Invest 95L Drenches Tampa Bay

Invest 95L slams Tampa Bay with training showers and embedded storms Monday. The weak area of low pressure over north central Florida only has a 10% chance of tropical depression develop as the center is over land and this is a sheared system. It is moving northeast. With that being said there is no shortage of plentiful tropical moisture an organized complex of rain and storms developed overnight and shows no signs of letting up anytime soon..An onshore flow brings catastrophic flooding to parts of the Tampa Bay area. As of Monday morning 4-7+” have fallen especially in very saturated west Pasco county, north Pinellas county and northwest and central Hillsborough county.  Monday is the 21st day in a row with at least a trace of rain recorded at Tampa International. Two out of the last three days have seen major flooding on roadways in South Tampa.

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Rivers like the Anclote River at Elfers in Pasco county receeded late last week but 6+” has fallen Monday morning alone. In just a few hours Monday the river will skyrocket from a moderate flood stage to a major flood stage. As of 9:15 AM Monday it sits at 21.93 feet and will rise another 4+feet by tonight especially with rain continuing to fall. The river is forecast to crest at over 26 feet. The last time this happened was in 2012 during Tropical Storm Debby. The river crested at 26.81 feet on June 26, 2012.

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Invest 94L Fizzles in the Atlantic; Guillermo Eyes Hawaii in the Pacific

Welcome to August the second busiest month of the Atlantic Hurricane season. Cape Verde season typically heats up later this month when the strongest named storms of the season originate near Africa. 27% of named storms typically form during August. Pretty much anywhere in the Atlantic Basin is fair game for tropical cyclone formation. With that being said, a strengthening El Niño may play a role in lowering the number of named storms this month. Water temperatures are still a few degrees below average in the main development region. Wind shear is still incredibly high in the southern Caribbean and the Saharan Air Layer remains active in the Atlantic. Officially no tropical depression development is expected over the next 5 days.

Climatology August

It hung on for a few days but dry, dusty air takes a toll on Invest 94L. It was a long shot anyways but no tropical development is expected as the weak area of low pressure moves westward.

Floater IR Enhanced to Formation Potential

Water vapor imagery shows dry air in the central Atlantic and east Caribbean. If more tropical waves roll off the coast Africa as they typically do this time of year, and as some long-range models suggest, this environment may moisten somewhat. For now all is quiet.

Water Vapor Floater

This is about a week and a half to two weeks away but the GFS suggests two healthy tropical waves are worth watching between the Lesser Antilles and Africa. Both head west-northwest. The Euro is less impressed.

gfs_atl_winds_85

In the east Pacific all eyes are on Hurricane Guillermo. The category two hurricane makes a b line for Hawaii and the 11 AM advisory from the NHC brings it just north of the Big Island Thursday morning as a minimal tropical storm. The good news is the environment in its path does not favor further strengthening and it will gradually weaken over the next few days. Models disagree quiet a bit on the long-range track of Guillermo and interest in Hawaii need to keep an eye on this system. Squalls and rough surf could reach the Big Island by late Wednesday.

Floater IR Enhanced

Phailin

Some Signs of Life in the Atlantic; Pacific Heating up as Well

The stalled frontal boundary off the east coast and over the Florida Peninsula continues to bring heavy rain to the state. Parts of Central Florida have seen 12″-18″ of rain since Friday morning, and more is on the way. The European model is rather bullish on rainfall estimates over the next few days, depicting several inches in some locations near Tampa Bay. Flooding in this area will likely continue to be an issue.

US 100km Euro Futurecast-Precip Acc

Meanwhile, along that frontal boundary a weak area of low pressure has formed and meandered into the western Atlantic. While water temperatures are warm, wind shear is not conducive to tropical development. Many of the models have tried to form more areas of low pressure along that front over the coming days. However, nothing tropical is expected at this point to come of that. The European model keeps a broad area of low pressure along the front through the weekend.

