Day 1 Severe Weather Outlook Verification for July 2, 2009...

Wrapup...

As promised, we always do a verification too see what was realized compared to forecasted. Today's action, as expected, was rather uneventful for most. If you experienced severe weather today, consider yourself very lucky as reports were few and far between. Folks out in Dukes and Barnstable County MA saw some good action this Morning with one rather large severe cell. This cell was responsible for 5/7 severe weather reports that were recorded Today, including 1 large hail report of hen egg size (2.00").

One other late term cell in Northeast PA (Lackawanna/Wyoming counties to be exact) was responsible for the other 2 severe reports this evening. Here was the quick break down...

-No Slight Risk was issued for Today. As it turned out, it quite obviously wasn't warranted.

Isolated Severe Zone captured 7/7 severe weather reports.
5% Severe Wind Zone: Captured 2/2 damaging wind reports.
5% Severe Hail Zone: Captured 5/5 severe hail reports.
2% Tornado Zone: Captured 0/0 reported/confirmed tornadoes.

And that's all she wrote with this event. Not much else to say as this wasn't an overly complex forecast. Onto Tomorrow...

..EGAN..

Afternoon Day 1 Severe Weather Outlook for July 2, 2009...

Discussion...

Currently some strong to severe storms on-going over far Southeastern Massachusetts in the vicinity of Cape Cod. Behind these, most of the region is under a very cloudy/showery regime that will aid in dampening the amount of destabilization this Afternoon. This ultimately should keep the severe threat to a rather minimum with only isolated storms approaching severe limits. Main threat will be the traditional damaging wind/large hail as well as some excessive rainfall, especially in areas already reeling from yesterday's rainfall.

Even though Overnight outlook was already well-drawn out like usual, the weather is always changing, and thus minimal changes were done to keep ahead. Decided to keep the low 2% Tornado probability in play with a bit more wesstward expansion. Overall dynamics support a general area of thunder just about anywhere in the northern Mid-Atlantic/Northeast to the east of the Appalachians. Within here, most favorable zone for isolated severe remains over Southern New England south/west into the Coastal Plain of NJ/much of New York State, respectively. Based on the lack of overall support for organized severe convection and consequential 5% Isolated severe, I would venture to expect there will be 15 or less severe weather reports this afternoon.

As always, because we care about how accurate we are, more so than most, whether it's good or bad, there will be the usual post-game wrapup and county level verification later this Evening.

..EGAN..

Day 1 Severe Weather Outlook for July 2, 2009...

Discussion...

Looking at Today's setup, there is certainly potential for severe weather. Going to have to agree with overall consesus that today's threat will be greatly impacted on the amount of destabilization that takes place. The NAM and GFS disagree rather markedly on the amount on CAPE for today, especially over southern New England. The NAM is rather putrid in terms overall destabilization across much of the area, generally 1000 J/KG or less. The GFS seems to be dead set on a fairly expansive area of 1500-2000 J/KG. This difference will not be resolved until mid-morning when the RUC and surface observations should be able to help better discern the amount of destabilization to occur.

If we can manage to muster enough instability, severe convection is likely, especially over Southern New England. Here, deep layer/low level shear values are progged around 40-50kts and would be very supportive of organized convection. In addition, storm relative helicity values are coming in right around 300, which is borderline condusive for supercellular development.

Because of the high uncertainty regarding amount of destabilization, going to remain a little more conservative at this point in time and keep severe hail/wind probabilities on the lowest 5% level until mid-morning analysis unveils a more deliberate area that warrants higher severe weather potential. Most favorable area for this happening would be over Southern New England southwest into NJ/DE vicinity.

Normally I wouldn't do this with out atleast a 15% Slight Risk in play, but due to the favorable kinematic environment over southern New England, don't feel comfortable leaving tornado probabilities less than 2%. Therefore, will carry a low 2% probability at this time.

..EGAN..

Day 1 Verification for July 1, 2009...

Putting a cap on Wednesday's severe weather. Verification ended up yielding a marginal at-best justification for a slight risk in my opinion.

Total reports ended up being 23, 13 severe hail/10 damaging wind reports.

Slight Risk captured 17/23 reports...
15% Severe Wind Zone: captured 6/10 damaging wind reports.
15% Severe Hail Zone: captured 11/13 severe hail reports.
2% Tornado Zone: captured 0/0 tornado reports. One briefly tornado warned cell in East Central VA, however no wind damage/tornado reports.

Isolated Severe captured 4/23 reports...
5% Wind Zone: captured 4/10 damaging wind reports.
5% Hail Zone: captured 0/13 severe hail reports. The 2 renegade hailers were located just outside the 5% severe hail zone into far southeastern Massachusetts in Barnstable/Plymouth Counties.

..EGAN..

Afternoon Day 1 Severe Weather Outlook for July 1, 2009

Updated and Final D1 Outlook is ready to go. Slight Risk has been extended into VA/VT/RI, and locally extended in NY/MA/PA/MD by a few counties. Slight Risk includes the following counties:

Connecticut: Fairfield, Hartford, Litchfield, Middlesex, New Haven, New London, Tolland, Windham.

Delaware: Kent, New Castle, Sussex.

Maryland: Anne Arundel, Baltimore, Baltimore City, Calvert, Caroline, Carroll, Cecil, Charles, Dorchester, Frederick, Harford, Howard, Kent, Montgomery, Prince George's, Queen Anne's, Saint Mary's, Somerset, Talbot, Washington, Wicomico, Worcester.

Massachusetts: Berkshire, Franklin, Hampden, Hampshire, Worcester.

New Jersey: Atlantic, Bergen, Burlington, Camden, Cape May, Cumberland, Essex, Gloucester, Hudson, Hunterdon, Mercer, Middlesex, Monmouth, Morris, Ocean, Passaic, Salem, Somerset, Sussex, Union, Warren.

