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May 14, 2014 1730 UTC Day 2 Convective Outlook

May 14, 2014

May 14, 2014 1730 UTC Day 2 Convective Outlook

day2otlk

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1218 PM CDT WED MAY 14 2014

VALID 151200Z – 161200Z

…NO SVR TSTM AREAS FORECAST…

…SUMMARY…
LOCALIZED DAMAGING WINDS ARE POSSIBLE FROM THE FLORIDA PENINSULA TO THE LOWER GREAT LAKES ON THURSDAY…AND ONE OR TWO TORNADOES CANNOT BE RULED OUT ACROSS PORTIONS OF THE CAROLINAS.

…SYNOPSIS…
IN THE MID LEVELS…A PAIR OF MERIDIONALLY SHEARED VORTICITY LOBES WILL MUTUALLY ORBIT DEEP LOW PRESSURE MEANDERING OVER THE UPPER MS VALLEY. A MID/UPPER JET STREAK FLANKING THE ERN LOBE WILL PROGRESS FROM THE OH VALLEY TO THE LOWER GREAT LAKES WHILE REORIENTING IN RESPONSE TO A SLIGHT NEGATIVE TILT IMPARTED TO THE VORT LOBE. MEANWHILE…AMPLIFICATION OF THE WRN PERTURBATION WILL RELOAD THE DEEPER TROUGH SURROUNDING THE LOW — MAINTAINING COLD MID-LEVEL TEMPERATURES FROM THE ERN PLAINS TO THE MS VALLEY. MID-LEVEL RIDGES FLANKING THE CONUS-FULL-LATITUDE TROUGH WILL OVERLIE THE WRN STATES AND THE EAST COAST VICINITY…WHILE A COLD FRONT ADVANCES EWD ACROSS THE ERN STATES TO THE S OF SFC LOW PRESSURE DEVELOPING FROM THE MID OHIO VALLEY TO ONTARIO.

…LOWER GREAT LAKES TO S ATLANTIC COAST EXCLUDING FL PENINSULA…
WIDESPREAD CLOUDS AND PRECIPITATION WILL BE ONGOING THU MORNING ALONG AND AHEAD OF THE COLD FRONT OWING TO ISENTROPIC ASCENT/UPPER DIVERGENCE JUXTAPOSED WITH A RIBBON OF 1.5-2.0-INCH PW IN THE WARM CONVEYOR PRECEDING THE ERN VORT LOBE. POOR MID-LEVEL LAPSE RATES ASSOCIATED WITH MOIST-NEUTRAL THERMODYNAMIC PROFILES WILL GREATLY SUPPRESS DIURNAL DESTABILIZATION AHEAD OF THE FRONT. HOWEVER…THE PRESENCE OF RICH LOW-LEVEL MOISTURE SHOULD SUPPORT MARGINAL INSTABILITY — LOCALLY ENHANCED WHERE CLOUDS THIN OR BREAK. STRONG MID-LEVEL FLOW ACCOMPANYING THE AFOREMENTIONED MID/UPPER JET STREAK IS FORECAST TO BE DISPLACED WELL W OF THE SFC BOUNDARY…THOUGH 35-40-KT H5 SLYS MAY OFFER SUFFICIENT DEEP SHEAR IN THE PRESENCE OF A 30-45-KT H85-H7 JET FOR A FEW ORGANIZED/SUSTAINED CONVECTIVE STRUCTURES. LOCALIZED DMGG WINDS COULD ENSUE WITH CONVECTION ALONG/AHEAD OF THE FRONT AS IT SPREADS EWD — AIDED BY A MODEST CROSS-FRONTAL ISALLOBARIC COUPLET AND WATER LOADING PROCESSES.

