February Could Start Like a Lion for Parts of the Southeastern U.S.

OK, so I go to the SPC page as I'm sorta bored. Then I see a risk area on the experimental 4-8 day outlook.
http://www.spc.noaa.gov/products/exper/day4-8/

OK, all right, all right, I look at the GFS.

I fall out of my chair.

Downright scary setup... downright scary.

90 kt at 500mb, 60-70 kt LLJ, lack of strong arctic highs, strong southerly flow from the Caribbean. What more can I say? This has the potential to be a significant tornado outbreak for areas of southeastern AL, southern GA, and the FL Panhandle. Truly amazing setup. The question mark is instability and lapse rates, as always. However, given that the last few days have been fairly cold for the east, lapse rates could be slightly steeper than progged. Right now, I don't see much of a reason to downplay this thread except for the aforementioned condition, along with possible contamination of the warm sector by earlier convection. Of course, that is a big if, and a big reason for someone to downplay this. Nevertheless, I've seen many outbreak days the past year where the convection did not harm things as much as expected. The warm sector should be expansive, aided by strong southerly flow across the GOM. IF the lapse rates can steepen some more, I expect a loosely organized squall line along the front with supercellular activity ahead of it. IF the low strengthens more quickly than progged, a derecho could be possible, although this option seems quite unlikely to me.

I'll provide images when I get the chance later tonight or tomorrow morning.

8 short years ago today, an intense pacific jet carved a deep progressive longwave trough over the High Plains

...following a sharp arctic blast across the midwest characterized by sub 490 dm heights over the Hudson Bay. The Pacific jet reached its full fury when the western ridge crashed, followed by the retreat of the PV over Hudson Bay. At H5, the jet streak reached speeds of over 110 kt as it crashed ashore in California. With very little impedement in the form of a SE ridge or a substantial PV over Hudson Bay anymore, a large low-amplitude longwave trough was carved, and with several days of moderation along with a strong surface low pressure, moisture streamed in. Strong speed and directional shear provided an adequate environment for strong, long track supercells capable of producing significant to violent tornadoes. SPC issued a High Risk for January 21, 1999, at 6Z.

Thanks to the SPC High Risk archive...

CONVECTIVE OUTLOOK...REF AFOS NMCGPH94O.

VALID 211200Z - 221200Z

THERE IS A HIGH RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER
PARTS OF CENTRAL/EASTERN AR...NORTHEAST LA...NORTHERN MS...AND
WESTERN TN...TO THE RIGHT OF A LINE FROM ARG DYR 30 WNW MSL CBM 45
NE JAN MLU HOT ARG.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM GLS
GGG PGO HRO MDH OWB BNA BHM MOB.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 E PSX TYR MKO SZL
PIA MIE CRW PSK SPA ATL PNS.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 WSW P28 CSM TCC
LVS ALS COS GCK 30 WSW P28.

STRONG UPPER JET MAX CURRENTLY OVER THE WESTERN STATES IS FORECAST
TO MOVE SOUTHEASTWARD INTO THE SOUTHERN ROCKIES BY THIS
AFTERNOON...WITH LARGE UPPER TROUGH RAPIDLY AMPLIFYING OVER THE
PLAINS. NOSE OF STRONG MID LEVEL WINDS WILL SPREAD INTO CENTRAL TX
BY 00Z...WITH SURFACE LOW DEEPENING OVER OK. SURFACE DRYLINE WILL
EXTEND SOUTHWARD ACROSS EAST TX...WITH WARM/HUMID AIRMASS ALREADY
IN PLACE TO THE EAST.

ISOLATED STRONG/SEVERE THUNDERSTORMS MAY BE ONGOING AT THE
BEGINNING OF THE PERIOD OVER SOUTHERN IL/WESTERN KY...WITH LARGE
HAIL BEING THE MAIN THREAT. THESE STORMS SHOULD SPREAD EASTWARD
ACROSS THE OH VALLEY DURING THE DAY IN REGION OF MODERATELY STRONG
WARM ADVECTION. HOWEVER...WEAKENING INSTABILITY WILL LIMIT
EASTWARD EXTENT OF SEVERE THREAT.

