Dr. Jeff Masters' WunderBlog

Tropical Storm Emily continues to threaten Haiti; More extreme heat in Central U.S.
Posted by: Dr. Jeff Masters, 4:47 PM GMT on August 04, 2011 +23
Tropical Storm Emily remains unorganized this morning, and continues to linger just south of Haiti, near 17.3°N, 72.3°W. Emily is 90 miles south of Port au Prince, Haiti. Storm motion over the past 24 hours has been slow, varying between completely stopped and west to west-northwest at 5 mph. This motion (or lack thereof) is still something that the models aren't analyzing well. Satellite imagery shows that thunderstorm activity on the north side of Emily seems to be disrupted, possibly by the terrain of Hispaniola, but also potentially by the continued moderate shear to the north of the storm. Wind shear has weakened to the northwest of the storm in the past 24 hours, but it will probably not be enough to allow Emily to undergo any significant intensification. The layer of dry air that we've been talking about for the past few days has also all but dissipated to the west and north of the storm. As the National Hurricane Center has been forecasting, environmental conditions are becoming slightly more favorable for the storm. Satellite estimates of wind motion suggest that low level circulation in the storm has become very broad and extends north over Hispaniola, which indicates that there's potential for the storm to undergo a quick jump to the north, but overall the storm remains weak and this seems unlikely. Emily continues to be tilted to the east with height, but doesn't appear as sheared as yesterday morning.

Conditions in Hispaniola have surely deteriorated over the past 24 hours, however, thunderstorm activity appears to have weakened over the island this morning. Infrared satellite imagery shows that cloud tops have warmed in the past 6 hours on the north side of the storm, which means that strong thunderstorms are no longer building high into the atmosphere. High resolution model forecasts (see Figure 1) have continued to predict that the heaviest rain will fall to the east of the storm. The longer Emily tracks west without taking a significant turn to the northwest, the more likely it is that Haiti will see the most extreme rainfall in the storm. Overall, 6 to 12 inches of rain is expected to fall, with local amounts up to 20 inches possible in higher terrain. Flash floods and mudslides are a serious threat.


Figure 1. Forecast radar and sea level pressure from the 06Z (2am EDT) run of the HWRF high resolution model. While I think that the model was initialized poorly and doesn't accurately represent where the storm will travel over the next 24 hours, I do think that the precipitation field is accurate. The strongest rain and winds have been on the east and north sides of the storm over the past couple of days. If Emily continues to move west before taking a significant turn to the northwest, Haiti could receive the strongest impact from the storm.

Forecast for Tropical Storm Emily
Models continue to waver back and forth on Emily's forecast track. Yesterday evening, the HWRF model forecast Emily to cross over Hispaniola and undergoing a close encounter with the Florida coastline. Last night, the National Hurricane Center wrote that "if Emily does not begin its northwestward turn soon…a watch could be required for parts of southern Florida today." Since the storm appears to be moving slightly more to the north than west this morning, this doesn't look like it will be necessary, although the forecast remains very uncertain. In today's 06Z runs, both the HWRF and the GFDL are probably forecasting Emily to move too far north in the next 12 hours. Given the present direction and speed of the storm, it's hard to see these two models' forecasts coming to fruition. The official forecast track from the National Hurricane Center is a turn to the northwest over the next 6 to 12 hours, with landfall in Haiti happening this afternoon. Beyond that, they forecast Emily to stay on a northwest course through the Bahamas, where Emily could restrengthen a bit before making a turn to the northeast on Sunday, although they qualify this forecast with the fact that it's very uncertain, and that the global models dissipate Emily after crossing Hispaniola. The official forecast track does not have Emily making any landfall in Florida, but the Miami to West Palm Beach area is still within the cone of uncertainty.

Interestingly, the models that have done the best job at predicting the track of Emily thus far are the less relied-on statistical track models—those that don't take into account any current atmospheric dynamics. If Emily remains on a west to west-northwest track today, we cannot rule out that it cross over a larger area of Cuba, approaching the southeast portion of Florida. However, given the amount of land interaction in this potential track, the probability of Emily remaining a tropical cyclone in this scenario is low.


Figure 2. Satellite imagery of Tropical Storm Emily at 10:15am EDT. The strongest thunderstorm activity is now in the southern portion of the storm. Thunderstorms over Hispaniola appeared to weaken this morning.

Typhoon Muifa

Typhoon Muifa continues to be a category 2 typhoon on the Saffir-Simpson scale. Satellite imagery shows a well developed storm that is moving west-northwest. Over the next day, Muifa is expect to turn to the northwest as it approaches China. Today's track forecast is more north and east of yesterday's, with a brief landfall just north of Shanghai, potentially as a category 3.


