN PLAINS AND SOUTHERN PRAIRIE PROVINCES OF CANADA. THE MAIN SHORTWAVE IMPULSE TRACKS SOUTHEAST ACROSS THE STATE TONIGHT AND INDUCES A SECONDARY SURFACE LOW THAT TRACKS RIGHT ALONG THE INTERNATIONAL BORDER. HAVE INCREASED POPS ALONG THE BORDER AS WELL AS ACROSS SOUTHERN NORTH DAKOTA. PRECIPITATION IS EXPECTED TO BE RAIN FRIDAY AND FRIDAY EVENING...THEN TRANSITION TO SNOW LATE FRIDAY NIGHT WITH THE PASSAGE OF THE COLD FRONT. THUS MAIN PRECIPITATION WILL BE RAIN AND/OR SNOW. WE COULD SEE A PERIOD OF LIGHT FREEZING RAIN OR FREEZING DRIZZLE OVER THE NORTH CENTRAL AND INTO THE JAMES VALLEY SATURDAY MORNING AS THE ATMOSPHERE DRIES THROUGH THE SNOW GROWTH ZONE. THE OTHER HAZARD LATE FRIDAY NIGHT AND SATURDAY WILL BE STRONG WINDS. THE STRONGEST BURST OF WINDS LOOKS TO BE LATE FRIDAY NIGHT INTO SATURDAY MORNING WEST...AND DURING THE DAY CENTRAL. CONFIDENCE IS LOW REGARDING THE STRENGTH/SPEED OF THE WINDS AS WELL AS THE DURATION OF THE STRONGEST WINDS. THE INITIAL PUSH OF NORTHWEST WINDS SHOULD BE FRIDAY NIGHT IN THE WEST AND SATURDAY IN CENTRAL NORTH DAKOTA...LINING UP WELL WITH THE TIGHTEST SURFACE PRESSURE GRADIENT. THEN WARM ADVECTION FOLLOWS IN THE WEST BY NOON SATURDAY AND BY LATE AFTERNOON IN CENTRAL NORTH DAKOTA. THE BUFKIT SOUNDINGS SUGGEST ADIABATIC LAPSE RATES WITH THE COLD ADVECTION...BUT MOMENTUM NOT REACHING THE GROUND WHILE WARM ADVECTION TAKES PLACE. THINK WE MAY SEE WIND ADVISORY STRENGTH WINDS AT SOME POINT IN MOST OF THE FORECAST AREA...BUT NOT FOR A LONG PERIOD OF TIME. A WIND ADVISORY MAY BE NEEDED FOR WESTERN AND CENTRAL NORTH DAKOTA...BUT CONFIDENCE NOT HIGH ENOUGH YET TO ISSUE THAT HEADLINE THIS FORECAST PACKAGE. A SPECIAL WEATHER STATEMENT WAS ISSUED THURSDAY AFTERNOON FOR THIS SYSTEM...AND WILL CONTINUE WITH ANOTHER ISSUANCE THIS MORNING...AS WELL AS IN THE HAZARDOUS WEATHER OUTLOOK. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 422 AM CST FRI JAN 16 2015 A GENERALLY PROGRESSIVE FLOW PATTERN BEGINS THE EXTENDED THROUGH MONDAY. FOR SUNDAY AND MONDAY THE GFS/ECMWF MODELS CONTINUE MID LEVEL PACIFIC FLOW BRINGING MILD AND DRY AIR INTO THE NORTHERN PLAINS. AFTER THIS A BUILDING RIDGE OFF THE WEST COAST RESULTS IN A DOWNSTREAM H500 TROUGH OVER THE NORTHERN PLAINS THAT WILL BEGIN A COOLING TREND BACK TO NEAR NORMAL TEMPERATURES BY WEDNESDAY AND THURSDAY. SOME SPOTTY LIGHT PRECIPITATION WILL BE THE RULE AS COOL CYCLONIC FLOW ALOFT WILL SUPPORT SOME SMALL CHANCES FOR SNOW DURING THIS PERIOD. HOWEVER THE FLOW CONTINUES OFF THE PACIFIC WITH NO REAL POOL OF ARCTIC AIR FORMING IN CANADA THAT CAN BE TAPPED FOR COLD AIR OUTBREAKS. PERHAPS LATER THIS MONTH THIS WILL BE POSSIBLE AS THE 8 TO 14 DAY NOW IS TRENDING BELOW NORMAL. FOR THIS FORECAST PERIOD THERE IS LITTLE POTENTIAL FOR WINTER STORMS ON THE HORIZON. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 639 AM CST FRI JAN 16 2015 LIFR CEILINGS AND VISIBILITY IN FOG AND STRATUS WITH INTERMITTENT FREEZING DRIZZLE WILL CONTINUE TO IMPACT KMOT...KBIS AND KJMS THROUGH MUCH OF TODAY. KMOT AND KBIS BECOMING VFR AFT 18Z. VFR CONDITIONS EXPECTED AT KISN AND KDIK. TONIGHT WINDS BECOMING WEST AND INCREASING TO 20-30 KNOTS AT KISN/KDIK AFT 03Z WITH A CHANCE OF LIGHT RAIN OR LIGHT SNOW. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...JV LONG TERM...WAA AVIATION...WAA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1014 AM PST FRI JAN 16 2015 .SYNOPSIS...HIGH PRESSURE OVER CALIFORNIA WILL WEAKEN SLIGHTLY TODAY AS A FRONTAL SYSTEM PUSHES INLAND FROM THE PACIFIC NORTHWEST. MINOR RAIN CHANCES ARE POSSIBLE MAINLY ACROSS THE NORTH BAY THROUGH THE WEEKEND. DRY AND MILD WEATHER WILL CONTINUE FOR AREAS SOUTH OF THE GOLDEN GATE. HIGH PRESSURE WILL REBUILD BY MONDAY AND RESULT IN DRY WEATHER FOR THE ENTIRE REGION THROUGH NEXT WEEK. && .DISCUSSION...AS OF 8:40 AM PST FRIDAY...A LITTLE LIGHT RAIN THIS MORNING ACROSS NAPA AND SONOMA COUNTY ASSOCIATED WITH A WEAK FRONT TO THE NORTH OF OUR CWA. AMOUNTS ARE GENERALLY .05" OR LESS ALTHOUGH HAWKEYE HAS PICKED UP 0.15" SO FAR. RADAR SHOWS ECHOS CURRENTLY SHIFTING TO THE EAST WITH THE HRRR INDICATING ALL OF THE RAIN SHOULD BE OVER BY 10 AM. RAIN SHOULD STAY NORTH OF SF. OTHER ITEM OF NOTE IS LOWER VISIBILITIES ACROSS THE EAST BAY THIS MORNING WITH CONCORD DROPPING DOWN TO A QUARTER MILE EARLIER. FOR THE REST OF THE DAY...PARTLY TO MOSTLY CLOUDY CONDITIONS ARE FORECAST TO REMAIN OVER THE NORTHERN HALF OF THE CWA WITH PARTLY TO MOSTLY SUNNY CONDITIONS FORECAST FOR THE SOUTHERN HALF. TEMPS WILL RANGE FROM THE MID 60S TO LOWER 70S IN THE SOUTHERN HALF OF THE CWA WITH UPPER 50S TO MID 6OS FOR THE NORTH. LATEST GUIDANCE IN CONTINUES TO KEEP THE MAIN STORM TRACK WELL TO OUR NORTH THROUGH ALL OF NEXT WEEK. .PREVIOUS DISCUSSION...SATELLITE IMAGERY IS SHOWING A LOT OF HIGH CLOUDS STREAMING OVER NORTHERN CALIFORNIA WITH BREAKS ACROSS THE BAY AREA REVEALING TULE FOG ONCE AGAIN PUSHING INTO THE EAST BAY VALLEYS. RIGHT NOW ONLY CONCORD AIRPORT IS BEING AFFECTED WITH REDUCED VISIBILITIES. WILL HOLD OFF ON ISSUING A DENSE FOG ADVISORY AT THIS TIME...WAITING TO SEE IF THIS AREA BECOMES MORE EXTENSIVE. MEANWHILE...THE HIGH CLOUDS TO THE NORTH ARE ASSOCIATED WITH AN APPROACHING FRONTAL SYSTEM THAT IS CURRENTLY SPREADING RAIN INTO EXTREME NORTHERN CALIFORNIA. CURRENT RADAR IMAGERY IS ONLY PICKING UP SOME LIGHT ECHOES...LIKELY ALOFT...OVER FAR NORTHERN SONOMA COUNTY. NO MEASURABLE RAINFALL HAS BEEN DETECTED AS OF YET...BUT MODEL DATA HAVE RAIN CHANCES PICKING UP IN THE NORTH BAY DURING THE MORNING HOURS. RAINFALL AMOUNTS THROUGH TODAY ARE EXPECTED TO BE LIGHT...MAINLY UNDER A TENTH OF AN INCH...WITH PERHAPS AS MUCH AS A THIRD OF AN INCH IN FAR NORTHWEST SONOMA COUNTY. THE UPPER RIDGE IS PROGGED TO REBOUND SOMEWHAT BY THIS EVENING AND SATURDAY BUT LIGHT SHOWERS ARE STILL POSSIBLE ACROSS THE NORTH BAY. ANOTHER IMPULSE IS FORECAST TO MOVE THROUGH ON SUNDAY WHICH WILL BRING RAIN CHANCES ACROSS MAINLY THE NORTH BAY. AFTER THIS SYSTEM MOVES THROUGH...HIGH PRESSURE IS FORECAST TO REBUILD OVER THE WEST FOR DRY AND MILD WEATHER THROUGH THE REMAINDER OF THE WEEK...WITH DRY CONDITIONS LIKELY PERSISTING THROUGH THE END OF THE MONTH IF CLIMATE PREDICTION OUTLOOKS ARE CORRECT. && .AVIATION...AS OF 3:33 AM PST FRIDAY... A WEAK FRONT AND AN ASSOCIATED MOISTURE PLUME ARE POSITIONED OVER NORTHERN CALIFORNIA THIS MORNING. THE MOUTH OF THE MOISTURE PLUME IS ADVECTING IN ADDITIONAL MOISTURE TO THE LOW AND MID LEVELS. THIS IS GENERATING HAZY CONDITIONS WITH POCKETS OF LINGERING MIST AND VARYING CLOUD DECKS THIS MORNING. ADDITIONALLY... KSFO/KOAK CIGS ARE EXPECTED TO BOUNCE BETWEEN MVFR/VFR THROUGH THE DAYLIGHT HOURS AS THE MOISTURE PLUME ADVECTS IN PATCHWORK BANDS OF MOISTURE. MODEL DATA INDICATES LINGERING MOISTURE INTO TOMORROW MORNING SO HZ/BR WITH POSBL MVFR CIGS SHOULD BE EXPECTED THROUGH THE NIGHT/SAT MORN. LOW CONFIDENCE FORECAST AROUND THE BAY AREA. VICINITY OF KSFO...LOW CONFIDENCE. HAZY WILL IMPACT SLANT VISIBILITY WITH PERIODIC MVFR CIGS OF BKN015-BKN025 THROUGH 04Z. SLIGHTLY LESS MID LEVEL MOISTURE TOMORROW MORNING... HOWEVER LOW LEVELS STAY MOIST. ANTICIPATE PERIODIC MVFR CIGS WITH HAZE AGAIN TOMORROW MORNING. LIGHT WINDS. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...EXPECTING ONLY HIGH CLOUDS FOR KMRY AND KSNS TODAY...LEADING TO VFR CONDITIONS. && .MARINE...AS OF 09:52 AM PST FRIDAY...A GLANCING BLOW FROM A STORM PASSING TO THE NORTH WILL BRING A SLIGHT CHANCE OF LIGHT RAIN NORTH OF POINT REYES. THE BAY AREA WILL SERVE AS A BOUNDARY BETWEEN LIGHT TO MODERATE SOUTHERLY WINDS TO THE NORTH AND NORTHERLY WINDS TO THE SOUTH THROUGH SATURDAY. BY SUNDAY NIGHT AND MONDAY STRONGER NW WINDS MAY DEVELOP ACROSS ALL OF THE WATERS. EXPECT NORTHWEST SWELL WITH MODERATE SEAS INTO EARLY NEXT WEEK. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...NONE. $$ PUBLIC FORECAST: BELL/SIMS AVIATION/MARINE: DRP VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
845 AM PST FRI JAN 16 2015 .SYNOPSIS...HIGH PRESSURE OVER CALIFORNIA WILL WEAKEN SLIGHTLY TODAY AS A FRONTAL SYSTEM PUSHES INLAND FROM THE PACIFIC NORTHWEST. MINOR RAIN CHANCES ARE POSSIBLE MAINLY ACROSS THE NORTH BAY THROUGH THE WEEKEND. DRY AND MILD WEATHER WILL CONTINUE FOR AREAS SOUTH OF THE GOLDEN GATE. HIGH PRESSURE WILL REBUILD BY MONDAY AND RESULT IN DRY WEATHER FOR THE ENTIRE REGION THROUGH NEXT WEEK. && .DISCUSSION...AS OF 8:40 AM PST FRIDAY...A LITTLE LIGHT RAIN THIS MORNING ACROSS NAPA AND SONOMA COUNTY ASSOCIATED WITH A WEAK FRONT TO THE NORTH OF OUR CWA. AMOUNTS ARE GENERALLY .05" OR LESS ALTHOUGH HAWKEYE HAS PICKED UP 0.15" SO FAR. RADAR SHOWS ECHOS CURRENTLY SHIFTING TO THE EAST WITH THE HRRR INDICATING ALL OF THE RAIN SHOULD BE OVER BY 10 AM. RAIN SHOULD STAY NORTH OF SF. OTHER ITEM OF NOTE IS LOWER VISIBILITIES ACROSS THE EAST BAY THIS MORNING WITH CONCORD DROPPING DOWN TO A QUARTER MILE EARLIER. FOR THE REST OF THE DAY...PARTLY TO MOSTLY CLOUDY CONDITIONS ARE FORECAST TO REMAIN OVER THE NORTHERN HALF OF THE CWA WITH PARTLY TO MOSTLY SUNNY CONDITIONS FORECAST FOR THE SOUTHERN HALF. TEMPS WILL RANGE FROM THE MID 60S TO LOWER 70S IN THE SOUTHERN HALF OF THE CWA WITH UPPER 50S TO MID 6OS FOR THE NORTH. LATEST GUIDANCE IN CONTINUES TO KEEP THE MAIN STORM TRACK WELL TO OUR NORTH THROUGH ALL OF NEXT WEEK. .PREVIOUS DISCUSSION...SATELLITE IMAGERY IS SHOWING A LOT OF HIGH CLOUDS STREAMING OVER NORTHERN CALIFORNIA WITH BREAKS ACROSS THE BAY AREA REVEALING TULE FOG ONCE AGAIN PUSHING INTO THE EAST BAY VALLEYS. RIGHT NOW ONLY CONCORD AIRPORT IS BEING AFFECTED WITH REDUCED VISIBILITIES. WILL HOLD OFF ON ISSUING A DENSE FOG ADVISORY AT THIS TIME...WAITING TO SEE IF THIS AREA BECOMES MORE EXTENSIVE. MEANWHILE...THE HIGH CLOUDS TO THE NORTH ARE ASSOCIATED WITH AN APPROACHING FRONTAL SYSTEM THAT IS CURRENTLY SPREADING RAIN INTO EXTREME NORTHERN CALIFORNIA. CURRENT RADAR IMAGERY IS ONLY PICKING UP SOME LIGHT ECHOES...LIKELY ALOFT...OVER FAR NORTHERN SONOMA COUNTY. NO MEASURABLE RAINFALL HAS BEEN DETECTED AS OF YET...BUT MODEL DATA HAVE RAIN CHANCES PICKING UP IN THE NORTH BAY DURING THE MORNING HOURS. RAINFALL AMOUNTS THROUGH TODAY ARE EXPECTED TO BE LIGHT...MAINLY UNDER A TENTH OF AN INCH...WITH PERHAPS AS MUCH AS A THIRD OF AN INCH IN FAR NORTHWEST SONOMA COUNTY. THE UPPER RIDGE IS PROGGED TO REBOUND SOMEWHAT BY THIS EVENING AND SATURDAY BUT LIGHT SHOWERS ARE STILL POSSIBLE ACROSS THE NORTH BAY. ANOTHER IMPULSE IS FORECAST TO MOVE THROUGH ON SUNDAY WHICH WILL BRING RAIN CHANCES ACROSS MAINLY THE NORTH BAY. AFTER THIS SYSTEM MOVES THROUGH...HIGH PRESSURE IS FORECAST TO REBUILD OVER THE WEST FOR DRY AND MILD WEATHER THROUGH THE REMAINDER OF THE WEEK...WITH DRY CONDITIONS LIKELY PERSISTING THROUGH THE END OF THE MONTH IF CLIMATE PREDICTION OUTLOOKS ARE CORRECT. && .AVIATION...AS OF 3:33 AM PST FRIDAY...FOR 12Z TAFS. STILL MAINLY DEALING WITH HAZE AND REDUCED VSBYS WITH MOST CIGS IN THE VFR RANGE. MID AND HIGH CLOUDS ASSOCIATED WITH INCOMING FRONTAL PASSAGE SEEMS TO HAVE PRECLUDED WIDESPREAD DENSE FOG EXCEPT OUT IN THE DELTA AND PLACES LIKE KCCR. HIGH CLOUDS MAKING LOW LEVEL FOG DETECTION DIFFICULT THIS MORNING. TAF PACKAGE WILL INTRODUCE -SHRA CHANCES FOR KSTS LATER TODAY BUT NOT EXPECTING PRECIP SOUTH OF SANTA ROSA. HAZY CONDITIONS LOOK TO BE THE MAJOR ISSUE FOR BAY AREA TERMINALS WITH MAINLY JUST VFR CIGS. FARTHER SOUTH JUST EXPECTING SOME HIGH CLOUDS AROUND KMRY AND KSNS. CONFIDENCE IS LOW TO MEDIUM THIS MORNING WITH NO GOOD FEEL FOR HOW CLOUDS WILL REFORM TONIGHT...THEREFORE TAFS SHOWING SIMILAR CONDITIONS FRIDAY NIGHT INTO EARLY SATURDAY. VICINITY OF KSFO...LOW TO MEDIUM CONFIDENCE. MAIN CONCERN IS HAZY CONDITIONS. BUST POTENTIAL IS THERE BUT NOT SEEING THE SAME DENSE FOG POTENTIAL COMPARED TO PREVIOUS DAYS WITH SYNOPTIC FRONT APPROACHING REGION WITH LIGHT SOUTHERLY FLOW AND OVERNIGHT HIGH CLOUDS PREVENTING WIDESPREAD RADIATION FOG FORMATION AROUND REGION. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...EXPECTING ONLY HIGH CLOUDS FOR KMRY AND KSNS TODAY...LEADING TO VFR CONDITIONS. && .MARINE...AS OF 3:33 AM PST FRIDAY...A WEAK FRONT WILL MOVE INTO THE WATERS NORTH OF THE GOLDEN GATE WITH LIGHT SOUTHERLY WINDS AND A CHANCE OF LIGHT RAIN. LIGHT NW WIND AND SEAS WILL CONTINUE ACROSS THE SOUTHERN WATERS. NO BIG CHANGES THROUGH THE WEEKEND WITH THE STORM TRACK NORTH OF POINT ARENA WITH GENERALLY LIGHT WIND AND MODERATE SEAS. BY SUNDAY NIGHT AND MONDAY STRONGER NW WINDS MAY DEVELOP ACROSS ALL OF THE WATERS. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...NONE. $$ PUBLIC FORECAST: BELL/SIMS AVIATION/MARINE: RWW VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
