National Hurricane Center (NHC) Pacific Map

000
ABPZ20 KNHC 271107
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Mon Sep 27 2021

For the eastern North Pacific...east of 140 degrees west longitude:

An area of low pressure is expected to form several hundred miles
offshore the southwestern coast of Mexico by midweek. Environmental
conditions could be conducive for some gradual development of this
system during the latter parts of the week while it moves slowly
northwestward or northward, remaining well offshore the southwestern
coast of Mexico.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...30 percent.

$$
Forecaster Latto

000
ABPZ20 KNHC 201134
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Mon Sep 20 2021

For the eastern North Pacific...east of 140 degrees west longitude:

An area of low pressure is forecast to form several hundred miles
southwest of the southern tip of the Baja California peninsula
within the next couple of days. Thereafter, some gradual
development of this system is possible, and a tropical depression
could form by the latter part of this week while it moves
west-northwestward to northwestward at 10 to 15 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...40 percent.

$$
Forecaster Latto

000
ABPZ20 KNHC 171115
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Fri Sep 17 2021

For the eastern North Pacific...east of 140 degrees west longitude:

Tropical cyclone formation is not expected during the next 5 days.

$$
Forecaster Brown

000
ABPZ20 KNHC 141739
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Tue Sep 14 2021

For the eastern North Pacific...east of 140 degrees west longitude:

Tropical cyclone formation is not expected during the next 5 days.

$$
Forecaster Brown

139
ABPZ20 KNHC 131136
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Mon Sep 13 2021

For the eastern North Pacific...east of 140 degrees west longitude:

Showers and thunderstorms have increased overnight in association
with an elongated area of low pressure located more than 100 miles
southwest of Acapulco, Mexico. Environmental conditions are
marginally conducive for development, and a tropical depression
could form during the next couple of days while it moves westward
or west-northwestward just offshore of the coast of southern
Mexico. Regardless of development, this system will likely produce
heavy rains across portions of southern and southwestern Mexico
through Tuesday.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...40 percent.

$$
Forecaster Brown/Hagen

5-Day Uncertainty Track last updated Fri, 10 Sep 2021 14:51:49 GMT


Wind Speed Probabilities last updated Fri, 10 Sep 2021 15:28:53 GMT

Issued at 900 AM MDT Fri Sep 10 2021 000 WTPZ45 KNHC 101450 TCDEP5 Tropical Storm Olaf Discussion Number 12 NWS National Hurricane Center Miami FL EP152021 900 AM MDT Fri Sep 10 2021 The satellite presentation of Olaf has significantly degraded over the past several hours after the center moved across the southern portion of Baja California Sur overnight. The system's organized convection has collapsed, and infrared satellite imagery indicates cloud top temperatures are rapidly warming near the estimated center position. The initial intensity is lowered to 60 kt for this advisory, which now makes Olaf a tropical storm. This estimate may still be generous, but limited surface observations and radar data make it difficult to confidently assess the intensity. Hopefully, scatterometer data this afternoon will provide more insight into changes in Olaf's surface wind field. The tropical storm has slowed down a bit since last night, and its estimated motion is northwest (310 degrees) at 9 kt. Recent microwave imagery suggests the center of Olaf is just offshore the southwestern coast of Baja California Sur, and the cyclone is likely to move roughly parallel to the coast today. Then, a strong mid-level high pressure ridge centered over the southern Rockies is expected to build westward to the north of Olaf. This ridge should turn Olaf toward the west by tonight, and then toward the southwest through early next week. The official NHC track forecast has been adjusted to the south of the previous forecast once again, in agreement with the latest multi-model consensus aids. Olaf is likely to continue rapidly weakening during the next couple of days. In the short-term, its proximity to the mountainous terrain of the Baja California peninsula will disrupt its ability to sustain organized convection. As Olaf moves away from land, the cyclone will encounter decreasing sea-surface temperatures and very dry mid-level air, which should expedite its transition into a post-tropical cyclone. In fact, the latest GFS and ECMWF model simulated satellite imagery show Olaf becoming completely devoid of convection within the next 24-36 h. The latest NHC intensity forecast shows more rapid weakening than the previous one, primarily based on recent satellite trends and the lower initial intensity. The official forecast remains below the HCCA and IVCN consensus aids, which are inflated by the SHIPS and LGEM models that fail to weaken Olaf during the next 24 h. Key Messages: 1. Olaf is forecast to move along the southwestern coast of the Baja California peninsula today, with tropical storm conditions continuing over southern portions of Baja California Sur through this evening. These winds should diminish tonight as Olaf continues weakening and turns westward away from land. 2. Heavy rains associated with Olaf are expected across portions of southern Baja California Sur through today. This will pose a threat of significant and life-threatening flash flooding and mudslides. FORECAST POSITIONS AND MAX WINDS INIT 10/1500Z 24.1N 111.3W 60 KT 70 MPH 12H 11/0000Z 24.5N 112.4W 50 KT 60 MPH 24H 11/1200Z 24.6N 113.6W 40 KT 45 MPH 36H 12/0000Z 24.3N 114.7W 35 KT 40 MPH...POST-TROPICAL 48H 12/1200Z 23.4N 115.9W 30 KT 35 MPH...POST-TROP/REMNT LOW 60H 13/0000Z 22.4N 117.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 13/1200Z 21.6N 118.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 14/1200Z 20.7N 121.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 15/1200Z 20.0N 123.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Reinhart