ECMWF MSL and Precip Rate

Meanwhile, as we get deeper into the summer, we are getting closer to our Cape Verde storm season. And just like that, we are monitoring Invest 94L in the eastern Atlantic – a weak tropical wave with some general cloudiness and convection. The National Hurricane Center gives Invest 94L a low (20%) chance to develop by Monday morning as it tracks westward.

Floater IR Enhanced to Formation Potential

At this point in the season, there is still too much dry air across the Atlantic basin for a tropical wave to survive the entire track across the Atlantic. A look at the Saharan Air Layer (via University of Wisconsin) shows a fairly robust wave of dry air traversing the basin.

saharan air layer

In addition to an active SAL, wind shear remains moderate over the storm and across the Atlantic. Finally, an issue that will plague 94L as well as many storms in the Atlantic this year is the ocean temperature. Sea surface temperatures across the Atlantic, especially along the main development region, are well below average. SST anomalies are 1°-2° below average in this basin.

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Across the globe in the Pacific, things have been temporarily quiet for the last week or so, a condition not all that uncommon for this time of the year. However, there are several areas of interest that must be monitored in the coming days.

Floater IR Enhanced2

The first area to note above is Tropical Depression Eight-E. While weak, the storm may still pose a risk to interests near the Hawaiian Islands toward the weekend. Most models at this point take the storm as a weak tropical depression south of the Islands but it will still need to be monitored.

Tropical Depression 8E Models

The bigger area of concern across the Pacific is the area of low pressure just southeast of T.D. 8-E. This disturbance is being given a 60% chance to develop by Friday morning, and a 90% chance to develop over the next 5 days. If it does develop, most of the models keep is on a straight westward path toward the Hawaiian Islands, potentially arriving at some point early-to-mid next week. Regardless of strength at that point, the storm would still pose a threat to the island chain. We will have to monitor this disturbance closely.

Invest 91L Models

Long Spell of Wet Weather Continues For Tampa Bay; Tropical Moisture Lingers

The trough we’ve been watching for a few days continues to dump intervals of tropical downpours in central Florida. A stubborn area of low pressure has slowly drifted north over north central Florida and will meander for a while longer and stay weak.  Another low sits over the western Atlantic and may organize bit as it drifts northeast Wednesday and Thursday. As of Tuesday afternoon tropical depression development still looks unlikely due to moderate to high northeasterly shear. Wind shear values are a bit lower near the west Atlantic low se we’ll continue to monitor. Officially the National Hurricane Center does not highlight this sheared system for tropical development over the next five days. Abundant tropical moisture will aid in more waves of heavy rain through the weekend in Tampa Bay.

Florida Satellite-Radar Weekend AM

High 20-40 kt northeasterly shear pushes a steady complex of thunderstorms east of Tampa Bay associated with a weak area of low pressure. The second low over the Atlantic also battles north and northeasterly shear. The graphic below is courtesy the University of Wisconsin at Madison.

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Water vapor imagery also shows two distinct disorganized complexes of moisture/showers and storms due to hostile upper level winds. There was some drying in the mid levels of the atmosphere inland south of Tampa Bay so rainfall coverage wasn’t as widespread Tuesday.

Florida WV - ICON

While the odds for tropical depression development near the Gulf coast states is unlikely in the coming days a moist air mass fuels more pockets of heavy rain through the weekend (possibly early next week) in Tampa Bay. Parts of northern Pinellas and southwest Pasco county have seen 10-12+” of rainfall since last Friday. Officially at Tampa International Airport over six and half inches have been recorded since Friday with more on deck. Additional rain will lead to flooding in the most saturated areas. A Flood Watch has been extended for parts of Tampa Bay through Wednesday evening.