102 PM EST FRI JAN 16 2015 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION TODAY. HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT AND THEN SLIDE ACROSS THE REGION ON SATURDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE CAROLINA COAST AND LIFT NORTHWARD INTO OUR AREA SUNDAY NIGHT INTO MONDAY. MEANWHILE, A LOW PRESSURE SYSTEM WILL CROSS SOUTHERN CANADA AND ENTER THE GREAT LAKES REGION OVER THE WEEKEND. THESE TWO LOWS WILL MERGE, THEN DEEPEN AND MOVE NORTHWARD. HIGH PRESSURE WILL PUSH ACROSS THE REGION EARLY IN THE WEEK. A CLIPPER SYSTEM WILL APPROACH THE REGION WHILE ANOTHER LOW PRESSURE SYSTEM MAY DEVELOP NEAR THE CAROLINAS AROUND MIDWEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FOR MID-DAY UPDATE, ONCE AGAIN USED LAV GUIDANCE AS TEMPERATURE/DEWPOINT INPUT FOR REMAINDER OF THE AFTERNOON. SNOW SHOWERS HAVE GOTTEN MORE ROBUST IN THE POCONOS AND GRIDS HAVE BEEN UPDATED FOR MORE WIDESPREAD SNOW SHOWERS AND SNOW ACCUMULATIONS OVER A HALF INCH. ITS WINTER. PREVIOUS DISCUSSION FOLLOWS.. TODAY...A WELL DEFINED COLD FRONT WITH STRONG COLD AIR ADVECTION BEHIND IT MOVES SEWD ACROSS THE FORECAST AREA THIS AFTERNOON WITH A WIND SHIFT TO THE NORTHWEST. THIS FRONT WILL BE MOISTURE STARVED BUT STILL WILL PROVIDE A PERIOD OF PARTLY TO MOSTLY CLOUDY SKIES OVER THE NW 2/3RDS OF OUR FCST AREA BETWEEN 11 AM AND 4 PM EST. ELEVATION AND FLOW OFF THE GREAT LAKES EARLY THIS AFTERNOON SHOULD PERMIT FLURRIES AND SNOW SHOWERS TO CROSS THE EXTREME NORTHWEST PORTION OF THE FORECAST AREA...POCONOS AND SUSSEX COUNTY NJ HIGH TERRAIN. ISOLATED SMALL AMOUNTS OF SNOW UNDER ONE HALF INCH ARE POSSIBLE...ESPECIALLY POCONOS. LAPSE RATES AND CONVERGENCE ALONG THE COLD FRONT PLUS LAKE EFFECT SNOW TRANSPORTED EASTWARD IN BANDS AHEAD OF THE FRONT ARE THE MAIN REASONS FOR THE FORECAST OF SNOW SHOWERS THERE. YOU CAN SEE THAT BAND ON THE 630 AM RADAR IMAGERY FROM SW NYS THROUGH KITH. PRIMARY TIMING FOR THE SNOW APPEARS TO BE NOON TO 2 PM. NSSL WRF HAS SLIGHTLY MORE EXTENSIVE SNOW FLURRIES IN NE PA THAN WE DO ATTM. THE SPC WRF AND HRRR WERE NOT THAT IMPRESSIVE AT LAST CHECK THROUGH 08Z. USUALLY 20F T/DEWPOINT SPREADS TAKE POTENTIAL SNOW SHOWERS AND LEAVE THEM AS VIRGA FLYING BY OVERHEAD...THE MILKY WHITE SKY LOOK AS I EXPECT TO SEE VIRGA IN NORTHERN AND CENTRAL NJ AND NE PA TODAY DOWN TO I78. FALLING TEMPERATURES A BIT SOONER THAN USUAL THIS AFTERNOON WITH MAX TEMPS EXPECTED 11 AM TO 1 PM PRIOR TO WIDESPREAD SC FORMATION. WEST WINDS WILL BECOME INCREASINGLY GUSTY THIS MORNING AND THEN NORTHWEST GUSTS 25-35 MPH THIS AFTERNOON. FORECAST TEMPS/DEWS/WINDS ARE A 50 50 BLEND OF THE 00Z/16 NCEP MOS GUIDANCE WITH THE TEMPS ON THE WARMER SIDE OF THE BLEND. THESE MAXIMUM TEMPERATURES TODAY ARE FORECAST AT OR UP TO 3 DEGREES ABOVE NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... COLDER BY 5 TO 15 DEGREES..DEPENDING ON LOCATION.. AS COMPARED TO THIS MORNING, ESPECIALLY WITH A WIND CHILL! GUSTY NORTHWEST WINDS 20 TO POSSIBLY 25 MPH CONTINUE TILL ABOUT MIDNIGHT WITH DECENT LOW LEVEL LAPSE RATES. WINDS TEND TO DECOUPLE IN THE COUNTRYSIDE LATE. WIND CHILL INDEX IS FORECAST TO BOTTOM OUT BETWEEN -10 AND -13 AT KMPO BETWEEN 4 AM AND 7 AM SATURDAY. FORECAST TEMPS/DEWS/WIND ARE A 50 50 BLEND OF THE 00Z/16 NCEP MOS GUIDANCE. THESE LOWS WILL RANGE FROM ABOUT 5 DEGREES BELOW NORMAL IN SOUTHERN DELAWARE TO ALMOST 15 DEGREES BELOW NORMAL IN THE POCONOS. && .LONG TERM /SATURDAY THROUGH THURSDAY/... AT THE SURFACE...HIGH PRESSURE SLIDES ACROSS THE REGION ON SATURDAY. A DEVELOPING COASTAL LOW WILL MOVE UP THE MIDDLE ATLANTIC COAST AND THEN MERGE WITH A LOW MOVING THROUGH THE GREAT LAKES REGION/ACROSS SOUTHERN CANADA. HIGH PRESSURE RETURNS FOR THE EARLY PART OF THE WEEK. A CLIPPER SYSTEM WILL APPROACH THE REGION WHILE ANOTHER LOW PRESSURE SYSTEM MAY DEVELOP NEAR THE CAROLINAS AROUND MIDWEEK. IN THE MID LEVELS...ZONAL FLOW ON SATURDAY WILL TRANSITION TO TROUGHING AS A DEEP MID LEVEL TROUGH MOVES INTO THE AREA ON SUNDAY. THE TROUGH BECOME NEGATIVELY TILTED BEFORE STARTING TO LIFT NORTHWARD ON MONDAY. ZONAL FLOW RETURNS FOR THE MID WEEK PERIOD. A FEW SHORTWAVES WILL ROTATE THROUGH THE MID LEVEL FLOW THROUGH THE PERIOD. SATURDAY...HIGH PRESSURE WILL SLIDE ACROSS THE REGION AND THIS SHOULD KEEP US NICE AND DRY TO START OFF THE WEEKEND. AS THE HIGH MOVES OFFSHORE, WE WILL SEE A SOUTHERLY FLOW DEVELOP. THIS SOUTHERLY FLOW SHOULD USHER IN A BIT MORE MOISTURE AND WE SHOULD TEMPERATURES START TO WARM UP JUST A BIT, AS WELL. SUNDAY...A COASTAL LOW STARTS TO DEVELOP NEAR THE CAROLINAS. MEANWHILE, ANOTHER LOW PRESSURE SYSTEM WILL BE CROSSING THE GREAT LAKES REGION AND CROSSING SOUTHERN CANADA. IN ADDITION, A DEEP MID LEVEL TROUGH WILL MOVING INTO THE AREA. THE DEVELOPING COASTAL LOW WILL START TO OVERSPREAD PRECIPITATION INTO OUR AREA SUNDAY MORNING AND THEN CONTINUE INTO THE AFTERNOON AND EVENING. THE TROUGH WILL CREATE ADDITIONAL LIFT AS IT STARTS TO NEGATIVELY TILT DURING THE EVENING AND THIS HAS THE POTENTIAL TO ENHANCE THE PRECIPITATION FOR A PERIOD OF TIME. THE SOUTHERN LOW WILL TAKE OVER AND ABSORB THE NORTHERN LOW. THE COMBINED LOW WILL DEEPEN AS IT PULLS TO THE NORTHEAST OF OUR AREA LATE SUNDAY INTO MONDAY. TEMPERATURES ON SUNDAY WILL BE COLD AT THE START BUT AS WE SEE SOME WARM ADVECTION OCCURRING, WE WILL START TO SEE TEMPERATURES RISE. MUCH OF THE AREA WILL BE BELOW FREEZING TO START THE DAY AND MIXED PRECIPITATION CAN BE EXPECTED. AS THE LOW LIFTS NORTHWARD, TEMPERATURES WILL RISE ABOVE FREEZING AND A CHANGEOVER TO RAIN CAN EXPECTED FROM SOUTH TO NORTH. A MIX MAY REMAIN ACROSS THE FAR NORTHERN PARTS OF OUR FORECAST AREA. THERE REMAINS SOME UNCERTAINTY TO HOW MUCH COLD AIR WILL BE IN PLACE WHEN THE PRECIPITATION ARRIVES ON SUNDAY. SHOULD COLD AIR BE STUBBORN AT THE SURFACE AS THE WARMER AIR MOVES IN, WE COULD SEE PRECIPITATION FALL AS FREEZING RAIN BEFORE THE TEMPERATURES AT THE SURFACE RISE ABOVE THE FREEZING MARK. FOR NOW, WE KEEP SNOW/RAIN IN THE FORECAST AND WILL ALLOW FOR ANOTHER ROUND OF DATA TO COME IN BEFORE WE FINALIZE THE DETAILS. MONDAY...AS THE LOW PULLS FURTHER TO THE NORTH, THE MID LEVEL TROUGH WILL GET PULLED TO THE NORTH DURING MONDAY MORNING. THE COLD FRONT FROM THE ABSORBED LOW WILL CROSS THE AREA. HOWEVER, IT WILL HAVE LOST MOST OF ITS OOMPH FROM HAVING BEEN ABSORBED INTO THE COASTAL LOW. WHILE THIS TYPICALLY WOULD MAKE FOR A DRY FRONTAL PASSAGE IN OUR AREA, THE STRONG NORTHWESTERLY WINDS SHOULD ALLOW FOR SOME LAKE EFFECT SNOWS TO MAKE INTO OUR AREA. IN ADDITION, WE WILL SEE A PUSH OF SOME COLDER AIR MOVE BACK ACROSS THE REGION. TUESDAY...A WEAK HIGH PRESSURE SYSTEM TRIES TO BUILD ACROSS THE AREA BUT LOOKS MORE LIKE A BRIEF RIDGE FOR OUR AREA. AS THE NEXT SYSTEM APPROACHES THE AREA, SOME PRECIPITATION MIGHT ARRIVE DURING TUESDAY NIGHT. WEDNESDAY AND THURSDAY...A CLIPPER SYSTEM LOOKS LIKE IT WILL APPROACH THE AREA ON WEDNESDAY BUT IT DOES NOT APPEAR TO BE ALL THAT STRONG. IN ADDITION, THERE IS THE POTENTIAL FOR ANOTHER LOW PRESSURE SYSTEM TO DEVELOP NEAR THE CAROLINAS. A FEW STRONG SHORTWAVES IN THE MID LEVELS LOOK TO CROSS OUR AREA DURING THIS TIME AS WELL. OVERALL, IT LOOKS LIKE WE WILL SEE SOME KIND OF STORM AFFECTING OUR AREA DURING THE MIDWEEK TIME FRAME BUT THERE IS A DIFFERENCE BETWEEN THE MODELS WITH RESPECT TO TIMING AND STRENGTH OF THESE ITEMS. WEDNESDAY LOOKS TO BE THE DAY WE SEE OUT NEXT ROUND OF MIXED PRECIPITATION WITH ANOTHER, SMALLER, CHANCE OF MORE ON THURSDAY. NEEDLESS TO SAY, THIS PART OF THE EXTENDED LOOKS UNSETTLED AND CONFIDENCE IS NOT HIGH. SATURDAY WILL BE A FAIRLY COLD DAY AND BELOW NORMAL. SUNDAY WILL WARM UP APPRECIABLY IN THE WAA AND TEMPS WILL RISE ABOVE NORMAL. THE REMAINDER OF THE WEEK LOOKS TO BE NEAR OR SLIGHTLY ABOVE NORMAL. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...VFR. SCT-BKN AOA 4500 FT. WEST WINDS GUST 20 KT THIS MORNING SHIFT NW AND GUST 25-33 KT DURING THE AFTERNOON. BRIEF IFR CONDS EXPECTED IN SCT SNOW SHOWERS OVER THE POCONOS 16Z- 21Z TODAY. ELSEWHERE... VIRGA EARLY THIS AFTN...POSSIBLE FLURRY DOWN TO KRDG AND KABE BUT TEMP DEW SPREADS OF 20F MAY PREVENT FLURRY OCCURRENCE THERE. TONIGHT...VFR CLEAR. NW WIND GUSTY AROUND 20 KT THROUGH 06Z THEN DIMINISH LATE. OUTLOOK... SATURDAY...VFR CONDITIONS EXPECTED. SUNDAY...VFR CONDITIONS EARLY...BECOMING MVFR, POSSIBLY IFR, IN RAIN/SNOW SHOWERS. SOUTH WINDS 5 TO 10 KNOTS. MONDAY...MAINLY VFR CONDITIONS EXPECTED. A CHANCE FOR SOME SNOW/RAIN SHOWERS EARLY NORTH AND WEST OF KPHL. GUSTY NORTHWEST WINDS 10 TO 15 KNOTS WITH GUSTS AROUND 20 TO 25 KNOTS, HIGHER TOWARDS THE EAST. TUESDAY...VFR CONDITIONS EXPECTED. LIGHT WESTERLY WINDS. && .MARINE... SCA PRIMARILY THIS AFTERNOON/EARLY TONIGHT. NW WIND GUSTS MAY TOUCH 34 KT FOR 2 OR 3 HOURS OVER ANZ450 - THE NORTHERN NEW JERSEY COASTAL WATERS...SOMETIME BETWEEN 5 PM AND 10 PM THIS EVENING. FOR NOW HAVE CAPPED GUSTS AT 32 KT AND NO GALE WARNING. 00Z/16 WW3 SEAS RAISED 1 FT AT 00Z AND 06Z/17. LIGHT FREEZING SPRAY IS FORECAST TO DEVELOP TONIGHT BY OUR TOOL AND AUTOMATED GUIDANCE FROM THE GFS MODEL. WINDS AND SEAS SLOWLY DIMINISH BEGINNING AROUND 06Z/17. OUTLOOK... SATURDAY...SEAS AND WINDS WILL DIMINISH BELOW SMALL CRAFT ADVISORY CRITERIA. SATURDAY NIGHT...WINDS WILL INCREASE THROUGH THE EVENING AND OVERNIGHT PERIOD AND MAY NEAR SMALL CRAFT ADVISORY CONDITIONS. SUNDAY AND MONDAY...SEAS WILL START TO BUILD SUNDAY AND WILL EXCEED 5 FEET BY SUNDAY AFTERNOON/EVENING. SEAS WILL REMAIN ELEVATED THROUGH MONDAY NIGHT BEFORE FALLING BELOW SMALL CRAFT ADVISORY LEVELS. WINDS WILL BECOME GUSTY, ESPECIALLY MONDAY, AND GUST ABOVE 25 KNOTS. WINDS WILL START TO DIMINISH LATE ON MONDAY. TUESDAY...BOTH WINDS AND SEAS SHOULD FALL BELOW SMALL CRAFT ADVISORY CRITERIA. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SATURDAY FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 2 AM EST SATURDAY FOR ANZ430-431. && $$ SYNOPSIS...MEOLA NEAR TERM...DRAG/SZATKOWSKI SHORT TERM...DRAG LONG TERM...MEOLA AVIATION...DRAG/SZATKOWSKI/MEOLA MARINE...DRAG/SZATKOWSKI/MEOLA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
258 PM CST FRI JAN 16 2015 .SHORT TERM... 257 PM CST REMAINDER OF THIS AFTERNOON AND TONIGHT... FOR THE REMAINDER OF THIS AFTERNOON AND OVERNIGHT TONIGHT... CONDITIONS WILL REMAIN RELATIVELY QUIET. THE UPPER LEVEL PATTERN IS GENERALLY LOW AMPLITUDE AND PROGRESSIVE...WITH A MODERATE NRN STREAM JET FROM THE UPPER MISSISSIPPI VALLEY THROUGH THE UPPER OHIO VALLEY. THIS JET IS GENERATING THE BULK OF THE CLOUD COVER WHICH IS GENERALLY CONFINED TO THE NRN PORTIONS OF THE CWA. OTHERWISE...THE REST OF THE AREA WILL BE UNDER MOSTLY CLEAR SKIES THIS AFTERNOON AND TONIGHT. ALSO...THE LATEST SATELLITE IMAGERY INDICATES A MIDDLE STREAM SHORT WAVE TRACKING ACROSS THE NRN PLAINS WHICH IS INDUCING A SFC TROUGH OVER THE CNTRL PLAINS. THE SFC TROUGH WILL DEEPEN AND MOVE EWD OVERNIGHT WHILE AN ASSOCIATED WARM FRONT SURGES NORTHWARD ACROSS THE REGION. BY SATURDAY MORNING...THE WARM FRONT SHOULD PUSH INTO WISCONSIN...SETTING UP BRISK SWLY FLOW AT THE SURFACE. TEMPERATURES OVERNIGHT TONIGHT SHOULD BE AROUND 10 DEGREES HIGHER THAN FRIDAY MORNING. KREIN && .LONG TERM... 257 PM CST SATURDAY THROUGH FRIDAY... THE GENERAL TREND FOR THE NEXT SEVERAL DAYS SHOULD REFLECT THE OVERALL LOW AMPLITUDE...QUICKLY PROGRESSIVE PATTERN THAT IS SETTING UP IN THE SHORT TERM. A NRN STREAM SHORTWAVE WILL DROP OUT OF THE NRN ROCKIES AND TRACK ACROSS THE NRN PLAINS SATURDAY...REINFORCING THE DEEP LAYER WARM ADVECTION SETTING UP ACROSS THE MIDWEST. THE WARMING TREND THAT HAS BEEN ONGOING FOR THE PAST FEW DAYS WILL REACH A PEAK SATURDAY WITH HIGH TEMPS REACHING INTO THE UPPER 30S TO LOWER 40S. THE MAIN FORCING ASSOCIATED WITH THIS SHORTWAVE WILL REMAIN WELL NORTH OF THE IL/WI BOARDER...SO NO PCPN IS EXPECTED FOR NRN IL/NWRN IN. RISING HEIGHTS FOLLOWING THE PASSAGE OF THE TROUGH WILL OFFSET THE NWLY FLOW ALOFT...AND THE GENERAL TREND FOR TEMPERATURES FOR SUNDAY AND INTO EARLY NEXT WEEK WILL BE FOR A NEAR STEADY STATE CONDITION WITH TEMPERATURES AROUND SEASONAL NORMAL LEVELS...WITH HIGHS IN THE LOW 30S AND LOWS IN THE 20S. THE NEXT SIGNIFICANT CHANCE FOR ANY PCPN WILL NOT BE UNTIL TUESDAY. A SERIES OF NRN STREAM SHORTWAVES ARE EXPECTED TO DROP OUT OF CANADA AND TRACK THROUGH THE GREAT LAKES REGION. WHILE THERE MAY BE SOME SLIGHT TIMING DIFFERENCES AMONG THE MODELS AT THIS POINT...THERE IS A GENERAL CONSENSUS ON THE PATTERN WITH THE SERIES OF SHORTWAVES TRACKING CLOSE ENOUGH TO THE LOCAL AREA...SUCH THAT THERE IS DECENT ENOUGH CONFIDENCE TO GO WITH HIGHER CHANCE POPS FOR TUESDAY AND TUESDAY NIGHT. PCPN TYPE COULD BE A LITTLE TRICKY DURG THE DAY ON TUESDAY WITH THE LOCATION OF A RAIN/SNOW LINE...BUT OTHERWISE PCPN SHOULD TRANSITION TO ALL SNOW OVERNIGHT. THE SFC REFLECTION OF THE UPPER LEVEL PATTERN IS GENERALLY INDICATED TO BE FAIRLY WEAK PER THE LATEST LONGER TERM MODELS...SO DO NOT EXPECT ANYTHING MORE THAN LIGHT PCPN AMOUNTS AS THE GLFMEX WILL REMAIN CUT OFF FROM THE NRN STREAM FLOW BY THE BERMUDA HIGH EXTENDING ACROSS THE GULF COAST. A SECOND WAVE FOLLOWING QUICKLY ON THE HEALS OF THE FIRST WAVE COULD KEEP SOME LIGHT SNOW GOING THROUGH TUESDAY NIGHT. OTHERWISE...THE EXTENDED FORECAST PERIOD SHOULD BE GENERALLY DRY WITH SEASONABLE TEMPERATURES. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * PERIOD OF THIN MVFR CIGS AROUND 2500 FT THROUGH MID-LATE AFTN. CHANCE OF MVFR CIG DEVELOPMENT SATURDAY. * NON-CONVECTIVE LOW LEVEL WIND SHEAR LATE TONIGHT INTO SATURDAY MORNING WITH SW WINDS 45 KT DEVELOPING AROUND 1500 FT AGL. * GUSTY SOUTH-SOUTHWEST WINDS SATURDAY 25-30 KT. RATZER //DISCUSSION...UPDATED 20Z... THIN MVFR STRATOCU HAS DEVELOPED ALONG STALLED COLD FRONTAL BOUNDARY ACROSS TERMINALS THIS AFTERNOON. SATELLITE IMAGERY INDICATES CONTINUED THINNING OF THIS DECK...LIKELY SCATTERING OUT DURING THE REMAINDER OF MID-LATE AFTN HOURS. IN ADDITION...EAST WINDS PICKING UP JUST A BIT 8-10 KTS. RATZER PREVIOUS DISCUSSION FROM 18Z... WEAK COLD FRONT HAS SAGGED INTO FAR NORTHERN ILLINOIS THIS MORNING BUT IS BECOMING STATIONARY AS LOW PRESSURE DEVELOPS TO THE WEST ACROSS THE PLAINS. STATIONARY FRONTAL BOUNDARY WILL LIFT BACK TO NORTH AS A WARM FRONT TONIGHT AS WINDS EVENTUALLY BECOME SOUTH AND INCREASE. PATCHY VFR/MVFR CIGS IN 2000-3500 FT RANGE HAVE DEVELOPED ALONG AND JUST NORTH OF THE SURFACE FRONT THIS AFTERNOON BUT PER SATELLITE IMAGERY APPEARS TO BE ERODING FROM THE SOUTH. THUS MVFR CIG THAT HAD MOVED INTO RFD EARLIER SHOULD MOVE BACK NORTH AND SUSPECT THAT CHICAGO TERMINALS WILL REMAIN VFR...THOUGH THERE IS A SMALL CHANCE THAT 2500-3000 FT CIGS COULD DEVELOP ESPECIALLY AT ORD/DPA EARLY THIS AFTERNOON. WINDS ABOVE THE SURFACE LAYER WILL INCREASE SIGNIFICANTLY OVERNIGHT AS 45 KT SOUTHWESTERLY LOW LEVEL JET DEVELOPS...WHICH WILL SET UP LLWS CONDITIONS WITH SOUTHWEST 45 KT WINDS DEVELOPING AT AROUND 1500 FT AGL...ABOVE SURFACE INVERSION. DURING THE DAY SATURDAY SURFACE WINDS WILL BECOME GUSTY...LIKELY PEAKING IN THE 25-30 KT RANGE. WITH SUCH STRONG SOUTH-SOUTHWEST FLOW...INCREASING LOW LEVEL MOISTURE EXPECTED. SOME GUIDANCE INDICATES DEVELOPMENT OF LOW STRATUS IN MVFR RANGE DURING THE DAY...THOUGH SOUNDINGS DEPICT RATHER SHALLOW MOIST LAYER AND HAVE ONLY LOW CONFIDENCE THAT SUCH CONDITIONS WILL DEVELOP. RATZER //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM IN TIMING OF MVFR CIG EROSION THIS AFTN. * HIGH IN WIND TRENDS THROUGH TAF PERIOD AND LLWS TONIGHT. * LOW IN MVFR CIG DEVELOPMENT SATURDAY. RATZER //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...SLIGHT CHANCE OF SNOW SHOWERS. MVFR POSSIBLE. WEST WINDS. SUNDAY...MVFR POSSIBLE. WEST WINDS. MONDAY...MVFR POSSIBLE. SOUTHEAST WINDS. TUESDAY...CHANCE OF SNOW AND IFR. SOUTHWEST WINDS. WEDNESDAY...MVFR POSSIBLE. NORTHWEST WINDS. THURSDAY...SLIGHT CHANCE OF SNOW. MVFR POSSIBLE. WEST WINDS. MTF && .MARINE... 