Issued at 1500 UTC FRI SEP 10 2021 000 FOPZ15 KNHC 101448 PWSEP5 TROPICAL STORM OLAF WIND SPEED PROBABILITIES NUMBER 12 NWS NATIONAL HURRICANE CENTER MIAMI FL EP152021 1500 UTC FRI SEP 10 2021 AT 1500Z THE CENTER OF TROPICAL STORM OLAF WAS LOCATED NEAR LATITUDE 24.1 NORTH...LONGITUDE 111.3 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 60 KTS...70 MPH...110 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) PACIFIC DAYLIGHT TIME (PDT)...SUBTRACT 7 HOURS FROM Z TIME HAWAIIAN STANDARD TIME (HST)...SUBTRACT 10 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 12Z FRI AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 12Z FRI 00Z SAT 12Z SAT 00Z SUN 12Z SUN 12Z MON 12Z TUE PERIODS TO TO TO TO TO TO TO 00Z SAT 12Z SAT 00Z SUN 12Z SUN 12Z MON 12Z TUE 12Z WED FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT LA PAZ 34 99 X(99) X(99) X(99) X(99) X(99) X(99) 25N 115W 34 1 5( 6) 9(15) 2(17) X(17) X(17) X(17) 20N 120W 34 X X( X) X( X) X( X) 1( 1) 2( 3) X( 3) $$ FORECASTER REINHART