AIRMASS ALONG AND EAST OF DRYLINE OVER AR/LA WILL BE MODERATELY
UNSTABLE BY MID AFTERNOON WITH SURFACE-BASED CAPE VALUES OF 1500-
2000 J/KG. ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP IN THIS
AREA AND SPREAD RAPIDLY EAST-NORTHEASTWARD ACROSS WESTERN
TN/NORTHERN MS DURING THE EVENING. MODEL FORECAST SOUNDINGS SHOW
VERY STEEP MID LEVEL LAPSE RATES AND DRY AIR ALOFT...FAVORABLE FOR
LARGE HAIL AND DAMAGING WINDS. ALSO...STORM-RELATIVE HELICITY
/300-500 M2/S2/...MAGNITUDE OF DEEP LAYER SHEAR /SFC-6KM SHEAR OF
45-55 KNOTS/...AND STRENGTH OF MID LEVEL STORM-RELATIVE WINDS /20-
30 KNOTS/ INDICATE POTENTIAL FOR A FEW TORNADIC SUPERCELLS ACROSS
THE HIGH RISK AREA. GIVEN THE STRENGTH OF FORECAST SHEAR
MAGNITUDES AND THERMODYNAMIC PROFILES...ISOLATED SIGNIFICANT
TORNADOES ARE POSSIBLE TODAY OVER PARTS OF SOUTHEAST AR...NORTHEAST
LA...SOUTHWEST TN...AND NORTHERN AL.

ACTIVITY WILL LIKELY PERSIST THROUGHOUT THE NIGHT...SPREADING INTO
PORTIONS OF MIDDLE TN AND AL BY 22/12Z. DAMAGING WINDS AND HAIL
SHOULD BE THE MAIN THREAT BY THAT TIME.

..HART.. 01/21/99


Nobody would've ever fathomed of the destruction that would follow. 84 tornadoes touched down on that fateful day, including 24 significant tornadoes and 10 tornadoes of F3 intensity or greater. Several counties in central AR were pummeled again and again by training tornadic supercells.

Image courtesy of JKTinMemphis:

http://www.easternuswx.com/bb/uploads/post-1877-1151183686.png

"Classic" string of pearls look, never before seen in January. It was by far the most powerful tornado outbreak in January ever, following the outbreak of January 17.

In all, 8 people were killed and hundreds injured in what would be the biggest January outbreak ever.

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

500mb plots, geopotential height and wind speeds:

0Z Jan 21

http://img66.imageshack.us/img66/8075/1999012100z2zj.png




0Z Jan 22

http://img66.imageshack.us/img66/3277/1999012200z2tw.png

How do I title this post... Vent I guess?

I've survived two finals and made it out alive...AP Euro and AP Calc. A in both classes, thank goodness. I'm really scared about the other two which are my hardest classes. Hon. Humanities and AP Chem. Biggest worry being the first one, since there aren't any AP tests to cover for it.

It's interesting to reflect upon the warnings my now junior year friends told me about the Humanities class. "Don't take it...it'll drop your GPA, don't get on [teacher name]'s nerves" etc. Really it's interesting how things would've been different had I not been forced to choose my classes in a 5-min time frame (it was due on a certain day and they forced us to choose 5 days before that day. I did not know and neither did anyone else). I probably would not have picked AP Euro, and replaced it with Orchestra, but just maybe I would've had time to do a better job on the Thesis paper.

Well anyway, as I stare at my screen, I realize that whatever has happened has happened. In middle school, getting straight A's was for my parents. In 9th grade, getting straight A's was for myself; I had changed. Now, I don't know what to think. I'm starting to go back to "I must get straight A's for parents" again. I really don't know what to say. My grandparents always had a lot of hope for me. To work until 2 AM nightly, and to have them know, only to get a B as the result, is undoubtedly heartbreaking for them. For my parents too. For me, I'm used to sleeping 6 hr per night and marginally passing.

I've always been very lucky. 90% in Orchestra 1st quarter of High School, after bombing playing tests. 90.3% in AP Chem 1st quarter of Sophomore year, after bombing the midterm. Countless times in previous English classes to have a C at the end of 1st quarter, and bounce back after stressing out. English has always been my weak spot, and always will be; as my first language was not English. I've always trended toward being brief and terse, and this is probably my longest post ever.

Now, as I stare down the possibility of getting a B in Humanities, I feel like giving up. Note that Thursday night at approximately 1 AM, I made a thread about giving up, but then I deleted it. (Tom may have seen it but there were only a couple of views other than my own.) There was reason to delete it as I'm sure people would've flamed me, and with good reason: whining is for jerks. We all do at some time but to do it on an open message board is downright naive and sinful.* Hopefully, I've tried to remove any traces that I'm complaining/whining in this post, although part of my intention is to vent, since I have no other human contact outside of message boards. It is time to accept reality and destiny, and getting a B is a part of that. Life's tough but it will go on. Perhaps this newfound attitude is the result of an intensification of my faith in God, one area which I feel like is necessary to improve on. Worrying has always been a big part of my sinful nature.