131 PM CST A SURFACE RIDGE OF HIGH PRESSURE IS CURRENTLY PRODUCING A PERIOD OF LIGHTER NORTHERLY WINDS ACROSS THE LAKE. THIS WILL BE SHORT LIVED...HOWEVER...AS ANOTHER AREA OF LOW PRESSURE QUICKLY MOVES EASTWARD ALONG THE INTERNATIONAL BOARDER TONIGHT...AND LEADS TO AN INCREASE IN SOUTH-SOUTHEASTERLY WINDS. THESE STRONG WINDS WILL SHIFT MORE SOUTH-SOUTHWESTERLY BY SATURDAY AFTERNOON AS A WARM FRONT LIFTS NORTHWARD ACROSS THE LAKE. WIND SPEEDS WITH THIS SYSTEM LOOK TO BE THE STRONGEST ACROSS THE SOUTHERN 2/3RDS OF THE OPEN WATERS OF LAKE MICHIGAN...WHERE GALES OF 35 TO 40 KT ARE LIKELY. THEREFORE...I HAVE UPGRADED THE GALE WATCH TO A WARNING AND RAN IT FROM MIDNIGHT TONIGHT THROUGH SATURDAY AFTERNOON. ALTHOUGH SOME GALE FORCE GUSTS ARE POSSIBLE ACROSS THE ILLINOIS AND INDIANA NEAR SHORE WATERS ON SATURDAY...I HAVE OPTED TO GO WITH A SMALL CRAFT ADVISORY FOR SOUTHERLY WINDS AROUND 30 KT. IT APPEARS THAT THE WINDS WILL REMAIN ELEVATED UP TO 30 KT OUT OF THE WEST OVER THE LAKE SATURDAY NIGHT INTO EARLY SUNDAY FOLLOWING A COLD FRONTAL PASSAGE. THIS WILL LIKELY CONTINUE TO LEAD TO SMALL CRAFT ADVISORY CONDITIONS ACROSS MY NEAR SHORE WATERS...SO I HAVE RUN THE ADVISORY HERE THROUGH EARLY SUNDAY. WINDS SHOULD ABATE ACROSS THE LAKE DURING THE DAY SUNDAY BEFORE BECOMING LIGHT AGAIN BY EARLY MONDAY AS ANOTHER SURFACE RIDGE OF HIGH PRESSURE MOVES OVER THE LAKE. FOLLOWING THIS SURFACE HIGH...IT APPEARS THAT SEVERAL CLIPPER SYSTEMS COULD TAKE AIM ON THE GREAT LAKES REGION NEXT WEEK. THIS WOULD LIKELY LEAD TO SOME ADDITIONAL SHORT PERIODS OF ENHANCED NORTHERLY WINDS OVER THE LAKE...DEPENDING ON THE ACTUAL TRACK OF THE SURFACE LOWS. KJB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...MIDNIGHT SATURDAY TO 3 PM SATURDAY. SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744- LMZ745...10 PM FRIDAY TO 9 AM SUNDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 245 PM CST Fri Jan 16 2015 .SHORT TERM...(Tonight) ISSUED AT 230 PM CST FRI JAN 16 2015 1026 mb high pressure over central Ontario and ridging southward across the Ohio & TN river valleys will slip off to the east and continue fair wx over IL tonight. Some patchy fog could develop again tonight ne of I-74 with lingering low level moisture from snow melt and winds staying lighter longer over eastern IL. Melting snow pack past 2 days and currently as far south as Lincoln to Champaign line. SE winds currently less than 10 mph over central/se IL this afternoon but increasing to 10-15 mph near near the MS river. A 997 mb surface low pressure along the southern Alberta and Saskatchewan province line to continue to deepen to 993 mb as it is located north of MN by 18Z/noon Sat. Increasing pressure gradient over IL during tonight into Sat to increase SSE winds to 10-15 mph and gusts by Saturday morning. Lows tonight range from upper 20s over east central IL to mid 30s from Jacksonville sw with fair skies prevailing. && .LONG TERM...(Saturday through Friday) ISSUED AT 230 PM CST FRI JAN 16 2015 Main forecast concern in the long term will be temperatures and precip chances with several fast moving shortwaves forecast to push across the region. One such wave pushing across the Pacific northwest and will track to our north on Saturday bring gusty southwest winds and unseasonably mild temperatures to our area. With the main dynamics shifting well to our north and no Gulf moisutre to tap into, it appears this frontal boundary will come through without much in the way of precip until it shifts east of Illinois Saturday night and Sunday. Models have trended a bit warmer behind the frontal passage on Sunday with our low level flow more westerly than northwest, and 925-850 mb temperature profiles a few degrees warmer than what we saw yesterday. As a result, have bumped temps up several degrees across the forecast area for Sunday and Monday. The strongest shortwave of the next 3 to 5 days will track north of us on Tuesday, with a secondary piece of energy digging southeast into the Great Lakes. This particular shortwave is further south than the track of the system on Saturday with the stronger lift associated with wave closer to our area on Tuesday, but again, moisture is quite limited. Will continue to carry slight chance POPs in the grids for Tuesday as the trof axis shifts over our area with the low chance POPs holding at least thru Tuesday evening as somewhat colder air filters in behind the upper wave. As we head thru the end of next week, the overall trend will be for 500 mb heights to lower with the main low level baroclinic zone forecast to take shape over the Southern Plains and lower Mississippi Valley. This should bring temperatures back closer to or just below normal, with the main storm track and precip chances remaining to our south. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) ISSUED AT 1159 AM CST FRI JAN 16 2015 VFR conditions generally expected to prevail across the central IL airports through 18Z/noon Sat. The exception will be MVFR vsbys next hour at CMI airport. HRRR models shows lingering low level moisture along with patchy fog this evening ne of I-74 and for now will keep fog out of TAFs though will be close at BMI and CMI tonight. Light sse winds to increase to 5-10 kts during the afternoon and be around 10 kts tonight. Increasing pressure gradient over IL Sat morning as 998 mb surface low pressure over southern Canadian rockies deepens to 992 mb to north of Lake Superior by Sat afternoon. SSW winds 13-17 kts with gusts 18-23 kts develops during Sat morning. Scattered cirrus clouds this afternoon and tonight with broken cirrus clouds arriving during Sat morning. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...07 LONG TERM...Smith AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
132 PM CST FRI JAN 16 2015 .SHORT TERM... 338 AM CST THROUGH SATURDAY... MAIN FORECAST CONCERNS/CHALLENGES ARE WITH CLOUD COVER TODAY...RISING TEMPS INTO SATURDAY...AND THEN RETURNING COLD AIR SATURDAY NIGHT AND CHANCES FOR LIGHT SNOW SHOWERS INTO EARLY SUNDAY. RELATIVELY QUIET CONDITIONS ONGOING THIS MORNING WITH SOME PATCHY FOG DEVELOPING ACROSS THE AREA...WITH CLEARER SKIES OVER NORTHERN ILLINOIS BEING REPLACED WITH MID CLOUDS DROPPING SOUTHEAST OUT OF WISCONSIN. ISENTROPIC ASCENT OUT AHEAD OF SEVERAL MID LEVEL FEATURES TRAVERSING THE UPPER MIDWEST WILL HELP FOR CONTINUED DEVELOPMENT THROUGH MOST OF THE MORNING...WITH A STEADY STREAM OF CLOUD COVER PUSHING SOUTHEAST INTO THE CWA. DID INCREASE CLOUD COVER FOR MOST OF THE MORNING WITH THESE CLOUDIER SKIES ANTICIPATED FOR AREAS ACROSS THE NORTHEAST HALF OF THE CWA. NOT OVERLY CONFIDENT TO THE SOUTHERN EXTENT OF THE THICKER CLOUD COVER...BUT CURRENT TRENDS WOULD SUGGEST THAT AREAS ALONG AND NORTHEAST OF A ROCHELLE ILLINOIS TO RENSSELAER INDIANA LINE WOULD OBSERVE THESE CLOUDIER SKIES. ALTHOUGH MODEL OUTPUT IS INDICATING SOME PRECIP ALONG PERSISTENT ASCENT OVER SOUTHERN WISCONSIN...CONDITIONS SHOULD REMAIN DRY TODAY FOR THE CWA WITH ANY DEVELOPMENT REMAINING JUST NORTH AND NORTHEAST OF THE CWA. TEMP AND DEWPOINT TRENDS A LITTLE DIFFICULT THIS MORNING AS OBS CONTINUE TO BOUNCE AROUND...OUT AHEAD OF DROPPING WEAK COLD FRONT. EXPECT THIS FRONT TO DROP FURTHER SOUTH TODAY BUT WASHING OUT AS IT DOES SO...WITH NO REAL AFFECT TO THE CWA TODAY. WASHED OUT FRONT LOOKS TO LINGER ACROSS THE REGION TONIGHT BEFORE LIFTING BACK NORTH LATE TONIGHT INTO SATURDAY MORNING...AS WAA PERSISTS. THIS CONTINUED WAA WILL ACTUALLY MAKE FOR A MILDER NIGHT ACROSS THE CWA TONIGHT WITH STEADY TEMPS THIS EVENING BEING REPLACED WITH RISING TEMPS BY EARLY SATURDAY MORNING...WITH LOW TO MID 30S POSSIBLE OVER CENTRAL ILLINOIS BY SUNRISE. SKY COVER TONIGHT MAY ONCE AGAIN BE A LITTLE DIFFICULT AS FORECAST SOUNDINGS INDICATING A VERY MOIST BOUNDARY LAYER TONIGHT. WOULD EXPECT THIS WITH RISING TEMPS/DEWPOINTS BUT NOT AM NOT OVERLY CONFIDENT WITH THE EXTENT OF ANY LOW STRATUS. DESPITE THE LINGERING FRONT BEING ANOTHER SOURCE FOR ADDED RH POOLING...DID INCREASE CLOUD COVER TONIGHT BUT ONLY TO PARTLY CLOUD SKIES AND DID ADD PATCHY FOG. ACTIVE MID/UPPER LEVEL FLOW WILL USHER IN ADDITIONAL WAVES OF ENERGY TONIGHT INTO SATURDAY BUT WITH A MORE DEFINED TROUGH APPROACHING SATURDAY MORNING. DO EXPECT ANY PRECIP TO REMAIN TO THE NORTH OF THE CWA ONCE AGAIN DURING THIS TIME...BUT DO ANTICIPATE INCREASING CLOUD COVER THROUGH MIDDAY...IF THE LOW STRATUS IS NOT ALREADY PRESENT. DESPITE INCREASING CLOUD COVER...STILL ANTICIPATE A FAIRLY MILD DAY ON SATURDAY WITH THE CURRENT SETUP PROVIDING THE POSSIBILITY FOR TEMPS AROUND 40 TO THE LOW 40S. RODRIGUEZ && .LONG TERM... 338 AM CST SATURDAY NIGHT THROUGH THURSDAY... THE MILDER TEMPS ON SATURDAY WILL QUICKLY CHANGE SATURDAY EVENING AS A COLD FRONT BRINGS THE RETURN TO A COLDER AIRMASS. GUIDANCE INDICATING DEVELOPING PRECIP SATURDAY EVENING THROUGH EARLY SUNDAY MORNING...WHICH MAKES SENSE WITH EXPECTED COLD ADVECTION AND THE ARRIVAL OF A STRONGER MID/UPPER LEVEL TROUGH. A STRONG PUSH OF COLD AIR SATURDAY EVENING WILL QUICKLY SUPPORT SNOW ACROSS THE CWA BUT WITH THE SCATTERED COVERAGE OF THESE SNOW SHOWERS AS WELL AS THE LIGHTER NATURE OF THIS PRECIP...HAVE NOT INCREASED POPS TOO MUCH DURING THIS TIME KEEPING SLIGHT CHANCE TO LOW CHANCE POPS. DRIER CONDITIONS AND SOME SLIGHT WARMING WILL BE PRESENT TO THE START OF NEXT WEEK. A FAIRLY ACTIVE PERIOD WITH SEVERAL WEAKER SYSTEMS DROPPING SOUTHEAST ACROSS THE REGION NEXT WEEK WILL PROVIDE CHANCES FOR PRECIP THROUGH MID WEEK. IT DOES APPEAR THAT A COLDER AIRMASS WILL RETURN AND STAY DURING THIS PERIOD...WITH SNOW THE LIKELY PRECIP TYPE. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * PATCHY MVFR CIGS 2000-3000 FT NORTHWEST OF CHICAGO THIS AFTERNOON. CHANCE OF MVFR CIG DEVELOPMENT SATURDAY. * NON-CONVECTIVE LOW LEVEL WIND SHEAR LATE TONIGHT INTO SATURDAY MORNING WITH SW WINDS 45 KT DEVELOPING AROUND 1500 FT AGL. * GUSTY SOUTH-SOUTHWEST WINDS SATURDAY 25-30 KT. RATZER //DISCUSSION...UPDATED 18Z... WEAK COLD FRONT HAS SAGGED INTO FAR NORTHERN ILLINOIS THIS MORNING BUT IS BECOMING STATIONARY AS LOW PRESSURE DEVELOPS TO THE WEST ACROSS THE PLAINS. STATIONARY FRONTAL BOUNDARY WILL LIFT BACK TO NORTH AS A WARM FRONT TONIGHT AS WINDS EVENTUALLY BECOME SOUTH AND INCREASE. PATCHY VFR/MVFR CIGS IN 2000-3500 FT RANGE HAVE DEVELOPED ALONG AND JUST NORTH OF THE SURFACE FRONT THIS AFTERNOON BUT PER SATELLITE IMAGERY APPEARS TO BE ERODING FROM THE SOUTH. THUS MVFR CIG THAT HAD MOVED INTO RFD EARLIER SHOULD MOVE BACK NORTH AND SUSPECT THAT CHICAGO TERMINALS WILL REMAIN VFR...THOUGH THERE IS A SMALL CHANCE THAT 2500-3000 FT CIGS COULD DEVELOP ESPECIALLY AT ORD/DPA EARLY THIS AFTERNOON. WINDS ABOVE THE SURFACE LAYER WILL INCREASE SIGNIFICANTLY OVERNIGHT AS 45 KT SOUTHWESTERLY LOW LEVEL JET DEVELOPS...WHICH WILL SET UP LLWS CONDITIONS WITH SOUTHWEST 45 KT WINDS DEVELOPING AT AROUND 1500 FT AGL...ABOVE SURFACE INVERSION. DURING THE DAY SATURDAY SURFACE WINDS WILL BECOME GUSTY...LIKELY PEAKING IN THE 25-30 KT RANGE. WITH SUCH STRONG SOUTH-SOUTHWEST FLOW...INCREASING LOW LEVEL MOISTURE EXPECTED. SOME GUIDANCE INDICATES DEVELOPMENT OF LOW STRATUS IN MVFR RANGE DURING THE DAY...THOUGH SOUNDINGS DEPICT RATHER SHALLOW MOIST LAYER AND HAVE ONLY LOW CONFIDENCE THAT SUCH CONDITIONS WILL DEVELOP. RATZER //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM-HIGH IN MVFR CIGS REMAINING NORTH/NORTHWEST OF ORD/MDW THIS AFTERNOON. * HIGH IN WIND TRENDS THROUGH TAF PERIOD AND LLWS TONIGHT. * LOW IN MVFR CIG DEVELOPMENT SATURDAY. RATZER //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...SLIGHT CHANCE OF SNOW SHOWERS. MVFR POSSIBLE. WEST WINDS. SUNDAY...MVFR POSSIBLE. WEST WINDS. MONDAY...MVFR POSSIBLE. SOUTHEAST WINDS. TUESDAY...CHANCE OF SNOW AND IFR. SOUTHWEST WINDS. WEDNESDAY...MVFR POSSIBLE. NORTHWEST WINDS. THURSDAY...SLIGHT CHANCE OF SNOW. MVFR POSSIBLE. WEST WINDS. MTF && .MARINE... 131 PM CST A SURFACE RIDGE OF HIGH PRESSURE IS CURRENTLY PRODUCING A PERIOD OF LIGHTER NORTHERLY WINDS ACROSS THE LAKE. THIS WILL BE SHORT LIVED...HOWEVER...AS ANOTHER AREA OF LOW PRESSURE QUICKLY MOVES EASTWARD ALONG THE INTERNATIONAL BOARDER TONIGHT...AND LEADS TO AN INCREASE IN SOUTH-SOUTHEASTERLY WINDS. THESE STRONG WINDS WILL SHIFT MORE SOUTH-SOUTHWESTERLY BY SATURDAY AFTERNOON AS A WARM FRONT LIFTS NORTHWARD ACROSS THE LAKE. WIND SPEEDS WITH THIS SYSTEM LOOK TO BE THE STRONGEST ACROSS THE SOUTHERN 2/3RDS OF THE OPEN WATERS OF LAKE MICHIGAN...WHERE GALES OF 35 TO 40 KT ARE LIKELY. THEREFORE...I HAVE UPGRADED THE GALE WATCH TO A WARNING AND RAN IT FROM MIDNIGHT TONIGHT THROUGH SATURDAY AFTERNOON. ALTHOUGH SOME GALE FORCE GUSTS ARE POSSIBLE ACROSS THE ILLINOIS AND INDIANA NEAR SHORE WATERS ON SATURDAY...I HAVE OPTED TO GO WITH A SMALL CRAFT ADVISORY FOR SOUTHERLY WINDS AROUND 30 KT. IT APPEARS THAT THE WINDS WILL REMAIN ELEVATED UP TO 30 KT OUT OF THE WEST OVER THE LAKE SATURDAY NIGHT INTO EARLY SUNDAY FOLLOWING A COLD FRONTAL PASSAGE. THIS WILL LIKELY CONTINUE TO LEAD TO SMALL CRAFT ADVISORY CONDITIONS ACROSS MY NEAR SHORE WATERS...SO I HAVE RUN THE ADVISORY HERE THROUGH EARLY SUNDAY. WINDS SHOULD ABATE ACROSS THE LAKE DURING THE DAY SUNDAY BEFORE BECOMING LIGHT AGAIN BY EARLY MONDAY AS ANOTHER SURFACE RIDGE OF HIGH PRESSURE MOVES OVER THE LAKE. FOLLOWING THIS SURFACE HIGH...IT APPEARS THAT SEVERAL CLIPPER SYSTEMS COULD TAKE AIM ON THE GREAT LAKES REGION NEXT WEEK. THIS WOULD LIKELY LEAD TO SOME ADDITIONAL SHORT PERIODS OF ENHANCED NORTHERLY WINDS OVER THE LAKE...DEPENDING ON THE ACTUAL TRACK OF THE SURFACE LOWS. KJB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 AM SATURDAY TO 3 PM SATURDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1159 AM CST Fri Jan 16 2015 .UPDATE... ISSUED AT 1045 AM CST FRI JAN 16 2015 Updated the forecast to remove the patchy dense fog along I-74 late this morning as fog has lifted. Also bumped up highs especially from Jacksonville sw with upper 40s since little or no snow pack left from I-72 south and also RUC soundings support milder temps today. Have coolest highs of low to mid 30s from I-74 ne over deeper snack pack and temps also slower to rise this morning due to fog. A fair amount of sun expected again rest of today with light and variable to calm winds becoming southeast 5-10 mph during the afternoon. && .SHORT TERM...(Today) ISSUED AT 319 AM CST FRI JAN 16 2015 A weak surface pressure trough associated with a storm system passing by well to the north of central Illinois will produce light SW winds shifting to W overnight, also helping to keep temperatures slightly warmer than previously anticipated. Most clouds expected to remain north of central IL as well. Not seeing much visibility reduction due to fog formation at this time as a result of mixing and shallow moisture depth, and latest HRRR model run has backed off the development of fog overnight as well. A surface pressure ridge will follow for early parts of the daytime, providing weak pressure gradients for light winds, but SSE winds will be on the increase by late afternoon as low pressure approaches from the west. Highs for today expected to feature little change from yesterday, with highs mainly mid 30s to low 40s, although expecting a warmer start to the morning due to mixing associated with the overnight pressure trough. && .LONG TERM...