Tropical Storm Barbra To Become Hurricane: Will Hawaii See Impacts?

Tropical Storm Barbra has developed in the eastern Pacific and will become a hurricane later today (Monday). TS Barbra is well south of Mexico (see Fig. 1), and currently has maximum sustained winds of 65mph (as of Monday morning) and is rapidly moving W at 21mph. The W to WNW motion is expected to continue thanks to a ridge to the north of the storm (see Fig. 2).

Fig. 1: TS Barbra’s current position
Fig. 2: Current upper-level features creating steering pattern for Barbra

Barbara is expected to intensify over the next week. The storm is currently over anomalously warm waters (see Fig. 3) and will move into an environment with minimal environmental shear (see Fig. 4). This should allow Barbra to quickly intensify. The National Hurricane Center calls for Barbra to become a Category 3 hurricane by Tuesday (see Fig. 5) before a gradual weakening trend occurs.

Fig. 3: Current SST anomalies
Fig. 4: Current wind shear over eastern Pacific
Fig. 5: NHC’s forecast track for Barbra

The weakening trend will be gradual and Barbra is expected to remain a hurricane as it moves west towards Hawaii. It is still too early to determine if Barbra will impact Hawaii. Current guidance does indicate Barbra will be close to the islands in about two weeks. Latest European ensembles spaghetti plots indicate Barbra will track south of the big island (see Fig. 6).

Fig. 6: Barbra’s spaghetti plots

However, a few members of the spaghetti plot do indicate a farther north track near the big island. Track uncertainty this far out makes it hard to forecast direct impacts on Hawaii but it is something that needs to be monitored closely. Steering patterns appear to guide Barbara towards the islands due to ridging north of the storm (see Fig. 7) , the environmental shear while not ideal will be low enough for Barbra to at least maintain Tropical Storm status (see Fig. 8) and sea-surface temperatures are anomalously warm near Hawaii (see Fig. 3).

Fig. 7: Upper-level features steering Barbra west during the second week of July
Fig. 8: Environmental wind shear during the second week of July

Regardless of direct impacts, the islands can expect a gradual increase in wave heights by the end of the first week of July with significantly larger waves entering week 2 of July (see Fig. 9).

Fig. 9: Wave height for Hawaii during the second week of July

Whether impacts may eventually reach Hawaii after next weekend will depend on the storm’s exact track. Many uncertainties exist so keep checking back for updates.

Weather vs. College Football

It’s that time of the year. Temperatures are getting warmer; weather is getting more bland; Omaha has cleared out after the conclusion of college baseball; and, we are left counting down the days until college football returns (the 2019 college football season officially begins on Saturday, August 24th). Weather and college athletics are boring this time of the year so let’s take a look at 3 college football games that were heavily impacted by weather in the last 20 years, and rank them from greatest weather impact (GOLD) to heavy weather impact (BRONZE).

I) GOLD

Mississippi State University vs. Texas A&M University: MSU and A&M met up in Shreveport, Louisiana in a bowl game to conclude the year 2000. This post-season meetup was before both teams were in the Southeastern Conference. At the time, A&M was still in the Big XII and MSU was in the SEC. Many dub this game the “Snow Bowl” New Year’s Eve. During warmups, snow begun to fall over northern Louisiana and the snow continued throughout the duration of the game. Several inches of snow fell on the city during the duration of the game; to make things worse (colder), the game went to overtime. While this made for a beautiful scene on television, the players, coaches, assistants and fans had to brave the winter elements of snow & temps in the 20s. Interestingly, the adverse weather did not keep the game low-scoring: 84 points were scored in this game! Given the type of weather (snow & cold) that impacted this game, the location of the game (far South), and the geographical locations of both teams (not common winter weather hotspots) this game is deserving of GOLD. (December 31st, 2000: MSU 43, A&M 41)

II) SILVER

The University of Notre Dame vs. North Carolina State University: ND traveled to Raleigh, North Carolina to take on NC State as Hurricane Matthew had its eyes set on the state of North Carolina. This game is known as the “Hurricane Game” due to Matthew’s impacts on the game. By the start of the game, extremely heavy rain was falling and winds were gusting over 40mph. Rain fell throughout the game making the field a nasty mess. Over 6″ of rain fell in Raleigh the day of the game. As you can imagine, the weather heavily impacted the game-plan–passing the ball was not an option in the rain & wind (less than 100 yards combined passing). This made for a low-scoring game: 13 points were scored in this game; ND only scored on a field goal! (October 8th, 2016: NCS 10, ND 3)

