Fwd: WEATHERAmerica Newsletter, Weather Extremes And Global Satellite Discussion, Saturday, October 7, 2023

[Larry Cosgrove]

---------- Forwarded message ---------
From: Larry Cosgrove <larry.c...@gmail.com>
Date: Sat, Oct 7, 2023 at 4:38 PM
Subject: WEATHERAmerica Newsletter, Weather Extremes And Global Satellite Discussion, Saturday, October 7, 2023
To: Larry Cosgrove <weather...@msn.com>

NASA Descriptions Of The Event And Observation Techniques

 

WEATHER HAZARDS (During The Next 24 Hours)

 

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

 

Some Thunderstorms May APPROACH Severe Limits

CA....AZ...W, C NM Mountainous Zones

STRONG WINDS

(Pressure Gradient Derived)

N, W ON....N, C QC....Labrador

ISOLATED Severe Thunderstorms

(Microbursts, Waterspouts)

S FL

 

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

 

Scattered Locations In

E ON....S, C QC....ME....NB....NS....PEI

(QPF 1 - 4")

 

EXCESSIVE HEAT RISK

(Potential For Temperature To Exceed 95 deg F)

 

Isolated Locations In

C, S CA....NV....Extreme S ID....W, S UT....AZ....W NM....SW CO

Isolated Locations In

S FL

GLOBAL WEATHER SUMMARY

(a review of important weather features around the world)

 

IODC

ECMWF; METEOBLUE; EUMETSAT

 

An active southern branch jet stream means more precipitation. For now, mostly along and above 35 N Latitude.

Visible in both satellite imagery and in numerical model depictions through the next ten days, the "typical El Nino" configuration of a condensed cold field across northern and central Russia and lateral heat ridge displays from the Sahel through the Arabian Peninsula into India is present. The 500MB shortwaves within the southern branch jet stream move roughly along an arc from the eastern Mediterranean Sea or Anatolia into northern Iraq and Iran, then into Afghanistan and Pakistan. A steep baroclinic zone separates cooler (not cold) temperatures from hot weather (which occasionally sneaks north into the lower Tigris/Euphrates watershed and Persian Gulf locations to the Indus Delta. 

The big point to make is that those living along and to the right of the subtropical jet stream are going to see strong thunderstorms and precipitation threats. This is not yet a snow accumulation issue, although that hydrometeor type will increase as we reach into the winter  months. Keep in mind that classic +ENSO environments almost always yield drought in tropical zones such as the southern Arabian Peninsula or South Asia.

Changes are coming. Be ready.

 

HIMAWARI 8

METEOBLUE; Kochi University

 

There are three main drivers in the weather patterns of EastAsia and the western/central Pacific Basin. One is the developing deep trough (and eventual vortex formation exiting the coastline of the PRC. Another is Tropical Storm Bolaven, now developing over the Marianas Chain and destined to become a typhoon with a recurve east of the Japanese Archipelago. The third and probably most important feature is the Madden-Julian Oscillation, currently well-formed and bulging north in Phases 7 and 8. Typhoon Koinu is skirting the coastline of southern China, and will drifte west-southwest before breaking up over Vietnam in about four days.

Bolaven will have its energy and moisture pulled into a formative gyre below the Aleutian Islands. The MJO related convective grouping will link with the broad trough along and west of the International Date Line. In much of the central and eastern USA in the 11-15 day time frame, and proceed to increase ridging over western and northern North America, setting up a cooler trend to the right of the Rocky Mountains. Much of eastern Asia behind those systems will be relatively mild and dry during the medium range.

Much of Indonesia and most of Australia is assuming the warm and dry look common with El Nino episodes. New Zealand has a different look, with a frontal structure and showers passing through.

 

GOES WEST

NOAA/NESDIS

 

Tropical Storm Lidia is on the verge of becoming a hurricane. There are two other convective systems below Central America which will follow Lidia, which very likely will strike come of the resorts on the Mexican shoreline before moving inland by Tuesday. The tropical cyclone or its two "followers" will then become enmeshed in the active subtropical jet stream now skirting Texas and the Gulf Coast. Model guidance suggests that an important shortwave will merge with the disturbances, setting up a heavy rain and severe weather event from the south central U.S. into the Mississippi Valley and points north and east on Thursday and Friday.

 

GOES EAST

NOAA/NESDIS

 

The merger of the Philippe remnants with a cold low in Quebec is drawing to a close. Heavy rain and strong winds (not a hurricane....) will be an issue across eastern Canada on Sunday and Monday before the entire system deflates and opens up into the polar jet stream around October 10-11. Most of the USA except for the Gulf Coast is fair, with some manner of hot air noticed across the Southwest.

South America seems to be more active as we move through the first ten days of austral spring. A strong cold front is advancing into southern Brazil. Another disturbed area is entering southern Chile. But note again the very dry, hot expanse over the northern half of the continent. Yet another sign that El Nino effects are taking hold.

 

METEOSAT

ECMWF; METEOBLUE; EUMETSAT

 

A firmly positive North Atlantic Oscillation and formative Russian vortex set up a mostly mild/warm European subcontinent.

The ridging over western Europe looks very stable. While not a subtropical high, the ridging over France and Spain is a warm and dry signature for most, holding off strong low pressure and frontal structures across the northern Atlantic Ocean. Russia will see colder turns with a trough and eventual vortex formation, but I doubt that the cPk regime will get much further west than Poland and the Czech Republic.

I am almost surprised that the ITCZ is flaring up again. And perhaps bemused that the lead impulse exiting the west African coastline is being monitored for tropical cyclone development. The shearing deep mean westerlies cover all of the Atlantic Basin and western/central Sahara Desert, and will destroy any convective circulation that happens to form west of the Cape Verde Islands. Thunderstorms development is slowly sagging southward below the Equator. The Kalahari heat ridge is strengthening again, allowing only a cold frontal passage through the lowest territory of South Africa.