(Tonight through Thursday) ISSUED AT 319 AM CST FRI JAN 16 2015 Overnight lows a bit warmer tonight...and southerly winds pushing some warmer temps and moisture back into the region after todays mix out. Dewpoints come back and RH is steadily increasing towards dawn, but winds should stay up enough to mitigate any fog threat. Southerly flow at the sfc continuing the significant WAA through Saturday, switching around to southwesterly ahead of the front as the winds increase through the afternoon. Warmer air resulting in high temps well above normal...into the 40s, and near 50 in the southeast for Saturday. The struggle for pops vs flurries in the forecast for overnight Saturday/Sunday remains. Models backing off on sfc QPF, and forecast soundings remaining dry. Convergence along the passing boundary not that impressive, but some very low pops remain in the far east. Still not confident in enough widespread measurable precip to warrant a chance pop. That being said...flurries a solid possibility. Into the extended, forecast highs a few degrees above normal through mid week, although another system potentially on Tuesday may see those temps drop a few degrees. Models inconsistent with the solutions as far as timing and strength. Timing with Tuesday morning would make a huge difference as sfc temps below freezing until midday and models depicting a significant warm mid layer, some warmer than others. Pops relatively low, with better chances in the far north/northeast. SuperBlend dry on Day 6/Wednesday for now, but both the GFS and ECMWF are having some issues with a pattern shift and the resultant QPF fields are erratic. Not willing to put too much in the way of precip in the remainder of the forecast. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) ISSUED AT 1159 AM CST FRI JAN 16 2015 VFR conditions generally expected to prevail across the central IL airports through 18Z/noon Sat. The exception will be MVFR vsbys next hour at CMI airport. HRRR models shows lingering low level moisture along with patchy fog this evening ne of I-74 and for now will keep fog out of TAFs though will be close at BMI and CMI tonight. Light sse winds to increase to 5-10 kts during the afternoon and be around 10 kts tonight. Increasing pressure gradient over IL Sat morning as 998 mb surface low pressure over southern Canadian rockies deepens to 992 mb to north of Lake Superior by Sat afternoon. SSW winds 13-17 kts with gusts 18-23 kts develops during Sat morning. Scattered cirrus clouds this afternoon and tonight with broken cirrus clouds arriving during Sat morning. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...07 SHORT TERM...Onton LONG TERM...HJS AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1142 AM CST FRI JAN 16 2015 .SHORT TERM... 338 AM CST THROUGH SATURDAY... MAIN FORECAST CONCERNS/CHALLENGES ARE WITH CLOUD COVER TODAY...RISING TEMPS INTO SATURDAY...AND THEN RETURNING COLD AIR SATURDAY NIGHT AND CHANCES FOR LIGHT SNOW SHOWERS INTO EARLY SUNDAY. RELATIVELY QUIET CONDITIONS ONGOING THIS MORNING WITH SOME PATCHY FOG DEVELOPING ACROSS THE AREA...WITH CLEARER SKIES OVER NORTHERN ILLINOIS BEING REPLACED WITH MID CLOUDS DROPPING SOUTHEAST OUT OF WISCONSIN. ISENTROPIC ASCENT OUT AHEAD OF SEVERAL MID LEVEL FEATURES TRAVERSING THE UPPER MIDWEST WILL HELP FOR CONTINUED DEVELOPMENT THROUGH MOST OF THE MORNING...WITH A STEADY STREAM OF CLOUD COVER PUSHING SOUTHEAST INTO THE CWA. DID INCREASE CLOUD COVER FOR MOST OF THE MORNING WITH THESE CLOUDIER SKIES ANTICIPATED FOR AREAS ACROSS THE NORTHEAST HALF OF THE CWA. NOT OVERLY CONFIDENT TO THE SOUTHERN EXTENT OF THE THICKER CLOUD COVER...BUT CURRENT TRENDS WOULD SUGGEST THAT AREAS ALONG AND NORTHEAST OF A ROCHELLE ILLINOIS TO RENSSELAER INDIANA LINE WOULD OBSERVE THESE CLOUDIER SKIES. ALTHOUGH MODEL OUTPUT IS INDICATING SOME PRECIP ALONG PERSISTENT ASCENT OVER SOUTHERN WISCONSIN...CONDITIONS SHOULD REMAIN DRY TODAY FOR THE CWA WITH ANY DEVELOPMENT REMAINING JUST NORTH AND NORTHEAST OF THE CWA. TEMP AND DEWPOINT TRENDS A LITTLE DIFFICULT THIS MORNING AS OBS CONTINUE TO BOUNCE AROUND...OUT AHEAD OF DROPPING WEAK COLD FRONT. EXPECT THIS FRONT TO DROP FURTHER SOUTH TODAY BUT WASHING OUT AS IT DOES SO...WITH NO REAL AFFECT TO THE CWA TODAY. WASHED OUT FRONT LOOKS TO LINGER ACROSS THE REGION TONIGHT BEFORE LIFTING BACK NORTH LATE TONIGHT INTO SATURDAY MORNING...AS WAA PERSISTS. THIS CONTINUED WAA WILL ACTUALLY MAKE FOR A MILDER NIGHT ACROSS THE CWA TONIGHT WITH STEADY TEMPS THIS EVENING BEING REPLACED WITH RISING TEMPS BY EARLY SATURDAY MORNING...WITH LOW TO MID 30S POSSIBLE OVER CENTRAL ILLINOIS BY SUNRISE. SKY COVER TONIGHT MAY ONCE AGAIN BE A LITTLE DIFFICULT AS FORECAST SOUNDINGS INDICATING A VERY MOIST BOUNDARY LAYER TONIGHT. WOULD EXPECT THIS WITH RISING TEMPS/DEWPOINTS BUT NOT AM NOT OVERLY CONFIDENT WITH THE EXTENT OF ANY LOW STRATUS. DESPITE THE LINGERING FRONT BEING ANOTHER SOURCE FOR ADDED RH POOLING...DID INCREASE CLOUD COVER TONIGHT BUT ONLY TO PARTLY CLOUD SKIES AND DID ADD PATCHY FOG. ACTIVE MID/UPPER LEVEL FLOW WILL USHER IN ADDITIONAL WAVES OF ENERGY TONIGHT INTO SATURDAY BUT WITH A MORE DEFINED TROUGH APPROACHING SATURDAY MORNING. DO EXPECT ANY PRECIP TO REMAIN TO THE NORTH OF THE CWA ONCE AGAIN DURING THIS TIME...BUT DO ANTICIPATE INCREASING CLOUD COVER THROUGH MIDDAY...IF THE LOW STRATUS IS NOT ALREADY PRESENT. DESPITE INCREASING CLOUD COVER...STILL ANTICIPATE A FAIRLY MILD DAY ON SATURDAY WITH THE CURRENT SETUP PROVIDING THE POSSIBILITY FOR TEMPS AROUND 40 TO THE LOW 40S. RODRIGUEZ && .LONG TERM... 338 AM CST SATURDAY NIGHT THROUGH THURSDAY... THE MILDER TEMPS ON SATURDAY WILL QUICKLY CHANGE SATURDAY EVENING AS A COLD FRONT BRINGS THE RETURN TO A COLDER AIRMASS. GUIDANCE INDICATING DEVELOPING PRECIP SATURDAY EVENING THROUGH EARLY SUNDAY MORNING...WHICH MAKES SENSE WITH EXPECTED COLD ADVECTION AND THE ARRIVAL OF A STRONGER MID/UPPER LEVEL TROUGH. A STRONG PUSH OF COLD AIR SATURDAY EVENING WILL QUICKLY SUPPORT SNOW ACROSS THE CWA BUT WITH THE SCATTERED COVERAGE OF THESE SNOW SHOWERS AS WELL AS THE LIGHTER NATURE OF THIS PRECIP...HAVE NOT INCREASED POPS TOO MUCH DURING THIS TIME KEEPING SLIGHT CHANCE TO LOW CHANCE POPS. DRIER CONDITIONS AND SOME SLIGHT WARMING WILL BE PRESENT TO THE START OF NEXT WEEK. A FAIRLY ACTIVE PERIOD WITH SEVERAL WEAKER SYSTEMS DROPPING SOUTHEAST ACROSS THE REGION NEXT WEEK WILL PROVIDE CHANCES FOR PRECIP THROUGH MID WEEK. IT DOES APPEAR THAT A COLDER AIRMASS WILL RETURN AND STAY DURING THIS PERIOD...WITH SNOW THE LIKELY PRECIP TYPE. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * PATCHY MVFR CIGS 2000-3000 FT NORTHWEST OF CHICAGO THIS AFTERNOON. CHANCE OF MVFR CIG DEVELOPMENT SATURDAY. * NON-CONVECTIVE LOW LEVEL WIND SHEAR LATE TONIGHT INTO SATURDAY MORNING WITH SW WINDS 45 KT DEVELOPING AROUND 1500 FT AGL. * GUSTY SOUTH-SOUTHWEST WINDS SATURDAY 25-30 KT. RATZER //DISCUSSION...UPDATED 18Z... WEAK COLD FRONT HAS SAGGED INTO FAR NORTHERN ILLINOIS THIS MORNING BUT IS BECOMING STATIONARY AS LOW PRESSURE DEVELOPS TO THE WEST ACROSS THE PLAINS. STATIONARY FRONTAL BOUNDARY WILL LIFT BACK TO NORTH AS A WARM FRONT TONIGHT AS WINDS EVENTUALLY BECOME SOUTH AND INCREASE. PATCHY VFR/MVFR CIGS IN 2000-3500 FT RANGE HAVE DEVELOPED ALONG AND JUST NORTH OF THE SURFACE FRONT THIS AFTERNOON BUT PER SATELLITE IMAGERY APPEARS TO BE ERODING FROM THE SOUTH. THUS MVFR CIG THAT HAD MOVED INTO RFD EARLIER SHOULD MOVE BACK NORTH AND SUSPECT THAT CHICAGO TERMINALS WILL REMAIN VFR...THOUGH THERE IS A SMALL CHANCE THAT 2500-3000 FT CIGS COULD DEVELOP ESPECIALLY AT ORD/DPA EARLY THIS AFTERNOON. WINDS ABOVE THE SURFACE LAYER WILL INCREASE SIGNIFICANTLY OVERNIGHT AS 45 KT SOUTHWESTERLY LOW LEVEL JET DEVELOPS...WHICH WILL SET UP LLWS CONDITIONS WITH SOUTHWEST 45 KT WINDS DEVELOPING AT AROUND 1500 FT AGL...ABOVE SURFACE INVERSION. DURING THE DAY SATURDAY SURFACE WINDS WILL BECOME GUSTY...LIKELY PEAKING IN THE 25-30 KT RANGE. WITH SUCH STRONG SOUTH-SOUTHWEST FLOW...INCREASING LOW LEVEL MOISTURE EXPECTED. SOME GUIDANCE INDICATES DEVELOPMENT OF LOW STRATUS IN MVFR RANGE DURING THE DAY...THOUGH SOUNDINGS DEPICT RATHER SHALLOW MOIST LAYER AND HAVE ONLY LOW CONFIDENCE THAT SUCH CONDITIONS WILL DEVELOP. RATZER //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM-HIGH IN MVFR CIGS REMAINING NORTH/NORTHWEST OF ORD/MDW THIS AFTERNOON. * HIGH IN WIND TRENDS THROUGH TAF PERIOD AND LLWS TONIGHT. * LOW IN MVFR CIG DEVELOPMENT SATURDAY. RATZER //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...SLIGHT CHANCE OF SNOW SHOWERS. MVFR POSSIBLE. WEST WINDS. SUNDAY...MVFR POSSIBLE. WEST WINDS. MONDAY...MVFR POSSIBLE. SOUTHEAST WINDS. TUESDAY...CHANCE OF SNOW AND IFR. SOUTHWEST WINDS. WEDNESDAY...MVFR POSSIBLE. NORTHWEST WINDS. THURSDAY...SLIGHT CHANCE OF SNOW. MVFR POSSIBLE. WEST WINDS. MTF && .MARINE... 150 AM CST A PROGRESSIVE WEATHER PATTERN WILL CONTINUE INTO THIS WEEKEND. FAIRLY STRONG HIGH PRESSURE WILL MOVE OVER THE LAKE TODAY BUT AT SUCH A SPEED THAT THE DIMINISHING IN WINDS WILL NOT LAST LONG. WINDS WILL BECOMING SOUTHEAST AND BE ON THE INCREASE TONIGHT AHEAD OF LOW PRESSURE ALONG THE INTERNATIONAL BORDER...WHICH WILL CONTINUE EAST TO LAKE SUPERIOR DURING THE DAY AND EVENING ON SATURDAY. THE PRESSURE GRADIENT AHEAD OF THIS LOW WILL SHARPLY TIGHTEN INCREASING SOUTHWEST WIND SPEEDS LATE TONIGHT AND SATURDAY MORNING. GUSTS SHOULD BE EASY TO COME BY DUE TO INSTABILITY OVER THE LAKE ESPECIALLY THE HEART OF THE OPEN WATERS. CIPS ANALOGS DO INDICATE SOME OCCURRENCES OF 35 KT GUSTS IN ADJACENT LAND AREAS IN SIMILAR PATTERNS. HAVE OPTED TO GO WITH A SHORT GALE WATCH AT THIS TIME BUT IT IS SOMEWHAT MARGINAL...ESPECIALLY FOR THE SCOPE OF THE ENTIRE LAKE. THE CENTRAL THIRD IS MOST LIKELY TO EXPERIENCE THE GALES. SMALL CRAFT ADVISORY CRITERIA WINDS WILL DEVELOP IN THE ILLINOIS AND INDIANA WATERS DURING OR EVEN POSSIBLY BEFORE SATURDAY MORNING. WILL ALLOW DAY SHIFT TO FURTHER ASSESS START TIME OF A SMALL CRAFT ADVISORY THAT WILL BE NEEDED. WITHIN THE COLD AIR ADVECTION OF THE SYSTEM ON SATURDAY NIGHT AND SUNDAY...WIND SPEEDS PRESENTLY LOOK TO REMAIN BELOW GALES ALTHOUGH ONE COMPUTER MODEL IS STILL ADVERTISING A NARROW WINDOW OF 35 KT WINDS...SO WILL CONTINUE TO MONITOR. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 AM SATURDAY TO 3 PM SATURDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1044 AM CST Fri Jan 16 2015 .UPDATE... ISSUED AT 1045 AM CST FRI JAN 16 2015 Updated the forecast to remove the patchy dense fog along I-74 late this morning as fog has lifted. Also bumped up highs especially from Jacksonville sw with upper 40s since little or no snow pack left from I-72 south and also RUC soundings support milder temps today. Have coolest highs of low to mid 30s from I-74 ne over deeper snack pack and temps also slower to rise this morning due to fog. A fair amount of sun expected again rest of today with light and variable to calm winds becoming southeast 5-10 mph during the afternoon. && .SHORT TERM...(Today) ISSUED AT 319 AM CST FRI JAN 16 2015 A weak surface pressure trough associated with a storm system passing by well to the north of central Illinois will produce light SW winds shifting to W overnight, also helping to keep temperatures slightly warmer than previously anticipated. Most clouds expected to remain north of central IL as well. Not seeing much visibility reduction due to fog formation at this time as a result of mixing and shallow moisture depth, and latest HRRR model run has backed off the development of fog overnight as well. A surface pressure ridge will follow for early parts of the daytime, providing weak pressure gradients for light winds, but SSE winds will be on the increase by late afternoon as low pressure approaches from the west. Highs for today expected to feature little change from yesterday, with highs mainly mid 30s to low 40, although expecting a warmer start to the morning due to mixing associated with the overnight pressure trough. && .LONG TERM...(Tonight through Thursday) ISSUED AT 319 AM CST FRI JAN 16 2015 Overnight lows a bit warmer tonight...and southerly winds pushing some warmer temps and moisture back into the region after todays mix out. Dewpoints come back and RH is steadily increasing towards dawn, but winds should stay up enough to mitigate any fog threat. Southerly flow at the sfc continuing the significant WAA through Saturday, switching around to southwesterly ahead of the front as the winds increase through the afternoon. Warmer air resulting in high temps well above normal...into the 40s, and near 50 in the southeast for Saturday. The struggle for pops vs flurries in the forecast for overnight Saturday/Sunday remains. Models backing off on sfc QPF, and forecast soundings remaining dry. Convergence along the passing boundary not that impressive, but some very low pops remain in the far east. Still not confident in enough widespread measurable precip to warrant a chance pop. That being said...flurries a solid possibility. Into the extended, forecast highs a few degrees above normal through mid week, although another system potentially on Tuesday may see those temps drop a few degrees. Models inconsistent with the solutions as far as timing and strength. Timing with Tuesday morning would make a huge difference as sfc temps below freezing until midday and models depicting a significant warm mid layer, some warmer than others. Pops relatively low, with better chances in the far north/northeast. SuperBlend dry on Day 6/Wednesday for now, but both the GFS and ECMWF are having some issues with a pattern shift and the resultant QPF fields are erratic. Not willing to put too much in the way of precip in the remainder of the forecast. && .AVIATION...(For the 12Z TAFS through 12Z Saturday morning) ISSUED AT 507 AM CST FRI JAN 16 2015 Mainly VFR conditions expected for the next 24 hours, however areas MVFR/local IFR fog affecting KPIA-KBMI-KCMI northward until 16Z. Winds generally light/variable to westerly up to 8 kts through morning, becoming SE and increasing through afternoon, reaching 10-12 kts by 00Z Saturday. Cloud cover minimal though the period, with a gradual increase in cirrus. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...07 SHORT TERM...Onton LONG TERM...HJS AVIATION...Onton
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
