WEATHERAmerica Newsletter, Saturday, June 20, 2015 (Weather Extremes And Global Discussion)

[Larry Cosgrove]

TODAY'S FUN LINKS:

New map of the UK pinpoints tornado hotspots for the first time in two decades

May 2015 was wettest month ever recorded in U.S.

Why the U.S. desperately needs weather satellite data from China and Russia, but Congress says no

Here's how tropical storms have impacted Texas in the past 35 years

Space ‘Buoy’ May Help Protect Power Grid From Sun’s Fury

Clearer Forecasts Ahead: Lockheed Martin Completes Assembly of NOAA's Next-Generation Geostationary Weather Satellite

 

WEATHER HAZARDS (During The Next 24 Hours)

 

SEVERE WEATHER OUTLOOK
(potential for tornadoes, damaging winds, and large hail within the next 24 hours)

 

ISOLATED Severe Thunderstorms

(Microbursts, Large Hail, Isolated Tornadoes)

SE NE....NE KS....N MO....S IA

ISOLATED Severe Thunderstorms

(Microbursts, Large Hail, Isolated Tornadoes)

S IN....N KY....S OH....WV....N VA....W MD

ISOLATED Severe Thunderstorms
(Microbursts, Isolated Tornadoes)

DE....NJ....NYC/LI NY

Some Thunderstorms May APPROACH Severe Limits

SE LA....S MS....C, S AL....C, S GA....FL

ISOLATED Severe Thunderstorms

(Microbursts, Large Hail, Isolated Tornadoes)

S AL....S SK....N ND...S, C MB....W ON

 

HEAVY RAINFALL OUTLOOK
(potential for an inch or more total rainfall within the next 24 hours)

 

Scattered Locations In

NB....NS....ME....NH....VT....MA....RI....CT....SE NY....NJ....DE

(QPF 1- 4")

Isolated Locations In

S IN....N KY....S OH....WV....N VA....W MD

(QPF 1 - 2")

Isolated Locations In

SE LA....S MS....C, S AL....C, S GA....FL

(QPF 1 - 2")

Isolated Locations In
S AL....S SK....N ND...S, C MB....W ON

(QPF 1 - 2")

 

 

GLOBAL WEATHER SUMMARY

(a review of important weather features around the world)

 

IODC

Dundee University

 

The intense convection associated with the monsoonal trough and the incoherent Madden-Julian Oscillation signal could turn much of South Asia into a quagmire of heavy rainfall. The summer monsoon has formed early, and shows signs of westward retrogression that should enable Pakistan and Afghanistan to see important moisture. Note also that the fetch of higher dewpoints off of the Bay of Bengal is moving across Indochina into the PRC, where the stream links into the polar westerlies. Shortwaves forming over Manchuria and eastern Siberia will play a very important part in the evolution of summer weather across North America.

 

MTSAT

Digital Typhoon

 

The succession of intense shortwaves that will be impacting the U.S. and southern Canada over the next two weeks (and possibly beyond) starts here. Energy moving off of the Eurasian super-continent merges with a moisture feed from two components: the monsoonal fetch from the Indian Ocean as well as the series of tropical disturbances lurching west and north from Oceania. This is not a "typical El Nino" episode in that the Maritime Continent should be very dry (see Australia have cold frontal passages and Indonesia into the Philippines has impulses with strong winds and torrential rain.

 

GOES WEST

NASA

 

You can see the two features likely to dominate apparent weather in the U.S. during July. One is the equatorial moisture axis, part of the incoherent Madden-Julian Oscillation signal. The other is the impressive (for early summer) storm sequence across the northern Pacific Ocean. The impulses moving toward the West Coast weaken due to a mean 500MB ridge axis stretching from British Columbia into California and the Great Basin, but usually regroup to the right of the Continental Divide. One major issue which will soon arise is that the disturbed area below Mexico is expected to be an input into the summer monsoon across the Desert Regions. Widespread heavy rainfall will be an issue from the Cordillera into the Great Basin and Salt Lake Valley within ten days.

 

GOES EAST

NASA

 

You can see the remnant circulation of Tropical Storm Bill over Appalachia, apparently no longer of a frontal structure with which the vestiges helped to dump amazing rainfall totals across parts of Texas, the lower Great Plains and Corn Belt. Note also the cold front straddling the U.S./Canada border, which may be pulled south into Appalachia and the Eastern Seaboard behind the dwindling storm.

Strong ITCZ waves have now moved into the equatorial Pacific Ocean, with only a few minor waves tracking across Venezuela into Colombia. Much of South America has seen a cooling and drying trend, with a frontal structure reaching as far north as the Mato Grosso of Brazil.

 

METEOSAT

SMHI

 

The Saharan heat ridge has regrouped, and is contributing a hot, dust-laden regime into the equatorial Atlantic Ocean. Note that the ridge complex extends as far afield as Iran and the Caucasus. Hotter air is reaching the Iberian Peninsula. However, the polar westerlies have dug into a trough associated with cooler, sometimes stormy conditions from the United Kingdom into most of central and Eastern Europe. The ITCZ is quite active in equatorial Africa, sandwiched between the Saharan anticyclone and the Kalahari heat ridge. But impulses moving westward are dying out due to dust and dry air infiltration.