Issued at 900 AM MDT Fri Sep 10 2021 000 WTPZ35 KNHC 101448 TCPEP5 BULLETIN Tropical Storm Olaf Advisory Number 12 NWS National Hurricane Center Miami FL EP152021 900 AM MDT Fri Sep 10 2021 ...TROPICAL STORM OLAF BRINGING STRONG WINDS AND HEAVY RAINS TO PORTIONS OF BAJA CALIFORNIA SUR... ...EXPECTED TO MOVE AWAY FROM LAND TONIGHT... SUMMARY OF 900 AM MDT...1500 UTC...INFORMATION ---------------------------------------------- LOCATION...24.1N 111.3W ABOUT 65 MI...100 KM W OF LA PAZ MEXICO ABOUT 80 MI...130 KM SE OF CABO SAN LAZARO MEXICO MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...990 MB...29.24 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Mexico has changed the Hurricane Warning to a Tropical Storm Warning for Baja California Sur Mexico from Todos Santos to Cabo San Lazaro. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Baja California Sur Mexico from Puerto San Andresito southward and around the peninsula to Loreto A Tropical Storm Warning means that tropical storm conditions are expected or occurring somewhere within the tropical storm warning area. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 900 AM MDT (1500 UTC), the center of Tropical Storm Olaf was located near latitude 24.1 North, longitude 111.3 West. Olaf is moving toward the northwest near 10 mph (17 km/h). A turn toward the west at a slower forward speed is expected tonight, followed by a turn toward the southwest on Saturday night and Sunday. On the forecast track, the center of Olaf will move along the southwestern coast of Baja California Sur today and then move westward away from land by tonight. Maximum sustained winds have decreased to near 70 mph (110 km/h) with higher gusts. Additional weakening is expected during the next couple of days, and Olaf is forecast to degenerate to a post-tropical cyclone on Saturday and weaken to a remnant low on Saturday night. Tropical-storm-force winds extend outward up to 70 miles (110 km) from the center. The estimated minimum central pressure is 990 mb (29.24 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Olaf can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP5 and WMO header WTPZ45 KNHC and on the web at hurricanes.gov/graphics_ep5.shtml?key_messages WIND: Tropical storm conditions are occurring within portions of the tropical storm warning area and will spread northward across central portions of Baja California Sur today. Tropical storm conditions should end over Baja California Sur by tonight. RAINFALL: Olaf is expected to produce total rainfall amounts of 5 to 10 inches with maximum amounts of 15 inches across portions of southern Baja California Sur through today. This rainfall may trigger significant and life-threatening flash flooding and mudslides. STORM SURGE: Storm surge is expected to produce coastal flooding in regions of onshore winds within the warning area. Near the coast, the surge will be accompanied by large and damaging waves. SURF: Swells generated by Olaf are affecting portions of the coasts of southern Baja California Sur, Nayarit, and Sinaloa, and will spread northward along the west coast of Baja California Sur through Saturday. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 1200 PM MDT. Next complete advisory at 300 PM MDT. $$ Forecaster Reinhart