Figure 3. MODIS satellite imagery of Typhoon Muifa from earlier today, plotted using NASA's new Rapid Response Web Mapping Service.

Central U.S. heatwave

The heat continues for the central U.S., where I've heard reports that local media in the region were canceling all of their outdoor shots because of the dangerous conditions. Here are some of yesterday's extreme temperatures, which were compiled by our weather historian, Christopher C. Burt:

Little Rock, Arkansas set an all-time record with 114°F (the old record was 112°F set in 1986). Fort Smith, Arkansas set an all time record of 115°F (the old record was 113°F set both Tuesday and previously in 1936).

State maximum air temperatures from Wednesday:

• Arkansas: 116° at Silver Hill (4° short of state all-time record)
• Oklahoma: 115° at Atoka
• Louisiana: 111° at Caney
• Texas: 111° at Fort Worth and Wichita Falls (that also had a record high minimum of 88° this morning)
• Missouri: 109° at Branson and Ava

The heat index is also at play in this heat wave; some incredible values recorded yesterday include 126° in Poplar Bluff, Missouri, 125° in Walnut Ridge, Arkansas, and 122° in Arkadelphia, Arkansas. The GFS continues to forecast heat index values around 120° in the lower Mississippi Valley through the weekend.

Angela
Categories: Heat Hurricane
  Permalink | A A A
Reader Comments
Display: 0, 50, 100, 200 Sort: Newest First - Order Posted
Viewing: 1 - 51

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47Blog Index

1. Ninj4 4:48 PM GMT on August 04, 2011    
Thanks for the update :-)
Member Since: February 11, 2011 Posts: 0 Comments: 15
2. galvestonhurricane 4:49 PM GMT on August 04, 2011    
Thanks for the update!
Member Since: June 18, 2010 Posts: 0 Comments: 176
4. galvestonhurricane 4:51 PM GMT on August 04, 2011    
By the way, this blog is great for a second opinion on the tropics (when you are not here).
http://blog.chron.com/sciguy/2011/08/emily-nears- haiti-and-hurricane-season-outlook-are-bumped-up-t he-tropical-waves-line-up/
Member Since: June 18, 2010 Posts: 0 Comments: 176
5. superpete 4:52 PM GMT on August 04, 2011    
Thanks for the update.
Member Since: October 10, 2007 Posts: 0 Comments: 498
6. IceCoast 4:53 PM GMT on August 04, 2011    
48 Hrs HWRF
Be skeptical of the intensity
Member Since: October 17, 2010 Posts: 0 Comments: 1254
7. LillyMyrrh 4:53 PM GMT on August 04, 2011    
Thanks for the update. This heatwave is almost unbelievable! I really hope that it's over quickly.
Member Since: September 8, 2004 Posts: 0 Comments: 47
8. gbreezegirl 4:53 PM GMT on August 04, 2011    
Great update! Thanks.
Member Since: September 7, 2005 Posts: 0 Comments: 273
9. muddertracker 4:53 PM GMT on August 04, 2011    
Emily is taking her clothes off again!!! Dang girl...make up your mind!
Member Since: August 16, 2007 Posts: 1 Comments: 2126
10. Skyepony (Mod) 4:54 PM GMT on August 04, 2011    
Hurricane Hunters are on the way..
Member Since: August 10, 2005 Posts: 144 Comments: 29343
11. chrisdscane 4:54 PM GMT on August 04, 2011    
thanks doc im not seeing wnw im seeing NW i dont know why
Member Since: July 21, 2010 Posts: 0 Comments: 738
13. PrivateIdaho 4:55 PM GMT on August 04, 2011    
Can I drain the water out of my bathtubs yet?
Member Since: August 29, 2010 Posts: 0 Comments: 5211
15. BoroDad17 4:56 PM GMT on August 04, 2011    
I will be honest, I see very little evidence of a LLC at all at the moment.
Member Since: September 5, 2008 Posts: 0 Comments: 121
17. TomTaylor 4:58 PM GMT on August 04, 2011    
Thanks Angela...you and Rob have done a great job fling in for Jeff
Member Since: August 24, 2010 Posts: 18 Comments: 3899
18. JRRP 4:58 PM GMT on August 04, 2011    


Member Since: August 16, 2007 Posts: 0 Comments: 4312
20. IceCoast 4:58 PM GMT on August 04, 2011    
12zHWRF is the polar opposite of the 12zGFS. Take it FWIW.
54Hrs
Member Since: October 17, 2010 Posts: 0 Comments: 1254
21. Neapolitan 4:58 PM GMT on August 04, 2011    
IMHO, Emily isn't going to make it. At her current pace, she'll be crawling through the islands, and that just isn't gonna do it. If I were a betting man--which I am--I'd put money on her dissipating by this time tomorrow.

