Alert archive / New York / Mesoscale Discussions in 2007
Mesoscale Discussion 902
The Storm Prediction Center issued this mesoscale discussion at May 27, 2007, 1:12 PM EDT for 21 counties in New York; 18 counties in Pennsylvania. It was in force for 93 min.
The area
The outline as issued.
The facts
- Issued
- May 27, 2007, 1:12 PM EDT (17:12 UTC)
- Expired
- May 27, 2007, 2:45 PM EDT
- In force
- 93 min
- Issued by
- the Storm Prediction Center
All 39 counties
Allegany County, NY, Broome County, NY, Cattaraugus County, NY, Cayuga County, NY, Chemung County, NY, Chenango County, NY, Cortland County, NY, Delaware County, NY, Livingston County, NY, Madison County, NY, Oneida County, NY, Onondaga County, NY, Ontario County, NY, Otsego County, NY, Schuyler County, NY, Seneca County, NY, Steuben County, NY, Tioga County, NY, Tompkins County, NY, Wayne County, NY, Yates County, NY, Bradford County, PA, Cameron County, PA, Centre County, PA, Clearfield County, PA, Clinton County, PA, Elk County, PA, Forest County, PA, Jefferson County, PA, Lycoming County, PA, McKean County, PA, Montour County, PA, Potter County, PA, Sullivan County, PA, Susquehanna County, PA, Tioga County, PA, Union County, PA, Wayne County, PA, Wyoming County, PA
The radar
The Binghamton radar (KBGM), 54 km from the middle of the area, began a volume at 17:14 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 5.2 hours before the alert went out and 187 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 139 J/kg
- Mixed-layer CIN
- -34 J/kg
- Mixed-layer LCL
- 788 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 162 m²/s²
- 0-3 km storm-relative helicity
- 182 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
000 ACUS11 KWNS 271712 SWOMCD SPC MCD 271712 NYZ000-PAZ000-271845- MESOSCALE DISCUSSION 0902 NWS STORM PREDICTION CENTER NORMAN OK 1212 PM CDT SUN MAY 27 2007 AREAS AFFECTED...NY...PA CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 271712Z - 271845Z ISOLATED TSTM INITIATION HAS COMMENCED ACROSS PARTS OF CNTRL NY AND A GENERAL INCREASE IN SEVERE TSTM POTENTIAL IS EXPECTED OVER THE NEXT HOUR OR TWO. A WATCH APPEARS POSSIBLE FOR PARTS OF THE REGION THIS AFTERNOON. A FEW CELLS HAVE RECENTLY ERUPTED NEAR/ALONG MESOSCALE WARM FRONT AND WEAK WIND SHIFTS SITUATED ACROSS SRN/CNTRL NY ATTM. DOUBLE WARM FRONTAL STRUCTURE APPEARS IN RECENT MESOANALYSIS TO THE SE OF LO...AND A WIND SHIFT/CONFLUENCE AXIS EXTENDS SOUTH OF A WEAK SURFACE WAVE NEAR THE SRN SHORE OF LO. WIND SHIFT HAS BEEN SPREADING EAST ACROSS THE SRN TIER AND EXTENDS SWD INTO PA. WITH AREAS OF STRONGER SURFACE HEATING ELIMINATING REMAINING INHIBITION ACROSS THE AREA...THESE WEAK MESOSCALE FEATURES WILL LIKELY AID ADDITIONAL TSTM DEVELOPMENT OVER THE NEXT FEW HOURS. OBSERVED AND MODEL SOUNDINGS ACROSS THE REGION SHOW SOMEWHAT MARGINAL MID LEVEL LAPSE RATES THAT ARE LIMITING GREATER CONVECTIVE INSTABILITY. HOWEVER...LOW LEVEL MOIST ADVECTION AND STEEPENING LOW LEVEL LAPSE RATES SHOULD BOOST INSTABILITY ENOUGH FOR AT LEAST A FEW ROBUST UPDRAFTS. CURRENT AND FORECAST SHEAR ACROSS NY AND NRN PA WILL SUPPORT UPDRAFT ORGANIZATION/PERSISTENCE WITH PRIMARY THREAT LIKELY COMING FROM BOWING LINE SEGMENTS PRODUCING STRONG TO DAMAGING WINDS. LARGER SCALE FORCING ASSOCIATED WITH THE UPPER TROUGH AND FRONT OVER MI WILL ARRIVE ACROSS THE REGION MUCH LATER TODAY. BUT...WEAK MID LEVEL HEIGHT FALLS AHEAD OF THIS SYSTEM WILL CONTRIBUTE TO STEEPENING MID LEVEL LAPSE RATES...AND RESULT IN A SUBSEQUENT INCREASE IN INSTABILITY THROUGH LATE TODAY. THE REGION MAY EXPERIENCE A COUPLE OF ROUNDS OF STRONG TO SEVERE STORMS AS INITIAL ACTIVITY NEAR THE WARM FRONT AND WIND SHIFTS SPREADS EWD TOWARD THE HUDSON VALLEY/NERN PA...AND PRE-FRONTAL ACTIVITY NOW DEVELOPING OVER OH /REF. MCD 901/ MOVES EWD INTO PARTS OF NWRN PA AND WRN NY...WITH ACCOMPANYING WIND DAMAGE THREAT...LATER THIS AFTERNOON. ..CARBIN.. 05/27/2007 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ALY...BGM...BUF...CTP...PBZ... 41787483 40497798 41097932 41987919 42347851 43327692 43397532 43327481 42547468
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 27, 1:52 PM EDT | Severe Thunderstorm Watch | SPC | Broome, Cayuga, Chemung, Chenango, Cortland, Delaware and 11 more | 6 hr |
| May 27, 6:56 PM EDT | Mesoscale Discussion | SPC | Broome, Cayuga, Chemung, Chenango, Cortland, Delaware and 12 more | 2 hr |
| May 27, 12:45 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Clarion, Fayette and 10 more | 90 min |
| May 27, 4:30 PM EDT | Mesoscale Discussion | SPC | Adams, Cumberland, Dauphin, Franklin, Juniata, Perry and 1 more | 60 min |
Nearby
Mesoscale Discussions in New York, 2007Mesoscale Discussions in Pennsylvania, 2007Every mesoscale discussion in 2007
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.