...TROPICAL STORM OLAF BRINGING STRONG WINDS AND HEAVY RAINS TO PORTIONS OF BAJA CALIFORNIA SUR... ...EXPECTED TO MOVE AWAY FROM LAND TONIGHT... As of 9:00 AM MDT Fri Sep 10 the center of Olaf was located near 24.1, -111.3 with movement NW at 10 mph. The minimum central pressure was 990 mb with maximum sustained winds of about 70 mph.

Issued at 1500 UTC FRI SEP 10 2021 007 WTPZ25 KNHC 101447 TCMEP5 TROPICAL STORM OLAF FORECAST/ADVISORY NUMBER 12 NWS NATIONAL HURRICANE CENTER MIAMI FL EP152021 1500 UTC FRI SEP 10 2021 CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY... THE GOVERNMENT OF MEXICO HAS CHANGED THE HURRICANE WARNING TO A TROPICAL STORM WARNING FOR BAJA CALIFORNIA SUR MEXICO FROM TODOS SANTOS TO CABO SAN LAZARO. SUMMARY OF WATCHES AND WARNINGS IN EFFECT... A TROPICAL STORM WARNING IS IN EFFECT FOR... * BAJA CALIFORNIA SUR MEXICO FROM PUERTO SAN ANDRESITO SOUTHWARD AND AROUND THE PENINSULA TO LORETO A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED OR OCCURRING SOMEWHERE WITHIN THE TROPICAL STORM WARNING AREA. TROPICAL STORM CENTER LOCATED NEAR 24.1N 111.3W AT 10/1500Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 310 DEGREES AT 9 KT ESTIMATED MINIMUM CENTRAL PRESSURE 990 MB MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT. 50 KT....... 20NE 30SE 30SW 20NW. 34 KT....... 50NE 50SE 60SW 50NW. 12 FT SEAS.. 90NE 0SE 45SW 0NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 24.1N 111.3W AT 10/1500Z AT 10/1200Z CENTER WAS LOCATED NEAR 23.9N 110.9W FORECAST VALID 11/0000Z 24.5N 112.4W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 20NE 10SE 10SW 20NW. 34 KT... 40NE 40SE 40SW 40NW. FORECAST VALID 11/1200Z 24.6N 113.6W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 30NE 20SE 20SW 30NW. FORECAST VALID 12/0000Z 24.3N 114.7W...POST-TROPICAL MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 20NE 0SE 20SW 20NW. FORECAST VALID 12/1200Z 23.4N 115.9W...POST-TROP/REMNT LOW MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 13/0000Z 22.4N 117.3W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 13/1200Z 21.6N 118.6W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 100 NM ON DAY 4 AND 125 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 14/1200Z 20.7N 121.0W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. OUTLOOK VALID 15/1200Z 20.0N 123.0W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 24.1N 111.3W INTERMEDIATE PUBLIC ADVISORY...WTNT35 KNHC/MIATCPEP5...AT 10/1800Z NEXT ADVISORY AT 10/2100Z $$ FORECASTER REINHART