III) BRONZE

The University of Michigan vs. Indiana University: Indiana traveled to Ann Arbor, Michigan to take on the number 3-ranked Wolverines (is Michigan back?!). While snow is nothing unusual for Big 10 Country in November, the intensity of the snow was impressive by the end of the game. To make things worse, temps this day started out in the 60s (very warm for Ann Arbor in November) before quickly falling into the 30s. By the start of the game, light snow begun to fall. By the fourth quarter, the snow picked up in intensity and winds were gusting over 30mph. This dropped the visibility to near 0! The wind & snow didn’t seem to impact the offensive production too much: 30 points were scored in this Big 10 matchup! (November 19th, 2016: UM 20, Indiana 10)

What the heck, lets do a runner-up that includes a Florida school since Florida is prime recruiting grounds for college athletics.

HONORABLE MENTION

West Virginia University vs. the University of South Florida: USF traveled to Morgantown to play WVU in December of 2008 in a game remembered as the Whiteout. While Morgantown is no stranger to winter weather in December, the people from south Florida were likely unprepared for cold temps–much less snow. Ironically, the fans planned the whiteout game (to wear all white attire) but the weather decided to join in on the whiteout and produce snow. Snow periodically fell throughout the game with temps in the 20s (Morgantown never got above freezing on this day–hopefully the couch burning kept fans warm). In 2008, both teams were part of the Big East before conference realignment sent WVU to the Big XII and USF to the American. The blustery and slick conditions kept this game low-scoring: a whopping 20 points were scored! This game doesn’t top the list because field crews were able to keep the field decently cleared. (December 6th, 2008: WVU 13, USF 7)

Severe Thunderstorms Likely For Parts Of Texas, Oklahoma and Arkansas

Severe thunderstorms are likely this afternoon for parts of Texas, Oklahoma and Arkansas. The Storm Prediction Center (SPC) has an enhanced risk of severe thunderstorms for northern Texas, southern Oklahoma and western Arkansas (see Fig. 1). An enhanced risk is a level 3 category out of 5 (see Fig. 2), which means numerous severe storms are possible throughout the afternoon & evening hours.

Fig. 1: Thunderstorm outlook map for this afternoon from the SPC
Fig. 2: SPC severe categories

At this hour, a weakening MCS is moving southeast across parts of Oklahoma and Arkansas. The cold-pool associated with this MCS is well-intact, however, which will allow new convection to develop along the leading edge this afternoon in northern Texas, southern Oklahoma and western Arkansas. The main hazard with the new convection will be damaging winds of 60-70mph (see Fig. 3). A few large hail events may occur, too.

Fig. 3: Damaging wind probability map

Higher impact severe weather is likely farther southwest into northwestern Texas and southwestern Oklahoma. In this vicinity, a tipple point will establish during peak afternoon heating. Near the triple point, very large hail (up to softball size) and a few tornadoes are possible (see Fig. 4 & 5). Storms will move east-southeast and organize into a complex–likely producing damaging winds for northern Texas and southern Oklahoma during the evening hours.

Fig. 4: Large hail probability map
Fig. 5: Tornado probability map

The best timing for severe thunderstorms will be from 2:00PM Central until Midnight Central. Make sure you take all watches and warnings seriously this afternoon, as damaging winds are just as dangerous as a tornado. It should be noted the severe threat does exist for all of Arkansas, central Texas, all of Louisiana, western Tennessee and western Mississippi. Main hazard is damaging wind gusts of 60-70mph.

Cities included in the Enhanced Risk: Dallas, TX; Fort Worth, TX; McKinney, TX; Denton, TX; Sherman-Denison, TX; Durant, OK; Ardmore, OK; Little Rock, AR.

Cities included in the Slight Risk: Waco, TX; Shreveport, LA; Memphis, TN.

Severe Storms Likely For The Southeast This Afternoon

Much of South Carolina, northeastern Georgia and south-central North Carolina have been upgraded to an enhanced risk (see Fig. 1) for severe thunderstorms this afternoon by the Storm Prediction Center (SPC). An enhanced risk is a level 3 category out of 5 (see Fig. 2), which means numerous severe storms are possible throughout the afternoon & evening hours.