558 PM EST FRI JAN 16 2015 .UPDATE... AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 330 PM EST FRI JAN 16 2015 MILD WEATHER WILL CONTINUE THROUGH SATURDAY AS HIGH PRESSURE SHIFTS EAST. A QUICK MOVING UPPER LEVEL WAVE WILL BRING LIGHT PRECIPITATION THROUGH CENTRAL INDIANA SATURDAY NIGHT AND SUNDAY MORNING...FOLLOWED BY COLDER WEATHER FOR THE END OF THE WEEKEND. TEMPERATURES WILL BRIEFLY WARM UP AGAIN ON MONDAY BEFORE A SERIES OF UPPER WAVES BRINGS LIGHT WINTRY PRECIPITATION TO THE AREA TUESDAY AND AGAIN THURSDAY WITH PROGRESSIVELY COLDER TEMPERATURES FOR THE SECOND HALF OF NEXT WEEK. && .NEAR TERM /TONIGHT/... ISSUED AT 330 PM EST FRI JAN 16 2015 EXTREME NORTHEAST PORTION OF THE FORECAST AREA REMAINS UNDER THE MID LEVEL CLOUD DECK ASSOCIATED WITH THE WEAK UPPER LEVEL DISTURBANCE PASSING BY TO THE NORTH. THESE WERE SHIFTING EAST AND EXPECT THEM TO BE LARGELY OUT OF DELAWARE AND RANDOLPH COUNTIES BY 21-22Z. SKIES WERE SUNNY ELSEWHERE ACROSS CENTRAL INDIANA AS WE ENJOY OUR WARMEST DAY IN NEARLY TWO WEEKS FOR MANY. TEMPS RANGED FROM THE MID 30S NORTH TO MID 40S SOUTH AT 20Z. CLOUDS IN NORTHERN COUNTIES AND TEMPS ARE THE PRIMARY ISSUES FOR THE NEAR TERM AS A WARM FRONT LIFTS NORTH LATER THIS EVENING. RAP AND HRRR BOTH SHOWING DEVELOPMENT OF DEEPER MOISTURE IN THE 925-950MB LAYER AFTER 02-03Z OVER THE NORTHERN PARTS OF THE FORECAST AREA... GRADUALLY LIFTING NORTH OVERNIGHT WITH THE BOUNDARY. BOTH THE NAM AND OP GFS HINT AT THIS AS WELL. EXPECT THIS TO MANIFEST AS A PERIOD OF LOWER CLOUDS OVER NORTHERN COUNTIES...FOLLOWED BY POTENTIALLY SOME LIGHT PATCHY FOG TOWARDS DAYBREAK WITH RAP/HRRR MODEL SOUNDINGS SHOWING LINGERING SHALLOW MOISTURE UNDERNEATH A SHARP INVERSION PRESENT AT 1000FT AND LOWER. ONE MITIGATING FACTOR THAT WOULD KEEP ANY FOG LIMITED IS THE INCREASE IN SURFACE FLOW AFTER MIDNIGHT AS THE SURFACE PRESSURE GRADIENT TIGHTENS. WILL KEEP ANY FOG MENTION OUT OF THE FORECAST AT THIS POINT...BUT THIS WILL BE SOMETHING TO MONITOR INTO THE EVENING. MAINLY CLEAR SKIES ARE EXPECTED ELSEWHERE OVERNIGHT. TEMPS...WITH WARM ADVECTION COMMENCING AS THE BOUNDARY LIFTS NORTH...EXPECT LOWS TO OCCUR MOST AREAS BY LATE EVENING WITH STEADY OR SLOWLY RISING TEMPS THEREAFTER. ENDED UP SLIGHTLY UNDERCUTTING MOS GUIDANCE WITH TEMPS RETURNING INTO THE UPPER 20S/LOWER 30S BY 12Z. && .SHORT TERM /SATURDAY THROUGH MONDAY/... ISSUED AT 330 PM EST FRI JAN 16 2015 FORECAST CHALLENGES REMAIN ON PRECIP CHANCES SATURDAY NIGHT AND SUNDAY...AND TEMPS THROUGHOUT THE PERIOD. SATURDAY STANDS A STRONG CHANCE TO BE THE PICK DAY OF THE MONTH SO FAR...DESPITE A WINDY DAY ACROSS THE HOOSIER STATE. MOSTLY SUNNY SKIES ARE ANTICIPATED FOR MUCH OF SATURDAY WITH CLOUDS ASSOCIATED WITH THE UPPER WAVE AND COLD FRONT HOLDING OFF UNTIL LATE IN THE DAY. 40-50KT 850MB JET WILL SWING AROUND THE BASE OF THE APPROACHING UPPER WAVE AND ACROSS THE OHIO VALLEY THROUGH THE DAY. THIS WILL ENSURE A BREEZY AFTERNOON FOR THE REGION WITH SUSTAINEDS NEAR 20MPH AND GUSTS INTO THE 30-35MPH RANGE. FRONT SWINGS THROUGH THE FORECAST AREA SATURDAY NIGHT. MODEL CONSENSUS STARTING TO ZERO IN ON A BAND OF PRECIP SWINGING ACROSS THE FORECAST AREA...STARTING FIRST AS RAIN THEN MIXING WITH AND CHANGING OVER TO LIGHT SNOW AS LOW LEVEL THERMALS BECOME SUPPORTIVE. STILL THINK SOME POTENTIAL EXISTS FOR A FEW TENTHS OF AN INCH OF SNOW OVER THE EASTERN HALF OF THE FORECAST AREA BY SUNDAY MORNING. WILL CARRY CHANCE POPS SATURDAY NIGHT...LINGERING INTO SUNDAY MORNING OVER FAR EASTERN COUNTIES. MODEL SOUNDINGS AND RH PROGS FAVOR HANGING ONTO LOWER CLOUDS FOR A GOOD PORTION OF SUNDAY WITH SLOW CLEARING FROM THE SOUTHWEST DURING THE AFTERNOON. REMAINDER OF THE SHORT TERM WILL BE QUIET AS HIGH PRESSURE BUILDS QUICKLY BACK IN BY SUNDAY EVENING. WINDS WILL RETURN TO SOUTHWEST ON MONDAY WITH WARM ADVECTION RESUMING. SHOULD SEE CLOUDS INCREASE ONCE AGAIN BY LATE MONDAY AS A WEAK UPPER WAVE APPROACHES FROM THE NORTHWEST. TEMPS...CONSIDERING TEMP PERFORMANCE SO FAR TODAY AND EXPECTATION OF A LOT OF SUNSHINE SATURDAY...PREFER LEANING CLOSER TO THE WARMER MAVMOS WITH HIGHS RANGING FROM THE MID 40S TO LOWER 50S FOR MANY. TRENDED TOWARDS COOLER METMOS SUNDAY WITH COLD ADVECTION AND LINGERING CLOUDS. UNDERCUT AGGRESSIVE MAVMOS FOR MONDAY AS WELL... BUT STILL SHOULD SEE TEMPS RECOVER BACK INTO THE 40S FOR MUCH OF THE AREA. TOOK MOS BLEND FOR LOWS THROUGH THE PERIOD. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ISSUED AT 219 PM EST FRI JAN 16 2015 MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND INITIALIZATION WAS ACCEPTED FOR MOST ITEMS. A COUPLE OF UPPER SYSTEMS WILL MOVE ACROSS THE AREA DURING THE LONG TERM. MOISTURE/FORCING ARE NOT IMPRESSIVE WITH EITHER FEATURE...SO WILL KEEP POPS LOW. THE FIRST ONE ALSO HAS A SURFACE FRONTAL SYSTEM ASSOCIATED WITH IT THAT WILL MOVE ACROSS THE AREA TUESDAY INTO WEDNESDAY. MODELS HAVE TRENDED A LITTLE WARMER...SO LIMITED ANY FREEZING RAIN TO THE NORTH HALF OF CENTRAL INDIANA EARLY TUESDAY...WITH JUST RAIN OTHERWISE. COLDER AIR MOVING IN BEHIND THE SYSTEM WILL KEEP SNOW AS THE PRECIPITATION TYPE TUESDAY NIGHT INTO WEDNESDAY. THE SECOND UPPER SYSTEM WILL MOVE ACROSS ON THURSDAY. AGAIN WITH LIMITED FORCING/MOISTURE JUST WENT SLIGHT CHANCE POPS DURING THE DAY THURSDAY. TEMPERATURES LOOK COOL ENOUGH FOR JUST SNOW. THERE WILL BE A GENERAL COOLING TREND DURING THE EXTENDED AS A BROAD UPPER TROUGH SETS UP ACROSS THE EASTERN USA. && .AVIATION /DISCUSSION FOR THE 170000Z TAF ISSUANCE/... ISSUED AT 558 PM EST FRI JAN 16 2015 MVFR CONDITIONS IN FOG POSSIBLE 04Z-14Z IN OUTLYING TAF SITES...OTHERWISE VFR. SATELLITE AND WEATHER DEPICTION INDICATED CLEAR SKIES OVER THE AREAS WITH SOME MID CLOUDS TO THE NORTH. A RIDGE OF HIGH PRESSURE OVER THE EASTERN GREAT LAKES AND OHIO WILL MOVE ON TO THE EAST. MAIN ISSUE TONIGHT WILL BE POSSIBILITY OF MVFR FOG LATE EVENING ON. WINDS WILL INCREASE SOME LATER TONIGHT WHICH SHOULD MITIGATE FOG THREAT. ON SATURDAY MAIN ISSUE WILL BE MODERATE WINDS UP TO 15 KNOTS AND GUSTS UP TO 25 KNOTS AS LOW PRESSURE MOVES INTO THE WESTERN GREAT LAKES. MID/HIGH CLOUDS MAY INCREASE LATE SATURDAY. A TRAILING COLD FRONT WILL MOVE INTO OUR AREA SATURDAY EVENING CAUSING A LOWERING FLIGHT CONDITIONS AFTER 00Z SUNDAY. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM...50 AVIATION...JH VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
330 PM EST FRI JAN 16 2015 .UPDATE... THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 330 PM EST FRI JAN 16 2015 MILD WEATHER WILL CONTINUE THROUGH SATURDAY AS HIGH PRESSURE SHIFTS EAST. A QUICK MOVING UPPER LEVEL WAVE WILL BRING LIGHT PRECIPITATION THROUGH CENTRAL INDIANA SATURDAY NIGHT AND SUNDAY MORNING...FOLLOWED BY COLDER WEATHER FOR THE END OF THE WEEKEND. TEMPERATURES WILL BRIEFLY WARM UP AGAIN ON MONDAY BEFORE A SERIES OF UPPER WAVES BRINGS LIGHT WINTRY PRECIPITATION TO THE AREA TUESDAY AND AGAIN THURSDAY WITH PROGRESSIVELY COLDER TEMPERATURES FOR THE SECOND HALF OF NEXT WEEK. && .NEAR TERM /TONIGHT/... ISSUED AT 330 PM EST FRI JAN 16 2015 EXTREME NORTHEAST PORTION OF THE FORECAST AREA REMAINS UNDER THE MID LEVEL CLOUD DECK ASSOCIATED WITH THE WEAK UPPER LEVEL DISTURBANCE PASSING BY TO THE NORTH. THESE WERE SHIFTING EAST AND EXPECT THEM TO BE LARGELY OUT OF DELAWARE AND RANDOLPH COUNTIES BY 21-22Z. SKIES WERE SUNNY ELSEWHERE ACROSS CENTRAL INDIANA AS WE ENJOY OUR WARMEST DAY IN NEARLY TWO WEEKS FOR MANY. TEMPS RANGED FROM THE MID 30S NORTH TO MID 40S SOUTH AT 20Z. CLOUDS IN NORTHERN COUNTIES AND TEMPS ARE THE PRIMARY ISSUES FOR THE NEAR TERM AS A WARM FRONT LIFTS NORTH LATER THIS EVENING. RAP AND HRRR BOTH SHOWING DEVELOPMENT OF DEEPER MOISTURE IN THE 925-950MB LAYER AFTER 02-03Z OVER THE NORTHERN PARTS OF THE FORECAST AREA... GRADUALLY LIFTING NORTH OVERNIGHT WITH THE BOUNDARY. BOTH THE NAM AND OP GFS HINT AT THIS AS WELL. EXPECT THIS TO MANIFEST AS A PERIOD OF LOWER CLOUDS OVER NORTHERN COUNTIES...FOLLOWED BY POTENTIALLY SOME LIGHT PATCHY FOG TOWARDS DAYBREAK WITH RAP/HRRR MODEL SOUNDINGS SHOWING LINGERING SHALLOW MOISTURE UNDERNEATH A SHARP INVERSION PRESENT AT 1000FT AND LOWER. ONE MITIGATING FACTOR THAT WOULD KEEP ANY FOG LIMITED IS THE INCREASE IN SURFACE FLOW AFTER MIDNIGHT AS THE SURFACE PRESSURE GRADIENT TIGHTENS. WILL KEEP ANY FOG MENTION OUT OF THE FORECAST AT THIS POINT...BUT THIS WILL BE SOMETHING TO MONITOR INTO THE EVENING. MAINLY CLEAR SKIES ARE EXPECTED ELSEWHERE OVERNIGHT. TEMPS...WITH WARM ADVECTION COMMENCING AS THE BOUNDARY LIFTS NORTH...EXPECT LOWS TO OCCUR MOST AREAS BY LATE EVENING WITH STEADY OR SLOWLY RISING TEMPS THEREAFTER. ENDED UP SLIGHTLY UNDERCUTTING MOS GUIDANCE WITH TEMPS RETURNING INTO THE UPPER 20S/LOWER 30S BY 12Z. && .SHORT TERM /SATURDAY THROUGH MONDAY/... ISSUED AT 330 PM EST FRI JAN 16 2015 FORECAST CHALLENGES REMAIN ON PRECIP CHANCES SATURDAY NIGHT AND SUNDAY...AND TEMPS THROUGHOUT THE PERIOD. SATURDAY STANDS A STRONG CHANCE TO BE THE PICK DAY OF THE MONTH SO FAR...DESPITE A WINDY DAY ACROSS THE HOOSIER STATE. MOSTLY SUNNY SKIES ARE ANTICIPATED FOR MUCH OF SATURDAY WITH CLOUDS ASSOCIATED WITH THE UPPER WAVE AND COLD FRONT HOLDING OFF UNTIL LATE IN THE DAY. 40-50KT 850MB JET WILL SWING AROUND THE BASE OF THE APPROACHING UPPER WAVE AND ACROSS THE OHIO VALLEY THROUGH THE DAY. THIS WILL ENSURE A BREEZY AFTERNOON FOR THE REGION WITH SUSTAINEDS NEAR 20MPH AND GUSTS INTO THE 30-35MPH RANGE. FRONT SWINGS THROUGH THE FORECAST AREA SATURDAY NIGHT. MODEL CONSENSUS STARTING TO ZERO IN ON A BAND OF PRECIP SWINGING ACROSS THE FORECAST AREA...STARTING FIRST AS RAIN THEN MIXING WITH AND CHANGING OVER TO LIGHT SNOW AS LOW LEVEL THERMALS BECOME SUPPORTIVE. STILL THINK SOME POTENTIAL EXISTS FOR A FEW TENTHS OF AN INCH OF SNOW OVER THE EASTERN HALF OF THE FORECAST AREA BY SUNDAY MORNING. WILL CARRY CHANCE POPS SATURDAY NIGHT...LINGERING INTO SUNDAY MORNING OVER FAR EASTERN COUNTIES. MODEL SOUNDINGS AND RH PROGS FAVOR HANGING ONTO LOWER CLOUDS FOR A GOOD PORTION OF SUNDAY WITH SLOW CLEARING FROM THE SOUTHWEST DURING THE AFTERNOON. REMAINDER OF THE SHORT TERM WILL BE QUIET AS HIGH PRESSURE BUILDS QUICKLY BACK IN BY SUNDAY EVENING. WINDS WILL RETURN TO SOUTHWEST ON MONDAY WITH WARM ADVECTION RESUMING. SHOULD SEE CLOUDS INCREASE ONCE AGAIN BY LATE MONDAY AS A WEAK UPPER WAVE APPROACHES FROM THE NORTHWEST. TEMPS...CONSIDERING TEMP PERFORMANCE SO FAR TODAY AND EXPECTATION OF A LOT OF SUNSHINE SATURDAY...PREFER LEANING CLOSER TO THE WARMER MAVMOS WITH HIGHS RANGING FROM THE MID 40S TO LOWER 50S FOR MANY. TRENDED TOWARDS COOLER METMOS SUNDAY WITH COLD ADVECTION AND LINGERING CLOUDS. UNDERCUT AGGRESSIVE MAVMOS FOR MONDAY AS WELL... BUT STILL SHOULD SEE TEMPS RECOVER BACK INTO THE 40S FOR MUCH OF THE AREA. TOOK MOS BLEND FOR LOWS THROUGH THE PERIOD. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ISSUED AT 219 PM EST FRI JAN 16 2015 MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND INITIALIZATION WAS ACCEPTED FOR MOST ITEMS. A COUPLE OF UPPER SYSTEMS WILL MOVE ACROSS THE AREA DURING THE LONG TERM. MOISTURE/FORCING ARE NOT IMPRESSIVE WITH EITHER FEATURE...SO WILL KEEP POPS LOW. THE FIRST ONE ALSO HAS A SURFACE FRONTAL SYSTEM ASSOCIATED WITH IT THAT WILL MOVE ACROSS THE AREA TUESDAY INTO WEDNESDAY. MODELS HAVE TRENDED A LITTLE WARMER...SO LIMITED ANY FREEZING RAIN TO THE NORTH HALF OF CENTRAL INDIANA EARLY TUESDAY...WITH JUST RAIN OTHERWISE. COLDER AIR MOVING IN BEHIND THE SYSTEM WILL KEEP SNOW AS THE PRECIPITATION TYPE TUESDAY NIGHT INTO WEDNESDAY. THE SECOND UPPER SYSTEM WILL MOVE ACROSS ON THURSDAY. AGAIN WITH LIMITED FORCING/MOISTURE JUST WENT SLIGHT CHANCE POPS DURING THE DAY THURSDAY. TEMPERATURES LOOK COOL ENOUGH FOR JUST SNOW. THERE WILL BE A GENERAL COOLING TREND DURING THE EXTENDED AS A BROAD UPPER TROUGH SETS UP ACROSS THE EASTERN USA. && .AVIATION /DISCUSSION FOR THE 16/2100Z TAF UPDATE/... ISSUED AT 319 PM EST FRI JAN 16 2015 UPDATE... NO CHANGES. PREVIOUS DISCUSSION... MVFR CONDITIONS IN FOG DEVELOPING DURING THE NIGHT AT MOST SITES...OTHERWISE VFR. LIGHT WINDS WILL CONTINUE THIS AFTERNOON ALONG WITH JUST SOME HIGH CLOUDS. DURING THE EVENING...LIGHT FOG WILL DEVELOP AT MOST SITES CREATING MVFR CONDITIONS. THESE SHOULD CONTINUE THROUGH THE NIGHT...BUT WINDS WILL BE ON THE INCREASE. THIS SHOULD PREVENT FOG FROM GETTING TOO DENSE. ON SATURDAY WINDS WILL INCREASE WITH GUSTS NEAR 20KT EXPECTED BY 18Z. HIGHER GUSTS ARE POSSIBLE AFTER 18Z FOR KIND 30 HOUR TAF. FOG SHOULD DIMINISH WITH THESE WINDS AND CEILINGS SHOULD REMAIN VFR. ONE ALTERNATE SCENARIO TO CONSIDER IS THAT THE WARMER AIR MOVING IN OVERNIGHT COULD CREATE SOME LOW STRATUS OR THICKER FOG AT KLAF DUE TO SNOW COVER. NOT CONFIDENT ENOUGH TO INCLUDE IN TAFS AT THIS TIME. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM...50 AVIATION...50/TDUD VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1137 AM CST FRI JAN 16 2015 .SHORT TERM /TODAY/... ISSUED AT 308 AM CST FRI JAN 16 2015 SURFACE FRONT WILL INTENSIFY ACROSS IOWA TODAY AS THERMAL RIDGE FROM THE PLAINS SHIFTS EASTWARD INTO THE MISSOURI RIVER VALLEY. CONCERN TODAY WILL BE WITH CLOUDS ACROSS THE NORTH AND TEMPERATURES AREA- WIDE. CURRENTLY...PATCHY FOG IS DEVELOPING IN PORTIONS OF THE FAR NORTHEAST FORECAST AREA WHERE LIGHT WINDS AND RADIATIONAL COOLING IS COMBINING TO ALLOW FOG FORMATION. THE FOG HAS FOUND IT DIFFICULT TO PERSIST WITH ONLY A VERY SHALLOW LAYER OF MOIST AIR NEAR THE SURFACE WITH DRY CONDITIONS JUST ALOFT OF THE SURFACE. THEREFORE...IT HAS BEEN DIFFICULT FOR THE FOG TO DEEPEN AND EXPAND TO ANY EXTENT SO FAR. HOWEVER...WITH A FEW HOURS OF NIGHT LEFT...LIKELY TO SEE SOME LIMITED EXPANSION IN THE NORTHEAST WHERE WINDS WILL BE NEARLY CALM. OTHERWISE...THE AREA OF STATUS ACROSS WESTERN MN WILL CONTINUE TO DROP SOUTHEAST THIS MORNING AND IS EXPECTED TO SLIDE INTO THE FAR NORTHEAST CWA. THIS WILL LIMIT SUNSHINE ALONG WITH HEATING WITH READINGS LIKELY ONLY REACHING FREEZING BY MID AFTERNOON. FARTHER SOUTHWEST...WHERE MORE SUN WILL OCCUR...SNOW COVER IS LIMITED AND SOUTHWEST WINDS ARE EXPECTED...TEMPERATURES ARE EXPECTED TO CLIMB WELL INTO THE 40S AND LOWER 50S BY AFTERNOON. THIS AREA IS GENERALLY SOUTH OF A LINE FROM OTTUMWA TO AMES AND SAC CITY. MOST RECENT RUN OF HRRR WOULD PROJECT EVEN SOME MID TO UPPER 50S IN OUR FAR SOUTHWEST BY 21Z. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 308 AM CST FRI JAN 16 2015 WAA WILL PERSIST ACROSS THE AREA TONIGHT...WITH MODELS TRENDING TEMPERATURES SLIGHTLY WARMER...HAVE INCREASED LOW TEMPERATURES IN THE SOUTH. LOW PRESSURE SYSTEM WILL PUSH QUICKLY SOUTH ACROSS NORTHER PLAIN STATES...WITH BOUNDARY PUSHING ACROSS IOWA TONIGHT. SYSTEM WILL BE QUICK MOVING. WILL SEE SLIGHTLY COOLER TEMPERATURES BEHIND BOUNDARY. MODELS CONTINUE TO BRING PRECIPITATION FURTHER SOUTH WITH THIS SYSTEM...INTO SOUTHERN MINNESOTA AND WISCONSIN SATURDAY AFTERNOON. SOME INDICATIONS OF PRECIPITATION POTENTIAL ACROSS THE NORTH SATURDAY...THOUGH HAVE KEPT FORECAST DRY FOR NOW. BE FORCING ARRIVES AHEAD OF BEST MOISTURE...WITH A LARGE DRY LAYER IN PLACE AT MID LEVELS HELPING TO KEEP CONDITIONS DRY. THOUGH...MODELS CONTINUE TO INDICATE LOW LEVEL MOISTURE IN THE NORTH...WHICH MAY BE INCREASED WITH MELTING OF SNOWPACK...THIS MAY ALLOW FOR SOME LIGHT PRECIPITATION...THOUGH HAVE CONTINUED TO KEEP FORECAST DRY. WINDS WILL BECOME ANOTHER CONCERN SATURDAY AS THEY SHIFT TO THE NORTHWEST AND INCREASE BEHIND THE BOUNDARY. TOP OF THE MIXED LAYER WINDS REMAIN NEAR 40KTS...AND WILL SEE HIGH SUSTAINED WINDS AND GUSTS ESPECIALLY IN THE WEST. ATTM WINDS APPEAR TO BE NEAR BUT BELOW ADVISORY CRITERIA. WAA WILL QUICKLY RETURN AS SYSTEM PULLS EAST BY SATURDAY NIGHT. MODELS HAVE CONTINUED SLIGHTLY WARMER TREND FOR THE END OF THE WEEKEND...WITH 850MB TEMPS NEAR 4C ACROSS CENTRAL CWA...WITH WARMER TEMPERATURES TO THE SOUTH. HAVE THEREFORE INCREASE TEMPERATURES SLIGHTLY FOR SUNDAY AND MONDAY...ESPECIALLY IN THE SOUTH. PATTERN BECOMES MORE UNSETTLED FOR BEGINNING OF WEEK. HOWEVER...MODELS ARE IN POOR AGREEMENT WITH HANDLING OF SYSTEM SET TO PUSH SOUTH...AND HAVE LOW CONFIDENCE IN FORECAST. MODELS DROP WEAK WAVE SOUTH THROUGH NORTHWESTERLY FLOW...THOUGH DIFFER ON TIMING...PLACEMENT AND STRENGTH OF SYSTEM. GFS IS SLOWER THOUGH STRONGER. AMOUNT OF MOISTURE WILL ALSO PLAY INTO SYSTEM...THOUGH MODELS INDICATING ENOUGH MOISTURE FOR PRECIPITATION ATTM. CURRENT TRENDS TRACK SYSTEM ACROSS NORTHEASTERN PORTIONS OF IOWA. HAVE THEREFORE KEPT PRECIPITATION CONFINED TO THE NORTH AND EAST. DO NOT HAVE HIGH CONFIDENCE IN TIMING OR PLACEMENT OF THIS PRECIPITATION GIVEN MODEL UNCERTAINTY...THOUGH WILL LIKELY SEE A PERIOD OF PRECIPITATION EARLY IN THE WEEK. PRECIPITATION TYPE WILL BE SOMEWHAT UNCERTAIN TOO AS TEMPERATURES WILL LIKELY BE WARM ENOUGH FOR RAIN IN THE SOUTH THOUGH COLD ENOUGH FOR SNOW IN THE NORTH. MODELS ARE SLIGHTLY SLOWER WITH WAVE...AND COULD SEE PRECIPITATION CHANCES LINGER INTO WEDNESDAY. HOWEVER...HAVE KEPT WITH TREND FOR FASTER PROGRESSION FOR NOW. BEHIND SYSTEM TEMPERATURES WILL BE COOLER...THOUGH WILL STILL BE NEAR NORMAL FOR LATE JAN. && .AVIATION...16/18Z ISSUED AT 1137 AM CST FRI JAN 16 2015 VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. STRATUS AND FOG ACROSS CENTRAL/SOUTHERN MINNESOTA TODAY DO NOT APPEAR TO BE MAKING SOUTHWARD PROGRESS AND SHOULD REMAIN NORTH OF OUR AREA. THERE IS SOME POSSIBILITY OF REDEVELOPMENT FURTHER SOUTH TONIGHT...MAINLY ACROSS NORTHEAST IA AROUND MCW/ALO...HOWEVER THE PROBABILITY IS FAIRLY LOW AND ONLY VFR CONDITIONS ARE ADVERTISED IN THE 18Z TAFS. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...COGIL LONG TERM...AWB AVIATION...LEE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
220 PM MST FRI JAN 16 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 220 PM MST FRI JAN 16 2015 AS OF 3 PM CST...2 PM MST...SKIES ACROSS THE TRI-STATE REGION ARE MOSTLY SUNNY TO PARTLY CLOUDY AS SOME CIRRUS PASSES OVERHEAD. TEMPERATURES REACHED THE MID 50S TO LOW 60S THIS AFTERNOON. WINDS ARE FROM THE WEST BUT QUITE LIGHT...LESS THAN 10 MPH WITH SOME STATIONS REPORTING CALM WINDS. ALOFT...A WEAK SHORTWAVE DISTURBANCE IS GLIDING OVER THE HIGH PLAINS...RESULTING IN THE CIRRUS. ANOTHER STRONGER DISTURBANCE IS LOCATED OVER MONTANA AND IDAHO. FOR THIS AFTERNOON AND TONIGHT...CALM WEATHER IS ANTICIPATED WITH NO PRECIPITATION. SKIES SHOULD CLOUD UP LATER TONIGHT AS THE NORTHERN DISTURBANCE SPREADS IN FROM WYOMING. THIS RESULTS IN NEAR-STAGNANT TEMPERATURES THAT FALL EXTREMELY SLOW AND REMAIN WELL ABOVE NORMAL FOR THIS TIME OF YEAR (NORMALLY FALLING INTO THE TEENS). BY EARLY TOMORROW MORNING...BEFORE SUNRISE...THE DISTURBANCE TO OUR NORTHWEST FORCES A COLD FRONT THROUGH OUR REGION. IMMEDIATELY BEHIND THE FRONT...GUSTY NORTH WINDS ARE ANTICIPATED. THIS SOLUTION HAS BEEN PERSISTENT IN SEVERAL GFS...WRF ARW...WRF NMM AND HRRR RUNS. WINDS WEAKEN SOME FURTHER BEHIND THE FRONT BUT ARE EXPECTED TO INCREASE IN SPEED ONCE AGAIN AS DAYTIME MIXING IS REALIZED. ALOFT...WINDS HAVE WEAKENED FROM PREVIOUS GUIDANCE BUT STILL SHOW A 50-60 KT JET 1 KM ABOVE THE SURFACE. INTERESTING ITEM TO NOTE IS THAT THE STRONGEST JET OF WINDS SHOULD SLIDE FURTHER EAST THAN PREVIOUS EXPECTATIONS. THIS MEANS THE STRONGEST WINDS ARE NOW EXPECTED GENERALLY EAST OF THE COLORADO BORDER...IF NOT EAST OF HIGHWAY 25. IN ADDITION...DAYTIME MIXING DOES NOT LOOK OVERLY STRONG WITH FORECAST LAPSE RATES AROUND 6-7 C/KM. OVERALL LOWERED WIND SPEEDS FROM PREVIOUS FORECAST CYCLES BUT STRONGEST WIND GUSTS MAY STILL EXCEED 40 KNOTS...OR 46 MPH. ANOTHER NOTE ABOUT TOMORROW`S WINDS...THERE HAVE BEEN SOME CONCERNS THAT SOME BLOWING DUST MAY BE OBSERVED. CHECKED THE SOIL MOISTURE THIS MORNING AND IT IS QUITE WET. PRECIPITATION ANALYSIS OVER THE LAST 30 DAYS INDICATES THAT WE HAVE BEEN AROUND 0.5" TO 1.0" ABOVE NORMAL. THIS DOES NOT EVEN INCLUDE THE WIDESPREAD 0.75" TO 1.00" RAINS RECEIVED ON DECEMBER 14TH...2014. AIR QUALITY FORECAST GUIDANCE FOR THE CENTRAL PLAINS INDICATES ONE PLUME OF DUST TOMORROW AROUND HILL CITY...KANSAS. WHILE THIS MAY BE POSSIBLE...THE DUST MODEL GUIDANCE DOES NOT INDICATE BLOWING DUST ANYWHERE ELSE SO IT IS QUITE ISOLATED. BY THIS REASONING AND THAT WE ARE FORECASTING LOWER WIND SPEEDS OVER THE PREVIOUSLY MENTIONED AREAS WITH BLOWING DUST...HAVE REMOVED BLOWING DUST FROM THE FORECAST. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 1231 PM MST FRI JAN 16 2015 THE LONG TERM PERIOD WILL BE DOMINATED BY NORTHWEST FLOW WITH SERIES OF FAST MOVING SYSTEMS BRINGING OCCASIONAL CHANCES FOR LIGHT PRECIPITATION AND TEMPERATURES NEAR NORMAL. ONE SHORTWAVE TROUGH MOVES THROUGH ON SUNDAY BUT MODELS KEEP THE PRECIPITATION CHANCES LIMITED TO THE MOUNTAINS OF COLORADO WITH THE PLAINS DRY PROBABLY DUE TO LOW LEVEL WESTERLY FLOW AND DOWNSLOPING EFFECT. MODELS SHOW A BIT MORE MOISTURE AVAILABLE ON MONDAY WITH ANOTHER WEAK SYSTEM SO WILL HAVE SOME SLIGHT CHANCE POPS FOR VERY LIGHT RAIN OR SNOW MONDAY AFTERNOON AND EVENING. TUESDAY LOOKS LIKE IT WILL BE DRY WITH LACK OF AN UPPER SHORTWAVE FOR LIFT. BY WEDNESDAY MODELS START TO DIVERGE WITH LATEST RUN OF THE ECMWF SHOWING SHORTWAVE DIGGING INTO THE HIGH PLAINS WITH ASSOCIATED LIGHT SNOWFALL BUT THE GFS DRY...SO WILL CARRY ONLY SLIGHT CHANCE POPS. FOR THE END OF THE WEEK...THE MODELS GENERALLY SHOW AN UPPER LOW OVER THE DESERT SOUTHWEST AND NORTHERLY FLOW INTO THE NORTHERN AND CENTRAL ROCKIES. TEMPERATURES WILL BE COOLING WITH PRECIPITATION CHANCES SLIM TO NONE IN THAT PATTERN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1025 AM MST FRI JAN 16 2015 CONTINUATION OF VFR CONDITIONS IS FORECAST FOR THE NEXT 24 HOURS. MAIN AVIATION CONCERN IS A COLD FRONT PASSAGE EARLY TOMORROW MORNING...BETWEEN 8Z-11Z. LIGHT WEST WINDS BACK SOUTHWEST BRIEFLY THIS EVENING BEFORE VEERING NORTHWEST/INCREASING IN SPEED AHEAD OF THE FRONT. AS THE FRONT PASSES...EXPECT SIGNIFICANT INCREASE IN SPEED WITH STRONGER GUSTS. WINDS INCREASE AGAIN AS DAYTIME MIXING IS REALIZED BY 15Z-16Z. AS FOR CLOUDS...CIRRUS IS SPREADING IN PRESENTLY AND MID-LEVEL CLOUDS AROUND 10KFT EXPECTED AROUND FRONT PASSAGE. CLOUDS CLEAR AGAIN BY LATE TOMORROW MORNING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...RRH LONG TERM...024 AVIATION...RRH
AREA FORECAST DISCUSSION
NWS TOPEKA KS
313 PM CST Fri Jan 16 2015 .SHORT TERM...(This Evening through Saturday) Issued at 312 PM CST FRI JAN 16 2015 Recent water vapor imagery and RAP analysis showing a weak upper wave moving east across South Dakota and Nebraska, with a much stronger wave exiting the Pacific Northwest into the Northern Rockies. Deep west to southwest flow has resulted over Kansas with dry and warm lower tropospheric conditions and breezy winds dominating. With fairly progressive flow in place, the upper waves make quick progress through the region through Saturday afternoon. The first wave brings some high clouds through this evening, but more and somewhat deeper cloud approaches late tonight and exits Saturday afternoon with the stronger wave. Rather strong lift exits ahead of this wave, but the still dry mid to lower levels should keep precipitation in check. Wind speeds diminish a bit this evening but pick up again Saturday as deeper mixing occurs in strong cold air advection around 850mb. Winds aloft don`t quite support Advisory levels but could be close in the north and west. The mixing and only modified airmass should still allow temps to reach into the 50s. .LONG TERM...(Saturday Night through Friday) Issued at 312 PM CST FRI JAN 16 2015 For Saturday night through Monday, models continue to show a warm and dry weather pattern with northwest flow aloft and low level trajectories either from the southwest or west. This low level pattern does not favor very good moisture return. Therefore think precip chances are pretty close to zero. Have again trended temps warmer for Sunday and Monday. Given today`s temps, think there is a chance the forecast for Sunday may be a little to cool. Although Models do not show 925MB temps quite as warm as today. Therefore have kept highs generally around 60. A frontal boundary should move through the area late Monday. At this time, think it will be late enough in the day that temps warm into the mid and upper 50s. Monday night through Friday should see a cooling trend as the models transition the pattern from northwest flow to more of a broad cyclonic split flow aloft, as energy tries to dig southwest into AZ and NM. There should be weak perturbations move across the forecast area through this period. However with a modified ridge of high pressure from the Pacific northwest building into the central plains, there is not much opportunity for moisture to advect north. The ECMWF remains the only solution to bring very light QPF into parts of the area, and it has not had the best run to run continuity of late. Therefore have maintained a dry forecast through the end of the week. Reinforcing surges of high pressure from the north and northwest should keep temps closer to climo with lows in the 20s and highs in the 40s. && .Fire Weather... Issued at 312 PM CST FRI JAN 16 2015 Temps and dewpoint values on the extreme of even the most aggressive guidance this afternoon have pushed fire weather conditions in to Red Flag levels in some locations this afternoon. Expect conditions to steadily improve in the next few hours with mixing weakening with diurnal trends. Saturday brings another day of concern. Winds, northwest this time, will be stronger behind the cold front and have high confidence in lower temperatures and moderate confidence in dewpoints thus moderate confidence in humidities. Though specifics are not certain, quick falls in dewpoints seen today are much less likely in this regime. RH values are still likely to fall to into the 30-38% range in the mid afternoon, with winds gusting from 30-40mph supporting Very High rangeland fire danger. && .AVIATION...(For the 18Z TAFs through 18Z Saturday Afternoon) Issued at 1144 AM CST FRI JAN 16 2015 VFR conditions expected. SSW winds increase a bit in the next few hours with minor decreases and backing ahead of a cold front. Increasing winds aloft should result in wind shear for much of the overnight, with front`s approach weakening shear just ahead of it and NW winds taking hold at the end of the forecast as mixing increases. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...65 LONG TERM...Wolters AVIATION...65
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1242 PM EST FRI JAN 16 2015 .AVIATION... VARIABLE SKY CONDITIONS AND CEILINGS ARE EXPECTED TO PERSIST OVER THE NEXT 12 HOURS WITH THE FRONTAL INVERSION LOCKED IN PLACE. THE FRONT WILL EVENTUALLY LIFT NORTHWARD AS A WARM FRONT WITH A GREATER CONFIDENCE IN THIS OCCURRING AFTER 6Z TONIGHT. THIS WILL BE DUE TO A LOW LEVEL JET FEATURE PUSHES TOWARD THE CENTRAL GREAT LAKES. THE GREATER SOUTHERLY WIND TRAJECTORY AND ADVECTIVE COMPONENT IS EXPECTED TO LEAD TO GREATER SATURATION TOWARDS 12Z. FOR DTW...RESTABLISHMENT OF THE TOP OF THE INVERSION THIS AFTERNOON MAY ALLOW CIGS TO DEVELOP AGAIN RIGHT AT THE 5000 FT AGL THRESHOLD FOR DTW. SOUTHERLY FLOW IS EXPECTED TO INCREASE TONIGHT IN THE MIDLEVELS WHICH BRINGS A GREATER POTENTIAL FOR MVFR CIGS BY 12Z TONIGHT. //DTW THRESHOLD PROBABILITIES... * LOW CONFIDENCE IN CEILINGS AOB 5000 FEET THIS AFTERNOON AND EVENING. HIGH CONFIDENCE LATE TONIGHT...WITH UNCERTAIN TIMING. && .PREV DISCUSSION...ISSUED 356 AM EST FRI JAN 16 2015 SHORT TERM...TODAY AND TONIGHT SURFACE COLD FRONT SLIDING THROUGH SOUTHEAST MICHIGAN EARLY THIS MORNING WITH LITTLE FANFARE...AS UPPER LEVEL TROUGH AXIS/SUPPORT IS ALREADY OVER THE EASTERN GREAT LAKES. THE FRONT WILL SINK SOUTH OF THE MICHIGAN BORDER AND WASH OUT AS UPPER LEVEL RIDGING BEGINS TO BUILD INTO THE CENTRAL GREAT LAKES THIS AFTERNOON INTO TONIGHT. SHARP BAROCLINIC ZONE LOOKS TO BE HUNG UP ACROSS LOWER MICHIGAN...MAKING IT DIFFICULT TO ACCESS EXACTLY HOW MUCH COLD AIR WILL BE ABLE TO FILTER INTO SOUTHERN LOW MICHIGAN DURING THE DAY. MODEL CONSENSUS IS FOR 925 MB TEMPS TO FALL INTO THE NEGATIVE LOWER TEENS...WHICH SUGGESTS TEMPS SHOULD HOLD/FALL INTO THE LOW/MID 20S. RAW SURFACE TEMPS OUT OF THE NAM/RAP13 EVEN SUGGEST TEENS WILL ENCOMPASS THE NORTH HALF OF THE CWA POST 12Z. RAP SOUNDINGS STILL INDICATING STEEP ENOUGH LOW LEVEL LAPSE RATES/SUPERSATURATION WITH RESPECT TO ICE TO MAINTAIN A CHANCE OF FLURRIES. THERE WILL BE A MODEST RETURN OF MOISTURE TONIGHT AS A SHORTWAVE TRACKS THROUGH SOUTH DAKOTA AND ARRIVES TOWARD 12Z SATURDAY...BUT THE INITIALLY DRY MID LEVELS (850 DEW PT DEPRESSIONS OF 20+ C) WILL NEED TO SATURATE...WHICH LOOKS TO BE A CHALLENGE...PER 00Z EURO. GFS IS INDICATING THE BEST MOISTURE AND TRIES TO TRIGGER LIGHT SNOW SHOWERS...BUT PREFERENCE WILL LEAN TOWARD DRIER SOLUTION...BUT WILL INCLUDE A CHANCE OF FLURRIES OVERNIGHT WITH THE INCREASING ISENTROPIC ASCENT. NONE-THE-LESS...BEFORE CLOUDS AND MOISTURE INCREASE...SHOULD BE SET UP FOR GOOD FALL IN TEMPS DURING THE EVENING WITH SURFACE HIGH/RIDGE IN PLACE. INHERITED TEMPS LOOKED REASONABLE...MID/UPPER SINGLE NUMBERS THUMB REGION TO AROUND 10/LOWER TEENS ELSEWHERE. LONG TERM... SATURDAY THROUGH THURSDAY THE COLD FRONT MOVING THROUGH THE GREAT LAKES TODAY WILL BE ON ITS WAY BACK NORTH AS A WARM FRONT TO START SATURDAY. THIS WILL TOUCH OFF A ROUND OF ABOVE NORMAL TEMPERATURES FOR THE WEEKEND. SATURDAY WILL BE THE WARMEST DAY AS MAX TEMPS MAKE A RUN INTO THE MID AND UPPER 30S FOLLOWED BY READINGS ABOUT A CATEGORY LOWER SUNDAY FOLLOWING THE ASSOCIATED MODEST COLD FRONT. THE MOISTURE SUPPLY WITH THE SYSTEM WILL