000
ABPZ20 KNHC 101116
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Fri Sep 10 2021

For the eastern North Pacific...east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Hurricane
Olaf, located over southern Baja California Sur, Mexico.

A large area of disorganized showers and thunderstorms near the
Pacific coast of Central America and the adjacent waters are
associated with the southern portion of a tropical wave. A broad
area of low pressure is expected to form along this wave south of
the southern coast of Mexico during the next day or two, and the low
could then develop further into a tropical depression late this
weekend or early next week while it moves west-northwestward or
northwestward near the southern and southwestern coasts of Mexico.
Regardless of development, this system is likely to produce heavy
rains across portions of Central America and southern Mexico during
the next few days.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...medium...60 percent.

$$
Forecaster Cangialosi

963
ABPZ20 KNHC 011138
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Wed Sep 1 2021

For the eastern North Pacific...east of 140 degrees west longitude:

Tropical cyclone formation is not expected during the next 5 days.

$$
Forecaster Papin

5-Day Uncertainty Track last updated Fri, 27 Aug 2021 17:35:02 GMT


Wind Speed Probabilities last updated Fri, 27 Aug 2021 15:28:47 GMT

Issued at 100 PM CDT Fri Aug 27 2021 000 WTPZ34 KNHC 271734 TCPEP4 BULLETIN Tropical Storm Nora Intermediate Advisory Number 8A NWS National Hurricane Center Miami FL EP142021 100 PM CDT Fri Aug 27 2021 ...RAINBANDS FROM NORA CONTINUE TO SPREAD ONSHORE THE COAST OF SOUTHWESTERN MEXICO... ...FLASH FLOODS AND MUDSLIDES POSSIBLE THOUGH THE WEEKEND... SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION ---------------------------------------------- LOCATION...15.7N 104.6W ABOUT 240 MI...385 KM S OF MANZANILLO MEXICO ABOUT 610 MI...980 KM SE OF CABO SAN LUCAS MEXICO MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...997 MB...29.44 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Watch is in effect for... * Lazaro Cardenas to Cabo Corrientes Mexico A Tropical Storm Warning is in effect for... * Tecpan de Galeana to San Blas Mexico A Tropical Storm Watch is in effect for... * North of San Blas to Mazatlan Mexico A Hurricane Watch means that hurricane conditions are possible within the watch area, in this case within the next 36 hours. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. Interests elsewhere along the northwestern coast of mainland Mexico and southern portions of Baja California Sur should monitor the progress of Nora. Additional watches and warnings will likely be required for portions of these areas later today or tonight. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 100 PM CDT (1800 UTC), the center of Tropical Storm Nora was located near latitude 15.7 North, longitude 104.6 West. Nora is moving toward the northwest near 12 mph (19 km/h). A motion toward the northwest or north-northwest is expected through Monday. On the forecast track, the center of Nora will approach the southwestern coast of Mexico today and tonight and pass very near the coasts of the states of Colima, Jalisco, and Nayarit Saturday and Saturday night. Nora will then approach and move into the Gulf of California on Sunday and Monday. Maximum sustained winds are near 50 mph (85 km/h) with higher gusts. Strengthening is forecast during the next couple of days, and Nora is expected to become a hurricane on Saturday. Nora is a large tropical storm, and tropical-storm-force winds extend outward up to 230 miles (370 km) from the center. A ship near the coast of Mexico about 200 miles northeast of Nora's center recently reported winds of 48 mph (78 km/h). The estimated minimum central pressure is 997 mb (29.44 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Nora can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP4, WMO header WTPZ44 KNHC, and on the web at hurricanes.gov/graphics_ep4.shtml?key_messages. WIND: Hurricane conditions are possible within the hurricane watch area on Saturday. Tropical storm conditions are likely occurring over southern portions of the tropical storm warning area and will spread to northern portions of the warning area through Saturday evening. Tropical storm conditions are possible within the tropical storm watch area Saturday night and Sunday. RAINFALL: Heavy rain associated with Nora is expected across coastal sections of the Mexican states of Oaxaca, Guerrero, Michoacan, Colima, and Jalisco. Rainfall totals of 8 to 12 inches are forecast through this weekend with isolated maximum amounts of 20 inches possible. As Nora continues northwest, heavy rainfall will move into Baja California Sur late Sunday into Monday. Rainfall totals of 4 to 8 inches are forecast, with isolated maximum amounts of 12 inches possible. Life-threatening flash flooding and mudslides may occur. SURF: Swells generated by Nora are affecting the southern and southwestern coast of Mexico and will spread northward to the coast of Baja California Sur and into the Gulf of California over the weekend into early next week. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 400 PM CDT. $$ Forecaster Berg