Fig. 1: Thunderstorm outlook map for this afternoon from the SPC
Fig. 2: SPC severe categories

At this hour, the atmosphere is become unstable across this region. At the same time a long-lived MCS is moving out of Tennessee. While much of the convection with this MCS has undergone weakening, the cold-pool from the convection is well-intact. This will allow new convection to develop this afternoon across the Southeast.

Widespread damaging winds are possible this afternoon in the Carolinas and Georgia. This wind threat is the main hazard for the afternoon with winds up to 70mph possible. The tornado threat is low but it is possible a brief tornado could spin-up along the leading edge of any complex of thunderstorms this afternoon.

The best timing for severe thunderstorms will be from 3:00PM Eastern until Midnight Eastern. Make sure you take all watches and warnings seriously this afternoon, as damaging winds are just as dangerous as a tornado. It should be noted the severe threat does exist west into central & northern Alabama, northeastern Mississippi and Tennessee.

Cities included in the Enhanced Risk: Asheville, NC; Charlotte, NC; and Columbia, SC.

Cities included in the Slight Risk: Knoxville, TN; Charleston, SC; August, GA; Atlanta, GA; Savannah, GA; Birmingham, AL; Huntsville, AL; and Tupelo, MS.

Damaging Storms Possible For The Southeast & Mid-Atlantic

The storm system that generated severe thunderstorms across central parts of the country yesterday will impact the East and Southeast today. A shortwave will move out of the Tennessee Valley into the Mid-Atlantic this afternoon. At the same time, afternoon heating will have taken place coupled with a feed of rich moisture into the region. This will allow a severe threat to exists from Georgia into the Carolinas and north into New York. The Storm Prediction Center (SPC) has an enhanced risk of severe storms from eastern Georgia to southern Virginia (see Fig. 1 & 2). Cities within the enhanced risk are: Charlotte, NC; Raleigh, NC; and Virginia Beach, VA. A slight risk exists from eastern Alabama up to New York.

Fig. 1: SPC’s thunderstorm outlook map for Thursday
Fig. 2: SPC’s thunderstorm outlook map for Thursday (Carolina emphasis)

Afternoon convection should develop just after the lunchtime hour along and just east of your eastern mountain chain and move east (see Fig. 3). As storms move east by mid to late afternoon, they will organize into clusters across the Southeast & Mid-Atlantic (see Fig. 4).

Fig. 3: Future radar early afternoon
Fig. 4: Future radar mid to late afternoon

The main hazards are damaging winds, flash flooding, large hail and isolated tornadoes (see Fig. 5, 6, 7). There is an enhanced risk for damaging wind gusts from southern Virginia down to eastern Georgia where wind gusts of 70-80mph are possible.

Fig. 5: Tornado probability
Fig. 6: Wind probability
Fig. 7: Hail probability

Make sure you have a plan in place this afternoon and stay weather aware! Take severe thunderstorm warnings as seriously as tornado warnings.

More Rain & Flooding For Parts Of The Southeast

It has been very wet across the Southeast over the past few days and more rain is in the forecast. Periodic tropical downpours will occur across the Southeast this evening through tomorrow (Monday). The best chance for flash flooding will occur in northern Georgia, upstate South Carolina, eastern Tennessee and western/central North Carolina on Monday (see Fig. 1).

Fig. 1: Excessive rainfall forecast on Monday (WPC) [Best chance for flooding is in yellow-shaded region]

Late Monday into Tuesday, a cold front will push into the Southeast. Along the cold front, a line of showers and thunderstorms is possible, which could dump brief but heavy rain. Luckily, behind the cold front, drying will take place (see Fig. 2), which will briefly put an end to most shower and thunderstorm activity for a large part of the Southeast (other than coastal areas of the Carolinas/Georgia and Florida where heavy rain may lead to flooding (see Fig. 3)).

Fig. 2: Dry air behind cold front on Tuesday (Tropical Tidbits) [Drier air is represented by the brown colors]
Fig. 3: Excessive rainfall forecast on Tuesday (WPC) [Best chance for flooding is in yellow-shaded region]

The drier airmass behind the cold front will be temporary. On Wednesday, a trough will push into the region (see Fig. 3) allowing a low to develop across northern Florida/southern Georgia. This low will intensify and lift northeast. This will pull Gulf moisture back into the Southeast (see Fig. 4) increasing rain chances for the Southeast Wednesday into Thursday. Some of this rain will be heavy, which will exacerbate the flooding issues in Georgia and the Carolinas on both Wednesday and early Thursday.