Rainfall Accumulations

 

More Tropical Downpours For Central Florida; Tropical Development Still Unlikely at This Time

The combination of a weak area of low pressure, an upper level trough and deep tropical moisture has brought a spell of wet weather/flooding to coastal east central Florida. More rain is on the way too. Hostile upper level winds will likely prevent any tropical characteristics from forming. This area of low pressure is nearly stationary in the Gulf and if anything will slowly lift north over the Sunshine State in the coming days. Whatever is ”left” of this feature may drift into the west Atlantic later this week. Overall upper level winds are not conducive for tropical depression development during this time. There is also some dry air in the mid levels of the atmosphere just north of the area of low pressure. Water temperatures are certainly warm enough, though. Officially no tropical depression development is expected over the next five days per the National Hurricane Center. We’ll continue to monitor.

Florida Satellite-Radar Weekend AM

Wind shear data from the University of Wisconsin shows moderate to high 20-30 kt northeasterly shear over the east Gulf low Tuesday afternoon.

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The heavy rain/flooding threat is a big concern through at least mid-week with plenty of deep tropical moisture in place. Since Friday 5-10″+ has fallen in the hardest hit areas.10+ of rain has fallen in Pasco county. Several more inches of rain are possible mainly near the coast in Tampa Bay through at least mid-week. The graphic below shows the RPM model suggests up to an addition 7+ of rain for west Pasco and Pinellas county through Thursday morning (this may be a little overdone).

US 100km Euro Futurecast-Precip Acc

Heavy Rain Continues in Central & South Florida; Tropical Development Not Expected Along Stalled Front

A weak area of low pressure has developed along a stalled front in the eastern Gulf just west of Tampa Bay Sunday. Tropical development isn’t expected at this time and this feature will remain weak. The National Center says there is a 0% chance of tropical depression development over the next 5 days. Computer models were very inconsistent with the possible future strength of this low. The area of low pressure only slowly meanders north and west into mid-week before it moves inland. It will help to ignite more tropical downpours in central and south Florida especially near the coast.

Southeast Satellite-Radar Weekend AM Florida Visible Satellite

The Weather Prediction Center and computer models keep the highest rainfall totals right along the immediate coast in Tampa Bay and southwest Florida. Up to 5″ is possible here by Wednesday morning. Drought stricken southeast Florida will also see tropical downpours/storms. Rainfall totals in this part of the state will be less impressive.

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Wet Weekend In Central Florida; Watching Stalled Front

A deep trough/frontal boundary moves into central Florida and stalls this weekend . Flooding is expected for parts of Tampa Bay with training showers and storms. We’re keeping an eye on this boundary as it can serve as the focal point for a tropical/subtropical system especially over warm gulf stream waters in the west Atlantic. Models have been back and forth on this possibility for about a week and there is a lot of inconsistency. Officially as of Saturday morning there is a 10% chance of subtropical or tropical cyclone development over the next five days so these odds remain low. Wet weather will linger in central Florida through much of the work week and beyond so if this boundary remains intact it’s worth keeping an eye on. The 0Z Euro backed off on tropical storm development but the 12Z Friday was quite aggressive with a hurricane east of the Carolinas Friday. The GFS has been less impressed but still keeps pressure generally low near Florida. It wouldn’t be out of the norm for something tropical to briefly spin up in the northern Gulf or Atlantic. As of Saturday the odds still remain low. We’ll continue to watch.

Florida Satellite-Radar Weekend AM

Floater IR Enhanced to Formation Potential

 

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Watching Stalled Front near Southeast Coast This Weekend/Next Week

Yet another frontal boundary stalls over the extreme western Atlantic and the Southeast U.S./north Florida late in the weekend. This brings an extended period of wet weather to north and central Florida. As mentioned in previous blogs this frontal boundary is worth watch for tropical development especially over warm Gulf stream waters early next week. Model runs have varied quite a bit. The GFS has not been overly impressed. The reliable European model suggests tropical development over the western Atlantic  mid-week next week. The possible low may be guided northeast by high pressure to its south. The graphic below shows the 0Z ECMWF next Thursday afternoon with a tropical storm forming south of the Carolinas. The new 12Z run backs off on this possibility.