New York: Albany, Bronx, Columbia, Delaware, Dutchess, Fulton, Greene, Kings, Montgomery, Nassau, New York, Orange, Putnam, Queens, Renssalaer, Richmond, Rockland, Saratoga, Schenectady, Schoharie, Suffolk, Sullivan, Ulster, Washington, West Chester.

Pennsylvania: Adams, Berks, Bucks, Carbon, Chester, Cumberland, Dauphin, Delaware, Franklin, Lackawanna, Lancaster, Lebanon, Lehigh, Monroe, Montgomery, Northampton, Perry, Philadelphia, Pike, Schuykill, Wayne, York.

Rhode Island: Bristol, Kent, Newport, Providence, Washington.

Vermont: Bennington, Windham.

Virginia: Accomack, Albermarle, Alleghany, Amelia, Amherst, Appomattox, Augusta, Bath, Bedford, Botetourt, Buckingham, Campbell, Caroline, Charlotte, Chesterfield, Clarke, Culpeper, Cumberland, Essex, Fairfax, Fauquier, Fluvanna, Franklin, Frederick, Goochland, Greene, Hanover, Henrico, Highland, King and Queen, King George, King William, Lancaster, Loudon, Louisa, Madison, Middlesex, New Kent, Northumberland, Nottoway, Orange, Page, Pittsylvania, Powhatan, Prince Edward, Prince William, Rappahannock, Richmond, Roanoke, Rockingham, Salem, Shenendoah, Spotsylvania, Stafford, Warren, Westmoreland.

West Virginia: Berkeley, Jefferson.

Discussion...
Not much has changed in terms of overall extent of expected perameters Today, however, overall spread of favorable severe weather perameters has increased. Thus, local extensions of the risk were warranted. Severe Weather checklisk features MLCAPE values exceeding 1350 J/KG over much of the risk area coupled with sufficient low level Bulk Shear of 30-45 kts. and Negative Lifted Indices of -3 to -7. This will continue to be supportive of multi-cellular/segments as well as few low-topped supercells, any of which could become severe and produce large hail/damaging winds, frequent lightning, heavy rainfall and perhaps a tornado or two.

..EGAN..

Day 1 Severe Weather Outlook for July 1, 2009

D1 Outlook for Wednesday is complete. Slight Risk will once again be in play for large hail and damaging winds over a good amount of the area. Slight Risk includes the following counties…

New York: Albany, Bronx, Columbia, Delaware, Dutchess, Greene, Kings, Nassau, New York, Orange, Putnam, Queens, Renssalaer, Richmond, Rockland, Schoharie, Suffolk, Sullivan, Ulster, West Chester.

Pennsylvania: Berks, Bucks, Carbon, Chester, Delaware, Lackawanna, Lehigh, Monroe, Montgomery, Northampton, Philadelphia, Pike, Wayne.

New Jersey: Atlantic, Bergen, Burlington, Camden, Cape May, Cumberland, Essex, Gloucester, Hudson, Hunterdon, Mercer, Middlesex, Monmouth, Morris, Ocean, Passaic, Salem, Somerset, Sussex, Union, Warren.

Connecticut: Fairfield, Hartford, Litchfield, Middlesex, New Haven, New London, Tolland, Windham.

Massachusetts: Berkshire, Franklin, Hampden, Hampshire.

Delaware: Kent, New Castle, Sussex.

Maryland: Caroline, Cecil, Dorchester, Kent, Queen Anne's, Somerset, Talbot, Wicomico, Worcester.

Discussion...

Some uncertainty surrounds the amount of instability that will be in play for tomorrow afternoon/evening. Trends will need to be monitored Wednesday Morning to see how well atmosphere rebounds following overnight convective remnants that are rotating about much of the region. Risk areas will likely need to be tweaked in Late Morning update once amount of destabilization is better discerned. Also may need to expand a bit further south into Delmarva/Eastern Va area.

Current thinking is that MLCAPE values will likely range from 1250-2000 J/KG over much of the risk area. This area of moderate destabilization will be accompanied by fairly modest Lift and low level Bulk shear, generally in the -3 to -6 and 30-45 kts range, respectively. This will support the initiation of showers and storms over most of the area by Early Afternoon, some of which will likely become severe with large hail/damaging winds along with excessive rainfall and frequent lightning.

Low-level Helicity is once again not strong, but present enough so that tornado threat will once again be non-zero. Therefore, a low 2% probability will also accompany Slight Risk area.

..EGAN..

Severe Weather Outlook Verification for June 30, 2009

Verification process complete and all severe weather reports are accounted for. A Slight Risk was indeed warranted as the amount and congestion of reports are more than ample enough to verify such a risk. As far as the models go, the NAM/RUC handily outperformed the GFS with this event, especially in terms of CAPE values as to what was actually realized. Here is the breakdown....

Total reports came to 45, of which, 25 Severe Wind Gusts/Wind Damage Reports, 20 Severe Hail Reports, and 0 Tornado reports/confirmations as of yet.

Of 45 total reports...

Slight Risk zone captured 42/45 severe weather reports.
15% Wind zone: captured 23/25 severe wind/damage reports.
15% Hail zone: captured 19/20 severe hail reports.
2% Tornado zone: captured 0/0 tornado reports/confirmations thus far. 1 Tornado warned cell in Sullivan/Delaware Counties NY did produce a Funnel Cloud and wind damage, although no confirmed/reported tornadoes. This could be subject to change.

Isolated Severe zone captured 2/45 severe weather reports.
5% Wind: 2/25 severe wind/damage reports.
5% Hail: 0/20 severe hail reports.

..EGAN..