Fig. 3: Trough moving into the eastern U.S. early Wednesday (Tropical Tidbits) [Trough is represented by cool-colors moving into Mississippi Valley]
Fig. 4: Moist Gulf air pulled back into Southeast on Wednesday (Tropical Tidbits) [Moist air represented by the yellow and green colors]

Additional rain accumulations of 3-6″ are likely through Thursday for Florida, eastern Georgia, central and eastern South Carolina and much of North Carolina (see Fig. 5).

Fig. 5: Additional rainfall accumulations next 7-days (WPC)

A gradual drying trend will take place from Thursday night into the weekend for the Southeast. Remember, if you come across a road that is covered in water, turn around!

Heavy Rain & Flooding Possible From Texas To The Carolinas

The tropical disturbance we mentioned over the weekend is still spinning over the southwest Gulf of Mexico (see Fig. 1). Proximity to land and moderate to high shear should keep this disturbance from intensifying into a tropical depression or tropical storm. The National Hurricane Center (NHC) has lowered the probability of this disturbance developing into a tropical cyclone to 40% (see Fig. 2).

Fig. 1: Tropical disturbance in southwestern Gulf of Mexico
Fig. 2: NHC development probabilities

Regardless of development, deep tropical moisture will move into the South-Central and Southeastern U.S. this week (see Fig. 3). Today through Thursday, Texas, Oklahoma, Louisiana and Arkansas will have the best shot to see heavy rain. (It should be noted, Florida and the coastal areas of Georgia and South Carolina may see some thunderstorms during this time-frame, too, do to a front lying across the area.) The heavy rain will shift east into Mississippi, Tennessee and Alabama by Thursday into Friday; followed by a shift east into Georgia and the Carolinas over the weekend into early next week.

Fig. 3: Precipitable water values

Widespread heavy rain accumulations are likely from Tuesday through Monday for Texas east into the Carolinas. 3-6″ of rain will be common in these areas with isolated higher amounts (see Fig. 4 & 5).¬†Flooding will become a concern. It should also be noted, the rivers and streams in the lower-Mississippi Valley are very high due to upstream runoff. The rain this week will exacerbate the swelling rivers/streams in Mississippi and Louisiana.

Fig. 4: WPC’s rainfall forecast next 7 days
Fig. 5: WPC’s rainfall forecast next 7 days (Southeast focus)

Please remember, always turn around if you drive upon a road that has water covering the roadway. 

Barry Developing In The Gulf?

Firsthand Weather is keeping a close eye on an area of convection in the Bay of Campeche (BOC) for tropical development over the next few days (see Fig. 1). This area of convection is expected to continue to organize over the next 24-48 hours as it moves west-northwest. The environment in the BOC is favorable for development. The environmental shear is weak (see Fig. 2), there’s decent upper-level divergence (see Fig. 3) and low-level convergence (see Fig. 4). These three variables will allow this area of convection to organize quickly as long as the area of convection can remain over water long enough.

Fig. 1: Area of convection over the BOC
Fig. 2: Environmental shear (University of Wisconsin)
Fig. 3: Upper-level divergence (University of Wisconsin)
Fig. 3: Low-level convergence (University of Wisconsin)

The National Hurricane Center (NHC) has given this area of convection a 40% chance of tropical development over the next 48 hours and a 50% chance of tropical development over the next 5 days (see Fig. 5). A west-northwest motion over the weekend looks likely due to a ridge to the north over the Gulf States (see Fig. 6). This should allow Barry (?) to make landfall in Mexico early next week. The limited time over water should allow Barry (or the area of disturbed weather if Barry doesn’t develop) to remain relatively weak. The ridge that will force the west-northwest movement will begin to breakdown and move east as a trough moves into central parts of the U.S. by mid-week.

Fig. 6: NHC’s % chance of development
Fig. 6: Upper-level pattern early next week
Fig. 6: Upper-level pattern mid next week

This will allow a northward movement of moisture from Barry (?) into Texas and Oklahoma as the trough picks it up (see Fig. 7). As the trough continues moving east into the Southeast by late-week, moisture from this system will be carried into the Southeast (see Fig. 8).

Fig. 7: Moisture moving into Texas mid next week

It appears all of the Gulf States have a chance to see an increase in instability and moisture mid to late next week, which will increase rain chances. Please keep in mind, this forecast is fluid. Forecasting undeveloped tropical cyclones is very difficult so changes to this forecast are likely. All interests along the coast of Mexico and Gulf Coast States need to keep a close eye on the evolution of this system.