Area Forecast Discussion
Issued by NWS Wilmington, OH

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000 FXUS61 KILN 281055 AFDILN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 655 AM EDT TUE OCT 28 2014 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS THE REGION TODAY...BRINGING A CHANCE OF SHOWERS AND STORMS...AND AN END OF THE WARM TEMPERATURES. COOLER CONDITIONS ARE EXPECTED THROUGH THE REST OF THE WEEK...WITH EVEN COLDER CONDITIONS BEHIND ANOTHER COLD FRONT FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SURFACE LOW PRESSURE IS CURRENTLY LOCATED OVER NORTHERN LAKE MICHIGAN. THIS LOW WILL DEEPEN AS IT WRAPS NORTHEAST AROUND A LARGE MID-LEVEL TROUGH. TRAILING FROM THIS SURFACE LOW IS A LENGTHY COLD FRONT...CURRENTLY EXTENDING THROUGH CHICAGO...ST LOUIS...AND JUST NORTH OF DALLAS. ALTHOUGH THERE IS A MARKED CHANGE IN AIR MASS BEHIND THE FRONT...THE FRONT IS FORECAST TO WEAKEN SLIGHTLY AS IT MOVES EAST. IN FACT...THE WIND SHIFT WILL BECOME LESS DRASTIC WITH TIME...WITH THE EVENTUAL CHANGE IN DIRECTION OVER THE ILN CWA ONLY EXPECTED TO BE SOUTHWESTERLY TO WESTERLY. ALTHOUGH THE FRONT IS WEAKENING...AND CONVERGENCE IS SOMEWHAT MODEST...THERE REMAINS STRONG MODEL AGREEMENT THAT RAIN WILL FALL ACROSS THE ENTIRE FORECAST AREA TODAY. PRECIPITATION AMOUNTS...HOWEVER...MAY BE QUITE LIGHT IN SOME PLACES. RECENT HRRR RUNS SUGGEST THAT THE COVERAGE WILL BE THAT OF BROKEN BANDS OF PRECIPITATION. THIS CREATED A CHALLENGE WITH THE POPS...AS THERE MAY BE SOME DRY SPOTS MIXED WITHIN THE AREA OF RAIN AHEAD OF THE FRONT. SINCE MEASURABLE RAIN IS EXPECTED EVERYWHERE...POPS ARE AT 100 PERCENT...BUT QPF AMOUNTS ARE LIGHT. A FAIRLY POTENT LOW-LEVEL JET IS CURRENTLY IN PLACE OVER THE ILN FORECAST AREA...WITH THE KILN VWP SHOWING WINDS OF OVER 50 KNOTS JUST 2000 FEET ABOVE THE GROUND. OCCASIONAL GUSTS ARE REACHING THE SURFACE...AND THIS SHOULD CONTINUE TODAY AS THE ATMOSPHERE MIXES AHEAD OF THE FRONT. A FEW GUSTS AS HIGH AS 30 KNOTS MAY BE POSSIBLE IN THE WARM AIR AHEAD OF THE FRONT. HOWEVER...THE STRONGEST WINDS JUST ALOFT WILL ACTUALLY ALREADY BE MOVING OUT OF THE AREA BY LATE MORNING. BY LATE MORNING AND INTO THE AFTERNOON...WEAK INSTABILITY IS FORECAST TO DEVELOP IN THE EASTERN HALF OF THE FORECAST AREA. A MODEL COMPROMISE WOULD SUGGEST AROUND 500 J/KG OF MIXED LAYER CAPE...BUT IN A NARROW PROFILE LIMITED BY RATHER UNIMPRESSIVE LAPSE RATES. SPC SREF PROBABILITIES INDICATE ZERO CHANCE OF CAPE > 1000 J/KG...AND AROUND 50 PERCENT CHANCE OF EVEN GETTING TO 500 J/KG. THUNDER IS EXPECTED TO BE SCATTERED AND EMBEDDED WITHIN THE BANDS OF PRECIPITATION AHEAD OF THE FRONT...THOUGH OBVIOUSLY BECOMING A LITTLE MORE LIKELY AS THE DAY PROGRESSES. ATMOSPHERIC WIND SHEAR IS