US Weather Commentary

Location: New York
Author: Michael Schlacter
Date: Friday, July 7, 2006

Ridging to Spread Across the Northern Tier, Before Contracting back to the Rockies

For each U.S. region listed below, the first section will focus on medium-range comments (updated each discussion), while the second bullet-point will focus on Seasonal comments (updated as research warrants)

Northeast

With New York getting rain on 12 out of the first 16 days of Summer, and Scranton, PA wet on 14 out of 16, the Northeast continues its soggy and mild pattern, with no real heat to speak of. Any high pressure ridging will be countered by soggy soil conditions, as much of the sun's energy goes into evaporation rather than heating.

While humid evenings and bouts of mugginess need to be eyed, routine frontal passages will help ensure that locations such as Detroit, Pittsburgh, Buffalo, Burlington, Hartford and even New York, will have some of the largest reductions in cumulative Cooling Degree Days from Summer 2005 to Summer 2006 [June-September].

Southeast

A front will cool the region from the recent heat for a few days before returning to a more seasonable pattern. Scattered afternoon showers and thunderstorms typical of this pattern will bring spotty precip to the region.

With (warmer) ridging extending eastward into the South at times, critical days (i.e. days > 90°F, 95°F, 100°F) should be more numerous than in 2005, and with Hurricane Season upon us, substantial stresses on both the Agricultural and Energy Industries are likely.

North-Central

Drought is spreading eastward across the High Plains and into the Upper Mississippi Valley and Western Great Lakes, an area which just saw its 9th driest June in 112 years. Expect heat to ramp up through early July as upper-air ridging settles over the parched region, allowing for more heat spikes to spread further Eastward.

Parts of Illinois and Indiana need to be monitored for possible worsening drought (approaching moderate conditions currently present in IA, MO, and portions of MN, WI or even severe conditions currently in SD and NE), and thus the potential for surface-enhanced heat-waves during the Summer.

South-Central

Recent recent storms helped ease long-term precipitation deficits along the Northeast TX coastline, but much of TX, OK, AR, and LA are still hurting (with New Orleans still less than 50% of normal year-to-date). With a drying and warming trend emerging, a return to temperatures near and exceeding 100°F should be deeper into July.

Being near the epicenter of our forecasted "Omega" or "Horseshoe" Summer pattern, these aforementioned States will be most consistently under the influence of ridging, subsidence and compressional warming, almost regardless of how the Hemispheric patterns oscillate this Summer.

Northwest

With the focus of the ridging shifting Eastward, the Pacific Northwest will escape major heat spikes for the next 10 days and remain within a handful of degrees of normal.

The protection of moist surface conditions which much of the Northwest has enjoyed, is slowly being eroded and could become an issue deeper into the Summer whenever U.S. ridging skews westward.

Southwest

After a hot June where AZ registered its 3rd hottest, NV its 2nd hottest and CA its 4th hottest June in 112 years, the Southwest is on its way to a very warm July as well. The monsoon so far this season has been on the weak side, helping to keep conditions dry and warm, and this should continue for the next week or two, at least.

Westward oscillations of upper-air ridging along with interior drought versus coastal maritime influences, should make for quite a heterogeneous Summer for the Southwest quadrant of the Nation.

Tropics Status

Gulf: Sea temperatures above normal but slightly cooler than last year ranging from 81°F in isolated pockets to 86°F along the Northern Coast. Wind Shear UNFAVORABLE. Twin upper-level disturbances are affecting the Texas/Louisiana and Florida coasts. No signs of tropical development here, but they are bringing much needed rain to Louisiana and sections of Florida.

Bahamas/Sargasso Sea: Sea temperatures normal and cooler than 2005 ranging from 80°F in pockets to 88°F in the Bahamas. Wind Shear SLIGHTLY FAVORABLE, with the most conducive areas in a line from the Bahamas to Bermuda. Upper level low and surface trough over the Florida Peninsula will ride up a frontal boundary. This system will be non-tropical in nature.

Caribbean/far Atlantic: Sea temperatures above normal but less warm than 2005. Temperatures range from the upper 70's near the Cape Verdes, to near 88°F around Cuba. Wind Shear UNFAVORABLE but becoming more conducive this weekend in the Caribbean. Tropical waves parading across the Atlantic are being inhibited by a strong African Dust Layer stretching from Africa to the Caribbean. Bermuda-Azores high pressure is anomalously strong, which is helping to suppress the ITCZ to near 5°N latitude.

Note: During the 2004 and 2005 Seasons, NHC declared the first classification of a tropical system in either the 5 PM or 11 PM advisory periods an imbalanced 65% of the time, and outside of the work day (i.e. weeknights, weekends) an imbalanced 79% of the time. So far in 2006, Tropical Depression #1 (later Alberto), was officially declared over a weekend.

Related link of interest (re: NY Hurricane threats): http://www.weather2000.com/NY_Hurricanes.html

Forecasting the Forecast

Models are again in good agreement, so confidence should remain high and very similar to the outlooks issued yesterday. Areas to watch are in the Northwest, where some more Below-normal temperatures may be indicated in both the 6-10 and 8-14 day periods, and in the Southeast, where they may decide to shift the area of Below normal temperatures farther Southeast.