BE LEAN ENOUGH TO LIMIT PRECIP POTENTIAL TO A CHANCE OF RAIN/SNOW MIX SATURDAY NIGHT AND A CHANCE OF SNOW EARLY SUNDAY. THE UPPER LEVEL WAVE THAT WILL AFFECT THE GREAT LAKES SATURDAY IS SHOWN DRIVING THROUGH THE PACIFIC NW WITH A STRONG LOOK IN SATELLITE IMAGERY. IT WILL HAVE NO PROBLEM MATCHING MODEL TIMING OF REACHING THE NORTHERN PLAINS SATURDAY MORNING. SURFACE CYCLOGENESIS IN THE LEE OF THE CENTRAL ROCKIES WILL THEN LATCH ON TO THE FRONT STALLED JUST TO OUR SOUTH AND PULL IT STEADILY NORTHWARD DURING THE DAY. PRECIPITATION POTENTIAL WILL BE TIED TO AND LIMITED BY THE LACK OF GULF MOISTURE AVAILABLE TO THE FRONTAL ZONE THAT WILL BE ENSURED BY THE BROAD REGION OF SURFACE HIGH PRESSURE CENTERED ON THE ENTIRE GULF COAST THROUGH MID ATLANTIC. MODEL PLAN DEPICTIONS AND CROSS SECTIONS OF THETA-E INDICATE A SHARP BUT SHALLOWLY SLOPED FRONTAL STRUCTURE CONTAINING SPECIFIC HUMIDITY AROUND 3 G/KG ON THE 285K SURFACE...NOT BAD FOR AN AIR MASS OF PACIFIC ORIGIN...BUT WITH THE BULK OF ISENTROPIC ASCENT CAPABLE OF PRECIP OCCURRING OVER THE NORTHERN GREAT LAKES. CONDITIONS IN SE MICHIGAN WILL RESEMBLE MORE OF WARM SECTOR REGION OF THE SYSTEM WITH THE SURFACE FRONT EXPECTED TO MOVE THROUGH IN TIME FOR MAX TEMPS TO MAKE A RUN INTO THE UPPER 30S BY LATE AFTERNOON NEAR THE OHIO BORDER TO MID 30S NORTHERN THUMB. THE UPPER WAVE WILL GET CLOSE ENOUGH TO OUR AREA SATURDAY EVENING TO HELP WRING OUT SOME MOISTURE FROM THE LOW LEVEL THETA-E RIDGE/PREFRONTAL SURFACE TROUGH. THE UPPER TROUGH AXIS AND SURFACE FRONT WILL THEN BRING ENOUGH COLD AIR BACK INTO THE LOW LEVELS FOR A CHANCE OF LIGHT SNOW OVERNIGHT. THE CHANCE POP CATEGORY IS MAINTAINED FOR NOW AS MODEL SOUNDINGS INDICATE INCONSISTENT LEVELS OF SATURATION DURING THE EVENING BUT WITH A THERMAL PROFILE SUPPORTIVE OF LIGHT RAIN. THE SOUNDINGS AND MEAN RH FIELDS TOGETHER SUGGEST JUST POCKETS OF LIGHT PRECIPITATION UNTIL POSSIBLY LATE SATURDAY NIGHT AND SUNDAY MORNING AS COLDER AIR ALOFT AND STRONGER DYNAMIC SUPPORT WITH THE UPPER TROUGH INCREASE FORCING AND LOWER STABILITY ENOUGH FOR BROADER COVERAGE. THE REST OF THE WEEK WILL BE ON THE ACTIVE SIDE IN TERMS OF SMALL SCALE SHORT WAVES/CLIPPER SYSTEMS THAT WILL HAVE MODERATE MOISTURE SUPPLY BUT LOW PREDICTABILITY. SO FAR...NO BIG ARCTIC AIR INTRUSIONS ARE INDICATED UNTIL POSSIBLY THE END OF NEXT WEEK. MARINE... A COLD FRONT WILL MOVE THE REST OF THE WAY THROUGH LAKE HURON AND LOWER MICHIGAN DURING THE MORNING. MODERATE NORTHWEST WIND WILL HAVE GUSTS AROUND 30 KNOTS...AND POSSIBLY A FEW STRAY GUSTS TO GALE FORCE...BEFORE DIMINISHING QUICKLY IN FAVOR OF HIGH PRESSURE BY AFTERNOON. THE NEXT LOW PRESSURE SYSTEM WILL THEN MOVE QUICKLY INTO THE NORTHERN PLAINS TONIGHT WHICH WILL RAPIDLY INCREASE WIND FROM THE SOUTH LATE TONIGHT AND SATURDAY. THE GRADIENT WIND WILL INCREASE WITHIN THE UNSTABLE AIR OVER THE LAKE AND AHEAD OF THE SURFACE WARM FRONT WHICH WILL SUPPORT A PERIOD OF GALE FORCE GUSTS BEGINNING SATURDAY MORNING TROUGH ABOUT MID AFTERNOON. THE PASSAGE OF THE WARM FRONT WILL THEN BRING ENOUGH STABILITY OVER THE WATER TO BRING WIND BELOW GALES BUT STILL ELEVATED NEAR 30 KNOTS AT TIMES. THE COLD FRONT IS ALSO EXPECTED TO PASS THROUGH THE REGION WITH GUSTS AT 30 KNOTS OR LESS THROUGH SUNDAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...GALE WARNING FROM 7 AM TO 4 PM EST SATURDAY FOR LHZ361>363-462. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....CB SHORT TERM...SF LONG TERM....BT MARINE.......BT YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
328 PM MST FRI JAN 16 2015 .SYNOPSIS... ANOTHER ROUND OF LOW CLOUDS AND FREEZING FOG IS POSSIBLE TONIGHT ACROSS NORTHWEST NEW MEXICO. LIKE PREVIOUS NIGHTS...VISIBILITIES MAY DROP BELOW ONE HALF MILE AND A THIN GLAZE OF ICE MAY FORM ON ROADWAYS. MEANWHILE...BREEZY TO WINDY CONDITIONS WILL RETURN FOR AREAS ALONG AND JUST DOWNSTREAM OF THE CENTRAL MOUNTAIN CHAIN OVERNIGHT. GUSTS BETWEEN 40 AND 45 MPH WILL BE POSSIBLE. A BACK DOOR COLD FRONT WILL SLIDE THROUGH THE PLAINS EARLY SATURDAY MORNING...BUT TEMPERATURES WILL NOT BE DRAMATICALLY COLDER BEHIND IT. DRY NORTHWEST FLOW WITH WARM TEMPERATURES WILL BE ON TAP FOR SUNDAY AND MONDAY. THEN...ANOTHER BACK DOOR COLD FRONT WILL DROP INTO THE PLAINS ON TUESDAY...BEFORE ANOTHER STORM SYSTEM IMPACTS THE STATE FROM THE NORTHWEST ON WEDNESDAY. IT IS TOO EARLY TO SAY HOW MUCH PRECIPITATION WILL ACCOMPANY THIS STORM SYSTEM...BUT THERE IS POTENTIAL FOR IT TO BE WIDESPREAD. && .DISCUSSION... LOW CLOUDS AND FOG ARE VERY SLOW TO ERODE ACROSS NORTHWEST NM TODAY. THE BIGGEST QUESTION FOR TONIGHTS FORECAST IS WHETHER THE FZFG WILL REFORM. THOUGH THERE ARE ABUNDANT MID/HIGH LEVEL CLOUDS ON THE HORIZON...IT APPEARS THAT MUCH OF THIS CLOUD COVER WILL HAVE MOVED EAST OF THE AREA SHORTLY AFTER MIDNIGHT...ALLOWING FOR STRONG RADIATIONAL COOLING AND THE POTENTIAL FOR MORE FOG DEVELOPMENT BEFORE SUNRISE. THE HRRR ALSO SUGGESTS ANOTHER ROUND OF LOW CLOUDS/FOG. THEREFORE HAVE ADDED AREAS OF FZFG TO THE GRIDS AROUND FMN AND GUP...BUT CONFIDENCE IS NOT HIGH ENOUGH TO PULL THE TRIGGER ON A FZFG ADVISORY ATTM. MEANWHILE...A SHORTWAVE TROUGH WILL CLIP NE NM OVERNIGHT...AND THOUGH THERE IS INSUFFICIENT MOISTURE ASSOCIATED WITH IT FOR PRECIPITATION...MID LEVEL WINDS INCREASE. 700 MB WINDS INCREASE TO NEAR 50KT ALONG AND JUST DOWNSTREAM OF THE CENTRAL MTN CHAIN. FAVORED LOCALES ALONG AND JUST EAST OF THE CENTRAL MTN CHAIN...INCLUDING CQC...WILL BE IN STORE FOR A BREEZY TO WINDY NIGHT...ESPECIALLY BETWEEN MIDNIGHT AND JUST AFTER SUNRISE. LOCALIZED AREAS MAY SEE BRIEF WIND ADVISORY CRITERIA...BUT IT IS NOT EXPECTED TO BE WIDESPREAD ENOUGH TO WARRANT A WIND ADVISORY. ACCOMPANING THE SHORTWAVE WILL BE A BACK DOOR COLD FRONT THAT WILL SLIDE DOWN THE PLAINS EARLY SATURDAY MORNING. TEMPERATURES ARE NOT DRAMATICALLY COLDER BEHIND THE FRONT...BUT DID LOWER TEMPS A FEW DEGREES FOR SAT AFTN. BREEZY CONDITIONS ARE ALSO POSSIBLE NEAR THE TEXAS BORDER BEHIND THE FRONT. THE FRONT QUICKLY WASHES OUT AND SOUTHWEST WINDS RETURN FOR SATURDAY NIGHT. THESE WINDS MAY BECOME BREEZY/WINDY ALONG THE I-40 CORRIDOR ON SUNDAY UNDER NORTHWEST FLOW ALOFT. DRY NORTHWEST FLOW WILL CONTINUE ON MONDAY. TEMPERATURES BOTH SUN AND MON WILL BE 5 TO 15 DEGREES ABOVE NORMAL. THE WARM TEMPERATURES WILL COME TO AN END TUESDAY THROUGH THURSDAY. A SHORTWAVE TROUGH MOVING ACROSS THE GREAT PLAINS MONDAY NIGHT AND EARLY TUESDAY WILL SEND A BACK DOOR COLD FRONT INTO EASTERN NM...THOUGH HEIGHTS WILL GRADUALLY LOWER AREAWIDE. TEMPS ON TUES WILL GENERALLY BE WITHIN 5 DEGREES OF NORMAL. MODELS CONTINUE TO REALLY STRUGGLE WITH HOW THE MID WEEK SYSTEM WILL EVOLVE. BOTH THE GFS AND EC HAVE A WAVE DROPPING OUT OF NW FLOW ON TUESDAY NIGHT AND STRENGTHENING AS IT APPROACHES/CROSSES NM ON WEDNESDAY. HOWEVER...THE DETAILS ARE QUITE DIFFERENT...WHICH RESULTS IN THE GFS HAVING VERY LITTLE PRECIP DESPITE THE BACK DOOR FRONT REINFORCEMENT...AND THE EC SHOWING WIDESPREAD PRECIPITATION. FURTHER...THE GFS SHOWS ANOTHER STRONG CLOSED LOW SYSTEM ON ITS HEELS. IT APPEARS THAT THERE WILL BE MULTIPLE PIECES OF ENERGY WITH THE NEXT SYSTEM AND MODELS ARE HAVING AN EXTREMELY DIFFICULT TIME RESOLVING THEM. NONETHELESS...THERE IS POTENTIAL FOR MORE PRECIPITATION MID WEEK...BUT TOO SOON TO SAY HOW MUCH OR WHAT AREAS WILL BE FAVORED. STAY TUNED. 34 && .FIRE WEATHER... A DRY AND RELATIVELY WARMER PATTERN HAS PREVAILED TODAY WITH NORTHWESTERLY FLOW ALOFT BEGINNING TO SHOW SIGNS OF STRENGTHENING. POOR VENTILATION HAS BEEN IN PLACE TODAY...AND WILL CONTINUE TO BE A THEME INTO THE WEEKEND. TODAY`S LIGHT BREEZES OVER THE CENTRAL TO WESTERN ZONES ARE ALSO COUPLING WITH STRONG TEMPERATURE INVERSIONS AND A STUBBORN LAYER OF LOW STRATUS CLOUDS OVER THE NORTHWEST QUADRANT OF THE STATE. THE LOW STRATUS CLOUDS HAVE HAMPERED THE WARMING TREND IN NORTHWEST NM...BUT OTHERWISE THE MOSTLY SUNNY SKIES HAVE YIELDED NEAR TO ABOVE AVERAGE TEMPERATURES. DOWNSLOPING BREEZES HAVE REALLY HELPED THE NORTHEAST WARM UP EVEN MORE...SOME 20 DEGREES ABOVE NORMAL. THESE EASTERN DOWNSLOPE AREAS ARE WHERE RH HAS DROPPED THE LOWEST...EVEN BELOW 10 PERCENT...BUT THE SNOW MELT AND LOW CLOUDS OVER NORTHWESTERN NM HAVE KEPT HIGHER DEWPOINTS AND RH INTACT. TONIGHT`S RECOVERY WILL BE EXCELLENT IN THE SAN JUAN BASIN...AND POOR TO FAIR IN THE NORTHEAST WITH DOWNSLOPING BREEZES STAYING ALIVE ALL NIGHT. A PASSING SHORT WAVE TROUGH ALOFT WILL ENHANCE SOME OF THESE WINDS...TURNING THEM GUSTY IMMEDIATELY EAST OF THE CENTRAL MOUNTAIN CHAIN OVERNIGHT. A FRONT WILL THEN SLIDE INTO THE EASTERN HALF OF NM SATURDAY MORNING...SHIFTING WINDS MORE NORTHERLY WHILE DROPPING TEMPERATURES A FEW DEGREES. CENTRAL TO WESTERN ZONES WILL OBSERVE LITTLE CHANGE TEMPERATURE-WISE WITH LIGHT TO MODERATE BREEZES. POOR VENTILATION WILL PERSIST. INTO SUNDAY NORTHWEST WINDS ALOFT RELAX SOME AND A LEE-SIDE SURFACE TROUGH REDEVELOPS. THE TEMPERATURES IN THE NORTHEAST ON SUNDAY WILL REBOUND WHAT THEY LOST ON SATURDAY...AND THE DRY CONDITIONS WILL CONTINUE AREA WIDE. BY MONDAY A STRONGER NORTHWEST FLOW WILL BE OBSERVED OVER NM AS A GREAT LAKES SHORT WAVE TROUGH USHERS ANOTHER COOLER AIR MASS CLOSER TO THE STATE. SOME BETTER VENTILATION RATES ARE CURRENTLY PROJECTED FOR MONDAY...BUT WOULD NOT BE SURPRISED IF THESE REDUCE WITH NEWER MODEL RUNS. THIS APPROACH OF COOLER AIR WILL ARRIVE INTO NM MONDAY NIGHT...YIELDING MUCH COOLER DAYTIME HIGHS INTO TUESDAY. THE NEXT FEATURE OF INTEREST WILL BE A TROUGH THAT TAKES SHAPE OVER AZ AND SWINGS SOUTHEASTWARD. THIS WOULD SPREAD SOME HIGHER PROBABILITIES FOR WETTING PRECIPITATION OVER THE FORECAST AREA THROUGH THE WEDNESDAY-THURSDAY TIME FRAME WHILE DROPPING TEMPERATURES BACK BELOW AVERAGE. THE FINER DETAILS OF PRECIPITATION AMOUNTS AND PLACEMENT ARE STILL BEING RESOLVED...BUT THIS COOLER AND WETTER PERIOD WILL CERTAINLY PRECLUDE ANY FIRE WEATHER CONCERNS. 52 && .AVIATION... 18Z TAF CYCLE UPDATED LOW STRATUS CLOUDS HAVE BEEN STUBBORN TO ERODE AWAY IN THE SAN JUAN BASIN OF NORTHWEST NEW MEXICO THIS AFTERNOON. WHILE A BRIEF STINT OF VFR CONDITIONS IS EXPECTED TO DEVELOP DURING THE EARLY EVENING HOURS...AN ABRUPT REDEVELOPMENT OF THE LOW STRATUS DECK COULD HAPPEN BEFORE MIDNIGHT. FORECAST MODELS ARE HAVING DIFFICULTY RESOLVING THE SATURATED SOILS AND HIGHER DEWPOINTS ARISING FROM MELTING SNOW NEAR THE AREA...THUS IT`S A TRICKY FORECAST. HAVE HEDGED PESSIMISTICALLY THAT KFMN WILL ENDURE BRUNT OF IFR CONDITIONS SATURDAY MORNING WITH POTENTIAL FOR KGUP TO ALSO SEE STRATUS/FOG. OTHERWISE A FRONT WILL INFILTRATE THE EASTERN HALF OF NEW MEXICO EARLY SATURDAY WHERE GUSTY WINDS TO 25 TO 30 KT WILL ACCOMPANY THE BOUNDARY. 52 && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 23 45 19 48 / 0 0 0 0 DULCE........................... 14 46 12 46 / 0 0 0 0 CUBA............................ 15 47 17 46 / 0 0 0 0 GALLUP.......................... 21 51 19 55 / 0 0 0 0 EL MORRO........................ 18 50 18 51 / 0 0 0 0 GRANTS.......................... 15 54 14 54 / 0 0 0 0 QUEMADO......................... 19 52 20 54 / 0 0 0 0 GLENWOOD........................ 27 62 28 62 / 0 0 0 0 CHAMA........................... 8 43 7 43 / 0 0 0 0 LOS ALAMOS...................... 25 46 22 46 / 0 0 0 0 PECOS........................... 27 48 22 48 / 0 0 0 0 CERRO/QUESTA.................... 10 40 6 41 / 5 0 0 0 RED RIVER....................... 11 40 6 39 / 5 0 0 0 ANGEL FIRE...................... 8 45 1 43 / 5 0 0 0 TAOS............................ 13 45 10 44 / 0 0 0 0 MORA............................ 26 51 20 53 / 0 0 0 0 ESPANOLA........................ 25 51 24 52 / 0 0 0 0 SANTA FE........................ 26 48 23 47 / 0 0 0 0 SANTA FE AIRPORT................ 24 50 21 49 / 0 0 0 0 ALBUQUERQUE FOOTHILLS........... 28 52 26 51 / 0 0 0 0 ALBUQUERQUE HEIGHTS............. 27 53 27 54 / 0 0 0 0 ALBUQUERQUE VALLEY.............. 23 54 22 55 / 0 0 0 0 ALBUQUERQUE WEST MESA........... 24 53 24 54 / 0 0 0 0 LOS LUNAS....................... 20 54 19 56 / 0 0 0 0 RIO RANCHO...................... 26 54 27 54 / 0 0 0 0 SOCORRO......................... 28 57 28 58 / 0 0 0 0 SANDIA PARK/CEDAR CREST......... 23 48 25 49 / 0 0 0 0 TIJERAS......................... 26 51 26 51 / 0 0 0 0 MORIARTY/ESTANCIA............... 21 51 19 51 / 0 0 0 0 CLINES CORNERS.................. 27 48 23 48 / 0 0 0 0 GRAN QUIVIRA.................... 24 51 24 51 / 0 0 0 0 CARRIZOZO....................... 26 56 26 56 / 0 0 0 0 RUIDOSO......................... 26 56 25 55 / 0 0 0 0 CAPULIN......................... 24 51 23 56 / 5 0 0 0 RATON........................... 22 52 17 56 / 0 0 0 0 SPRINGER........................ 25 54 21 58 / 0 0 0 0 LAS VEGAS....................... 28 54 22 57 / 0 0 0 0 CLAYTON......................... 33 57 28 66 / 0 0 0 0 ROY............................. 30 56 24 61 / 0 0 0 0 CONCHAS......................... 31 60 30 65 / 0 0 0 0 SANTA ROSA...................... 34 60 30 62 / 0 0 0 0 TUCUMCARI....................... 31 59 30 65 / 0 0 0 0 CLOVIS.......................... 32 57 29 60 / 0 0 0 0 PORTALES........................ 31 59 28 62 / 0 0 0 0 FORT SUMNER..................... 31 59 30 63 / 0 0 0 0 ROSWELL......................... 26 62 26 65 / 0 0 0 0 PICACHO......................... 31 62 28 64 / 0 0 0 0 ELK............................. 30 59 29 61 / 0 0 0 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 34