MARGINALLY IMPRESSIVE IN TERMS OF NUMBERS (45 KNOTS 0-6KM / 30 KNOTS 0-3KM)...BUT NOT IMPRESSIVE AT ALL IN TERMS OF ORIENTATION (UNIDIRECTIONAL AND MOSTLY PARALLEL TO THE FRONT). THIS ADDS UP TO JUST A VERY SMALL CHANCE OF STRONG THUNDERSTORMS...AND LIMITED TO JUST THE NORTHEAST KENTUCKY / SCIOTO VALLEY REGIONS. SEVERE WEATHER APPEARS UNLIKELY...BUT IF STORMS DO DEVELOP IN THIS REGION (AS HRRR/WRF-NMM PROJECTIONS INDICATE)...FORWARD PROPAGATING LINE SEGMENTS COULD PRODUCE STRONG WINDS. WITH THE FRONT COMING INTO THE AREA...IT IS NO SURPRISE THAT THE MAX TEMPERATURE GRID WILL USE A SIGNIFICANT GRADIENT. TEMPERATURES WILL BEGIN THE MORNING SIGNIFICANTLY AND ANOMALOUSLY WARM...ABOUT AS WARM AS EVER OBSERVED DURING AN OVERNIGHT PERIOD IN LATE OCTOBER. THE WARMEST TEMPERATURES (UPPER 70S) ARE EXPECTED IN THE SOUTHEASTERN CWA...WHERE WARM ADVECTION SHOULD CONTINUE AHEAD OF THE FRONT FOR SEVERAL HOURS. MAX TEMPS MAY VERY WELL BE SET DURING THE MORNING IN THE NORTHWESTERN CWA...WHERE THE FRONT WILL MOVE THROUGH EARLIEST IN THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... PRECIPITATION SHOULD END QUICKLY BEHIND THE COLD FRONT...AS A COOLER AND DRIER AIR MASS MOVES INTO THE OHIO VALLEY. MIN TEMPS WERE LOWERED A FEW DEGREES FOR WEDNESDAY MORNING...ESPECIALLY IN THE NORTHEASTERN CWA. SURFACE HIGH PRESSURE WILL BUILD TO THE WEST OF THE AREA...INFLUENCING THE WEATHER ENOUGH TO KEEP CONDITIONS DRY. HOWEVER...THE CONTINUED COLD ADVECTION WILL KEEP TEMPERATURES FROM WARMING...ESPECIALLY WITH OCCASIONAL CLOUDS (ESPECIALLY CLOSER TO THE GREAT LAKES). WITH CALMING WINDS ON THURSDAY MORNING...FROST IS LOOKING INCREASINGLY LIKELY...EVEN THOUGH THERE IS SOME CONCERN THAT CLOUDS COULD BE BUILDING IN BY MORNING. TEMPERATURES HAVE BEEN DECREASED A COUPLE DEGREES HERE AS WELL. THE NEXT BIG CHANGE IN AIR MASS WILL BEGIN TO TAKE SHAPE ON FRIDAY...AND IT WILL AGAIN BE A CHANGE IN THE COOLER DIRECTION. && .LONG TERM /FRIDAY THROUGH MONDAY/... A STRONGER SHORT WAVE WILL ROTATE DOWN ACROSS THE WESTERN GREAT LAKES AND PIVOT THROUGH THE UPPER OHIO VALLEY FRIDAY INTO FRIDAY NIGHT. WHILE THE STRONGEST FORCING WILL GENERALLY REMAIN TO OUR NORTH AND EAST...WE SHOULD STILL AT LEAST SEE SOME SOME SCATTERED SHOWER ACTIVITY THROUGH THE DAY...ESPECIALLY ACROSS ABOUT THE NORTHEAST HALF OF OUR FA. STRONG CA WILL DEVELOP BEHIND THE SHORT WAVE...PUSHING DOWN FROM THE NORTH THROUGH LATE AFTERNOON. THIS WILL LIKELY LEAD TO SOME NON-DIURNAL TEMPERATURE TRENDS LATER IN THE DAY...ESPECIALLY ACROSS NORTHERN PORTIONS OF OUR FA. IT LOOKS LIKE THE COLDEST AIR WILL NOT ARRIVE UNTIL ONCE THE DEEPER MOISTURE HAS SHIFTED OFF TO THE EAST FRIDAY EVENING. FORECAST SOUNDINGS AND THE COBB METHOD ARE BOTH SUGGESTING THAT