Thanks for reading, whoever read this. I'm sorry if I wasted your time, I tried to make this read as interesting as possible for whoever was going to finish it. I'll post it in my blog as well. I hope you don't hate me because of this.

*Note: Paragraph before last one, ignore part bolded.

Extreme cold in SoCal

Bitter cold here. Bitter cold...for our standards of course. Haven't been this cold in some time. In fact, there was snow yesterday.

NWS San Diego Pub Info Statement on cold temps

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
1100 AM PST SUN JAN 14 2007


...OBSERVED MINIMUM TEMPERATURES AROUND THE REGION FOR THIS MORNING...

LOCATION             OBSERVED MINIMUM TEMPERATURE

SAN BERNARDINO COUNTY

FAWNSKIN RAWS.................. 0
BIG BEAR LAKE.................. 3
WRIGHTWOOD..................... 4
HESPERIA....................... 6
EL MIRAGE RAWS................. 6
APPLE VALLEY................... 8
LAKE ARROWHEAD................. 9
VICTORVILLE....................12
MORMON ROCK RAWS...............13
MEANS LAKE RAWS................14
ANGELUS OAKS...................16
TWENTYNINE PALMS...............16
LYTLE CREEK RAWS...............23
ONTARIO AIRPORT................25
DEVORE RAWS....................28

RIVERSIDE COUNTY

IDYLLWILD......................11
ANZA RAWS......................12
PALM SPRINGS TRAMWAY...........13
PINE COVE......................16
LOST HORSE RAWS................17
THERMAL........................18
HEMET RYAN ARPT AT 7 AM........19
MARCH FIELD....................19
CLARK RAWS.....................19
CHINO AIRPORT..................20
MENIFEE VALLEY.................20
BEAUMONT 1 E...................21
LAKE ELSINORE..................21
TEMECULA 3SE...................23
THOUSAND PALMS.................23
PALM SPRINGS...................24
RIVERSIDE AIRPORT..............24
INDIO FIRE STN.................25
RIVERSIDE UCR..................26

SAN DIEGO COUNTY

MT LAGUNA RAWS................. 6
MOUNT LAGUNA................... 9
BORREGO VALLEY ARPT AT 7 AM....10
CAMPO..........................12
POTRERO RAWS...................16
OAK GROVE RAWS.................16
JULIAN RAWS....................18
PALOMAR MOUNTAIN...............18
RANCHITA RAWS..................18
RAMONA APRSWXNET/CWOP..........19
RAMONA AIRPORT.................20
CAMP PENDLETON MCAS............20
WILD ANIMAL PARK...............22
ESCONDIDO......................25
ALPINE RAWS....................25
OCEANSIDE AIRPORT..............27
BROWN FIELD....................27
NWS RANCHO BERNARDO............28
MCAS MIRAMAR...................28
EL CAJON.......................28
VISTA..........................30
CARLSBAD AIPORT................33
SAN DIEGO LINDBERGH FIELD......36
CABRILLO NATL MNMT.............36

ORANGE COUNTY

YORBA LINDA APRSWXNET/CWOP.....26
FULLERTON AIRPORT..............28
COSTA MESA APRSWXNET/CWOP......30
HUNTINGTON BEACH...............31
SANTA ANA FIRE STN.............31
JOHN WAYNE AIRPORT.............33
NEWPORT BEACH..................34
BELL CANYON RAWS...............34
TONNER CANYON RAWS.............34


...SEE LAXRERSGX FOR LIST OF OFFICIAL RECORD LOW TEMPS...

$$

EXPIRE DAY:01/16/07

TITLE:REMARKABLY COLD TEMPERATURES THIS MORNING-JANUARY 14



One final thing, correction to previous post:
A strong Santa Ana event is still possible tonight. Not as
strong as progged before, however.

Severe Wx, Santa Ana potential down the drain, new winter threats arise

No more. As expected, the front surged southward much stronger than originally anticipated, ruining the warm sector. Santa Ana doesn't seem to kick up.

BUT, that brings up some winter threats...

First of all, in my backyard, the cold! Lows are expected to dip below freezing which is quite rare here.

Second of all, the ice storm across the southern plains and Mid-Mississippi River Valley. Reports are that already 1.5" of ice has cut down power at WFO SGF (Springfield, MO). I don't really have anything to add since winter wx is not my specialty.