But I've been wrong before. ;-)

That heat is intense, and still going on. I've read that another heavy duty heat wave may be setting up for the East Coast by the end of next week; we'll have to see whether that pans out. I hope not; there've already been hundreds of heat-related deaths in the past month.
Member Since: November 8, 2009 Posts: 4 Comments: 11161
22. MahFL 4:59 PM GMT on August 04, 2011    
You can fry eggs on hoods of cars anytime in FL during the summer.....
Member Since: June 9, 2004 Posts: 0 Comments: 2430
24. 69Viking 5:00 PM GMT on August 04, 2011    
Quoting chrisdscane:



Sry man i just dont see this i see a more NW motion


Emily moved .2N and .5W as of last advisory, even the NHC knows that's WNW movement.
Member Since: August 25, 2006 Posts: 0 Comments: 2247
25. chrisdscane 5:00 PM GMT on August 04, 2011    
now shes stationary
Member Since: July 21, 2010 Posts: 0 Comments: 738
26. DFWjc 5:00 PM GMT on August 04, 2011    
Quoting MahFL:
You can fry eggs on hoods of cars anytime in FL during the summer.....


i cooked a hot pocket on my porch yesterday..
Member Since: July 19, 2011 Posts: 1 Comments: 967
27. kmanislander 5:01 PM GMT on August 04, 2011    
It almost looks as if the center is partially exposed near 17.2 N and 72.8 West. The next few frames should tell.
Member Since: August 19, 2006 Posts: 0 Comments: 14939
28. Torgen 5:01 PM GMT on August 04, 2011    
Quoting ITCZmike:
Thanks for the update. This heatwave is almost unbelievable!

It's so hot you can almost fry an egg on the hood of your car!

:)


Almost? You lightweights. Come to Florida! I have potholders in the car so I can hold the steering wheel. :D
Member Since: June 3, 2010 Posts: 0 Comments: 321
29. zawxdsk 5:01 PM GMT on August 04, 2011    
Quoting IceCoast:
12zHWRF is the polar opposite of the 12zGFS. Take it FWIW.
54Hrs


HWRF has been trying to make Emily extra strong after Hispanola for quite a few runs now. It also seems to initialize a bit strong.

I don't buy it at all, but its an interesting picture.
Member Since: August 2, 2011 Posts: 0 Comments: 118
30. HarryMc 5:02 PM GMT on August 04, 2011    
Quoting Skyepony:
Hurricane Hunters are on the way..


I just looked at the live data and got all confused for a second, then realized they're at 25,000 feet and not quite there yet
Member Since: March 30, 2010 Posts: 4 Comments: 325
31. muddertracker 5:02 PM GMT on August 04, 2011    
Emily is spinning in at least two different locations on RGB floater...what a mess she is.
Member Since: August 16, 2007 Posts: 1 Comments: 2126
32. HurriJoeCain 5:03 PM GMT on August 04, 2011    
She sure doesn't look very good, but I'm not ready to count her out yet.
Member Since: June 23, 2011 Posts: 0 Comments: 19
33. ecflweatherfan 5:03 PM GMT on August 04, 2011    
NOTE: LLC appears to be at 17.1N 72.8W



Member Since: March 19, 2010 Posts: 0 Comments: 947
34. kmanislander 5:03 PM GMT on August 04, 2011    
Quoting ecflweatherfan:
NOTE: LLC appears to be at 17.1N 72.8W





Agree, I just posted that below
Member Since: August 19, 2006 Posts: 0 Comments: 14939
35. zawxdsk 5:04 PM GMT on August 04, 2011    
From the looks of the water vapor, it might be getting ready to climb up against the mountains on the southern end of Haiti.

Edit: I'm off an hour.
Member Since: August 2, 2011 Posts: 0 Comments: 118
36. chrisdscane 5:04 PM GMT on August 04, 2011    
looks like her MLC seems to be on land alrdy
Member Since: July 21, 2010 Posts: 0 Comments: 738
38. Skyepony (Mod) 5:04 PM GMT on August 04, 2011    
Checking some average model error stats (thru 8-4 12z) for Emily..error in nm 0hr, 24hr, 48hr & etc..