THE LOWER LEVELS WILL REMAIN WARM ENOUGH TO KEEP PCPN ALL LIQUID THROUGH THE AFTERNOON HOURS. THAT BEING SAID...IF THE SHOWERS BECOME A BIT CONVECTIVE THROUGH THE AFTERNOON...SUPPOSE A FEW WET SNOW FLAKES COULD MIX IN LATE IN THE DAY ACROSS OUR NORTHEAST. IN CONTINUED CAA...EXPECT THE POTENTIAL FOR OUR FIRST WIDESPREAD FREEZE FRIDAY NIGHT WITH LOWS DROPPING DOWN INTO THE UPPER 20S TO LOWER 30S. SURFACE HIGH PRESSURE WILL PUSH EAST ACROSS THE AREA SATURDAY AND SUNDAY. THIS WILL LEAD TO DRY CONDITIONS WITH TEMPERATURES REMAINING WELL BELOW NORMAL. LOW LEVEL THICKNESSES ARE ONLY SUPPORTING HIGHS IN THE UPPER 30S TO LOWER 40S ON SATURDAY. WILL NOT GO QUITE THAT COLD AT THIS POINT BUT WILL NUDGE DOWN HIGHS A BIT...GENERALLY INTO THE LOWER TO MID 40S. MODELS ARE A LITTLE FASTER NOW SHIFTING THE HIGH OFF TO THE EAST SO IT MAY BE CENTERED JUST OFF TO OUR EAST BY SUNDAY MORNING. WE SHOULD STILL HAVE MOSTLY CLEAR SKIES THOUGH AND LIGHT WINDS...SO WOULD EXPECT SATURDAY NIGHT TO BE OUR COLDEST NIGHT WITH LOWS IN THE MID TO UPPER 20S POSSIBLE. TEMPERATURES SHOULD THEN SLOWLY MODERATE THROUGH THE FIRST OF NEXT WEEK AS THE HIGH PUSHES OFF TO THE EAST AND WE GET INTO RETURN FLOW. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/...
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FOR TODAY AND TONIGHT...A COLD FRONT TO OUR WEST WILL PUSH EAST THROUGH THE REGION. THIS FRONT WILL BRING SHOWERS AND EMBEDDED THUNDERSTORMS ALONG AND AHEAD OF IT. LOOKING AT MANY MODEL SOLUTIONS...IT LOOKS LIKE THERE WILL BE APPROXIMATELY A 4 HOUR WINDOW OF PCPN AT ALL TAF SITES. THINK WE WILL SEE AT LEAST SOME MVFR CEILINGS/VISIBILITIES WITH SHOWERS. THREAT OF THUNDER IS LOW ENOUGH TO JUST MENTION AS VCTS AT THIS TIME. THERE WILL BE A SLIGHTLY HIGHER THREAT NEAR THE EASTERN TAF SITES OF KCMH/KLCK WHERE THE LATER ARRIVAL OF THE FRONT WILL ALLOW FOR A LITTLE BIT MORE DIURNAL INSTABILITY. GUSTY SOUTH/SOUTHWEST WINDS WILL DIMINISH AND SHIFT TO THE WEST AFTER COLD FRONTAL PASSAGE. MUCH DRIER AIR WILL FILTER INTO THE REGION AS WELL...ALLOWING VFR CONDITIONS TO RETURN RATHER QUICKLY. FOR THE OVERNIGHT HOURS...AS THE FRONT CONTINUES EAST/SOUTHEAST...JUST SOME MID AND HIGH LEVEL CLOUDS ARE EXPECTED. ON WEDNESDAY...ADDITIONAL UPPER LEVEL ENERGY WILL ROTATE EAST/SOUTHEAST ACROSS THE GREAT LAKES AND OHIO VALLEY REGION. SOME LOW LEVEL MOISTURE IS EXPECTED WITH INCREASING STRATOCUMULUS/CUMULUS CLOUDS THROUGH THE DAY. .OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
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&& .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HATZOS NEAR TERM...HATZOS SHORT TERM...HATZOS LONG TERM...JGL AVIATION...HICKMAN

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