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1233 PM CST FRI JAN 16 2015 .UPDATE... ISSUED AT 1224 PM CST FRI JAN 16 2015 MAIN CONCERN WITH EARLY AFTERNOON UPDATE WAS THE RELUCTANCE OF THE LOW CLOUDS AND FOG TO DISSIPATE ACROSS THE AREA. LATEST HRRR GUIDANCE SEEMS TO HAVE THE BEST GRASP ON THE SITUATION...AND CONTINUES A VERY SLOW EROSION ON THE WEST SIDE OF THE CLOUD/FOG AREA THROUGH THE AFTERNOON INTO EARLY EVENING. HAVE REFLECTED THIS IN THE UPDATE AND HAVE ALSO ADJUSTED TEMPERATURES TO COOL TEMPS DOWN QUITE A BIT UNDER THE CLOUD COVER. UPDATE ISSUED AT 831 AM CST FRI JAN 16 2015 FOG/LOW CLOUDS REMAIN PARKED OVER CENTRAL INTO PARTS OF WESTERN NORTH DAKOTA THIS MORNING. LATEST GUIDANCE TRIES TO RETRACT THIS LATER THIS MORNING INTO THE AFTERNOON...THOUGH STILL SOME QUESTION ON HOW MUCH THIS ERODES. HIGH TEMPERATURE FORECAST REMAINS TRICKY AS THE POSITION OF THE CLOUD COVER WILL HAVE A GREAT INFLUENCE ON IT. FOR MORNING UPDATE HAVE INCREASED FOG COVERAGE A BIT...PARTICULARLY ON THE LEADING EDGE WHERE A BROAD AREA OF REDUCED VISIBILITIES ARE BEING REPORTED. UPDATE ISSUED AT 639 AM CST FRI JAN 16 2015 CLOUDS AND AREAS OF FOG CLOSELY FOLLOWS THE LATEST HRRR LOW CLOUD FRACTION FORECAST. THIS MODEL ERODES THE CLOUDS SLOWLY FROM THE WEST IN WARM ADVECTION BY NOON. WILL MAINTAIN THE FOG AND FREEZING DRIZZLE FORECAST AS HAVE HAD SEVERAL REPORTS EARLIER ACROSS THE NORTH CENTRAL AS THE CLOUDS WEE MOVING IN. BELIEVE ITS SOMEWHAT PATCHY BUT APPEARS REASONABLE. && .SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON) ISSUED AT 422 AM CST FRI JAN 16 2015 MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE LOW CLOUDS...AND POSSIBLE FLURRIES AND FREEZING DRIZZLE TODAY OVER MUCH OF CENTRAL AND PARTS OF NORTHWESTERN NORTH DAKOTA. THE FOCUS THEN SHIFTS TO TONIGHT AND SATURDAY AS A LOW PRESSURE SYSTEM BRINGS A CHANCE OF PRECIPITATION FRIDAY NIGHT INTO SATURDAY MORNING AND STRONG WINDS LATE FRIDAY NIGHT AND SATURDAY. CURRENTLY...SATELLITE INDICATES IFR STRATUS ALONG AND EAST OF A LINE FROM CROSBY TO TIOGA...TO HAZEN AND BISMARCK...TO NEAR WISHEK. LATEST HRRR/RAP CONTINUE TO SHOW THIS BAND SLOWING ITS PROGRESSION SOUTHWESTWARD...AND GRADUALLY RETREATING EASTWARD DURING THE DAY. THIS OCCURS AS WARM ADVECTION TAKES HOLD FROM THE WEST AHEAD OF THE LOW PRESSURE SYSTEM. NO HIGHER CLOUDS ABOVE THE LOW STRATUS...AND THIS AREA REMAINS UNDER THREAT OF FREEZING DRIZZLE ALONG WITH THE FOG. WILL KEEP A MENTION OF PATCHY FREEZING DRIZZLE THIS MORNING...GRADUALLY ENDING FROM WEST TO EAST. WARM ADVECTION AND PARTLY CLOUDY SKIES WEST WITH HIGHS IN THE MID 30S TO MID 40S. HOWEVER...EXPECT STRATUS CLOUDS TO BE SLOW TO RETREAT IN THE TURTLE MOUNTAINS AND JAMES RIVER VALLEY - WITH HIGHS TODAY ONLY REACHING INTO THE 20S. FRIDAY NIGHT AND SATURDAY AN UPPER LEVEL SHORTWAVE WITH AN ASSOCIATED SURFACE LOW AND FRONT TRAVERSES THE NORTHERN PLAINS AND SOUTHERN PRAIRIE PROVINCES OF CANADA. THE MAIN SHORTWAVE IMPULSE TRACKS SOUTHEAST ACROSS THE STATE TONIGHT AND INDUCES A SECONDARY SURFACE LOW THAT TRACKS RIGHT ALONG THE INTERNATIONAL BORDER. HAVE INCREASED POPS ALONG THE BORDER AS WELL AS ACROSS SOUTHERN NORTH DAKOTA. PRECIPITATION IS EXPECTED TO BE RAIN FRIDAY AND FRIDAY EVENING...THEN TRANSITION TO SNOW LATE FRIDAY NIGHT WITH THE PASSAGE OF THE COLD FRONT. THUS MAIN PRECIPITATION WILL BE RAIN AND/OR SNOW. WE COULD SEE A PERIOD OF LIGHT FREEZING RAIN OR FREEZING DRIZZLE OVER THE NORTH CENTRAL AND INTO THE JAMES VALLEY SATURDAY MORNING AS THE ATMOSPHERE DRIES THROUGH THE SNOW GROWTH ZONE. THE OTHER HAZARD LATE FRIDAY NIGHT AND SATURDAY WILL BE STRONG WINDS. THE STRONGEST BURST OF WINDS LOOKS TO BE LATE FRIDAY NIGHT INTO SATURDAY MORNING WEST...AND DURING THE DAY CENTRAL. CONFIDENCE IS LOW REGARDING THE STRENGTH/SPEED OF THE WINDS AS WELL AS THE DURATION OF THE STRONGEST WINDS. THE INITIAL PUSH OF NORTHWEST WINDS SHOULD BE FRIDAY NIGHT IN THE WEST AND SATURDAY IN CENTRAL NORTH DAKOTA...LINING UP WELL WITH THE TIGHTEST SURFACE PRESSURE GRADIENT. THEN WARM ADVECTION FOLLOWS IN THE WEST BY NOON SATURDAY AND BY LATE AFTERNOON IN CENTRAL NORTH DAKOTA. THE BUFKIT SOUNDINGS SUGGEST ADIABATIC LAPSE RATES WITH THE COLD ADVECTION...BUT MOMENTUM NOT REACHING THE GROUND WHILE WARM ADVECTION TAKES PLACE. THINK WE MAY SEE WIND ADVISORY STRENGTH WINDS AT SOME POINT IN MOST OF THE FORECAST AREA...BUT NOT FOR A LONG PERIOD OF TIME. A WIND ADVISORY MAY BE NEEDED FOR WESTERN AND CENTRAL NORTH DAKOTA...BUT CONFIDENCE NOT HIGH ENOUGH YET TO ISSUE THAT HEADLINE THIS FORECAST PACKAGE. A SPECIAL WEATHER STATEMENT WAS ISSUED THURSDAY AFTERNOON FOR THIS SYSTEM...AND WILL CONTINUE WITH ANOTHER ISSUANCE THIS MORNING...AS WELL AS IN THE HAZARDOUS WEATHER OUTLOOK. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 422 AM CST FRI JAN 16 2015 A GENERALLY PROGRESSIVE FLOW PATTERN BEGINS THE EXTENDED THROUGH MONDAY. FOR SUNDAY AND MONDAY THE GFS/ECMWF MODELS CONTINUE MID LEVEL PACIFIC FLOW BRINGING MILD AND DRY AIR INTO THE NORTHERN PLAINS. AFTER THIS A BUILDING RIDGE OFF THE WEST COAST RESULTS IN A DOWNSTREAM H500 TROUGH OVER THE NORTHERN PLAINS THAT WILL BEGIN A COOLING TREND BACK TO NEAR NORMAL TEMPERATURES BY WEDNESDAY AND THURSDAY. SOME SPOTTY LIGHT PRECIPITATION WILL BE THE RULE AS COOL CYCLONIC FLOW ALOFT WILL SUPPORT SOME SMALL CHANCES FOR SNOW DURING THIS PERIOD. HOWEVER THE FLOW CONTINUES OFF THE PACIFIC WITH NO REAL POOL OF ARCTIC AIR FORMING IN CANADA THAT CAN BE TAPPED FOR COLD AIR OUTBREAKS. PERHAPS LATER THIS MONTH THIS WILL BE POSSIBLE AS THE 8 TO 14 DAY NOW IS TRENDING BELOW NORMAL. FOR THIS FORECAST PERIOD THERE IS LITTLE POTENTIAL FOR WINTER STORMS ON THE HORIZON. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1224 PM CST FRI JAN 16 2015 LIFR CEILINGS AND VISIBILITY IN FOG AND STRATUS WILL CONTINUE TO IMPACT KMOT...KBIS...AND KJMS THROUGH MUCH OF TODAY. CEILINGS AT KMOT WILL FLUCTUATE BETWEEN VFR/MVFR AFT 23Z. KBIS TRANSITIONS TO VFR/MVFR AFT 21Z WITH IFR CONDITIONS RETURNING AFT 09Z/17. KJMS BRIEFLY MOVES INTO VFR CEILINGS AFT 06Z/17 BEFORE RETURNING TO IFR CONDITIONS AROUND 10Z/17. VFR/MVFR CONDITIONS EXPECTED AT KISN AND KDIK. TONIGHT WINDS BECOMING WEST AND INCREASING TO 20-30 KNOTS AT KISN/KDIK AFT 03Z WITH LIGHT RAIN OR SNOW EXPECTED AT KMOT...KDIK...AND KJMS AFT 02Z/17. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...JV LONG TERM...WAA AVIATION...ZH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1122 AM EST FRI JAN 16 2015 .SYNOPSIS... WEAK FRONT/VORT MAX ALOFT PUSHES INTO NORTHERN WEST VIRGINIA TODAY. HIGH PRESSURE SATURDAY. COLD FRONT SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... 1115 AM UPDATE... LOWERED TEMPERATURES THIS AFTERNOON ON ACCOUNT OF THE CLOUD COVER...AND RAISED TONIGHT BASED ON SW WINDS. ALSO ADJUSTED POPS THROUGH THIS EVENING TO CUT OFF WESTERN EXTENT...SNOW SHOWERS AND FLURRIES SHOULD BE LIMITED TO THE FAVORED UPSLOPE AREAS IN AND NEAR THE NRN MOUNTAINS OF WV. 530 AM UPDATE... NO CHANGES THIS MORNING. PREVIOUS DISCUSSION... USING THE HRRR FOR THE LOW LEVEL STRATUS AND ITS EVOLUTION THROUGH THE REMAINDER OF THE MORNING AND INTO THE EARLY AFTERNOON AS IT SEEMS TO BE FOLLOWING THE REAL TIME DEVELOPMENT. WEAK VORTICITY MAX ALOFT OVER THE SOUTHERN END OF LAKE MICHIGAN WILL ADVECT INTO THE OHIO VALLEY WITH A WEAK COLD FRONT BY 12Z THIS MORNING. LOW LEVEL THERMAL TROUGH WILL PUSH THROUGH THE NORTHERN ZONES OF THE CWA AND INTO THE MOUNTAINS WITH THIS WAVE. SREF IS AGGRESSIVE IN PROBABILITIES FOR MEASURABLE...AND HAVE DECENT UPLIFT IN THE LOW LEVELS OVER THE MOUNTAINS AS WELL...SO CANNOT IGNORE THE POTENTIAL FOR LIGHT SNOW LATER THIS MORNING AND ENDING IN THE AFTERNOON. SHALLOW MOISTURE DEPTH AND MARGINAL CRYSTAL GROWTH KEEPS THE POPS BELOW 50 PERCENT HOWEVER. MAV PERFORMED POORLY LAST NIGHT...SO EXCLUDED THIS FROM A BLEND FOR THE AFTERNOON HIGH TEMPERATURES TODAY. SHOULD BE AT FREEZING OR JUST ABOVE FOR THE LOWLANDS. KEEPING THE NORTHEAST MOUNTAINS AND VALLEYS...INCLUDING EKN...AT FREEZING OR BELOW. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... HIGH PRESSURE SHIFTING EAST OF THE AREA BRINGS A DRY...BREEZY AND MILDER DAY SATURDAY AS SOUTHERLY FLOW TAKES OVER. TEMPERATURES LOOK TO GO ABOVE NORMAL...IN THE 50 TO 55 DEGREE RANGE IN THE LOWLANDS. MODELS HAVE AN ILL DEFINED COLD FRONT MOVING ACROSS SOMETIME SUNDAY. LOOKS LIKE THE WEATHER WILL BE MORE INFLUENCED BY A COOLING UPPER TROUGH DEVELOPING OVER THE AREA RATHER THAN FOLLOWING A WELL DEFINED COLD FRONT. LIGHT PRECIPITATION MOVES IN FROM THE WEST LATER SATURDAY NIGHT AND SUNDAY...AND CONTINUING INTO SUNDAY NIGHT AS THE THERMAL TROUGH WITHIN THE UPPER TROUGH SETTLES OVER THE AREA. TEMPERATURES FOR THE MOST PART SATURDAY NIGHT AND SUNDAY WILL WARM ENOUGH FOR RAIN SHOWERS AS THE BOUNDARY LAYER REMAINS RELATIVELY MILD. HOWEVER...THE NORTHERN MOUNTAINS MAY SEE A RAIN AND SNOW MIX...BENEFITING FROM THE COOLING ALOFT...BUT LITTLE TO NO SNOW ACCUMULATION IS EXPECTED THRU MOST OF SUNDAY. BY SUNDAY NIGHT WITH THE THERMAL TROUGH MOVING ACROSS...RAIN SHOWERS IN THE LOWLANDS WILL CHANGE TO SNOW SHOWERS BEFORE ENDING...BUT WITH LITTLE OR NO ACCUMULATION. THE MOUNTAINS...ESPECIALLY THE NORTHERN MOUNTAINS WITH MAXIMUM COOLING...WILL SEE SNOW SHOWERS. HOWEVER...MOISTURE WITH THE SYSTEM IS LIMITED SO THAT QPF AMOUNTS WILL BE LIGHT AND SNOW ACCUMULATIONS SUNDAY NIGHT WILL MAINLY BE IN THE HIGHER ELEVATIONS OF THE NORTHERN MOUNTAINS...PERHAPS ON THE ORDER OF A COUPLE OF INCHES. TEMPERATURES WILL DROP BELOW FREEZING ALL AREAS SUNDAY NIGHT. FOR MONDAY...UPPER TROUGH AND THERMAL AXIS LIFTS OUT WITH CANADIAN HIGH PRESSURE BUILDING IN...LEADING TO A MOSTLY DRY AND SEASONABLY COLD MONDAY. && .LONG TERM /TUESDAY THROUGH THURSDAY/... UPSLOPE SNOW SHOWERS WITH ADDITIONAL LIGHT ACCUMULATIONS TO START THE LONG TERM...GRADUALLY TAPERING OFF LATER IN THE DAY MONDAY AS WEAK RIDGING BUILDS INTO THE REGION AND FLOW BACKS. LOOKING FOR A BRIEF BREAK IN THE PRECIPITATION ON TUESDAY...BEFORE ANOTHER CLIPPER MOVES IN MID WEEK...SPREADING MORE LIGHT RAIN AND SNOW SHOWERS BACK INTO THE AREA. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... FOG CHANNEL SATELLITE IMAGERY SHOWS A COMPLEX SITUATION WITH THE MVFR STRATUS DECK IN PLACE...WITH IT SHRINKING IN SIZE ACROSS SOUTHERN AND EASTERN WEST VIRGINIA AND EXPANDING OVER THE NORTH CENTRAL PORTION OF THE STATE AND INTO SOUTHEAST OHIO AND DOWN TOWARDS THE TRI STATE AREA/HTS. A WEAK VORTICITY MAX PUSHING SOUTHEAST WITH A WEAK COLD FRONT IS BRINGING MVFR CEILINGS IN FROM THE NORTHWEST TOWARDS THE OHIO VALLEY. THIS WILL REACH PKB FIRST...BY 12Z. IN THE END...EXPECT THE STRATUS TO FILL BACK IN LATER THIS MORNING BASED ON THE HRRR MODEL WITH HTS AND CRW LAST TO GET BACK INTO MVFR CEILINGS. LIGHT SNOW POSSIBLE AT EKN AFTER 13Z. DO NOT EXPECT ANY IFR AT EKN. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY... FORECAST CONFIDENCE: LOW TO MEDIUM. ALTERNATE SCENARIO: TIMING AND EVOLUTION OF THE MVFR STRATUS TODAY IS IN QUESTION. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE FRI 01/16/15 UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19 EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14 CRW CONSISTENCY H H H H L H H H H H H M HTS CONSISTENCY L L L L L L H H H M M M BKW CONSISTENCY M L L M H H H H H H M M EKN CONSISTENCY H H H M M M M H H H H H PKB CONSISTENCY H H M M L M M M H H H H CKB CONSISTENCY M M M M M M H H H H H H AFTER 18Z SATURDAY... IFR CONDITIONS POSSIBLE SUNDAY INTO MONDAY IN LIGHT RAIN AND SNOW SHOWERS...NOT LIMITED TO BUT MOST LIKELY IN THE MOUNTAINS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/26 NEAR TERM...TRM/26 SHORT TERM...JMV LONG TERM...SL AVIATION...26
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
327 PM CST FRI JAN 16 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 326 PM CST FRI JAN 16 2015 STRONG SHORTWAVE ENERGY CURRENTLY MOVING ACROSS MT/IDAHO WILL BRING SOME SENSIBLE WEATHER TO THE AREA THROUGH SATURDAY EVENING. GOES WATER VAPOR IMAGERY SHOWS THE STRONG TROUGH ENERGY IN TWO PARTS...OVER THE NORTHCENTRAL MT-CANADA BORDER AND SECOND PIECE OVER SRN IDAHO. TWO FRONTS IN THE REGION CAUSING A BIT MORE CHALLENGING TEMPERATURE AND CLOUD/FOG FORECAST TONIGHT. OLD FRONTAL BOUNDARY REMAINS STATIONARY KMKT-KMSN ROUGHLY WITH COLDER/DRIER AIR MASS TO THE NORTHEAST...AND CLEARLY MARKED BY OVERCAST SKIES TO THE NORTHEAST OF IT. SECONDARY FRONT IS ACROSS SRN IA WITH WARM SECTOR SOUTHWEST WINDS IN A MIXED BOUNDARY LAYER AND TEMPERATURES IN THE 50S /NO SNOW COVER THERE/. AS THE ENERGY SHIFTS INTO THE PLAINS TONIGHT...LOW-LEVEL GRADIENT WILL INCREASE AND ISENTROPIC LIFT WILL INCREASE. MOST OF THE WARM ADVECTION WILL GO INTO WARMING AND NOT LIFT...WITH 850MB TEMPERATURES WARMING 5F. THE WEAK LIFT OF 1-3UB/S WILL BE LOCATED A BIT INTO THE LOWER BASED SATURATED LAYER FOR DZ/FZDZ POTENTIAL NEAR AND NORTH OF THE NORTHERN FRONT...NEAR AND NORTH OF I-94. NCEP MODELS SUGGEST VERY LIGHT PRECIPITATION IN THIS AREA IN THE EVENING AND OVERNIGHT. WITHOUT DEEP SATURATION...THIS WOULD BE A LIQUID LAYER AND FZDZ. HOWEVER...THE MODEL MOISTURE DEPTH IS LESSENING THROUGH THE OVERNIGHT /PER NCEP MODEL SOUNDINGS/ AND NEAR OR LESS THAN 1KM. THIS SUGGESTS PRECIPITATION GENERATION FROM THIS LAYER LESS PROBABLE. THUS...HAVE LEFT THE SLIGHT CHANCE OF FZDZ IN THE NORTH OVERNIGHT...EVEN THOUGH MINOR PRECIPITATION IS GENERATED FROM THE MODELS...DIDNT FEEL CONFIDENT IT COULD BE GENERATED. ACROSS THE CENTRAL AND SOUTHERN FORECAST AREA DEWPOINT DEPRESSIONS ARE 4-5F RIGHT NOW AND AN INVERTED TEMPERATURE PROFILE...SOME SNOW MELT TODAY...SO AM CONCERNED WITH MORE THAN PATCHY FOG. WITH CLEAR SKIES...THINKING THERE COULD BE SOME EVENING FOG FORMATION IN THE COOLING AFTER SUNDOWN. HOWEVER...THE EVOLUTION OVERNIGHT OF HIGHER AND VEERING WINDS IN THE LOW-LEVELS AS THE CYCLONE APPROACHES WOULD TEND TO ADVECT THAT FOG NORTH OR DIMINISH IT. THE INVERSION IS ALSO STRENGTHENING OVERNIGHT IN WARM ADVECTION /VERSUS LIFT/. MODEL GUIDANCE HAS BEEN ON THE DECREASING TREND WITH FOG /HRRR AND RAP RUNS/ AND LATEST 16.15Z SREF IS SLIGHTLY LESS AGGRESSIVE WITH A LARGE 1 MILE OR LESS VISIBILITY AREA OVER SWRN WI-SERN MN. BUT MODELS ARE ALSO BIASED TOWARD SNOW PACK FOG...ESPECIALLY THE SREF...AS THE FOG FOOTPRINT MATCHES THE SNOW DEPTH CLOSELY. A CHALLENGE TO KNOW HOW THAT AREA WILL BEHAVE FOR FOG BUT HAVE INCLUDED IT IN THE FORECAST. WILL HAVE TO WATCH FOR DENSE FOG. QG FORCING SUGGESTS THE TWO SHORTWAVE TROUGH LIFT WILL SPLIT THE FORECAST AREA TO THE NORTH AND SOUTH. KEPT SMALL CHANCES OF DZ/FZDZ/SN- NORTH OF I-90 SATURDAY. THE COLD FRONT WILL MOVE IN DURING THE AFTERNOON WITH WIND GUSTS TO 30 MPH DEVELOPING IN THE AFTERNOON WEST OF THE MISS RIVER. THIS LOOKS LIKE IT SHOULD CARRY INTO THE EVENING BASED ON A MIXED-BOUNDARY LAYER AND 0-1KM LAPSE RATES OVER 8C/KM AND 30-35 KTS AT 1 KM. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 326 PM CST FRI JAN 16 2015 OVERALL A NO/LOW IMPACT WEATHER PERIOD IT SEEMS. ANOTHER SYSTEM FOR MONDAY WILL AFFECT THE NORTHERN AREAS WITH PRECIPITATION CHANCES. ANOTHER WARM UP AND COOL DOWN AND LIGHT PRECIPITATION EVENT. OVERALL A TREND IS TOWARD COOLER TEMPERATURES AS THE WEEK PROGRESSES...BUT STILL NEAR NORMAL...AND LIGHT PRECIPITATION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1157 AM CST FRI JAN 16 2015 WITH WARM...PACIFIC AIRMASS IN PLACE AND A STALLED FRONTAL BOUNDARY KLSE WAS UNDER MVFR CONDITIONS WITH A STRATUS DECK WHILE KRST WAS IN LIFR CONDITIONS DUE TO VISIBILITIES UNDER A HALF MILE. LOOK FOR THE STRATUS DECK TO REMAIN IN PLACE OVER KLSE THIS AFTERNOON WITH SOME LOWERING DURING THE OVERNIGHT HOURS AS A WARM FRONT ADVANCES NORTH. SOME UNCERTAINTY HOW MUCH VISIBILITY RESTRICTIONS WILL OCCUR IN THE VALLEY AT KLSE WHILE KRST LOOKS TO HAVE CEILINGS UNDER A 1000FT AND VISIBILITIES LESS THAN A MILE RETURN THIS EVENING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...CC/HALBACH