AEMN 36.4 75.9 95.2 134.1 174.6 -
AP01 47.7 78.4 86.0 151.8 160.7 186.4
BAMS - 93.5 92.4 123.2 105.8 139.5
CMC 59.6 94.0 101.7 127.2 127.5 251.8
GFDL 16.6 97.4 120.3 169.5 152.0 199.9
GFDN 12.6 60.4 - - - -
HWRF 16.2 89.2 147.2 234.4 322.1 458.8
LBAR 0 103.4 124.4 177.1 266.1 334.3
LGEM 0 99.6 136.9 193.9 243.7 265.7
NGP2 0 25.1 31.2 132.4 - -
OFCL 2.0 92.5 120.7 114.9 200.5 -
TVCN 0 94.4 108.3 163.6 198.1 251.8
XTRP 0 135.0 206.1 256.1 341.6 462.6
Member Since: August 10, 2005 Posts: 144 Comments: 29343
39. chrisdscane 5:05 PM GMT on August 04, 2011    
17.1N 72.8W
and it'll miss the next forecast piont more importantly
Member Since: July 21, 2010 Posts: 0 Comments: 738
40. chevycanes 5:06 PM GMT on August 04, 2011    
Quoting zawxdsk:
NHC coming in late on this update. They must be having a really difficult time trying to find the Center of Circulation. It's further west than the convection again.

From the looks of the water vapor, it might be right up against the mountains on the southern end of Haiti.

it's still 55 mins. till 2PM. they aren't late at all.
Member Since: August 6, 2007 Posts: 0 Comments: 687
41. ProgressivePulse 5:07 PM GMT on August 04, 2011    
Thanks for the update Angela.


Thinking it's about time to put down the "Emily" and pick it up tomorrow if there is anything left.
Member Since: August 19, 2005 Posts: 5 Comments: 4326
42. JRRP 5:07 PM GMT on August 04, 2011    
where is the recon ?
Member Since: August 16, 2007 Posts: 0 Comments: 4312
43. islander101010 5:08 PM GMT on August 04, 2011    
repeat of yesterday smart one
Member Since: September 11, 2010 Posts: 0 Comments: 2968
45. PrivateIdaho 5:08 PM GMT on August 04, 2011    
Quoting DFWjc:


i cooked a hot pocket on my porch yesterday..


You're just an adrenaline junky!
Member Since: August 29, 2010 Posts: 0 Comments: 5211
46. HarryMc 5:09 PM GMT on August 04, 2011    
Quoting JRRP:
where is the recon ?


Approximately 181.2 miles out, heading there now.
Member Since: March 30, 2010 Posts: 4 Comments: 325
47. ecflweatherfan 5:09 PM GMT on August 04, 2011    
Quoting chrisdscane:
17.1N 72.8W
and it'll miss the next forecast piont more importantly


Nevermind, location is south of due west of previous spot at 11am
Member Since: March 19, 2010 Posts: 0 Comments: 947
48. stormpetrol 5:10 PM GMT on August 04, 2011    
Time: 17:00:00Z
Coordinates: 16.45N 69.7833W
Acft. Static Air Press: 392.6 mb (~ 11.59 inHg)
Acft. Geopotential Hgt: 7,736 meters (~ 25,381 feet)
Extrap. Sfc. Press: -
D-value: 419 meters (~ 1,375 feet)
Flt. Lvl. Wind (30s): From 202° at 27 knots (From the SSW at ~ 31.0 mph)
Air Temp: -17.0°C (~ 1.4°F)
Dew Pt: -20.9°C (~ -5.6°F)
Peak (10s) Flt. Lvl. Wind: 27 knots (~ 31.0 mph)
SFMR Peak (10s) Sfc. Wind: -
SFMR Rain Rate: -
(*) Denotes suspect data

Well on should be interesting to see what they find!
Member Since: April 29, 2007 Posts: 0 Comments: 6400
49. jnhouston 5:10 PM GMT on August 04, 2011    
Quoting PrivateIdaho:
Can I drain the water out of my bathtubs yet?


No you cannot! and we are requesting that everyone in Idaho keep water in their tubs in hopes that they will bathe one day. ;)
Member Since: August 15, 2008 Posts: 0 Comments: 4
50. islander101010 5:11 PM GMT on August 04, 2011    
bet they find pretty much the same as yesterday look for a blow up of convection soon might just slip under s cuba
Member Since: September 11, 2010 Posts: 0 Comments: 2968
51. chrisdscane 5:11 PM GMT on August 04, 2011    
Quoting ecflweatherfan:


Nevermind, location is south of due west of previous spot at 11am


you mean she's moved south i dont understand what u ment
Member Since: July 21, 2010 Posts: 0 Comments: 738

Viewing: 1 - 51

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47Blog Index

New Comment
Community Standards Policy Comments will take a few seconds to appear.
Post Your Comments
Please sign in to post comments.
Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.
About JeffMasters
Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Community Activity