...RAINBANDS FROM NORA CONTINUE TO SPREAD ONSHORE THE COAST OF SOUTHWESTERN MEXICO... ...FLASH FLOODS AND MUDSLIDES POSSIBLE THOUGH THE WEEKEND... As of 1:00 PM CDT Fri Aug 27 the center of Nora was located near 15.7, -104.6 with movement NW at 12 mph. The minimum central pressure was 997 mb with maximum sustained winds of about 50 mph.

000
ABPZ20 KNHC 271724
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Fri Aug 27 2021

For the eastern North Pacific...east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Tropical
Storm Nora, located a couple hundred miles south of Manzanillo,
Mexico.

Tropical cyclone formation is not expected during the next 5 days.

$$
Forecaster Roberts

Issued at 1000 AM CDT Fri Aug 27 2021 000 WTPZ44 KNHC 271435 TCDEP4 Tropical Storm Nora Discussion Number 8 NWS National Hurricane Center Miami FL EP142021 1000 AM CDT Fri Aug 27 2021 As was expected, vertical shear appears to be decreasing, with deep convection expanding over Nora's surface center just within the past few hours. Water vapor imagery also suggests an expansion of upper-level outflow to the north of the storm. Since Dvorak data-T numbers are 3.0/45 kt from TAFB and SAB, Nora's intensity is being held at that value for now. Nora has turned toward the northwest (310/10 kt) in response to a weakness in the subtropical ridge that has developed over the U.S. southern Rockies. Little change to this steering pattern is expected during the next several days, and Nora is forecast to move toward the northwest or north-northwest for the entire 5-day forecast period. Compared to the last few days, nearly all the track models now have Nora's center staying just offshore of Cabo Corrientes, Mexico, in about 36 hours. The GFS and HMON model fields still show a landfall in that area, but their interpolated trackers--which have been shifted to begin at our estimated initial position--also stay just offshore. After 36 hours, the track guidance has shifted slightly eastward, and the new NHC track forecast now keeps Nora's center over water up into the Gulf of California from days 2 through 5. That will be a small needle to thread, however, and any future shifts in the models could increase the risk of impacts to either the Baja California peninsula or the northwestern coast of mainland Mexico through the middle of next week. SHIPS model diagnostics indicate that the northeasterly deep-layer shear over Nora has decreased to about 15 kt, and this shear is expected to decrease further to below 10 kt in about 12 hours. Along with warm waters of about 29 degrees Celsius and significant upper-level divergence (at least for the next 36 hours), these conditions should foster strengthening, and Nora is still forecast to become a hurricane on Saturday. The part of the forecast after 48 hours remains uncertain depending on how much Nora interacts with land, but based on the new forecast that keeps the cyclone over water in the Gulf of California (where SSTs are even warmer -- around 31 degrees Celsius), Nora could maintain hurricane intensity through at least day 4. The NHC intensity forecast continues to hedge on the side of the ECMWF-based SHIPS and LGEM models, since most of the other models show Nora's center interacting with land to at least some degree. The new forecast has necessitated an extension of the Tropical Storm Warning northward to San Blas, Mexico, and the issuance of a new Tropical Storm Watch north of there to Mazatlan. Key Messages: 1. Nora is forecast to strengthen to a hurricane on Saturday while passing nearby the coasts of the Mexican states of Colima, Jalisco, and Nayarit, and hurricane watches and tropical storm warnings are in effect for portions of that coastline. Interests in these areas should closely monitor the progress of Nora and subsequent updates to the forecast. 2. Heavy rain associated with Nora is expected across coastal sections of the Mexican states of Oaxaca, Guerrero, Michoacan, Colima, and Jalisco, as well as Baja California Sur. Life-threatening flash flooding and mudslides may occur. 3. Nora is forecast to move over the Gulf of California as a hurricane early next week, bringing a risk of wind and rain impacts to portions of the Mexican states of Baja California Sur, Sinaloa, and Sonora. Given the above-average uncertainty in the forecast, it is still too soon to determine the magnitude and location of these potential impacts. FORECAST POSITIONS AND MAX WINDS INIT 27/1500Z 15.4N 104.3W 45 KT 50 MPH 12H 28/0000Z 16.3N 105.2W 50 KT 60 MPH 24H 28/1200Z 17.9N 105.9W 60 KT 70 MPH 36H 29/0000Z 19.9N 106.5W 65 KT 75 MPH 48H 29/1200Z 21.7N 107.4W 70 KT 80 MPH 60H 30/0000Z 23.1N 108.3W 75 KT 85 MPH 72H 30/1200Z 24.2N 109.1W 75 KT 85 MPH 96H 31/1200Z 26.1N 110.7W 65 KT 75 MPH 120H 01/1200Z 28.4N 111.7W 50 KT 60 MPH $$ Forecaster Berg

