Severe Weather May 26th, 2006

Severe Weather Episode Friday May 26th 2006

The combination of a cold front crossing during the afternoon hours and an upper level disturbance spawned numerous showers and thunderstorms along and east of the Ohio River Friday afternoon May 26^th. A total of seven severe thunderstorm warnings were issued for counties in West Virginia between the hours of 2pm and 4pm. Quarter size hail was observed at the National Weather Service Office in Charleston, WV, while a microburst caused damage to several trees east of Charleston in the Kanawha City vicinity later in the evening. The Storm Prediction Center on its 1230 pm issuance outlooked much of West Virginia in a slight risk as pictured in Figure 1.

Figure 1 SPC day 1 outlook issued at 1630 Zulu

Below is a water vapor image taken at 1730 Zulu depicting an upper level disturbance passing through Ohio with thunderstorms developing out ahead. Darker shading over northern Kentucky and western West Virginia portrays drier mid levels of the atmosphere. Drier air would result in a chance of damaging winds due to evaporation of water further accelerating downdraft winds. Although gusty winds were observed with the storms, most reports relayed to the National Weather Service were nickel to quarter size hail.

Figure 2 Water Vapor Image at 1730z

The surface map (Figure 3) analyzed by HPC has the cold front almost on top of the Ohio River at 18Z. If you compare the water vapor image above to the surface analysis, storms formed just ahead of the cold front.

Figure 3 HPC surface analysis at 18z Friday May 26^th 2006.

Although most of the morning was dominated by a canopy of clouds, sunshine broke through as mixing scoured out some of the clouds. The visible satellite image from 18Z shows scattered to broken cumulus clouds downstream of the front. In addition, it also shows towering cumulus clouds across West Virginia. The atmosphere was not as unstable in the mountains since little vertical growth in the cumulus clouds is indicated from Figure 4.

The corresponding surface map at 18z is shown in figure 5. It portrays moderate surface instability with temperatures in the lower to mid 70s and dewpoints in the lower 60s.

Figure 4 Visible Satellite Image taken at 18z Friday May 26^th. 

Figure 5 18Z surface map

The 0.5 degree reflectivity pictured below illustrates scattered to numerous showers and thunderstorms in the warm sector ahead of the front. The first severe thunderstorm warning was issued minutes after this image for Putnam and Kanawha counties. The storm is noted by the white arrow. Quarter size hail was reported in the town of Tornado in western Kanawha County, while nickel size hail fell in Putnam County.

Convective parameters used by meteorologists supported the threat of severe thunderstorms. Figure 6 is a sounding for Charleston and is the zero hour forecast from the 18Z NAM model. Surface based CAPE exceeded 1500 J/KG with little if any cap since negative energy was -25 J/KG.

Figure 5 KRLX reflectivity taken shortly after 18z

Figure 6 NAM zero hour forecast for Charleston valid at 18z Friday May 26^th

By 19z storms continued to develop and move southeast through West Virginia. The 19z 0.5 degree reflectivity (figure 7) shows higher reflectivity values just east of the radar. This cell produced nickel to quarter size hail at the National Weather Service Office in Charleston.

Figure 7 19z 0.5 degree reflectivity

The storms continue their eastward progression for the balance of the afternoon and weakened as they moved into more stable air in the West Virginia mountains. The final count of storm reports, wind or hail can be found below (figure 8). A complete listing of wind and hail reports relayed to the Charleston, WV forecast office can be found at the bottom of the page.

Figure 8 Storm reports for the calendar day of May 26^th 2006

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHARLESTON WEST VIRGINIA
241 PM EDT FRI MAY 26 2006


..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0230 PM     HAIL             SAINT ALBANS            38.38N 81.83W
05/26/2006  U0.75 INCH       KANAWHA            WV   PUBLIC
            EVENT OCCURRED BETWEEN
            215 PM 05/26/2006 AND 230 PM 05/26/2006

0240 PM     HAIL             TORNADO                 38.33N 81.86W
05/26/2006  M1.00 INCH       KANAWHA            WV   NWS EMPLOYEE

0242 PM     HAIL             SAINT ALBANS            38.38N 81.83W
05/26/2006  U0.88 INCH       KANAWHA            WV   PUBLIC
            EVENT OCCURRED BETWEEN
            227 PM 05/26/2006 AND 242 PM 05/26/2006

0251 PM     HAIL             SAINT ALBANS            38.38N 81.83W
05/26/2006  U1.00 INCH       KANAWHA            WV   PUBLIC
            EVENT OCCURRED BETWEEN
            236 PM 05/26/2006 AND 251 PM 05/26/2006

0250 PM     HAIL             CHARLESTON              38.35N 81.63W
05/26/2006  M1.00 INCH       KANAWHA            WV   OFFICIAL NWS OBS
            OBSERVED AT NWS OFFICE.

0250 PM     HAIL             SAINT ALBANS            38.38N 81.83W
05/26/2006  U0.75 INCH       KANAWHA            WV   PUBLIC
            EVENT OCCURRED BETWEEN
            245 PM 05/26/2006 AND 300 PM 05/26/2006

0305 PM     HAIL             CHARLESTON              38.35N 81.63W
05/26/2006  E1.00 INCH       KANAWHA            WV   PUBLIC          
            GREENVIEW ROAD AND SMITH CREEK

0308 PM     HAIL             CHARLESTON              38.30N 81.55W
05/26/2006  U1.00 INCH       KANAWHA            WV   PUBLIC
            EVENT OCCURRED BETWEEN
            253 PM 05/26/2006 AND 308 PM 05/26/2006

0308 PM     HAIL             CHARLESTON              38.34N 81.66W
05/26/2006  U1.25 INCH       KANAWHA            WV   PUBLIC
            EVENT OCCURRED BETWEEN
            253 PM 05/26/2006 AND 308 PM 05/26/2006

0308 PM     HAIL             CHARLESTON              38.30N 81.55W
05/26/2006  U0.88 INCH       KANAWHA            WV   PUBLIC
            EVENT OCCURRED BETWEEN
            253 PM 05/26/2006 AND 308 PM 05/26/2006

0311 PM     HAIL             CHARLESTON              38.32N 81.59W
05/26/2006  U0.75 INCH       KANAWHA            WV   PUBLIC
            EVENT OCCURRED BETWEEN
            256 PM 05/26/2006 AND 311 PM 05/26/2006

0314 PM     HAIL             CHARLESTON              38.35N 81.63W
05/26/2006  U0.88 INCH       KANAWHA            WV   PUBLIC
            EVENT OCCURRED BETWEEN
            259 PM 05/26/2006 AND 314 PM 05/26/2006

0315 PM     HAIL             3 S GRANTSVILLE         38.88N 81.09W
05/26/2006  E0.75 INCH       CALHOUN            WV   TRAINED SPOTTER

0415 PM     HAIL             SUTTON                  38.67N 80.71W
05/26/2006  E0.75 INCH       BRAXTON            WV   TRAINED SPOTTER