Update on 1/13 svr; major Santa Ana could also on tap

I don't feel like writing much more, but the following has been written on the Eastern US Wx thread the past few days:
---------------------------
Jan 7 2007, 09:31 AM

The northern wave that goes into Canada will do its job in helping advect moisture northward, so that's a good thing for svr wx. But it will also leave a cold high behind. Where this high sets up could be important. Somewhere, there could be a blizzard (I agree with LC* on this) with a 32mb gradient across the Denver area. Ice could also be a problem as the warm air overrides the cold air of the high.

The low should intensify and draw in enough warm air to weaken the high - but is the 12Z overdoing it? The boundary starts to become more S-N rather than W-E, but a 1036 high doesn't dissapear like that. Nevertheless, I still think the severe threat could extend up to the OH Vlly.

Lapse rates still stink, no need to explain there. Of course clustering/excessive convection will need to be watched.

*Meterologist Larry Cosgrove

---------------------------------
Jan 7 2007, 06:03 PM

A couple of things to note: one is that the reason 12Z has it more positively tilted is the shortwave dropping down from northern Canada. Much stronger and pulls the vort max northward, leading to a more positive. One thing I've noticed about the GFS is that these little shortwaves can passed unnoticed only to show up around hr 120-180 and then have a big influence come the day of the event (April 2 comes to mind). Now, this could be spurious as well, so don't take my word for it.

The strength of the SE Ridge will also be very important again in dictating lapse rates and tilt of trough, and the Euro, GFS, and their ensembles (I heard that 12Z Euro and GFS ensembles were similar) still have slight differences.

---------------------------------
And then what I just wrote now:

Ensembles are still in disagreement. Again it is all up to the piece of energy in Canada and also the strength of the SE Ridge which will dictate if this will be a strong closed low or a weak positively tilted system. I suspect a compromised solution - which is similar to what the OP GFS and Euro are showing, is the most likely outcome.

With that said, the 12Z GFS is extremely ominous. Of course, two model biases to be concerned about.
1) Arctic air often underestimated in strength and southward advection.
2) Too fast in ejecting lows into the Plains.

With regards to the first one, there's a 1038 high in the Dakotas which suddenly dissapears 12 hr later. Maybe a bit unrealistic. That has to be watched in intruding on the warm sector, and I suspect that the models are overdoing the width of the warm sector on the 12th (Friday). 12Z has trended slower with the low, BTW.

Suspect that the 12th could verify as a marginal slight, but nothing too much more with shallow moisture. Maybe some elevated storms invof the warm front.

The big day should be the 13th. Strong WAA could be stronger than anticipated, depending on the strength of the low, causing the warm front to lift up into northern AR. As the dryline advances eastward in the day, strong deep layer shear and so-so low level shear will promote the growth of supercells with tornado potential. My thinking right now is right along the I-35 corridor, and maybe even further west given the current model trends. Lapse rates will be weak though, and that could be a limiting factor for instability. Another big problem will be the cold high following the system. Again, as I said, models tend to underdo CAA just as they can underdo WAA. That could prove disastrous to this setup if the warm front does not lift as far north as anticipated. From past observations, this type of a setup often can be ruined by that.

Minimal threat on the 14th with lapse rates continuing to weaken and the main energy moving northward.

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

With regards to the Santa Ana event here, models are painting a downright scary setup on the 13th (same day as the possible severe wx outbreak). ~1030mb high parked over the Great Basin with extremely strong, northerly cold air advection. Once again, the brunt of the wind could bypass San Diego and slam Los Angeles due to the geography and the orientation of the inland mountains (N-S vs. W-E, respectively). 2m temps are progged to be around freezing, 850mb temps around -5. That's rare for southern California, and portions of the coast could even see a bout of freezing temperatures.

Stay tuned, exciting weather times ahead seem likely...

Update on storm around 1/13

I'm not going to start a thread on Eastern yet, b/c I am still in speculation mode.

The 0Z ECM is completely flipped-flopped, so I am concerned about that. The general consensus had been so far...
1) shortwave dives into the Pacific NW
2) splits, one part goes down into SoCal, one part flies off into oblivion in Canada
3) part that goes into SoCal, slowly trudges eastward while a ridge amplifies in the Gulf of Alaska.
4) ejects out into plains positively tilted

Except now the ECM is showing the northern split to be the dominant one, and little to no part that goes down into SoCal. Given, it's one run, so am not too concerned right now.