Issued at 1500 UTC FRI AUG 27 2021 000 FOPZ14 KNHC 271435 PWSEP4 TROPICAL STORM NORA WIND SPEED PROBABILITIES NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL EP142021 1500 UTC FRI AUG 27 2021 AT 1500Z THE CENTER OF TROPICAL STORM NORA WAS LOCATED NEAR LATITUDE 15.4 NORTH...LONGITUDE 104.3 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 45 KTS...50 MPH...85 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) PACIFIC DAYLIGHT TIME (PDT)...SUBTRACT 7 HOURS FROM Z TIME HAWAIIAN STANDARD TIME (HST)...SUBTRACT 10 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 12Z FRI AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 12Z FRI 00Z SAT 12Z SAT 00Z SUN 12Z SUN 12Z MON 12Z TUE PERIODS TO TO TO TO TO TO TO 00Z SAT 12Z SAT 00Z SUN 12Z SUN 12Z MON 12Z TUE 12Z WED FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT PUNTA EUGENIA 34 X X( X) X( X) X( X) X( X) 2( 2) 4( 6) P ABREOJOS 34 X X( X) X( X) X( X) 1( 1) 6( 7) 6(13) P ABREOJOS 50 X X( X) X( X) X( X) X( X) 1( 1) 2( 3) CABO SAN LUCAS 34 X X( X) 3( 3) 10(13) 36(49) 4(53) X(53) CABO SAN LUCAS 50 X X( X) X( X) X( X) 13(13) 2(15) X(15) CABO SAN LUCAS 64 X X( X) X( X) X( X) 4( 4) 1( 5) X( 5) SAN JOSE CABO 34 X X( X) 3( 3) 11(14) 43(57) 3(60) X(60) SAN JOSE CABO 50 X X( X) X( X) 1( 1) 17(18) 3(21) X(21) SAN JOSE CABO 64 X X( X) X( X) X( X) 6( 6) 1( 7) X( 7) LA PAZ 34 X X( X) X( X) 1( 1) 22(23) 12(35) 1(36) LA PAZ 50 X X( X) X( X) X( X) 4( 4) 5( 9) X( 9) LA PAZ 64 X X( X) X( X) X( X) 1( 1) 1( 2) X( 2) LORETO 34 X X( X) X( X) X( X) 5( 5) 14(19) 4(23) LORETO 50 X X( X) X( X) X( X) 1( 1) 4( 5) X( 5) P PENASCO 34 X X( X) X( X) X( X) X( X) 1( 1) 2( 3) HERMOSILLO 34 X X( X) X( X) X( X) X( X) 2( 2) 4( 6) BAHIA KINO 34 X X( X) X( X) X( X) 1( 1) 5( 6) 7(13) GUAYMAS 34 X X( X) X( X) X( X) 3( 3) 11(14) 8(22) GUAYMAS 50 X X( X) X( X) X( X) X( X) 2( 2) 3( 5) HUATABAMPO 34 X X( X) X( X) X( X) 5( 5) 12(17) 2(19) LOS MOCHIS 34 X X( X) X( X) 1( 1) 16(17) 11(28) 2(30) LOS MOCHIS 50 X X( X) X( X) X( X) 2( 2) 4( 6) X( 6) LOS MOCHIS 64 X X( X) X( X) X( X) X( X) 1( 1) X( 1) CULIACAN 34 X X( X) X( X) 3( 3) 21(24) 2(26) 1(27) CULIACAN 50 X X( X) X( X) X( X) 3( 3) 1( 4) X( 4) ISLAS MARIAS 34 X 5( 5) 38(43) 37(80) 2(82) X(82) X(82) ISLAS MARIAS 50 X X( X) 5( 5) 28(33) 3(36) X(36) X(36) ISLAS MARIAS 64 X X( X) 1( 1) 10(11) 1(12) X(12) X(12) MAZATLAN 34 X X( X) 8( 8) 30(38) 16(54) 1(55) X(55) MAZATLAN 50 X X( X) X( X) 4( 4) 7(11) X(11) X(11) MAZATLAN 64 X X( X) X( X) 1( 1) 1( 2) X( 2) X( 2) SAN BLAS 34 X 1( 1) 15(16) 14(30) 2(32) X(32) X(32) SAN BLAS 50 X X( X) X( X) 3( 3) X( 3) X( 3) X( 3) P VALLARTA 34 X 4( 4) 40(44) 4(48) 1(49) X(49) X(49) P VALLARTA 50 X X( X) 4( 4) 2( 6) X( 6) X( 6) X( 6) 15N 105W 34 99 X(99) X(99) X(99) X(99) X(99) X(99) BARRA NAVIDAD 34 1 39(40) 17(57) X(57) 1(58) X(58) X(58) BARRA NAVIDAD 50 X X( X) 3( 3) X( 3) X( 3) X( 3) X( 3) MANZANILLO 34 10 38(48) 8(56) 1(57) 1(58) X(58) X(58) MANZANILLO 50 X 2( 2) 1( 3) X( 3) X( 3) X( 3) X( 3) L CARDENAS 34 8 4(12) 2(14) X(14) X(14) X(14) X(14) ZIHUATANEJO 34 4 3( 7) 1( 8) X( 8) X( 8) X( 8) X( 8) 15N 110W 34 X 2( 2) 1( 3) X( 3) X( 3) X( 3) X( 3) 20N 110W 34 X 2( 2) 4( 6) 8(14) 5(19) X(19) X(19) ISLA SOCORRO 34 X 1( 1) 3( 4) 2( 6) 2( 8) X( 8) X( 8) 25N 115W 34 X X( X) X( X) X( X) 1( 1) 3( 4) 2( 6) $$ FORECASTER BERG

