Severe Weather Threat thru Jan 18

Sat Jan 11 Convective Outlook
Slgt Risk Of Svr Tstms Over The Sern U.S. To Mid Atlantic Coast...

A High-Amplitude..Yet Progressive Pattern Will Persist Through The
D1 Period With The Primary Feature Of Interest Being An Intense
Mid/Upper-Level Trough Translating From The Ms River Valley To
Atlantic Seaboard.

This System Will Be Attended By A 90-100+ Kt Midlevel Jet Streak Developing Downstream From The Trough Base And A Corridor Of 500-Mb Height Falls Exceeding 100-150 M/12 Hr.

In The Low Levels...A Cold Front From The Upper Great Lakes To Lower Ms Valley Will Advance Ewd To Off The Middle And Srn Atlantic Coast By Tonight.

This Boundary Will Gradually Overtake A Warm/Wedge Front Lifting Nwd Into The Srn Appalachians...And More Nwwd From The Coastal Plain Into The Va/Carolina Piedmont.

Sern U.S. Into The Mid Atlantic...

The Mass Response To The Approaching Midlevel Trough Has Induced An Intense /50-60+ Kt/ Llj From The Cntrl Gulf States To New England With This Feature Strengthening Further Today While Migrating Ewd/Newd To The Atlantic Coast.

This High-Momentum Air Stream Will Hasten The Poleward Flux Of An Increasingly Moist Boundary Layer Off The Ern Gulf Of Mexico And Atlantic With Dewpoints In The Low/Mid 60s To The South And East Of The Above-Mentioned Warm Front.

However...Widespread Clouds And Increasing Warm-Conveyor-Related Shower And Tstm Development Will Limit Destabilization Within The Warm Sector With Mlcape Of Generally Less Than 500-1000 J/Kg.

As Of 12z...A Pre-Frontal Qlcs Is Ongoing From Nrn Ga To Cntrl Gulf
Coast...Along The Wrn Edge Of The Llj Where Confluent Flow In The
Low Levels Coincides With Deeper-Layer Ascent/Dcva Attendant To The Upper Trough.

Latest Convection-Allowing Model Guidance Suggests That This Qlcs Will Continue Ewd Today...Gradually Developing Nwd Through The Piedmont By Afternoon As The Attending Belt Of Ascent Encounters An Increasingly Moist/Unstable Environment E/Se Of The Warm Front.

Based On Recent Radar Trends...It/S Possible That One Or More Bands Of Tstms May Precede The Primary Convective Band /Qlcs/ From Sern Al And Nrn Fl Newd Through Ga Into The Carolinas.

Even In The Absence Of More Appreciable Air Mass Destabilization ...Intense Forcing For Ascent And Vertical Shear May Yield Embedded Bowing/Lewp Structures And Supercells With A Risk For Damaging Winds And A Few Tornadoes.

Given The Evolution Of Semi-Discrete Storm Modes And Sufficient Air Mass Destabilization...The Greatest Tornado Threat Will Exist From Ern Nc Into Sern Va This Afternoon...Along The Core Of The Llj Where
Effective Srh Values Will Approach 300-400 M2/S2.

The Severe Weather Threat Will Diminish By Late Evening Along
Coastal Locations With The Passage Of The More Intense Storms Into The Atlantic.

------------------------------------------------------------------------------------------

Sun Jan 12 Convective Outlook
Storm Prediction Center Norman Ok
No Svr Tstm Areas Forecast...

As The Vigorous Upper Trough Now Approaching The Pacific Northwest Progresses Inland Later Today And Tonight...Models Suggest That Upstream Ridging Will Begin To Build Across The Eastern Pacific.

Further Amplification Of The Ridge Is Then Forecast Through This
Forecast Period...Along With An Eastward Expansion Across The
Pacific Coast.

As This Occurs...The Splitting Remnants Of The Inland Advancing Upper Trough Still Appear Likely To Continue East Of The Rockies...Through The Plains/Mississippi Valley Sunday Into Sunday Night.

However...Considerable Spread Persists Among The Models Concerning These Developments...Including The Movement Of The
Southern Portion Of The Split East Of The Central And Southern
Rockies...And Its Possible Influence On Another Impulse Within A
Lingering Weak Belt Of Westerlies Across The Northern Mexican
Plateau Into The Western Gulf Of Mexico/Gulf Coast Region.

This Contributes To Uncertainty Regarding Convective Potential For This Period.

In General Though...At Least Some Boundary Layer Recovery Does Appear Possible Across The Western Gulf Of Mexico...Which May
Contribute To Weak To Modest Moistening Within A Southerly Return
Flow Toward The Western/Central Gulf Coast.

Within The Presence Of A Band Or Bands Of Strengthening Lower / Mid Tropospheric Warm Advection...This Seems To Support At Least Minimum Threshold Probabilities For A Categorical Thunderstorm Inland Of Coastal Areas.

------------------------------------------------------------------------------------------

Mon Jan 13 Convective Outlook
Storm Prediction Center Norman Ok
No Svr Tstm Areas Forecast...

Models Indicate That Amplification Of Upper Flow Will Continue
Through This Forecast Period Across The Eastern Pacific Into The
U.S...With A Ridge Continuing To Build Either Side Of An Axis Near
The Pacific Coast...While Large-Scale Downstream Troughing Evolves Across The Central And Eastern States.

This Latter Feature Will Include A Split Pair Of Short Wave Impulses Which Are Expected To Progress East Of The Central Canadian Prairies And U.S. Plains.

The 11/00z Ecmwf Is Considerably Weaker Than Prior Runs With The
Southern Impulse And Associated Secondary Surface Wave Development Along An Eastward Advancing Cold Front...Which Now Is Forecast To Track From Western And Central Gulf Coastal Areas Into The Lee Of The Southern Appalachians.

This Appears To Reduce The Model Spread For This Period And Generally Increases Confidence That Convective Potential For Monday And Monday Night Will Remain Relatively Low.

Boundary Layer Moistening Over The Western And Northern Gulf Of
Mexico...Inland Into The Southeast States...Should Be More Modest
Than That Which Has Occurred Ahead Of The Upper Trough And
Associated Cold Front Advancing East Of The Mississippi Valley
Through The Atlantic Seaboard Today.

It Still Could Be Sufficient To Support Vigorous Organized Storm Development In The Presence Of Strengthening Deep Layer Shear Over Parts Of The North Central And Northeastern Gulf Of Mexico... Which Could Impact Immediate Adjacent Coastal Areas Monday Into Monday Evening.

However...Severe Potential Farther Inland Appears Negligible At The Present Time.

--------------------------------------------------------------------------------------------

Jan 14-18 Convective Outlook
Storm Prediction Center Norman Ok

Medium Range Models Indicate That Amplified Western North American Upper Ridging And Eastern North American Upper Troughing...Developing Early This Coming Work Week...Will Persist Into Latter Portions Of The Week.

In The Wake Of An Initial Frontal Passage Tuesday...Drying Northerly / Westerly Low-Level Flow Across The Gulf And South Atlantic Coasts Is Forecast Through Much Of The Period...Along With A Series Of Reinforcing Cold Intrusions Into The Central And Eastern United States.

Given These Conditions... Convective Potential Appears Negligible.


WTVY-TV 285 N Foster Street Dothan, AL 36303 334-792-3195
Copyright © 2002-2014 - Designed by Gray Digital Media - Powered by Clickability 239745581 - wtvy.com/a?a=239745581
Gray Television, Inc.