RELATIVELY RICHER TROPICAL MOISTURE — E.G. SFC DEWPOINTS IN THE UPPER 60S/LOWER 70S — WILL EXTEND INTO THE PIEDMONT AND COASTAL PLAIN OF THE CAROLINAS WHERE LOW-LEVEL BUOYANCY COULD BE RELATIVELY ENHANCED. SOME NUMERICAL MODEL GUIDANCE — E.G. NAM/CMC MODELS — CONTINUES TO INDICATE RELATIVELY ENHANCED LOW-LEVEL CYCLOGENESIS ALONG THE FRONT INVOF THIS REGION. ATTENDANT ENHANCED LOW-LEVEL SHEAR MAY BOLSTER THE RISK FOR TORNADOES. THIS GUIDANCE APPEARS TO DEPICT SOME LINKAGE BETWEEN THE CYCLOGENESIS PROCESS AND /1/ THE APPROACH OF AN H85 PERTURBATION EMANATING FROM A LOWER-LATITUDE ELY WAVE INVOF THE BAHAMAS…AND/OR /2/ CONVECTIVELY ENHANCED MID-LEVEL PERTURBATIONS DEVELOPING NNEWD FROM THE MIDDLE/ERN GULF. HOWEVER…OBSERVATIONAL DATA SUGGEST LIMITED EVIDENCE OF A COHERENT ELY WAVE…AND THE EVOLUTION OF GULF CONVECTION IN THE D1/WED PERIOD IS TOO UNCERTAIN TO SUBSTANTIATE CONCLUSIONS REGARDING RELATED LOW-LEVEL MASS RESPONSES IN THE D2/THU PERIOD. FURTHERMORE…SEVERAL OTHER MODEL SOLUTIONS INDICATE A NOTABLY WEAKER LLJ JUXTAPOSED WITH THE HIGHER BOUNDARY-LAYER THETA-E OVER THE CAROLINAS. ALSO…THE POTENTIAL FOR DEPLETION OF PRE-FRONTAL BUOYANCY OWING TO WIDESPREAD CONVECTION…AND EXPECTED LAGGING DEEP FORCING FOR ASCENT RELATIVE TO THE SFC FRONT…BREED SUBSTANTIAL UNCERTAINTY IN A GREATER SVR TSTM/TORNADO POTENTIAL. AS SUCH…ANY CATEGORICAL UPGRADE WILL BE DEFERRED TO LATER OUTLOOKS.

…THE FL PENINSULA…
MID-LEVEL FLOW WILL BE WEAKER ACROSS THE FL PENINSULA RELATIVE TO AREAS FARTHER NORTH. HOWEVER…A PRE-FRONTAL CONFLUENCE AXIS WILL CROSS THE STATE IN JUXTAPOSITION WITH A PLUME OF RICH TROPICAL MOISTURE — E.G. PW AROUND 2.0-2.1 INCHES — FOSTERING NUMEROUS THUNDERSTORMS. MODEST VEERING OF THE FLOW WITH INCREASING HEIGHT ABOVE THE SFC…WITH PERHAPS A FEW AREAS OF CLOUD TRANSLUCENCE/THINNING TO BOLSTER LOW-LEVEL LAPSE RATES…MAY YIELD A FEW MARGINALLY ORGANIZED/SUSTAINED CONVECTIVE STRUCTURES WITH LOCALIZED DMGG WINDS. WATER LOADING WOULD BE THE PRIMARY PROCESS ENHANCING SUCH POTENTIAL.

…CNTRL/SRN AR…SERN OK…NERN TX…
WEAK SFC CONVERGENCE/HEATING BENEATH COLD MID-LEVEL TEMPERATURES WILL SUPPORT MARGINAL INSTABILITY AND EWD/SEWD-MOVING BANDS OF LOCALLY STRONG THUNDERSTORMS DURING THE AFTERNOON. GUSTY WINDS AND SMALL HAIL WILL BE PRIMARY CONCERNS. HOWEVER…THE PAUCITY OF TROPOSPHERIC MOISTURE SHOULD LIMIT THE SVR RISK…SUCH THAT SVR PROBABILITIES HAVE NOT BEEN INCLUDED AT THIS TIME.

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