Issued at 1500 UTC FRI AUG 27 2021 000 WTPZ24 KNHC 271434 TCMEP4 TROPICAL STORM NORA FORECAST/ADVISORY NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL EP142021 1500 UTC FRI AUG 27 2021 CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY... THE GOVERNMENT OF MEXICO HAS ISSUED A TROPICAL STORM WARNING NORTH OF CABO CORRIENTES TO SAN BLAS MEXICO. A TROPICAL STORM WATCH HAS BEEN ISSUED NORTH OF SAN BLAS TO MAZATLAN MEXICO. SUMMARY OF WATCHES AND WARNINGS IN EFFECT... A HURRICANE WATCH IS IN EFFECT FOR... * LAZARO CARDENAS TO CABO CORRIENTES MEXICO A TROPICAL STORM WARNING IS IN EFFECT FOR... * TECPAN DE GALEANA TO SAN BLAS MEXICO A TROPICAL STORM WATCH IS IN EFFECT FOR... * NORTH OF SAN BLAS TO MAZATLAN MEXICO A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...IN THIS CASE WITHIN THE NEXT 36 HOURS. A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS. A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 48 HOURS. INTERESTS ELSEWHERE ALONG THE NORTHWESTERN COAST OF MAINLAND MEXICO AND SOUTHERN PORTIONS OF BAJA CALIFORNIA SUR SHOULD MONITOR THE PROGRESS OF NORA. ADDITIONAL WATCHES AND WARNINGS WILL LIKELY BE REQUIRED FOR PORTIONS OF THESE AREAS LATER TODAY OR TONIGHT. TROPICAL STORM CENTER LOCATED NEAR 15.4N 104.3W AT 27/1500Z POSITION ACCURATE WITHIN 40 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 310 DEGREES AT 10 KT ESTIMATED MINIMUM CENTRAL PRESSURE 997 MB MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT. 34 KT.......200NE 100SE 90SW 90NW. 12 FT SEAS..180NE 240SE 150SW 150NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 15.4N 104.3W AT 27/1500Z AT 27/1200Z CENTER WAS LOCATED NEAR 15.2N 104.0W FORECAST VALID 28/0000Z 16.3N 105.2W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 40NE 30SE 0SW 20NW. 34 KT...180NE 110SE 90SW 90NW. FORECAST VALID 28/1200Z 17.9N 105.9W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 40NE 40SE 30SW 30NW. 34 KT...130NE 130SE 90SW 90NW. FORECAST VALID 29/0000Z 19.9N 106.5W MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 20NE 20SE 0SW 0NW. 50 KT... 40NE 40SE 30SW 30NW. 34 KT...100NE 130SE 70SW 60NW. FORECAST VALID 29/1200Z 21.7N 107.4W MAX WIND 70 KT...GUSTS 85 KT. 64 KT... 25NE 20SE 0SW 15NW. 50 KT... 50NE 50SE 30SW 30NW. 34 KT...100NE 120SE 70SW 60NW. FORECAST VALID 30/0000Z 23.1N 108.3W MAX WIND 75 KT...GUSTS 90 KT. 50 KT... 50NE 50SE 30SW 30NW. 34 KT...100NE 110SE 60SW 60NW. FORECAST VALID 30/1200Z 24.2N 109.1W MAX WIND 75 KT...GUSTS 90 KT. 50 KT... 40NE 40SE 30SW 30NW. 34 KT...100NE 100SE 60SW 70NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 100 NM ON DAY 4 AND 125 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 31/1200Z 26.1N 110.7W MAX WIND 65 KT...GUSTS 80 KT. OUTLOOK VALID 01/1200Z 28.4N 111.7W MAX WIND 50 KT...GUSTS 60 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 15.4N 104.3W INTERMEDIATE PUBLIC ADVISORY...WTNT34 KNHC/MIATCPEP4...AT 27/1800Z NEXT ADVISORY AT 27/2100Z $$ FORECASTER BERG