ECMWF MSLP and Precip Rate

As we’ve seen with Ana and most recently Claudette warm west Atlantic/gulf stream waters can serve as breeding grounds for a tropical depression/tropical storm. This is still a ways out and models may continue to change. The next named storm is Danny. Officially per the NHC no tropical cyclone development is expected through Monday afternoon. The mid and long-range forecast is worth keeping an eye on.

Floater Water Temperatures

Meanwhile in the east Pacific Invest 99L still has not reach tropical depression strength. The odds are still high, though. By Friday the disturbance moves into waters cooled from former tropical storm Dolores and weakens. It is no threat to land.

Floater IR Enhanced

 

July Winds Down in the Atlantic

Only a week and half remains in the second month of the 2015 Atlantic Hurricane season. With the exception of short-lived Claudette in the northwest Atlantic July has been a quiet month. This is to be expected especially in a strengthening El Niño year. Through the remainder of the month the Gulf of Mexico, western Atlantic and even the southern Atlantic feature named storm development since 1851. Only 49 named storms have formed in the entire Atlantic Basin from July 21-31st since 1851.

MyFoxHurricane Google Earth

Water temperatures in the main development region in the southern Atlantic are still below average in spots but they are showing some signs of warming. There is still a pocket of water temperatures running 1 °C below average as evident on the sea surface temperature anomalies map below. We shift our focus to the Atlantic and eastern Caribbean for tropical cyclone development in August. Water temperatures may still be running somewhat cool for August during this time.

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Two of the three named storms (Ana & Claudette) in 2015 have been short-lived and both formed closer to home over warm Gulf stream waters. Models have been back and forth about this possibility yet again late this work week or early next week. Nothing is concrete but a frontal boundary off the Southeast coast is worth watch for low pressure (possibly tropical nature) to develop along it. The 12Z GFS spins up a weak low Friday evening of the Carolinas. This heads out to sea into an environment of unfavorable upper level winds. The new Euro shows a similar setup but the low meanders over the extreme western Atlantic for a few days. Officially per the NHC no tropical depression development is expected through Sunday afternoon.

GFS Wind Shear

It still looks promising for Invest 99E to become the next tropical depression in the east Pacific. The broad low moves northwest into a region of lighter upper level winds. This future tropical cyclone will dissipate late in the weekend or early next week over cooler Pacific waters.

Floater IR Enhanced

Showers from Former Dolores Continue in the Southwest U.S.; Quiet For Now in the Atlantic

In rare July fashion moisture from the remnants of former Hurricane Dolores (in the east Pacific) bring more rainfall to parts of California and the Southwest. While moisture content/rainfall totals aren’t as impressive as they were over the weekend this is still unusual nonetheless. A Flash Watch is in effect from central California to southeast Nevada through Monday evening due to a heavy rain threat and possible mudslides near mountainous terrain. Showers are possible again Tuesday. July is typically the driest month of the year in places in like Los Angeles. Over the weekend .36″ fell making it the wettest July on record (since 1886).

Floater Satellite-Radar Weekend AM

Hostile wind shear and pockets of dry air keep the Atlantic Basin tranquil Monday. Officially no tropical cyclone development is expected through Saturday per the National Hurricane Center. As mentioned in Sunday’s blog the extreme western Atlantic along warm gulf stream waters has been the focal point for two named storms in 2015: Ana and most recently short-lived Claudette. With an active frontal pattern into early next week this area is worth keeping an eye. Water temperatures are in the mid 80s.

Floater Water Temperatures

It’s a ways off but the 0Z Euro still suggests a few areas of low pressure possibly tropical in nature may spin up along a stalled/old frontal boundary early next week. The low in the western Atlantic looks like a fair bet for long-range tropical depression/storm development. This possible low would move northeast away for the U.S. and out to sea over cooler waters into the middle of next week. 12Z GFS suggests a few weak areas of low pressure along this same boundary in the western Atlantic Friday and again mid-week next week. We’ll keep an eye things as most of these solutions are over a week away.

ECMWF MSLP and Precip Rate