About thermodynamics, looks like that with the strong SE ridge and positive tilted nature of this system, that we are going to see problems with lapse rates again. Low level cyclogenesis east of the Rockies seems to be weak. So those will be the problems.

Obviously, though, for January, it's not too bad. We'll see if we can muster a good event out of this.

First tornado-related fatalities of the year today; More thoughts on Day 10 storm

First of all, kudos to Tony at easternuswx.com for keeping tabs with today's event. I sorta forgot about it a few days ago.

3 fatalities in New Iberia, LA, sadly:

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAKE CHARLES LA
1152 PM CST THU JAN 04 2007

..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..

0355 PM TORNADO NEW IBERIA 30.01N 91.82W
01/04/2007 IBERIA LA BROADCAST MEDIA

*** 3 FATAL, 15 INJ *** A THIRD FATALITY HAS BEEN
REPORTED WITH THE NEW IBERIA TORNADO.


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

Now onto next week's threat. As expected, the op GFS has come in line with its ensemble counterparts. Latest 0Z run of the European coming out, and it has come in line as well. And let me tell you that such good agreement 10 days out is rare!

Scenario 2 from yesterday's post is pretty much dead now, although rains still likely for SoCal next week from this system (and possible snow in NorCal). Just not going to be drenching. Won't go into details on that. A more progressive solution is looking likely. Which means a severe wx outbreak is looking increasing likely around the January 11-15 timeframe.

To be short, sweet, and right to the point, I'll start out with looking at the 500mb pattern.

Following outbreak days (centered west of the Mississippi) used:
05/04/1999
01/21/1999
03/12/2006
05/07/1993
05/04/2003
04/26/1991
04/06/2006
05/08/1988
04/02/1982
04/23/2000
06/07/1984
06/08/1974
03/13/1990
05/03/1999
06/16/1992
03/01/1997
05/08/2003
04/08/1999

Composite for above days:



Now, 500mb pattern from last night's 0Z GFS ensemble mean:



I'll let you, the reader, interpret that for yourself.

Thermodynamics are going to still be a crucial question. More on that when the time gets closer.

So, like, I'm new at this Blog thing; Thoughts on the upcoming pattern

Took me long enough to start.

Anyway, all you need to know about me is that I like weather (abbreviated wx, I'll use abbreviations a lot). Specifically severe wx.

IMO there are two options for upcoming week, both interesting for me of course.

1) Severe wx outbreak in the Plains followed by cooldown and the arrival of winter conditions (finally!) for the East.

2) Cutoff low forms off SoCal. MJO wave tapping leads to a significant rain event for the American Southwest. Meanwhile, the eastern 2/3 of the country remain blowtorched.

12Z GFS ensemble members

12Z operational GFS

And finally, European

(I'm too lazy to actually post images now, but I'll see if I can later)

You can compare the scenarios I present to the what the models project. The op GFS and Euro cut off the low while many of the ensembles eject the longwave into the Plains.

FIRST OPTION:
I'll discuss the severe option first. Many significant tornado outbreaks (I'll spare you the details of my research) follow periods where there was a significant vortex over Quebec or Hudson Bay (or an eastern trough/western ridge configuration). What followed was a flattening of the jet stream, zonal flow across the CONUS (Continental U.S.) and an increase in power of the pacific jet. Then a disturbance along the Pacific jet (or a jet streak) carves out a longwave trough over the west, and voila. Many times, there was a large Southeast ridge and a progressive pattern throughout which kept things moving.

The pacific jet is there. The eastern trough/western ridge configuration is there temporarily a few days before the outbreak. The southeast ridge is there. But the progressive pattern is not -- after the longwave is carved, a blocking ridge builds in the Gulf of Alaska. Perhaps that won't be a problem, I don't know.

SECOND OPTION:
The Euro tends to have a bias in cutting off lows too quickly, so it can be discarded in this case. Froms a classic omega block and cuts of the low for presumably several days (extrapolating the 240 hr forecast). This option -- which is the upper low cutting off and spinning is SoCal, is supported by the operational GFS -- but not the GFS ensembles. This is most likely the result of either the Southeast ridge being too strong and the "kicker" behind it being too weak. OR a rex block forms and the upper low is trapped. If this materializes, the MJO could be a factor where some tropical convection is drawn up. The MJO is moving toward Phase 7 and 8 and if the timing is right, a significant rain event is possible for SoCal if the MJO can maintain its intensity.

Although it's still over a week out, the model and ensemble agreement is actually quite good.

In any situation, exciting times ahead!